Merge pull request #5192 from ziglang/stage2-tests

add ZIR compare output test case to test suite

build.zig

@@ -44,7 +44,7 @@ pub fn build(b: *Builder) !void {
         try findAndReadConfigH(b);
 
     var test_stage2 = b.addTest("src-self-hosted/test.zig");
-    test_stage2.setBuildMode(builtin.Mode.Debug);
+    test_stage2.setBuildMode(.Debug); // note this is only the mode of the test harness
     test_stage2.addPackagePath("stage2_tests", "test/stage2/test.zig");
 
     const fmt_build_zig = b.addFmt(&[_][]const u8{"build.zig"});
@@ -68,7 +68,6 @@ pub fn build(b: *Builder) !void {
         var ctx = parseConfigH(b, config_h_text);
         ctx.llvm = try findLLVM(b, ctx.llvm_config_exe);
 
-        try configureStage2(b, test_stage2, ctx);
         try configureStage2(b, exe, ctx);
 
         b.default_step.dependOn(&exe.step);

lib/std/child_process.zig

@@ -46,6 +46,12 @@ pub const ChildProcess = struct {
 
     /// Set to change the current working directory when spawning the child process.
     cwd: ?[]const u8,
+    /// Set to change the current working directory when spawning the child process.
+    /// This is not yet implemented for Windows. See https://github.com/ziglang/zig/issues/5190
+    /// Once that is done, `cwd` will be deprecated in favor of this field.
+    /// The directory handle must be opened with the ability to be passed
+    /// to a child process (no `O_CLOEXEC` flag on POSIX).
+    cwd_dir: ?fs.Dir = null,
 
     err_pipe: if (builtin.os.tag == .windows) void else [2]os.fd_t,
 
@@ -183,6 +189,7 @@ pub const ChildProcess = struct {
         allocator: *mem.Allocator,
         argv: []const []const u8,
         cwd: ?[]const u8 = null,
+        cwd_dir: ?fs.Dir = null,
         env_map: ?*const BufMap = null,
         max_output_bytes: usize = 50 * 1024,
         expand_arg0: Arg0Expand = .no_expand,
@@ -194,6 +201,7 @@ pub const ChildProcess = struct {
         child.stdout_behavior = .Pipe;
         child.stderr_behavior = .Pipe;
         child.cwd = args.cwd;
+        child.cwd_dir = args.cwd_dir;
         child.env_map = args.env_map;
         child.expand_arg0 = args.expand_arg0;
 
@@ -414,7 +422,9 @@ pub const ChildProcess = struct {
                 os.close(stderr_pipe[1]);
             }
 
-            if (self.cwd) |cwd| {
+            if (self.cwd_dir) |cwd| {
+                os.fchdir(cwd.fd) catch |err| forkChildErrReport(err_pipe[1], err);
+            } else if (self.cwd) |cwd| {
                 os.chdir(cwd) catch |err| forkChildErrReport(err_pipe[1], err);
             }
 

lib/std/fmt.zig

@@ -1058,7 +1058,7 @@ pub fn charToDigit(c: u8, radix: u8) (error{InvalidCharacter}!u8) {
     return value;
 }
 
-fn digitToChar(digit: u8, uppercase: bool) u8 {
+pub fn digitToChar(digit: u8, uppercase: bool) u8 {
     return switch (digit) {
         0...9 => digit + '0',
         10...35 => digit + ((if (uppercase) @as(u8, 'A') else @as(u8, 'a')) - 10),

lib/std/fs.zig

@@ -606,7 +606,8 @@ pub const Dir = struct {
         } else 0;
 
         const O_LARGEFILE = if (@hasDecl(os, "O_LARGEFILE")) os.O_LARGEFILE else 0;
-        const os_flags = lock_flag | O_LARGEFILE | os.O_CLOEXEC | if (flags.write and flags.read)
+        const O_CLOEXEC: u32 = if (flags.share_with_child_process) 0 else os.O_CLOEXEC;
+        const os_flags = lock_flag | O_LARGEFILE | O_CLOEXEC | if (flags.write and flags.read)
             @as(u32, os.O_RDWR)
         else if (flags.write)
             @as(u32, os.O_WRONLY)
@@ -689,7 +690,8 @@ pub const Dir = struct {
         } else 0;
 
         const O_LARGEFILE = if (@hasDecl(os, "O_LARGEFILE")) os.O_LARGEFILE else 0;
-        const os_flags = lock_flag | O_LARGEFILE | os.O_CREAT | os.O_CLOEXEC |
+        const O_CLOEXEC: u32 = if (flags.share_with_child_process) 0 else os.O_CLOEXEC;
+        const os_flags = lock_flag | O_LARGEFILE | os.O_CREAT | O_CLOEXEC |
             (if (flags.truncate) @as(u32, os.O_TRUNC) else 0) |
             (if (flags.read) @as(u32, os.O_RDWR) else os.O_WRONLY) |
             (if (flags.exclusive) @as(u32, os.O_EXCL) else 0);
@@ -787,6 +789,15 @@ pub const Dir = struct {
         }
     }
 
+    /// This function performs `makePath`, followed by `openDir`.
+    /// If supported by the OS, this operation is atomic. It is not atomic on
+    /// all operating systems.
+    pub fn makeOpenPath(self: Dir, sub_path: []const u8, open_dir_options: OpenDirOptions) !Dir {
+        // TODO improve this implementation on Windows; we can avoid 1 call to NtClose
+        try self.makePath(sub_path);
+        return self.openDir(sub_path, open_dir_options);
+    }
+
     /// Changes the current working directory to the open directory handle.
     /// This modifies global state and can have surprising effects in multi-
     /// threaded applications. Most applications and especially libraries should
@@ -807,6 +818,11 @@ pub const Dir = struct {
         /// `true` means the opened directory can be scanned for the files and sub-directories
         /// of the result. It means the `iterate` function can be called.
         iterate: bool = false,
+
+        /// `true` means the opened directory can be passed to a child process.
+        /// `false` means the directory handle is considered to be closed when a child
+        /// process is spawned. This corresponds to the inverse of `O_CLOEXEC` on POSIX.
+        share_with_child_process: bool = false,
     };
 
     /// Opens a directory at the given path. The directory is a system resource that remains
@@ -832,9 +848,11 @@ pub const Dir = struct {
             return self.openDirW(&sub_path_w, args);
         } else if (!args.iterate) {
             const O_PATH = if (@hasDecl(os, "O_PATH")) os.O_PATH else 0;
-            return self.openDirFlagsZ(sub_path_c, os.O_DIRECTORY | os.O_RDONLY | os.O_CLOEXEC | O_PATH);
+            const O_CLOEXEC: u32 = if (args.share_with_child_process) 0 else os.O_CLOEXEC;
+            return self.openDirFlagsZ(sub_path_c, os.O_DIRECTORY | os.O_RDONLY | O_CLOEXEC | O_PATH);
         } else {
-            return self.openDirFlagsZ(sub_path_c, os.O_DIRECTORY | os.O_RDONLY | os.O_CLOEXEC);
+            const O_CLOEXEC: u32 = if (args.share_with_child_process) 0 else os.O_CLOEXEC;
+            return self.openDirFlagsZ(sub_path_c, os.O_DIRECTORY | os.O_RDONLY | O_CLOEXEC);
         }
     }
 

lib/std/fs/file.zig

@@ -69,6 +69,11 @@ pub const File = struct {
         /// It allows the use of `noasync` when calling functions related to opening
         /// the file, reading, and writing.
         always_blocking: bool = false,
+
+        /// `true` means the opened directory can be passed to a child process.
+        /// `false` means the directory handle is considered to be closed when a child
+        /// process is spawned. This corresponds to the inverse of `O_CLOEXEC` on POSIX.
+        share_with_child_process: bool = false,
     };
 
     /// TODO https://github.com/ziglang/zig/issues/3802
@@ -107,6 +112,11 @@ pub const File = struct {
         /// For POSIX systems this is the file system mode the file will
         /// be created with.
         mode: Mode = default_mode,
+
+        /// `true` means the opened directory can be passed to a child process.
+        /// `false` means the directory handle is considered to be closed when a child
+        /// process is spawned. This corresponds to the inverse of `O_CLOEXEC` on POSIX.
+        share_with_child_process: bool = false,
     };
 
     /// Upon success, the stream is in an uninitialized state. To continue using it,

lib/std/math.zig

@@ -986,6 +986,43 @@ pub const Order = enum {
 
     /// Greater than (`>`)
     gt,
+
+    pub fn invert(self: Order) Order {
+        return switch (self) {
+            .lt => .gt,
+            .eq => .eq,
+            .gt => .gt,
+        };
+    }
+
+    pub fn compare(self: Order, op: CompareOperator) bool {
+        return switch (self) {
+            .lt => switch (op) {
+                .lt => true,
+                .lte => true,
+                .eq => false,
+                .gte => false,
+                .gt => false,
+                .neq => true,
+            },
+            .eq => switch (op) {
+                .lt => false,
+                .lte => true,
+                .eq => true,
+                .gte => true,
+                .gt => false,
+                .neq => false,
+            },
+            .gt => switch (op) {
+                .lt => false,
+                .lte => false,
+                .eq => false,
+                .gte => true,
+                .gt => true,
+                .neq => true,
+            },
+        };
+    }
 };
 
 /// Given two numbers, this function returns the order they are with respect to each other.

lib/std/math/big.zig

@@ -1,7 +1,24 @@
-pub usingnamespace @import("big/int.zig");
-pub usingnamespace @import("big/rational.zig");
+const std = @import("../std.zig");
+const assert = std.debug.assert;
 
-test "math.big" {
-    _ = @import("big/int.zig");
-    _ = @import("big/rational.zig");
+pub const Rational = @import("big/rational.zig").Rational;
+pub const int = @import("big/int.zig");
+pub const Limb = usize;
+pub const DoubleLimb = std.meta.IntType(false, 2 * Limb.bit_count);
+pub const SignedDoubleLimb = std.meta.IntType(true, DoubleLimb.bit_count);
+pub const Log2Limb = std.math.Log2Int(Limb);
+
+comptime {
+    assert(std.math.floorPowerOfTwo(usize, Limb.bit_count) == Limb.bit_count);
+    assert(Limb.bit_count <= 64); // u128 set is unsupported
+    assert(Limb.is_signed == false);
+}
+
+test "" {
+    _ = int;
+    _ = Rational;
+    _ = Limb;
+    _ = DoubleLimb;
+    _ = SignedDoubleLimb;
+    _ = Log2Limb;
 }

lib/std/math/big/rational.zig

@@ -5,10 +5,10 @@ const mem = std.mem;
 const testing = std.testing;
 const Allocator = mem.Allocator;
 
-const bn = @import("int.zig");
-const Limb = bn.Limb;
-const DoubleLimb = bn.DoubleLimb;
-const Int = bn.Int;
+const Limb = std.math.big.Limb;
+const DoubleLimb = std.math.big.DoubleLimb;
+const Int = std.math.big.int.Managed;
+const IntConst = std.math.big.int.Const;
 
 /// An arbitrary-precision rational number.
 ///
@@ -17,6 +17,9 @@ const Int = bn.Int;
 ///
 /// Rational's are always normalized. That is, for a Rational r = p/q where p and q are integers,
 /// gcd(p, q) = 1 always.
+///
+/// TODO rework this to store its own allocator and use a non-managed big int, to avoid double
+/// allocator storage.
 pub const Rational = struct {
     /// Numerator. Determines the sign of the Rational.
     p: Int,
@@ -98,20 +101,20 @@ pub const Rational = struct {
         if (point) |i| {
             try self.p.setString(10, str[0..i]);
 
-            const base = Int.initFixed(([_]Limb{10})[0..]);
+            const base = IntConst{ .limbs = &[_]Limb{10}, .positive = true };
 
             var j: usize = start;
             while (j < str.len - i - 1) : (j += 1) {
-                try self.p.mul(self.p, base);
+                try self.p.mul(self.p.toConst(), base);
             }
 
             try self.q.setString(10, str[i + 1 ..]);
-            try self.p.add(self.p, self.q);
+            try self.p.add(self.p.toConst(), self.q.toConst());
 
             try self.q.set(1);
             var k: usize = i + 1;
             while (k < str.len) : (k += 1) {
-                try self.q.mul(self.q, base);
+                try self.q.mul(self.q.toConst(), base);
             }
 
             try self.reduce();
@@ -218,14 +221,14 @@ pub const Rational = struct {
         }
 
         // 2. compute quotient and remainder
-        var q = try Int.init(self.p.allocator.?);
+        var q = try Int.init(self.p.allocator);
         defer q.deinit();
 
         // unused
-        var r = try Int.init(self.p.allocator.?);
+        var r = try Int.init(self.p.allocator);
         defer r.deinit();
 
-        try Int.divTrunc(&q, &r, a2, b2);
+        try Int.divTrunc(&q, &r, a2.toConst(), b2.toConst());
 
         var mantissa = extractLowBits(q, BitReprType);
         var have_rem = r.len() > 0;
@@ -293,14 +296,14 @@ pub const Rational = struct {
 
     /// Set a Rational directly from an Int.
     pub fn copyInt(self: *Rational, a: Int) !void {
-        try self.p.copy(a);
+        try self.p.copy(a.toConst());
         try self.q.set(1);
     }
 
     /// Set a Rational directly from a ratio of two Int's.
     pub fn copyRatio(self: *Rational, a: Int, b: Int) !void {
-        try self.p.copy(a);
-        try self.q.copy(b);
+        try self.p.copy(a.toConst());
+        try self.q.copy(b.toConst());
 
         self.p.setSign(@boolToInt(self.p.isPositive()) ^ @boolToInt(self.q.isPositive()) == 0);
         self.q.setSign(true);
@@ -327,13 +330,13 @@ pub const Rational = struct {
 
     /// Returns math.Order.lt, math.Order.eq, math.Order.gt if a < b, a == b or a
     /// > b respectively.
-    pub fn cmp(a: Rational, b: Rational) !math.Order {
+    pub fn order(a: Rational, b: Rational) !math.Order {
         return cmpInternal(a, b, true);
     }
 
     /// Returns math.Order.lt, math.Order.eq, math.Order.gt if |a| < |b|, |a| ==
     /// |b| or |a| > |b| respectively.
-    pub fn cmpAbs(a: Rational, b: Rational) !math.Order {
+    pub fn orderAbs(a: Rational, b: Rational) !math.Order {
         return cmpInternal(a, b, false);
     }
 
@@ -341,16 +344,16 @@ pub const Rational = struct {
     fn cmpInternal(a: Rational, b: Rational, is_abs: bool) !math.Order {
         // TODO: Would a div compare algorithm of sorts be viable and quicker? Can we avoid
         // the memory allocations here?
-        var q = try Int.init(a.p.allocator.?);
+        var q = try Int.init(a.p.allocator);
         defer q.deinit();
 
-        var p = try Int.init(b.p.allocator.?);
+        var p = try Int.init(b.p.allocator);
         defer p.deinit();
 
-        try q.mul(a.p, b.q);
-        try p.mul(b.p, a.q);
+        try q.mul(a.p.toConst(), b.q.toConst());
+        try p.mul(b.p.toConst(), a.q.toConst());
 
-        return if (is_abs) q.cmpAbs(p) else q.cmp(p);
+        return if (is_abs) q.orderAbs(p) else q.order(p);
     }
 
     /// rma = a + b.
@@ -364,7 +367,7 @@ pub const Rational = struct {
 
         var sr: Rational = undefined;
         if (aliased) {
-            sr = try Rational.init(rma.p.allocator.?);
+            sr = try Rational.init(rma.p.allocator);
             r = &sr;
             aliased = true;
         }
@@ -373,11 +376,11 @@ pub const Rational = struct {
             r.deinit();
         };
 
-        try r.p.mul(a.p, b.q);
-        try r.q.mul(b.p, a.q);
-        try r.p.add(r.p, r.q);
+        try r.p.mul(a.p.toConst(), b.q.toConst());
+        try r.q.mul(b.p.toConst(), a.q.toConst());
+        try r.p.add(r.p.toConst(), r.q.toConst());
 
-        try r.q.mul(a.q, b.q);
+        try r.q.mul(a.q.toConst(), b.q.toConst());
         try r.reduce();
     }
 
@@ -392,7 +395,7 @@ pub const Rational = struct {
 
         var sr: Rational = undefined;
         if (aliased) {
-            sr = try Rational.init(rma.p.allocator.?);
+            sr = try Rational.init(rma.p.allocator);
             r = &sr;
             aliased = true;
         }
@@ -401,11 +404,11 @@ pub const Rational = struct {
             r.deinit();
         };
 
-        try r.p.mul(a.p, b.q);
-        try r.q.mul(b.p, a.q);
-        try r.p.sub(r.p, r.q);
+        try r.p.mul(a.p.toConst(), b.q.toConst());
+        try r.q.mul(b.p.toConst(), a.q.toConst());
+        try r.p.sub(r.p.toConst(), r.q.toConst());
 
-        try r.q.mul(a.q, b.q);
+        try r.q.mul(a.q.toConst(), b.q.toConst());
         try r.reduce();
     }
 
@@ -415,8 +418,8 @@ pub const Rational = struct {
     ///
     /// Returns an error if memory could not be allocated.
     pub fn mul(r: *Rational, a: Rational, b: Rational) !void {
-        try r.p.mul(a.p, b.p);
-        try r.q.mul(a.q, b.q);
+        try r.p.mul(a.p.toConst(), b.p.toConst());
+        try r.q.mul(a.q.toConst(), b.q.toConst());
         try r.reduce();
     }
 
@@ -430,8 +433,8 @@ pub const Rational = struct {
             @panic("division by zero");
         }
 
-        try r.p.mul(a.p, b.q);
-        try r.q.mul(b.p, a.q);
+        try r.p.mul(a.p.toConst(), b.q.toConst());
+        try r.q.mul(b.p.toConst(), a.q.toConst());
         try r.reduce();
     }
 
@@ -442,7 +445,7 @@ pub const Rational = struct {
 
     // reduce r/q such that gcd(r, q) = 1
     fn reduce(r: *Rational) !void {
-        var a = try Int.init(r.p.allocator.?);
+        var a = try Int.init(r.p.allocator);
         defer a.deinit();
 
         const sign = r.p.isPositive();
@@ -450,15 +453,15 @@ pub const Rational = struct {
         try a.gcd(r.p, r.q);
         r.p.setSign(sign);
 
-        const one = Int.initFixed(([_]Limb{1})[0..]);
-        if (a.cmp(one) != .eq) {
-            var unused = try Int.init(r.p.allocator.?);
+        const one = IntConst{ .limbs = &[_]Limb{1}, .positive = true };
+        if (a.toConst().order(one) != .eq) {
+            var unused = try Int.init(r.p.allocator);
             defer unused.deinit();
 
             // TODO: divexact would be useful here
             // TODO: don't copy r.q for div
-            try Int.divTrunc(&r.p, &unused, r.p, a);
-            try Int.divTrunc(&r.q, &unused, r.q, a);
+            try Int.divTrunc(&r.p, &unused, r.p.toConst(), a.toConst());
+            try Int.divTrunc(&r.q, &unused, r.q.toConst(), a.toConst());
         }
     }
 };
@@ -596,25 +599,25 @@ test "big.rational copy" {
     var a = try Rational.init(testing.allocator);
     defer a.deinit();
 
-    const b = try Int.initSet(testing.allocator, 5);
+    var b = try Int.initSet(testing.allocator, 5);
     defer b.deinit();
 
     try a.copyInt(b);
     testing.expect((try a.p.to(u32)) == 5);
     testing.expect((try a.q.to(u32)) == 1);
 
-    const c = try Int.initSet(testing.allocator, 7);
+    var c = try Int.initSet(testing.allocator, 7);
     defer c.deinit();
-    const d = try Int.initSet(testing.allocator, 3);
+    var d = try Int.initSet(testing.allocator, 3);
     defer d.deinit();
 
     try a.copyRatio(c, d);
     testing.expect((try a.p.to(u32)) == 7);
     testing.expect((try a.q.to(u32)) == 3);
 
-    const e = try Int.initSet(testing.allocator, 9);
+    var e = try Int.initSet(testing.allocator, 9);
     defer e.deinit();
-    const f = try Int.initSet(testing.allocator, 3);
+    var f = try Int.initSet(testing.allocator, 3);
     defer f.deinit();
 
     try a.copyRatio(e, f);
@@ -680,7 +683,7 @@ test "big.rational swap" {
     testing.expect((try b.q.to(u32)) == 23);
 }
 
-test "big.rational cmp" {
+test "big.rational order" {
     var a = try Rational.init(testing.allocator);
     defer a.deinit();
     var b = try Rational.init(testing.allocator);
@@ -688,11 +691,11 @@ test "big.rational cmp" {
 
     try a.setRatio(500, 231);
     try b.setRatio(18903, 8584);
-    testing.expect((try a.cmp(b)) == .lt);
+    testing.expect((try a.order(b)) == .lt);
 
     try a.setRatio(890, 10);
     try b.setRatio(89, 1);
-    testing.expect((try a.cmp(b)) == .eq);
+    testing.expect((try a.order(b)) == .eq);
 }
 
 test "big.rational add single-limb" {
@@ -703,11 +706,11 @@ test "big.rational add single-limb" {
 
     try a.setRatio(500, 231);
     try b.setRatio(18903, 8584);
-    testing.expect((try a.cmp(b)) == .lt);
+    testing.expect((try a.order(b)) == .lt);
 
     try a.setRatio(890, 10);
     try b.setRatio(89, 1);
-    testing.expect((try a.cmp(b)) == .eq);
+    testing.expect((try a.order(b)) == .eq);
 }
 
 test "big.rational add" {
@@ -723,7 +726,7 @@ test "big.rational add" {
     try a.add(a, b);
 
     try r.setRatio(984786924199, 290395044174);
-    testing.expect((try a.cmp(r)) == .eq);
+    testing.expect((try a.order(r)) == .eq);
 }
 
 test "big.rational sub" {
@@ -739,7 +742,7 @@ test "big.rational sub" {
     try a.sub(a, b);
 
     try r.setRatio(979040510045, 290395044174);
-    testing.expect((try a.cmp(r)) == .eq);
+    testing.expect((try a.order(r)) == .eq);
 }
 
 test "big.rational mul" {
@@ -755,7 +758,7 @@ test "big.rational mul" {
     try a.mul(a, b);
 
     try r.setRatio(571481443, 17082061422);
-    testing.expect((try a.cmp(r)) == .eq);
+    testing.expect((try a.order(r)) == .eq);
 }
 
 test "big.rational div" {
@@ -771,7 +774,7 @@ test "big.rational div" {
     try a.div(a, b);
 
     try r.setRatio(75531824394, 221015929);
-    testing.expect((try a.cmp(r)) == .eq);
+    testing.expect((try a.order(r)) == .eq);
 }
 
 test "big.rational div" {
@@ -784,11 +787,11 @@ test "big.rational div" {
     a.invert();
 
     try r.setRatio(23341, 78923);
-    testing.expect((try a.cmp(r)) == .eq);
+    testing.expect((try a.order(r)) == .eq);
 
     try a.setRatio(-78923, 23341);
     a.invert();
 
     try r.setRatio(-23341, 78923);
-    testing.expect((try a.cmp(r)) == .eq);
+    testing.expect((try a.order(r)) == .eq);
 }

lib/std/target.zig

@@ -404,6 +404,7 @@ pub const Target = struct {
     };
 
     pub const ObjectFormat = enum {
+        /// TODO Get rid of this one.
         unknown,
         coff,
         elf,

lib/std/testing.zig

@@ -12,7 +12,7 @@ pub const failing_allocator = &failing_allocator_instance.allocator;
 pub var failing_allocator_instance = FailingAllocator.init(&base_allocator_instance.allocator, 0);
 
 pub var base_allocator_instance = std.heap.ThreadSafeFixedBufferAllocator.init(allocator_mem[0..]);
-var allocator_mem: [1024 * 1024]u8 = undefined;
+var allocator_mem: [2 * 1024 * 1024]u8 = undefined;
 
 /// This function is intended to be used only in tests. It prints diagnostics to stderr
 /// and then aborts when actual_error_union is not expected_error.
@@ -193,6 +193,44 @@ pub fn expect(ok: bool) void {
     if (!ok) @panic("test failure");
 }
 
+pub const TmpDir = struct {
+    dir: std.fs.Dir,
+    parent_dir: std.fs.Dir,
+    sub_path: [sub_path_len]u8,
+
+    const random_bytes_count = 12;
+    const sub_path_len = std.base64.Base64Encoder.calcSize(random_bytes_count);
+
+    pub fn cleanup(self: *TmpDir) void {
+        self.dir.close();
+        self.parent_dir.deleteTree(&self.sub_path) catch {};
+        self.parent_dir.close();
+        self.* = undefined;
+    }
+};
+
+pub fn tmpDir(opts: std.fs.Dir.OpenDirOptions) TmpDir {
+    var random_bytes: [TmpDir.random_bytes_count]u8 = undefined;
+    std.crypto.randomBytes(&random_bytes) catch
+        @panic("unable to make tmp dir for testing: unable to get random bytes");
+    var sub_path: [TmpDir.sub_path_len]u8 = undefined;
+    std.fs.base64_encoder.encode(&sub_path, &random_bytes);
+
+    var cache_dir = std.fs.cwd().makeOpenPath("zig-cache", .{}) catch
+        @panic("unable to make tmp dir for testing: unable to make and open zig-cache dir");
+    defer cache_dir.close();
+    var parent_dir = cache_dir.makeOpenPath("tmp", .{}) catch
+        @panic("unable to make tmp dir for testing: unable to make and open zig-cache/tmp dir");
+    var dir = parent_dir.makeOpenPath(&sub_path, opts) catch
+        @panic("unable to make tmp dir for testing: unable to make and open the tmp dir");
+
+    return .{
+        .dir = dir,
+        .parent_dir = parent_dir,
+        .sub_path = sub_path,
+    };
+}
+
 test "expectEqual nested array" {
     const a = [2][2]f32{
         [_]f32{ 1.0, 0.0 },

lib/std/zig.zig

@@ -9,6 +9,23 @@ pub const ast = @import("zig/ast.zig");
 pub const system = @import("zig/system.zig");
 pub const CrossTarget = @import("zig/cross_target.zig").CrossTarget;
 
+pub fn findLineColumn(source: []const u8, byte_offset: usize) struct { line: usize, column: usize } {
+    var line: usize = 0;
+    var column: usize = 0;
+    for (source[0..byte_offset]) |byte| {
+        switch (byte) {
+            '\n' => {
+                line += 1;
+                column = 0;
+            },
+            else => {
+                column += 1;
+            },
+        }
+    }
+    return .{ .line = line, .column = column };
+}
+
 test "" {
     @import("std").meta.refAllDecls(@This());
 }

lib/std/zig/system.zig

@@ -415,7 +415,12 @@ pub const NativeTargetInfo = struct {
         // over our own shared objects and find a dynamic linker.
         self_exe: {
             const lib_paths = try std.process.getSelfExeSharedLibPaths(allocator);
-            defer allocator.free(lib_paths);
+            defer {
+                for (lib_paths) |lib_path| {
+                    allocator.free(lib_path);
+                }
+                allocator.free(lib_paths);
+            }
 
             var found_ld_info: LdInfo = undefined;
             var found_ld_path: [:0]const u8 = undefined;

src-self-hosted/codegen.zig

@@ -39,7 +39,7 @@ pub fn generateSymbol(typed_value: ir.TypedValue, module: ir.Module, code: *std.
             defer function.inst_table.deinit();
             defer function.errors.deinit();
 
-            for (module_fn.body) |inst| {
+            for (module_fn.body.instructions) |inst| {
                 const new_inst = function.genFuncInst(inst) catch |err| switch (err) {
                     error.CodegenFail => {
                         assert(function.errors.items.len != 0);
@@ -77,32 +77,63 @@ const Function = struct {
 
     fn genFuncInst(self: *Function, inst: *ir.Inst) !MCValue {
         switch (inst.tag) {
-            .unreach => return self.genPanic(inst.src),
+            .breakpoint => return self.genBreakpoint(inst.src),
+            .unreach => return MCValue{ .unreach = {} },
             .constant => unreachable, // excluded from function bodies
             .assembly => return self.genAsm(inst.cast(ir.Inst.Assembly).?),
             .ptrtoint => return self.genPtrToInt(inst.cast(ir.Inst.PtrToInt).?),
             .bitcast => return self.genBitCast(inst.cast(ir.Inst.BitCast).?),
+            .ret => return self.genRet(inst.cast(ir.Inst.Ret).?),
+            .cmp => return self.genCmp(inst.cast(ir.Inst.Cmp).?),
+            .condbr => return self.genCondBr(inst.cast(ir.Inst.CondBr).?),
+            .isnull => return self.genIsNull(inst.cast(ir.Inst.IsNull).?),
+            .isnonnull => return self.genIsNonNull(inst.cast(ir.Inst.IsNonNull).?),
         }
     }
 
-    fn genPanic(self: *Function, src: usize) !MCValue {
-        // TODO change this to call the panic function
+    fn genBreakpoint(self: *Function, src: usize) !MCValue {
         switch (self.module.target.cpu.arch) {
             .i386, .x86_64 => {
                 try self.code.append(0xcc); // int3
             },
-            else => return self.fail(src, "TODO implement panic for {}", .{self.module.target.cpu.arch}),
+            else => return self.fail(src, "TODO implement @breakpoint() for {}", .{self.module.target.cpu.arch}),
         }
         return .unreach;
     }
 
-    fn genRet(self: *Function, src: usize) !void {
-        // TODO change this to call the panic function
+    fn genRet(self: *Function, inst: *ir.Inst.Ret) !MCValue {
         switch (self.module.target.cpu.arch) {
             .i386, .x86_64 => {
                 try self.code.append(0xc3); // ret
             },
-            else => return self.fail(src, "TODO implement ret for {}", .{self.module.target.cpu.arch}),
+            else => return self.fail(inst.base.src, "TODO implement return for {}", .{self.module.target.cpu.arch}),
+        }
+        return .unreach;
+    }
+
+    fn genCmp(self: *Function, inst: *ir.Inst.Cmp) !MCValue {
+        switch (self.module.target.cpu.arch) {
+            else => return self.fail(inst.base.src, "TODO implement cmp for {}", .{self.module.target.cpu.arch}),
+        }
+    }
+
+    fn genCondBr(self: *Function, inst: *ir.Inst.CondBr) !MCValue {
+        switch (self.module.target.cpu.arch) {
+            else => return self.fail(inst.base.src, "TODO implement condbr for {}", .{self.module.target.cpu.arch}),
+        }
+    }
+
+    fn genIsNull(self: *Function, inst: *ir.Inst.IsNull) !MCValue {
+        switch (self.module.target.cpu.arch) {
+            else => return self.fail(inst.base.src, "TODO implement isnull for {}", .{self.module.target.cpu.arch}),
+        }
+    }
+
+    fn genIsNonNull(self: *Function, inst: *ir.Inst.IsNonNull) !MCValue {
+        // Here you can specialize this instruction if it makes sense to, otherwise the default
+        // will call genIsNull and invert the result.
+        switch (self.module.target.cpu.arch) {
+            else => return self.fail(inst.base.src, "TODO call genIsNull and invert the result ", .{}),
         }
     }
 
@@ -501,11 +532,19 @@ fn Reg(comptime arch: Target.Cpu.Arch) type {
             bh,
             ch,
             dh,
+            bph,
+            sph,
+            sih,
+            dih,
 
             al,
             bl,
             cl,
             dl,
+            bpl,
+            spl,
+            sil,
+            dil,
             r8b,
             r9b,
             r10b,

src-self-hosted/ir/text.zig

@@ -4,7 +4,8 @@ const std = @import("std");
 const mem = std.mem;
 const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
-const BigInt = std.math.big.Int;
+const BigIntConst = std.math.big.int.Const;
+const BigIntMutable = std.math.big.int.Mutable;
 const Type = @import("../type.zig").Type;
 const Value = @import("../value.zig").Value;
 const ir = @import("../ir.zig");
@@ -18,6 +19,7 @@ pub const Inst = struct {
 
     /// These names are used directly as the instruction names in the text format.
     pub const Tag = enum {
+        breakpoint,
         str,
         int,
         ptrtoint,
@@ -26,6 +28,7 @@ pub const Inst = struct {
         as,
         @"asm",
         @"unreachable",
+        @"return",
         @"fn",
         @"export",
         primitive,
@@ -34,10 +37,15 @@ pub const Inst = struct {
         bitcast,
         elemptr,
         add,
+        cmp,
+        condbr,
+        isnull,
+        isnonnull,
     };
 
     pub fn TagToType(tag: Tag) type {
         return switch (tag) {
+            .breakpoint => Breakpoint,
             .str => Str,
             .int => Int,
             .ptrtoint => PtrToInt,
@@ -46,6 +54,7 @@ pub const Inst = struct {
             .as => As,
             .@"asm" => Asm,
             .@"unreachable" => Unreachable,
+            .@"return" => Return,
             .@"fn" => Fn,
             .@"export" => Export,
             .primitive => Primitive,
@@ -54,6 +63,10 @@ pub const Inst = struct {
             .bitcast => BitCast,
             .elemptr => ElemPtr,
             .add => Add,
+            .cmp => Cmp,
+            .condbr => CondBr,
+            .isnull => IsNull,
+            .isnonnull => IsNonNull,
         };
     }
 
@@ -64,6 +77,14 @@ pub const Inst = struct {
         return @fieldParentPtr(T, "base", base);
     }
 
+    pub const Breakpoint = struct {
+        pub const base_tag = Tag.breakpoint;
+        base: Inst,
+
+        positionals: struct {},
+        kw_args: struct {},
+    };
+
     pub const Str = struct {
         pub const base_tag = Tag.str;
         base: Inst,
@@ -79,7 +100,7 @@ pub const Inst = struct {
         base: Inst,
 
         positionals: struct {
-            int: BigInt,
+            int: BigIntConst,
         },
         kw_args: struct {},
     };
@@ -151,19 +172,23 @@ pub const Inst = struct {
         kw_args: struct {},
     };
 
+    pub const Return = struct {
+        pub const base_tag = Tag.@"return";
+        base: Inst,
+
+        positionals: struct {},
+        kw_args: struct {},
+    };
+
     pub const Fn = struct {
         pub const base_tag = Tag.@"fn";
         base: Inst,
 
         positionals: struct {
             fn_type: *Inst,
-            body: Body,
+            body: Module.Body,
         },
         kw_args: struct {},
-
-        pub const Body = struct {
-            instructions: []*Inst,
-        };
     };
 
     pub const Export = struct {
@@ -297,6 +322,50 @@ pub const Inst = struct {
         },
         kw_args: struct {},
     };
+
+    pub const Cmp = struct {
+        pub const base_tag = Tag.cmp;
+        base: Inst,
+
+        positionals: struct {
+            lhs: *Inst,
+            op: std.math.CompareOperator,
+            rhs: *Inst,
+        },
+        kw_args: struct {},
+    };
+
+    pub const CondBr = struct {
+        pub const base_tag = Tag.condbr;
+        base: Inst,
+
+        positionals: struct {
+            condition: *Inst,
+            true_body: Module.Body,
+            false_body: Module.Body,
+        },
+        kw_args: struct {},
+    };
+
+    pub const IsNull = struct {
+        pub const base_tag = Tag.isnull;
+        base: Inst,
+
+        positionals: struct {
+            operand: *Inst,
+        },
+        kw_args: struct {},
+    };
+
+    pub const IsNonNull = struct {
+        pub const base_tag = Tag.isnonnull;
+        base: Inst,
+
+        positionals: struct {
+            operand: *Inst,
+        },
+        kw_args: struct {},
+    };
 };
 
 pub const ErrorMsg = struct {
@@ -309,6 +378,10 @@ pub const Module = struct {
     errors: []ErrorMsg,
     arena: std.heap.ArenaAllocator,
 
+    pub const Body = struct {
+        instructions: []*Inst,
+    };
+
     pub fn deinit(self: *Module, allocator: *Allocator) void {
         allocator.free(self.decls);
         allocator.free(self.errors);
@@ -321,7 +394,7 @@ pub const Module = struct {
         self.writeToStream(std.heap.page_allocator, std.io.getStdErr().outStream()) catch {};
     }
 
-    const InstPtrTable = std.AutoHashMap(*Inst, struct { index: usize, fn_body: ?*Inst.Fn.Body });
+    const InstPtrTable = std.AutoHashMap(*Inst, struct { index: usize, fn_body: ?*Module.Body });
 
     /// The allocator is used for temporary storage, but this function always returns
     /// with no resources allocated.
@@ -357,6 +430,7 @@ pub const Module = struct {
     ) @TypeOf(stream).Error!void {
         // TODO I tried implementing this with an inline for loop and hit a compiler bug
         switch (decl.tag) {
+            .breakpoint => return self.writeInstToStreamGeneric(stream, .breakpoint, decl, inst_table),
             .str => return self.writeInstToStreamGeneric(stream, .str, decl, inst_table),
             .int => return self.writeInstToStreamGeneric(stream, .int, decl, inst_table),
             .ptrtoint => return self.writeInstToStreamGeneric(stream, .ptrtoint, decl, inst_table),
@@ -365,6 +439,7 @@ pub const Module = struct {
             .as => return self.writeInstToStreamGeneric(stream, .as, decl, inst_table),
             .@"asm" => return self.writeInstToStreamGeneric(stream, .@"asm", decl, inst_table),
             .@"unreachable" => return self.writeInstToStreamGeneric(stream, .@"unreachable", decl, inst_table),
+            .@"return" => return self.writeInstToStreamGeneric(stream, .@"return", decl, inst_table),
             .@"fn" => return self.writeInstToStreamGeneric(stream, .@"fn", decl, inst_table),
             .@"export" => return self.writeInstToStreamGeneric(stream, .@"export", decl, inst_table),
             .primitive => return self.writeInstToStreamGeneric(stream, .primitive, decl, inst_table),
@@ -373,6 +448,10 @@ pub const Module = struct {
             .bitcast => return self.writeInstToStreamGeneric(stream, .bitcast, decl, inst_table),
             .elemptr => return self.writeInstToStreamGeneric(stream, .elemptr, decl, inst_table),
             .add => return self.writeInstToStreamGeneric(stream, .add, decl, inst_table),
+            .cmp => return self.writeInstToStreamGeneric(stream, .cmp, decl, inst_table),
+            .condbr => return self.writeInstToStreamGeneric(stream, .condbr, decl, inst_table),
+            .isnull => return self.writeInstToStreamGeneric(stream, .isnull, decl, inst_table),
+            .isnonnull => return self.writeInstToStreamGeneric(stream, .isnonnull, decl, inst_table),
         }
     }
 
@@ -432,7 +511,7 @@ pub const Module = struct {
                 }
                 try stream.writeByte(']');
             },
-            Inst.Fn.Body => {
+            Module.Body => {
                 try stream.writeAll("{\n");
                 for (param.instructions) |inst, i| {
                     try stream.print("  %{} ", .{i});
@@ -443,7 +522,7 @@ pub const Module = struct {
             },
             bool => return stream.writeByte("01"[@boolToInt(param)]),
             []u8, []const u8 => return std.zig.renderStringLiteral(param, stream),
-            BigInt => return stream.print("{}", .{param}),
+            BigIntConst => return stream.print("{}", .{param}),
             else => |T| @compileError("unimplemented: rendering parameter of type " ++ @typeName(T)),
         }
     }
@@ -497,7 +576,7 @@ const Parser = struct {
         name_map: std.StringHashMap(usize),
     };
 
-    fn parseBody(self: *Parser) !Inst.Fn.Body {
+    fn parseBody(self: *Parser) !Module.Body {
         var body_context = Body{
             .instructions = std.ArrayList(*Inst).init(self.allocator),
             .name_map = std.StringHashMap(usize).init(self.allocator),
@@ -532,9 +611,10 @@ const Parser = struct {
             else => |byte| return self.failByte(byte),
         };
 
-        return Inst.Fn.Body{
-            .instructions = body_context.instructions.toOwnedSlice(),
-        };
+        // Move the instructions to the arena
+        const instrs = try self.arena.allocator.alloc(*Inst, body_context.instructions.items.len);
+        mem.copy(*Inst, instrs, body_context.instructions.items);
+        return Module.Body{ .instructions = instrs };
     }
 
     fn parseStringLiteral(self: *Parser) ![]u8 {
@@ -565,7 +645,7 @@ const Parser = struct {
         };
     }
 
-    fn parseIntegerLiteral(self: *Parser) !BigInt {
+    fn parseIntegerLiteral(self: *Parser) !BigIntConst {
         const start = self.i;
         if (self.source[self.i] == '-') self.i += 1;
         while (true) : (self.i += 1) switch (self.source[self.i]) {
@@ -573,41 +653,46 @@ const Parser = struct {
             else => break,
         };
         const number_text = self.source[start..self.i];
-        var result = try BigInt.init(&self.arena.allocator);
-        result.setString(10, number_text) catch |err| {
-            self.i = start;
-            switch (err) {
-                error.InvalidBase => unreachable,
-                error.InvalidCharForDigit => return self.fail("invalid digit in integer literal", .{}),
-                error.DigitTooLargeForBase => return self.fail("digit too large in integer literal", .{}),
-                else => |e| return e,
-            }
+        const base = 10;
+        // TODO reuse the same array list for this
+        const limbs_buffer_len = std.math.big.int.calcSetStringLimbsBufferLen(base, number_text.len);
+        const limbs_buffer = try self.allocator.alloc(std.math.big.Limb, limbs_buffer_len);
+        defer self.allocator.free(limbs_buffer);
+        const limb_len = std.math.big.int.calcSetStringLimbCount(base, number_text.len);
+        const limbs = try self.arena.allocator.alloc(std.math.big.Limb, limb_len);
+        var result = BigIntMutable{ .limbs = limbs, .positive = undefined, .len = undefined };
+        result.setString(base, number_text, limbs_buffer, self.allocator) catch |err| switch (err) {
+            error.InvalidCharacter => {
+                self.i = start;
+                return self.fail("invalid digit in integer literal", .{});
+            },
         };
-        return result;
+        return result.toConst();
     }
 
     fn parseRoot(self: *Parser) !void {
         // The IR format is designed so that it can be tokenized and parsed at the same time.
-        while (true) : (self.i += 1) switch (self.source[self.i]) {
-            ';' => _ = try skipToAndOver(self, '\n'),
-            '@' => {
-                self.i += 1;
-                const ident = try skipToAndOver(self, ' ');
-                skipSpace(self);
-                try requireEatBytes(self, "=");
-                skipSpace(self);
-                const inst = try parseInstruction(self, null);
-                const ident_index = self.decls.items.len;
-                if (try self.global_name_map.put(ident, ident_index)) |_| {
-                    return self.fail("redefinition of identifier '{}'", .{ident});
-                }
-                try self.decls.append(inst);
-                continue;
-            },
-            ' ', '\n' => continue,
-            0 => break,
-            else => |byte| return self.fail("unexpected byte: '{c}'", .{byte}),
-        };
+        while (true) {
+            switch (self.source[self.i]) {
+                ';' => _ = try skipToAndOver(self, '\n'),
+                '@' => {
+                    self.i += 1;
+                    const ident = try skipToAndOver(self, ' ');
+                    skipSpace(self);
+                    try requireEatBytes(self, "=");
+                    skipSpace(self);
+                    const inst = try parseInstruction(self, null);
+                    const ident_index = self.decls.items.len;
+                    if (try self.global_name_map.put(ident, ident_index)) |_| {
+                        return self.fail("redefinition of identifier '{}'", .{ident});
+                    }
+                    try self.decls.append(inst);
+                },
+                ' ', '\n' => self.i += 1,
+                0 => break,
+                else => |byte| return self.fail("unexpected byte: '{c}'", .{byte}),
+            }
+        }
     }
 
     fn eatByte(self: *Parser, byte: u8) bool {
@@ -752,7 +837,7 @@ const Parser = struct {
             };
         }
         switch (T) {
-            Inst.Fn.Body => return parseBody(self),
+            Module.Body => return parseBody(self),
             bool => {
                 const bool_value = switch (self.source[self.i]) {
                     '0' => false,
@@ -779,7 +864,7 @@ const Parser = struct {
             },
             *Inst => return parseParameterInst(self, body_ctx),
             []u8, []const u8 => return self.parseStringLiteral(),
-            BigInt => return self.parseIntegerLiteral(),
+            BigIntConst => return self.parseIntegerLiteral(),
             else => @compileError("Unimplemented: ir parseParameterGeneric for type " ++ @typeName(T)),
         }
         return self.fail("TODO parse parameter {}", .{@typeName(T)});
@@ -878,11 +963,12 @@ const EmitZIR = struct {
     }
 
     fn emitComptimeIntVal(self: *EmitZIR, src: usize, val: Value) !*Inst {
+        const big_int_space = try self.arena.allocator.create(Value.BigIntSpace);
         const int_inst = try self.arena.allocator.create(Inst.Int);
         int_inst.* = .{
             .base = .{ .src = src, .tag = Inst.Int.base_tag },
             .positionals = .{
-                .int = try val.toBigInt(&self.arena.allocator),
+                .int = val.toBigInt(big_int_space),
             },
             .kw_args = .{},
         };
@@ -937,96 +1023,19 @@ const EmitZIR = struct {
                 var instructions = std.ArrayList(*Inst).init(self.allocator);
                 defer instructions.deinit();
 
-                for (module_fn.body) |inst| {
-                    const new_inst = switch (inst.tag) {
-                        .unreach => blk: {
-                            const unreach_inst = try self.arena.allocator.create(Inst.Unreachable);
-                            unreach_inst.* = .{
-                                .base = .{ .src = inst.src, .tag = Inst.Unreachable.base_tag },
-                                .positionals = .{},
-                                .kw_args = .{},
-                            };
-                            break :blk &unreach_inst.base;
-                        },
-                        .constant => unreachable, // excluded from function bodies
-                        .assembly => blk: {
-                            const old_inst = inst.cast(ir.Inst.Assembly).?;
-                            const new_inst = try self.arena.allocator.create(Inst.Asm);
-
-                            const inputs = try self.arena.allocator.alloc(*Inst, old_inst.args.inputs.len);
-                            for (inputs) |*elem, i| {
-                                elem.* = try self.emitStringLiteral(inst.src, old_inst.args.inputs[i]);
-                            }
-
-                            const clobbers = try self.arena.allocator.alloc(*Inst, old_inst.args.clobbers.len);
-                            for (clobbers) |*elem, i| {
-                                elem.* = try self.emitStringLiteral(inst.src, old_inst.args.clobbers[i]);
-                            }
-
-                            const args = try self.arena.allocator.alloc(*Inst, old_inst.args.args.len);
-                            for (args) |*elem, i| {
-                                elem.* = try self.resolveInst(&inst_table, old_inst.args.args[i]);
-                            }
-
-                            new_inst.* = .{
-                                .base = .{ .src = inst.src, .tag = Inst.Asm.base_tag },
-                                .positionals = .{
-                                    .asm_source = try self.emitStringLiteral(inst.src, old_inst.args.asm_source),
-                                    .return_type = try self.emitType(inst.src, inst.ty),
-                                },
-                                .kw_args = .{
-                                    .@"volatile" = old_inst.args.is_volatile,
-                                    .output = if (old_inst.args.output) |o|
-                                        try self.emitStringLiteral(inst.src, o)
-                                    else
-                                        null,
-                                    .inputs = inputs,
-                                    .clobbers = clobbers,
-                                    .args = args,
-                                },
-                            };
-                            break :blk &new_inst.base;
-                        },
-                        .ptrtoint => blk: {
-                            const old_inst = inst.cast(ir.Inst.PtrToInt).?;
-                            const new_inst = try self.arena.allocator.create(Inst.PtrToInt);
-                            new_inst.* = .{
-                                .base = .{ .src = inst.src, .tag = Inst.PtrToInt.base_tag },
-                                .positionals = .{
-                                    .ptr = try self.resolveInst(&inst_table, old_inst.args.ptr),
-                                },
-                                .kw_args = .{},
-                            };
-                            break :blk &new_inst.base;
-                        },
-                        .bitcast => blk: {
-                            const old_inst = inst.cast(ir.Inst.BitCast).?;
-                            const new_inst = try self.arena.allocator.create(Inst.BitCast);
-                            new_inst.* = .{
-                                .base = .{ .src = inst.src, .tag = Inst.BitCast.base_tag },
-                                .positionals = .{
-                                    .dest_type = try self.emitType(inst.src, inst.ty),
-                                    .operand = try self.resolveInst(&inst_table, old_inst.args.operand),
-                                },
-                                .kw_args = .{},
-                            };
-                            break :blk &new_inst.base;
-                        },
-                    };
-                    try instructions.append(new_inst);
-                    try inst_table.putNoClobber(inst, new_inst);
-                }
+                try self.emitBody(module_fn.body, &inst_table, &instructions);
 
                 const fn_type = try self.emitType(src, module_fn.fn_type);
 
+                const arena_instrs = try self.arena.allocator.alloc(*Inst, instructions.items.len);
+                mem.copy(*Inst, arena_instrs, instructions.items);
+
                 const fn_inst = try self.arena.allocator.create(Inst.Fn);
                 fn_inst.* = .{
                     .base = .{ .src = src, .tag = Inst.Fn.base_tag },
                     .positionals = .{
                         .fn_type = fn_type,
-                        .body = .{
-                            .instructions = instructions.toOwnedSlice(),
-                        },
+                        .body = .{ .instructions = arena_instrs },
                     },
                     .kw_args = .{},
                 };
@@ -1037,6 +1046,159 @@ const EmitZIR = struct {
         }
     }
 
+    fn emitTrivial(self: *EmitZIR, src: usize, comptime T: type) Allocator.Error!*Inst {
+        const new_inst = try self.arena.allocator.create(T);
+        new_inst.* = .{
+            .base = .{ .src = src, .tag = T.base_tag },
+            .positionals = .{},
+            .kw_args = .{},
+        };
+        return &new_inst.base;
+    }
+
+    fn emitBody(
+        self: *EmitZIR,
+        body: ir.Module.Body,
+        inst_table: *std.AutoHashMap(*ir.Inst, *Inst),
+        instructions: *std.ArrayList(*Inst),
+    ) Allocator.Error!void {
+        for (body.instructions) |inst| {
+            const new_inst = switch (inst.tag) {
+                .breakpoint => try self.emitTrivial(inst.src, Inst.Breakpoint),
+                .unreach => try self.emitTrivial(inst.src, Inst.Unreachable),
+                .ret => try self.emitTrivial(inst.src, Inst.Return),
+                .constant => unreachable, // excluded from function bodies
+                .assembly => blk: {
+                    const old_inst = inst.cast(ir.Inst.Assembly).?;
+                    const new_inst = try self.arena.allocator.create(Inst.Asm);
+
+                    const inputs = try self.arena.allocator.alloc(*Inst, old_inst.args.inputs.len);
+                    for (inputs) |*elem, i| {
+                        elem.* = try self.emitStringLiteral(inst.src, old_inst.args.inputs[i]);
+                    }
+
+                    const clobbers = try self.arena.allocator.alloc(*Inst, old_inst.args.clobbers.len);
+                    for (clobbers) |*elem, i| {
+                        elem.* = try self.emitStringLiteral(inst.src, old_inst.args.clobbers[i]);
+                    }
+
+                    const args = try self.arena.allocator.alloc(*Inst, old_inst.args.args.len);
+                    for (args) |*elem, i| {
+                        elem.* = try self.resolveInst(inst_table, old_inst.args.args[i]);
+                    }
+
+                    new_inst.* = .{
+                        .base = .{ .src = inst.src, .tag = Inst.Asm.base_tag },
+                        .positionals = .{
+                            .asm_source = try self.emitStringLiteral(inst.src, old_inst.args.asm_source),
+                            .return_type = try self.emitType(inst.src, inst.ty),
+                        },
+                        .kw_args = .{
+                            .@"volatile" = old_inst.args.is_volatile,
+                            .output = if (old_inst.args.output) |o|
+                                try self.emitStringLiteral(inst.src, o)
+                            else
+                                null,
+                            .inputs = inputs,
+                            .clobbers = clobbers,
+                            .args = args,
+                        },
+                    };
+                    break :blk &new_inst.base;
+                },
+                .ptrtoint => blk: {
+                    const old_inst = inst.cast(ir.Inst.PtrToInt).?;
+                    const new_inst = try self.arena.allocator.create(Inst.PtrToInt);
+                    new_inst.* = .{
+                        .base = .{ .src = inst.src, .tag = Inst.PtrToInt.base_tag },
+                        .positionals = .{
+                            .ptr = try self.resolveInst(inst_table, old_inst.args.ptr),
+                        },
+                        .kw_args = .{},
+                    };
+                    break :blk &new_inst.base;
+                },
+                .bitcast => blk: {
+                    const old_inst = inst.cast(ir.Inst.BitCast).?;
+                    const new_inst = try self.arena.allocator.create(Inst.BitCast);
+                    new_inst.* = .{
+                        .base = .{ .src = inst.src, .tag = Inst.BitCast.base_tag },
+                        .positionals = .{
+                            .dest_type = try self.emitType(inst.src, inst.ty),
+                            .operand = try self.resolveInst(inst_table, old_inst.args.operand),
+                        },
+                        .kw_args = .{},
+                    };
+                    break :blk &new_inst.base;
+                },
+                .cmp => blk: {
+                    const old_inst = inst.cast(ir.Inst.Cmp).?;
+                    const new_inst = try self.arena.allocator.create(Inst.Cmp);
+                    new_inst.* = .{
+                        .base = .{ .src = inst.src, .tag = Inst.Cmp.base_tag },
+                        .positionals = .{
+                            .lhs = try self.resolveInst(inst_table, old_inst.args.lhs),
+                            .rhs = try self.resolveInst(inst_table, old_inst.args.rhs),
+                            .op = old_inst.args.op,
+                        },
+                        .kw_args = .{},
+                    };
+                    break :blk &new_inst.base;
+                },
+                .condbr => blk: {
+                    const old_inst = inst.cast(ir.Inst.CondBr).?;
+
+                    var true_body = std.ArrayList(*Inst).init(self.allocator);
+                    var false_body = std.ArrayList(*Inst).init(self.allocator);
+
+                    defer true_body.deinit();
+                    defer false_body.deinit();
+
+                    try self.emitBody(old_inst.args.true_body, inst_table, &true_body);
+                    try self.emitBody(old_inst.args.false_body, inst_table, &false_body);
+
+                    const new_inst = try self.arena.allocator.create(Inst.CondBr);
+                    new_inst.* = .{
+                        .base = .{ .src = inst.src, .tag = Inst.CondBr.base_tag },
+                        .positionals = .{
+                            .condition = try self.resolveInst(inst_table, old_inst.args.condition),
+                            .true_body = .{ .instructions = true_body.toOwnedSlice() },
+                            .false_body = .{ .instructions = false_body.toOwnedSlice() },
+                        },
+                        .kw_args = .{},
+                    };
+                    break :blk &new_inst.base;
+                },
+                .isnull => blk: {
+                    const old_inst = inst.cast(ir.Inst.IsNull).?;
+                    const new_inst = try self.arena.allocator.create(Inst.IsNull);
+                    new_inst.* = .{
+                        .base = .{ .src = inst.src, .tag = Inst.IsNull.base_tag },
+                        .positionals = .{
+                            .operand = try self.resolveInst(inst_table, old_inst.args.operand),
+                        },
+                        .kw_args = .{},
+                    };
+                    break :blk &new_inst.base;
+                },
+                .isnonnull => blk: {
+                    const old_inst = inst.cast(ir.Inst.IsNonNull).?;
+                    const new_inst = try self.arena.allocator.create(Inst.IsNonNull);
+                    new_inst.* = .{
+                        .base = .{ .src = inst.src, .tag = Inst.IsNonNull.base_tag },
+                        .positionals = .{
+                            .operand = try self.resolveInst(inst_table, old_inst.args.operand),
+                        },
+                        .kw_args = .{},
+                    };
+                    break :blk &new_inst.base;
+                },
+            };
+            try instructions.append(new_inst);
+            try inst_table.putNoClobber(inst, new_inst);
+        }
+    }
+
     fn emitType(self: *EmitZIR, src: usize, ty: Type) Allocator.Error!*Inst {
         switch (ty.tag()) {
             .isize => return self.emitPrimitiveType(src, .isize),

src-self-hosted/link.zig

@@ -7,11 +7,6 @@ const fs = std.fs;
 const elf = std.elf;
 const codegen = @import("codegen.zig");
 
-/// On common systems with a 0o022 umask, 0o777 will still result in a file created
-/// with 0o755 permissions, but it works appropriately if the system is configured
-/// more leniently. As another data point, C's fopen seems to open files with the
-/// 666 mode.
-const executable_mode = 0o777;
 const default_entry_addr = 0x8000000;
 
 pub const ErrorMsg = struct {
@@ -35,29 +30,29 @@ pub const Result = struct {
 /// If incremental linking fails, falls back to truncating the file and rewriting it.
 /// A malicious file is detected as incremental link failure and does not cause Illegal Behavior.
 /// This operation is not atomic.
-pub fn updateExecutableFilePath(
+pub fn updateFilePath(
     allocator: *Allocator,
     module: ir.Module,
     dir: fs.Dir,
     sub_path: []const u8,
 ) !Result {
-    const file = try dir.createFile(sub_path, .{ .truncate = false, .read = true, .mode = executable_mode });
+    const file = try dir.createFile(sub_path, .{ .truncate = false, .read = true, .mode = determineMode(module) });
     defer file.close();
 
-    return updateExecutableFile(allocator, module, file);
+    return updateFile(allocator, module, file);
 }
 
 /// Atomically overwrites the old file, if present.
-pub fn writeExecutableFilePath(
+pub fn writeFilePath(
     allocator: *Allocator,
     module: ir.Module,
     dir: fs.Dir,
     sub_path: []const u8,
 ) !Result {
-    const af = try dir.atomicFile(sub_path, .{ .mode = executable_mode });
+    const af = try dir.atomicFile(sub_path, .{ .mode = determineMode(module) });
     defer af.deinit();
 
-    const result = try writeExecutableFile(allocator, module, af.file);
+    const result = try writeFile(allocator, module, af.file);
     try af.finish();
     return result;
 }
@@ -67,10 +62,10 @@ pub fn writeExecutableFilePath(
 /// Returns an error if `file` is not already open with +read +write +seek abilities.
 /// A malicious file is detected as incremental link failure and does not cause Illegal Behavior.
 /// This operation is not atomic.
-pub fn updateExecutableFile(allocator: *Allocator, module: ir.Module, file: fs.File) !Result {
-    return updateExecutableFileInner(allocator, module, file) catch |err| switch (err) {
+pub fn updateFile(allocator: *Allocator, module: ir.Module, file: fs.File) !Result {
+    return updateFileInner(allocator, module, file) catch |err| switch (err) {
         error.IncrFailed => {
-            return writeExecutableFile(allocator, module, file);
+            return writeFile(allocator, module, file);
         },
         else => |e| return e,
     };
@@ -436,7 +431,7 @@ const Update = struct {
                 },
             }
         }
-        if (self.entry_addr == null) {
+        if (self.entry_addr == null and self.module.output_mode == .Exe) {
             const msg = try std.fmt.allocPrint(self.errors.allocator, "no entry point found", .{});
             errdefer self.errors.allocator.free(msg);
             try self.errors.append(.{
@@ -485,7 +480,15 @@ const Update = struct {
 
         assert(index == 16);
 
-        mem.writeInt(u16, hdr_buf[index..][0..2], @enumToInt(elf.ET.EXEC), endian);
+        const elf_type = switch (self.module.output_mode) {
+            .Exe => elf.ET.EXEC,
+            .Obj => elf.ET.REL,
+            .Lib => switch (self.module.link_mode) {
+                .Static => elf.ET.REL,
+                .Dynamic => elf.ET.DYN,
+            },
+        };
+        mem.writeInt(u16, hdr_buf[index..][0..2], @enumToInt(elf_type), endian);
         index += 2;
 
         const machine = self.module.target.cpu.arch.toElfMachine();
@@ -496,10 +499,11 @@ const Update = struct {
         mem.writeInt(u32, hdr_buf[index..][0..4], 1, endian);
         index += 4;
 
+        const e_entry = if (elf_type == .REL) 0 else self.entry_addr.?;
+
         switch (ptr_width) {
             .p32 => {
-                // e_entry
-                mem.writeInt(u32, hdr_buf[index..][0..4], @intCast(u32, self.entry_addr.?), endian);
+                mem.writeInt(u32, hdr_buf[index..][0..4], @intCast(u32, e_entry), endian);
                 index += 4;
 
                 // e_phoff
@@ -512,7 +516,7 @@ const Update = struct {
             },
             .p64 => {
                 // e_entry
-                mem.writeInt(u64, hdr_buf[index..][0..8], self.entry_addr.?, endian);
+                mem.writeInt(u64, hdr_buf[index..][0..8], e_entry, endian);
                 index += 8;
 
                 // e_phoff
@@ -750,7 +754,20 @@ const Update = struct {
 
 /// Truncates the existing file contents and overwrites the contents.
 /// Returns an error if `file` is not already open with +read +write +seek abilities.
-pub fn writeExecutableFile(allocator: *Allocator, module: ir.Module, file: fs.File) !Result {
+pub fn writeFile(allocator: *Allocator, module: ir.Module, file: fs.File) !Result {
+    switch (module.output_mode) {
+        .Exe => {},
+        .Obj => {},
+        .Lib => return error.TODOImplementWritingLibFiles,
+    }
+    switch (module.object_format) {
+        .unknown => unreachable, // TODO remove this tag from the enum
+        .coff => return error.TODOImplementWritingCOFF,
+        .elf => {},
+        .macho => return error.TODOImplementWritingMachO,
+        .wasm => return error.TODOImplementWritingWasmObjects,
+    }
+
     var update = Update{
         .file = file,
         .module = &module,
@@ -778,7 +795,7 @@ pub fn writeExecutableFile(allocator: *Allocator, module: ir.Module, file: fs.Fi
 }
 
 /// Returns error.IncrFailed if incremental update could not be performed.
-fn updateExecutableFileInner(allocator: *Allocator, module: ir.Module, file: fs.File) !Result {
+fn updateFileInner(allocator: *Allocator, module: ir.Module, file: fs.File) !Result {
     //var ehdr_buf: [@sizeOf(elf.Elf64_Ehdr)]u8 = undefined;
 
     // TODO implement incremental linking
@@ -822,3 +839,19 @@ fn sectHeaderTo32(shdr: elf.Elf64_Shdr) elf.Elf32_Shdr {
         .sh_entsize = @intCast(u32, shdr.sh_entsize),
     };
 }
+
+fn determineMode(module: ir.Module) fs.File.Mode {
+    // On common systems with a 0o022 umask, 0o777 will still result in a file created
+    // with 0o755 permissions, but it works appropriately if the system is configured
+    // more leniently. As another data point, C's fopen seems to open files with the
+    // 666 mode.
+    const executable_mode = if (std.Target.current.os.tag == .windows) 0 else 0o777;
+    switch (module.output_mode) {
+        .Lib => return switch (module.link_mode) {
+            .Dynamic => executable_mode,
+            .Static => fs.File.default_mode,
+        },
+        .Exe => return executable_mode,
+        .Obj => return fs.File.default_mode,
+    }
+}

src-self-hosted/test.zig

@@ -1,237 +1,248 @@
 const std = @import("std");
-const mem = std.mem;
-const Target = std.Target;
-const Compilation = @import("compilation.zig").Compilation;
-const introspect = @import("introspect.zig");
-const testing = std.testing;
-const errmsg = @import("errmsg.zig");
-const ZigCompiler = @import("compilation.zig").ZigCompiler;
+const link = @import("link.zig");
+const ir = @import("ir.zig");
+const Allocator = std.mem.Allocator;
 
-var ctx: TestContext = undefined;
+var global_ctx: TestContext = undefined;
 
-test "stage2" {
-    // TODO provide a way to run tests in evented I/O mode
-    if (!std.io.is_async) return error.SkipZigTest;
+test "self-hosted" {
+    try global_ctx.init();
+    defer global_ctx.deinit();
 
-    // TODO https://github.com/ziglang/zig/issues/1364
-    // TODO https://github.com/ziglang/zig/issues/3117
-    if (true) return error.SkipZigTest;
+    try @import("stage2_tests").addCases(&global_ctx);
 
-    try ctx.init();
-    defer ctx.deinit();
-
-    try @import("stage2_tests").addCases(&ctx);
-
-    try ctx.run();
+    try global_ctx.run();
 }
 
-const file1 = "1.zig";
-// TODO https://github.com/ziglang/zig/issues/3783
-const allocator = std.heap.page_allocator;
-
 pub const TestContext = struct {
-    zig_compiler: ZigCompiler,
-    zig_lib_dir: []u8,
-    file_index: std.atomic.Int(usize),
-    group: std.event.Group(anyerror!void),
-    any_err: anyerror!void,
+    zir_cmp_output_cases: std.ArrayList(ZIRCompareOutputCase),
+    zir_transform_cases: std.ArrayList(ZIRTransformCase),
 
-    const tmp_dir_name = "stage2_test_tmp";
+    pub const ZIRCompareOutputCase = struct {
+        name: []const u8,
+        src: [:0]const u8,
+        expected_stdout: []const u8,
+    };
+
+    pub const ZIRTransformCase = struct {
+        name: []const u8,
+        src: [:0]const u8,
+        expected_zir: []const u8,
+    };
+
+    pub fn addZIRCompareOutput(
+        ctx: *TestContext,
+        name: []const u8,
+        src: [:0]const u8,
+        expected_stdout: []const u8,
+    ) void {
+        ctx.zir_cmp_output_cases.append(.{
+            .name = name,
+            .src = src,
+            .expected_stdout = expected_stdout,
+        }) catch unreachable;
+    }
+
+    pub fn addZIRTransform(
+        ctx: *TestContext,
+        name: []const u8,
+        src: [:0]const u8,
+        expected_zir: []const u8,
+    ) void {
+        ctx.zir_transform_cases.append(.{
+            .name = name,
+            .src = src,
+            .expected_zir = expected_zir,
+        }) catch unreachable;
+    }
 
     fn init(self: *TestContext) !void {
-        self.* = TestContext{
-            .any_err = {},
-            .zig_compiler = undefined,
-            .zig_lib_dir = undefined,
-            .group = undefined,
-            .file_index = std.atomic.Int(usize).init(0),
+        self.* = .{
+            .zir_cmp_output_cases = std.ArrayList(ZIRCompareOutputCase).init(std.heap.page_allocator),
+            .zir_transform_cases = std.ArrayList(ZIRTransformCase).init(std.heap.page_allocator),
         };
-
-        self.zig_compiler = try ZigCompiler.init(allocator);
-        errdefer self.zig_compiler.deinit();
-
-        self.group = std.event.Group(anyerror!void).init(allocator);
-        errdefer self.group.wait() catch {};
-
-        self.zig_lib_dir = try introspect.resolveZigLibDir(allocator);
-        errdefer allocator.free(self.zig_lib_dir);
-
-        try std.fs.cwd().makePath(tmp_dir_name);
-        errdefer std.fs.cwd().deleteTree(tmp_dir_name) catch {};
     }
 
     fn deinit(self: *TestContext) void {
-        std.fs.cwd().deleteTree(tmp_dir_name) catch {};
-        allocator.free(self.zig_lib_dir);
-        self.zig_compiler.deinit();
+        self.zir_cmp_output_cases.deinit();
+        self.zir_transform_cases.deinit();
+        self.* = undefined;
     }
 
     fn run(self: *TestContext) !void {
-        std.event.Loop.startCpuBoundOperation();
-        self.any_err = self.group.wait();
-        return self.any_err;
+        var progress = std.Progress{};
+        const root_node = try progress.start("zir", self.zir_cmp_output_cases.items.len +
+            self.zir_transform_cases.items.len);
+        defer root_node.end();
+
+        const native_info = try std.zig.system.NativeTargetInfo.detect(std.heap.page_allocator, .{});
+
+        for (self.zir_cmp_output_cases.items) |case| {
+            std.testing.base_allocator_instance.reset();
+            try self.runOneZIRCmpOutputCase(std.testing.allocator, root_node, case, native_info.target);
+            try std.testing.allocator_instance.validate();
+        }
+        for (self.zir_transform_cases.items) |case| {
+            std.testing.base_allocator_instance.reset();
+            try self.runOneZIRTransformCase(std.testing.allocator, root_node, case, native_info.target);
+            try std.testing.allocator_instance.validate();
+        }
     }
 
-    fn testCompileError(
+    fn runOneZIRCmpOutputCase(
         self: *TestContext,
-        source: []const u8,
-        path: []const u8,
-        line: usize,
-        column: usize,
-        msg: []const u8,
+        allocator: *Allocator,
+        root_node: *std.Progress.Node,
+        case: ZIRCompareOutputCase,
+        target: std.Target,
     ) !void {
-        var file_index_buf: [20]u8 = undefined;
-        const file_index = try std.fmt.bufPrint(file_index_buf[0..], "{}", .{self.file_index.incr()});
-        const file1_path = try std.fs.path.join(allocator, [_][]const u8{ tmp_dir_name, file_index, file1 });
+        var tmp = std.testing.tmpDir(.{ .share_with_child_process = true });
+        defer tmp.cleanup();
 
-        if (std.fs.path.dirname(file1_path)) |dirname| {
-            try std.fs.cwd().makePath(dirname);
+        var prg_node = root_node.start(case.name, 4);
+        prg_node.activate();
+        defer prg_node.end();
+
+        var zir_module = x: {
+            var parse_node = prg_node.start("parse", null);
+            parse_node.activate();
+            defer parse_node.end();
+
+            break :x try ir.text.parse(allocator, case.src);
+        };
+        defer zir_module.deinit(allocator);
+        if (zir_module.errors.len != 0) {
+            debugPrintErrors(case.src, zir_module.errors);
+            return error.ParseFailure;
         }
 
-        try std.fs.cwd().writeFile(file1_path, source);
+        var analyzed_module = x: {
+            var analyze_node = prg_node.start("analyze", null);
+            analyze_node.activate();
+            defer analyze_node.end();
 
-        var comp = try Compilation.create(
-            &self.zig_compiler,
-            "test",
-            file1_path,
-            .Native,
-            .Obj,
-            .Debug,
-            true, // is_static
-            self.zig_lib_dir,
-        );
-        errdefer comp.destroy();
+            break :x try ir.analyze(allocator, zir_module, .{
+                .target = target,
+                .output_mode = .Exe,
+                .link_mode = .Static,
+                .optimize_mode = .Debug,
+            });
+        };
+        defer analyzed_module.deinit(allocator);
+        if (analyzed_module.errors.len != 0) {
+            debugPrintErrors(case.src, analyzed_module.errors);
+            return error.ParseFailure;
+        }
 
-        comp.start();
+        var link_result = x: {
+            var link_node = prg_node.start("link", null);
+            link_node.activate();
+            defer link_node.end();
 
-        try self.group.call(getModuleEvent, comp, source, path, line, column, msg);
+            break :x try link.updateFilePath(allocator, analyzed_module, tmp.dir, "a.out");
+        };
+        defer link_result.deinit(allocator);
+        if (link_result.errors.len != 0) {
+            debugPrintErrors(case.src, link_result.errors);
+            return error.LinkFailure;
+        }
+
+        var exec_result = x: {
+            var exec_node = prg_node.start("execute", null);
+            exec_node.activate();
+            defer exec_node.end();
+
+            break :x try std.ChildProcess.exec(.{
+                .allocator = allocator,
+                .argv = &[_][]const u8{"./a.out"},
+                .cwd_dir = tmp.dir,
+            });
+        };
+        defer allocator.free(exec_result.stdout);
+        defer allocator.free(exec_result.stderr);
+        switch (exec_result.term) {
+            .Exited => |code| {
+                if (code != 0) {
+                    std.debug.warn("elf file exited with code {}\n", .{code});
+                    return error.BinaryBadExitCode;
+                }
+            },
+            else => return error.BinaryCrashed,
+        }
+        std.testing.expectEqualSlices(u8, case.expected_stdout, exec_result.stdout);
     }
 
-    fn testCompareOutputLibC(
+    fn runOneZIRTransformCase(
         self: *TestContext,
-        source: []const u8,
-        expected_output: []const u8,
+        allocator: *Allocator,
+        root_node: *std.Progress.Node,
+        case: ZIRTransformCase,
+        target: std.Target,
     ) !void {
-        var file_index_buf: [20]u8 = undefined;
-        const file_index = try std.fmt.bufPrint(file_index_buf[0..], "{}", .{self.file_index.incr()});
-        const file1_path = try std.fs.path.join(allocator, [_][]const u8{ tmp_dir_name, file_index, file1 });
+        var prg_node = root_node.start(case.name, 4);
+        prg_node.activate();
+        defer prg_node.end();
 
-        const output_file = try std.fmt.allocPrint(allocator, "{}-out{}", .{ file1_path, (Target{ .Native = {} }).exeFileExt() });
-        if (std.fs.path.dirname(file1_path)) |dirname| {
-            try std.fs.cwd().makePath(dirname);
+        var parse_node = prg_node.start("parse", null);
+        parse_node.activate();
+        var zir_module = try ir.text.parse(allocator, case.src);
+        defer zir_module.deinit(allocator);
+        if (zir_module.errors.len != 0) {
+            debugPrintErrors(case.src, zir_module.errors);
+            return error.ParseFailure;
         }
+        parse_node.end();
 
-        try std.fs.cwd().writeFile(file1_path, source);
-
-        var comp = try Compilation.create(
-            &self.zig_compiler,
-            "test",
-            file1_path,
-            .Native,
-            .Exe,
-            .Debug,
-            false,
-            self.zig_lib_dir,
-        );
-        errdefer comp.destroy();
-
-        _ = try comp.addLinkLib("c", true);
-        comp.link_out_file = output_file;
-        comp.start();
-
-        try self.group.call(getModuleEventSuccess, comp, output_file, expected_output);
-    }
-
-    async fn getModuleEventSuccess(
-        comp: *Compilation,
-        exe_file: []const u8,
-        expected_output: []const u8,
-    ) anyerror!void {
-        defer comp.destroy();
-        const build_event = comp.events.get();
-
-        switch (build_event) {
-            .Ok => {
-                const argv = [_][]const u8{exe_file};
-                // TODO use event loop
-                const child = try std.ChildProcess.exec(.{
-                    .allocator = allocator,
-                    .argv = argv,
-                    .max_output_bytes = 1024 * 1024,
-                });
-                switch (child.term) {
-                    .Exited => |code| {
-                        if (code != 0) {
-                            return error.BadReturnCode;
-                        }
-                    },
-                    else => {
-                        return error.Crashed;
-                    },
-                }
-                if (!mem.eql(u8, child.stdout, expected_output)) {
-                    return error.OutputMismatch;
-                }
-            },
-            .Error => @panic("Cannot return error: https://github.com/ziglang/zig/issues/3190"), // |err| return err,
-            .Fail => |msgs| {
-                const stderr = std.io.getStdErr();
-                try stderr.write("build incorrectly failed:\n");
-                for (msgs) |msg| {
-                    defer msg.destroy();
-                    try msg.printToFile(stderr, .Auto);
-                }
-            },
+        var analyze_node = prg_node.start("analyze", null);
+        analyze_node.activate();
+        var analyzed_module = try ir.analyze(allocator, zir_module, .{
+            .target = target,
+            .output_mode = .Obj,
+            .link_mode = .Static,
+            .optimize_mode = .Debug,
+        });
+        defer analyzed_module.deinit(allocator);
+        if (analyzed_module.errors.len != 0) {
+            debugPrintErrors(case.src, analyzed_module.errors);
+            return error.ParseFailure;
         }
-    }
+        analyze_node.end();
 
-    async fn getModuleEvent(
-        comp: *Compilation,
-        source: []const u8,
-        path: []const u8,
-        line: usize,
-        column: usize,
-        text: []const u8,
-    ) anyerror!void {
-        defer comp.destroy();
-        const build_event = comp.events.get();
+        var emit_node = prg_node.start("emit", null);
+        emit_node.activate();
+        var new_zir_module = try ir.text.emit_zir(allocator, analyzed_module);
+        defer new_zir_module.deinit(allocator);
+        emit_node.end();
 
-        switch (build_event) {
-            .Ok => {
-                @panic("build incorrectly succeeded");
-            },
-            .Error => |err| {
-                @panic("build incorrectly failed");
-            },
-            .Fail => |msgs| {
-                testing.expect(msgs.len != 0);
-                for (msgs) |msg| {
-                    if (mem.endsWith(u8, msg.realpath, path) and mem.eql(u8, msg.text, text)) {
-                        const span = msg.getSpan();
-                        const first_token = msg.getTree().tokens.at(span.first);
-                        const last_token = msg.getTree().tokens.at(span.first);
-                        const start_loc = msg.getTree().tokenLocationPtr(0, first_token);
-                        if (start_loc.line + 1 == line and start_loc.column + 1 == column) {
-                            return;
-                        }
-                    }
-                }
-                std.debug.warn("\n=====source:=======\n{}\n====expected:========\n{}:{}:{}: error: {}\n", .{
-                    source,
-                    path,
-                    line,
-                    column,
-                    text,
-                });
-                std.debug.warn("\n====found:========\n", .{});
-                const stderr = std.io.getStdErr();
-                for (msgs) |msg| {
-                    defer msg.destroy();
-                    try msg.printToFile(stderr, errmsg.Color.Auto);
-                }
-                std.debug.warn("============\n", .{});
-                return error.TestFailed;
-            },
-        }
+        var write_node = prg_node.start("write", null);
+        write_node.activate();
+        var out_zir = std.ArrayList(u8).init(allocator);
+        defer out_zir.deinit();
+        try new_zir_module.writeToStream(allocator, out_zir.outStream());
+        write_node.end();
+
+        std.testing.expectEqualSlices(u8, case.expected_zir, out_zir.items);
     }
 };
+
+fn debugPrintErrors(src: []const u8, errors: var) void {
+    std.debug.warn("\n", .{});
+    var nl = true;
+    var line: usize = 1;
+    for (src) |byte| {
+        if (nl) {
+            std.debug.warn("{: >3}| ", .{line});
+            nl = false;
+        }
+        if (byte == '\n') {
+            nl = true;
+            line += 1;
+        }
+        std.debug.warn("{c}", .{byte});
+    }
+    std.debug.warn("\n", .{});
+    for (errors) |err_msg| {
+        const loc = std.zig.findLineColumn(src, err_msg.byte_offset);
+        std.debug.warn("{}:{}: error: {}\n", .{ loc.line + 1, loc.column + 1, err_msg.msg });
+    }
+}

src-self-hosted/translate_c.zig

@@ -3913,18 +3913,20 @@ fn transCreateNodeAPInt(c: *Context, int: *const ZigClangAPSInt) !*ast.Node {
     };
     var aps_int = int;
     const is_negative = ZigClangAPSInt_isSigned(int) and ZigClangAPSInt_isNegative(int);
-    if (is_negative)
-        aps_int = ZigClangAPSInt_negate(aps_int);
-    var big = try math.big.Int.initCapacity(c.a(), num_limbs);
-    if (is_negative)
-        big.negate();
-    defer big.deinit();
+    if (is_negative) aps_int = ZigClangAPSInt_negate(aps_int);
+    defer if (is_negative) {
+        ZigClangAPSInt_free(aps_int);
+    };
+
+    const limbs = try c.a().alloc(math.big.Limb, num_limbs);
+    defer c.a().free(limbs);
+
     const data = ZigClangAPSInt_getRawData(aps_int);
-    switch (@sizeOf(std.math.big.Limb)) {
+    switch (@sizeOf(math.big.Limb)) {
         8 => {
             var i: usize = 0;
             while (i < num_limbs) : (i += 1) {
-                big.limbs[i] = data[i];
+                limbs[i] = data[i];
             }
         },
         4 => {
@@ -3934,23 +3936,23 @@ fn transCreateNodeAPInt(c: *Context, int: *const ZigClangAPSInt) !*ast.Node {
                 limb_i += 2;
                 data_i += 1;
             }) {
-                big.limbs[limb_i] = @truncate(u32, data[data_i]);
-                big.limbs[limb_i + 1] = @truncate(u32, data[data_i] >> 32);
+                limbs[limb_i] = @truncate(u32, data[data_i]);
+                limbs[limb_i + 1] = @truncate(u32, data[data_i] >> 32);
             }
         },
         else => @compileError("unimplemented"),
     }
-    const str = big.toString(c.a(), 10, false) catch |err| switch (err) {
+
+    const big: math.big.int.Const = .{ .limbs = limbs, .positive = !is_negative };
+    const str = big.toStringAlloc(c.a(), 10, false) catch |err| switch (err) {
         error.OutOfMemory => return error.OutOfMemory,
-        else => unreachable,
     };
+    defer c.a().free(str);
     const token = try appendToken(c, .IntegerLiteral, str);
     const node = try c.a().create(ast.Node.IntegerLiteral);
     node.* = .{
         .token = token,
     };
-    if (is_negative)
-        ZigClangAPSInt_free(aps_int);
     return &node.base;
 }
 

src-self-hosted/type.zig

@@ -20,37 +20,40 @@ pub const Type = extern union {
 
     pub fn zigTypeTag(self: Type) std.builtin.TypeId {
         switch (self.tag()) {
-            .@"u8",
-            .@"i8",
-            .@"isize",
-            .@"usize",
-            .@"c_short",
-            .@"c_ushort",
-            .@"c_int",
-            .@"c_uint",
-            .@"c_long",
-            .@"c_ulong",
-            .@"c_longlong",
-            .@"c_ulonglong",
-            .@"c_longdouble",
+            .u8,
+            .i8,
+            .isize,
+            .usize,
+            .c_short,
+            .c_ushort,
+            .c_int,
+            .c_uint,
+            .c_long,
+            .c_ulong,
+            .c_longlong,
+            .c_ulonglong,
+            .c_longdouble,
+            .int_signed,
+            .int_unsigned,
             => return .Int,
 
-            .@"f16",
-            .@"f32",
-            .@"f64",
-            .@"f128",
+            .f16,
+            .f32,
+            .f64,
+            .f128,
             => return .Float,
 
-            .@"c_void" => return .Opaque,
-            .@"bool" => return .Bool,
-            .@"void" => return .Void,
-            .@"type" => return .Type,
-            .@"anyerror" => return .ErrorSet,
-            .@"comptime_int" => return .ComptimeInt,
-            .@"comptime_float" => return .ComptimeFloat,
-            .@"noreturn" => return .NoReturn,
+            .c_void => return .Opaque,
+            .bool => return .Bool,
+            .void => return .Void,
+            .type => return .Type,
+            .anyerror => return .ErrorSet,
+            .comptime_int => return .ComptimeInt,
+            .comptime_float => return .ComptimeFloat,
+            .noreturn => return .NoReturn,
 
             .fn_naked_noreturn_no_args => return .Fn,
+            .fn_ccc_void_no_args => return .Fn,
 
             .array, .array_u8_sentinel_0 => return .Array,
             .single_const_pointer => return .Pointer,
@@ -153,35 +156,36 @@ pub const Type = extern union {
         while (true) {
             const t = ty.tag();
             switch (t) {
-                .@"u8",
-                .@"i8",
-                .@"isize",
-                .@"usize",
-                .@"c_short",
-                .@"c_ushort",
-                .@"c_int",
-                .@"c_uint",
-                .@"c_long",
-                .@"c_ulong",
-                .@"c_longlong",
-                .@"c_ulonglong",
-                .@"c_longdouble",
-                .@"c_void",
-                .@"f16",
-                .@"f32",
-                .@"f64",
-                .@"f128",
-                .@"bool",
-                .@"void",
-                .@"type",
-                .@"anyerror",
-                .@"comptime_int",
-                .@"comptime_float",
-                .@"noreturn",
+                .u8,
+                .i8,
+                .isize,
+                .usize,
+                .c_short,
+                .c_ushort,
+                .c_int,
+                .c_uint,
+                .c_long,
+                .c_ulong,
+                .c_longlong,
+                .c_ulonglong,
+                .c_longdouble,
+                .c_void,
+                .f16,
+                .f32,
+                .f64,
+                .f128,
+                .bool,
+                .void,
+                .type,
+                .anyerror,
+                .comptime_int,
+                .comptime_float,
+                .noreturn,
                 => return out_stream.writeAll(@tagName(t)),
 
                 .const_slice_u8 => return out_stream.writeAll("[]const u8"),
                 .fn_naked_noreturn_no_args => return out_stream.writeAll("fn() callconv(.Naked) noreturn"),
+                .fn_ccc_void_no_args => return out_stream.writeAll("fn() callconv(.C) void"),
                 .single_const_pointer_to_comptime_int => return out_stream.writeAll("*const comptime_int"),
 
                 .array_u8_sentinel_0 => {
@@ -200,6 +204,14 @@ pub const Type = extern union {
                     ty = payload.pointee_type;
                     continue;
                 },
+                .int_signed => {
+                    const payload = @fieldParentPtr(Payload.IntSigned, "base", ty.ptr_otherwise);
+                    return out_stream.print("i{}", .{payload.bits});
+                },
+                .int_unsigned => {
+                    const payload = @fieldParentPtr(Payload.IntUnsigned, "base", ty.ptr_otherwise);
+                    return out_stream.print("u{}", .{payload.bits});
+                },
             }
             unreachable;
         }
@@ -207,32 +219,33 @@ pub const Type = extern union {
 
     pub fn toValue(self: Type, allocator: *Allocator) Allocator.Error!Value {
         switch (self.tag()) {
-            .@"u8" => return Value.initTag(.u8_type),
-            .@"i8" => return Value.initTag(.i8_type),
-            .@"isize" => return Value.initTag(.isize_type),
-            .@"usize" => return Value.initTag(.usize_type),
-            .@"c_short" => return Value.initTag(.c_short_type),
-            .@"c_ushort" => return Value.initTag(.c_ushort_type),
-            .@"c_int" => return Value.initTag(.c_int_type),
-            .@"c_uint" => return Value.initTag(.c_uint_type),
-            .@"c_long" => return Value.initTag(.c_long_type),
-            .@"c_ulong" => return Value.initTag(.c_ulong_type),
-            .@"c_longlong" => return Value.initTag(.c_longlong_type),
-            .@"c_ulonglong" => return Value.initTag(.c_ulonglong_type),
-            .@"c_longdouble" => return Value.initTag(.c_longdouble_type),
-            .@"c_void" => return Value.initTag(.c_void_type),
-            .@"f16" => return Value.initTag(.f16_type),
-            .@"f32" => return Value.initTag(.f32_type),
-            .@"f64" => return Value.initTag(.f64_type),
-            .@"f128" => return Value.initTag(.f128_type),
-            .@"bool" => return Value.initTag(.bool_type),
-            .@"void" => return Value.initTag(.void_type),
-            .@"type" => return Value.initTag(.type_type),
-            .@"anyerror" => return Value.initTag(.anyerror_type),
-            .@"comptime_int" => return Value.initTag(.comptime_int_type),
-            .@"comptime_float" => return Value.initTag(.comptime_float_type),
-            .@"noreturn" => return Value.initTag(.noreturn_type),
+            .u8 => return Value.initTag(.u8_type),
+            .i8 => return Value.initTag(.i8_type),
+            .isize => return Value.initTag(.isize_type),
+            .usize => return Value.initTag(.usize_type),
+            .c_short => return Value.initTag(.c_short_type),
+            .c_ushort => return Value.initTag(.c_ushort_type),
+            .c_int => return Value.initTag(.c_int_type),
+            .c_uint => return Value.initTag(.c_uint_type),
+            .c_long => return Value.initTag(.c_long_type),
+            .c_ulong => return Value.initTag(.c_ulong_type),
+            .c_longlong => return Value.initTag(.c_longlong_type),
+            .c_ulonglong => return Value.initTag(.c_ulonglong_type),
+            .c_longdouble => return Value.initTag(.c_longdouble_type),
+            .c_void => return Value.initTag(.c_void_type),
+            .f16 => return Value.initTag(.f16_type),
+            .f32 => return Value.initTag(.f32_type),
+            .f64 => return Value.initTag(.f64_type),
+            .f128 => return Value.initTag(.f128_type),
+            .bool => return Value.initTag(.bool_type),
+            .void => return Value.initTag(.void_type),
+            .type => return Value.initTag(.type_type),
+            .anyerror => return Value.initTag(.anyerror_type),
+            .comptime_int => return Value.initTag(.comptime_int_type),
+            .comptime_float => return Value.initTag(.comptime_float_type),
+            .noreturn => return Value.initTag(.noreturn_type),
             .fn_naked_noreturn_no_args => return Value.initTag(.fn_naked_noreturn_no_args_type),
+            .fn_ccc_void_no_args => return Value.initTag(.fn_ccc_void_no_args_type),
             .single_const_pointer_to_comptime_int => return Value.initTag(.single_const_pointer_to_comptime_int_type),
             .const_slice_u8 => return Value.initTag(.const_slice_u8_type),
             else => {
@@ -245,35 +258,38 @@ pub const Type = extern union {
 
     pub fn isSinglePointer(self: Type) bool {
         return switch (self.tag()) {
-            .@"u8",
-            .@"i8",
-            .@"isize",
-            .@"usize",
-            .@"c_short",
-            .@"c_ushort",
-            .@"c_int",
-            .@"c_uint",
-            .@"c_long",
-            .@"c_ulong",
-            .@"c_longlong",
-            .@"c_ulonglong",
-            .@"c_longdouble",
-            .@"f16",
-            .@"f32",
-            .@"f64",
-            .@"f128",
-            .@"c_void",
-            .@"bool",
-            .@"void",
-            .@"type",
-            .@"anyerror",
-            .@"comptime_int",
-            .@"comptime_float",
-            .@"noreturn",
+            .u8,
+            .i8,
+            .isize,
+            .usize,
+            .c_short,
+            .c_ushort,
+            .c_int,
+            .c_uint,
+            .c_long,
+            .c_ulong,
+            .c_longlong,
+            .c_ulonglong,
+            .c_longdouble,
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_void,
+            .bool,
+            .void,
+            .type,
+            .anyerror,
+            .comptime_int,
+            .comptime_float,
+            .noreturn,
             .array,
             .array_u8_sentinel_0,
             .const_slice_u8,
             .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
+            .int_unsigned,
+            .int_signed,
             => false,
 
             .single_const_pointer,
@@ -284,36 +300,39 @@ pub const Type = extern union {
 
     pub fn isSlice(self: Type) bool {
         return switch (self.tag()) {
-            .@"u8",
-            .@"i8",
-            .@"isize",
-            .@"usize",
-            .@"c_short",
-            .@"c_ushort",
-            .@"c_int",
-            .@"c_uint",
-            .@"c_long",
-            .@"c_ulong",
-            .@"c_longlong",
-            .@"c_ulonglong",
-            .@"c_longdouble",
-            .@"f16",
-            .@"f32",
-            .@"f64",
-            .@"f128",
-            .@"c_void",
-            .@"bool",
-            .@"void",
-            .@"type",
-            .@"anyerror",
-            .@"comptime_int",
-            .@"comptime_float",
-            .@"noreturn",
+            .u8,
+            .i8,
+            .isize,
+            .usize,
+            .c_short,
+            .c_ushort,
+            .c_int,
+            .c_uint,
+            .c_long,
+            .c_ulong,
+            .c_longlong,
+            .c_ulonglong,
+            .c_longdouble,
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_void,
+            .bool,
+            .void,
+            .type,
+            .anyerror,
+            .comptime_int,
+            .comptime_float,
+            .noreturn,
             .array,
             .array_u8_sentinel_0,
             .single_const_pointer,
             .single_const_pointer_to_comptime_int,
             .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
+            .int_unsigned,
+            .int_signed,
             => false,
 
             .const_slice_u8 => true,
@@ -323,34 +342,37 @@ pub const Type = extern union {
     /// Asserts the type is a pointer type.
     pub fn pointerIsConst(self: Type) bool {
         return switch (self.tag()) {
-            .@"u8",
-            .@"i8",
-            .@"isize",
-            .@"usize",
-            .@"c_short",
-            .@"c_ushort",
-            .@"c_int",
-            .@"c_uint",
-            .@"c_long",
-            .@"c_ulong",
-            .@"c_longlong",
-            .@"c_ulonglong",
-            .@"c_longdouble",
-            .@"f16",
-            .@"f32",
-            .@"f64",
-            .@"f128",
-            .@"c_void",
-            .@"bool",
-            .@"void",
-            .@"type",
-            .@"anyerror",
-            .@"comptime_int",
-            .@"comptime_float",
-            .@"noreturn",
+            .u8,
+            .i8,
+            .isize,
+            .usize,
+            .c_short,
+            .c_ushort,
+            .c_int,
+            .c_uint,
+            .c_long,
+            .c_ulong,
+            .c_longlong,
+            .c_ulonglong,
+            .c_longdouble,
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_void,
+            .bool,
+            .void,
+            .type,
+            .anyerror,
+            .comptime_int,
+            .comptime_float,
+            .noreturn,
             .array,
             .array_u8_sentinel_0,
             .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
+            .int_unsigned,
+            .int_signed,
             => unreachable,
 
             .single_const_pointer,
@@ -363,32 +385,35 @@ pub const Type = extern union {
     /// Asserts the type is a pointer or array type.
     pub fn elemType(self: Type) Type {
         return switch (self.tag()) {
-            .@"u8",
-            .@"i8",
-            .@"isize",
-            .@"usize",
-            .@"c_short",
-            .@"c_ushort",
-            .@"c_int",
-            .@"c_uint",
-            .@"c_long",
-            .@"c_ulong",
-            .@"c_longlong",
-            .@"c_ulonglong",
-            .@"c_longdouble",
-            .@"f16",
-            .@"f32",
-            .@"f64",
-            .@"f128",
-            .@"c_void",
-            .@"bool",
-            .@"void",
-            .@"type",
-            .@"anyerror",
-            .@"comptime_int",
-            .@"comptime_float",
-            .@"noreturn",
+            .u8,
+            .i8,
+            .isize,
+            .usize,
+            .c_short,
+            .c_ushort,
+            .c_int,
+            .c_uint,
+            .c_long,
+            .c_ulong,
+            .c_longlong,
+            .c_ulonglong,
+            .c_longdouble,
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_void,
+            .bool,
+            .void,
+            .type,
+            .anyerror,
+            .comptime_int,
+            .comptime_float,
+            .noreturn,
             .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
+            .int_unsigned,
+            .int_signed,
             => unreachable,
 
             .array => self.cast(Payload.Array).?.elem_type,
@@ -398,7 +423,7 @@ pub const Type = extern union {
         };
     }
 
-    /// Asserts the type is an array.
+    /// Asserts the type is an array or vector.
     pub fn arrayLen(self: Type) u64 {
         return switch (self.tag()) {
             .u8,
@@ -427,9 +452,12 @@ pub const Type = extern union {
             .comptime_float,
             .noreturn,
             .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
             .single_const_pointer,
             .single_const_pointer_to_comptime_int,
             .const_slice_u8,
+            .int_unsigned,
+            .int_signed,
             => unreachable,
 
             .array => self.cast(Payload.Array).?.len,
@@ -437,23 +465,67 @@ pub const Type = extern union {
         };
     }
 
+    /// Returns true if and only if the type is a fixed-width, signed integer.
+    pub fn isSignedInt(self: Type) bool {
+        return switch (self.tag()) {
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_longdouble,
+            .c_void,
+            .bool,
+            .void,
+            .type,
+            .anyerror,
+            .comptime_int,
+            .comptime_float,
+            .noreturn,
+            .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
+            .array,
+            .single_const_pointer,
+            .single_const_pointer_to_comptime_int,
+            .array_u8_sentinel_0,
+            .const_slice_u8,
+            .int_unsigned,
+            .u8,
+            .usize,
+            .c_ushort,
+            .c_uint,
+            .c_ulong,
+            .c_ulonglong,
+            => false,
+
+            .int_signed,
+            .i8,
+            .isize,
+            .c_short,
+            .c_int,
+            .c_long,
+            .c_longlong,
+            => true,
+        };
+    }
+
     /// Asserts the type is a fixed-width integer.
     pub fn intInfo(self: Type, target: Target) struct { signed: bool, bits: u16 } {
         return switch (self.tag()) {
-            .@"f16",
-            .@"f32",
-            .@"f64",
-            .@"f128",
-            .@"c_longdouble",
-            .@"c_void",
-            .@"bool",
-            .@"void",
-            .@"type",
-            .@"anyerror",
-            .@"comptime_int",
-            .@"comptime_float",
-            .@"noreturn",
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_longdouble,
+            .c_void,
+            .bool,
+            .void,
+            .type,
+            .anyerror,
+            .comptime_int,
+            .comptime_float,
+            .noreturn,
             .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
             .array,
             .single_const_pointer,
             .single_const_pointer_to_comptime_int,
@@ -461,18 +533,46 @@ pub const Type = extern union {
             .const_slice_u8,
             => unreachable,
 
-            .@"u8" => .{ .signed = false, .bits = 8 },
-            .@"i8" => .{ .signed = true, .bits = 8 },
-            .@"usize" => .{ .signed = false, .bits = target.cpu.arch.ptrBitWidth() },
-            .@"isize" => .{ .signed = true, .bits = target.cpu.arch.ptrBitWidth() },
-            .@"c_short" => .{ .signed = true, .bits = CInteger.short.sizeInBits(target) },
-            .@"c_ushort" => .{ .signed = false, .bits = CInteger.ushort.sizeInBits(target) },
-            .@"c_int" => .{ .signed = true, .bits = CInteger.int.sizeInBits(target) },
-            .@"c_uint" => .{ .signed = false, .bits = CInteger.uint.sizeInBits(target) },
-            .@"c_long" => .{ .signed = true, .bits = CInteger.long.sizeInBits(target) },
-            .@"c_ulong" => .{ .signed = false, .bits = CInteger.ulong.sizeInBits(target) },
-            .@"c_longlong" => .{ .signed = true, .bits = CInteger.longlong.sizeInBits(target) },
-            .@"c_ulonglong" => .{ .signed = false, .bits = CInteger.ulonglong.sizeInBits(target) },
+            .int_unsigned => .{ .signed = false, .bits = self.cast(Payload.IntUnsigned).?.bits },
+            .int_signed => .{ .signed = true, .bits = self.cast(Payload.IntSigned).?.bits },
+            .u8 => .{ .signed = false, .bits = 8 },
+            .i8 => .{ .signed = true, .bits = 8 },
+            .usize => .{ .signed = false, .bits = target.cpu.arch.ptrBitWidth() },
+            .isize => .{ .signed = true, .bits = target.cpu.arch.ptrBitWidth() },
+            .c_short => .{ .signed = true, .bits = CType.short.sizeInBits(target) },
+            .c_ushort => .{ .signed = false, .bits = CType.ushort.sizeInBits(target) },
+            .c_int => .{ .signed = true, .bits = CType.int.sizeInBits(target) },
+            .c_uint => .{ .signed = false, .bits = CType.uint.sizeInBits(target) },
+            .c_long => .{ .signed = true, .bits = CType.long.sizeInBits(target) },
+            .c_ulong => .{ .signed = false, .bits = CType.ulong.sizeInBits(target) },
+            .c_longlong => .{ .signed = true, .bits = CType.longlong.sizeInBits(target) },
+            .c_ulonglong => .{ .signed = false, .bits = CType.ulonglong.sizeInBits(target) },
+        };
+    }
+
+    pub fn isFloat(self: Type) bool {
+        return switch (self.tag()) {
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_longdouble,
+            => true,
+
+            else => false,
+        };
+    }
+
+    /// Asserts the type is a fixed-size float.
+    pub fn floatBits(self: Type, target: Target) u16 {
+        return switch (self.tag()) {
+            .f16 => 16,
+            .f32 => 32,
+            .f64 => 64,
+            .f128 => 128,
+            .c_longdouble => CType.longdouble.sizeInBits(target),
+
+            else => unreachable,
         };
     }
 
@@ -480,6 +580,7 @@ pub const Type = extern union {
     pub fn fnParamLen(self: Type) usize {
         return switch (self.tag()) {
             .fn_naked_noreturn_no_args => 0,
+            .fn_ccc_void_no_args => 0,
 
             .f16,
             .f32,
@@ -511,6 +612,8 @@ pub const Type = extern union {
             .c_ulong,
             .c_longlong,
             .c_ulonglong,
+            .int_unsigned,
+            .int_signed,
             => unreachable,
         };
     }
@@ -520,6 +623,7 @@ pub const Type = extern union {
     pub fn fnParamTypes(self: Type, types: []Type) void {
         switch (self.tag()) {
             .fn_naked_noreturn_no_args => return,
+            .fn_ccc_void_no_args => return,
 
             .f16,
             .f32,
@@ -551,6 +655,8 @@ pub const Type = extern union {
             .c_ulong,
             .c_longlong,
             .c_ulonglong,
+            .int_unsigned,
+            .int_signed,
             => unreachable,
         }
     }
@@ -559,6 +665,7 @@ pub const Type = extern union {
     pub fn fnReturnType(self: Type) Type {
         return switch (self.tag()) {
             .fn_naked_noreturn_no_args => Type.initTag(.noreturn),
+            .fn_ccc_void_no_args => Type.initTag(.void),
 
             .f16,
             .f32,
@@ -590,6 +697,8 @@ pub const Type = extern union {
             .c_ulong,
             .c_longlong,
             .c_ulonglong,
+            .int_unsigned,
+            .int_signed,
             => unreachable,
         };
     }
@@ -598,6 +707,7 @@ pub const Type = extern union {
     pub fn fnCallingConvention(self: Type) std.builtin.CallingConvention {
         return switch (self.tag()) {
             .fn_naked_noreturn_no_args => .Naked,
+            .fn_ccc_void_no_args => .C,
 
             .f16,
             .f32,
@@ -629,10 +739,148 @@ pub const Type = extern union {
             .c_ulong,
             .c_longlong,
             .c_ulonglong,
+            .int_unsigned,
+            .int_signed,
             => unreachable,
         };
     }
 
+    pub fn isNumeric(self: Type) bool {
+        return switch (self.tag()) {
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_longdouble,
+            .comptime_int,
+            .comptime_float,
+            .u8,
+            .i8,
+            .usize,
+            .isize,
+            .c_short,
+            .c_ushort,
+            .c_int,
+            .c_uint,
+            .c_long,
+            .c_ulong,
+            .c_longlong,
+            .c_ulonglong,
+            .int_unsigned,
+            .int_signed,
+            => true,
+
+            .c_void,
+            .bool,
+            .void,
+            .type,
+            .anyerror,
+            .noreturn,
+            .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
+            .array,
+            .single_const_pointer,
+            .single_const_pointer_to_comptime_int,
+            .array_u8_sentinel_0,
+            .const_slice_u8,
+            => false,
+        };
+    }
+
+    pub fn onePossibleValue(self: Type) bool {
+        var ty = self;
+        while (true) switch (ty.tag()) {
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_longdouble,
+            .comptime_int,
+            .comptime_float,
+            .u8,
+            .i8,
+            .usize,
+            .isize,
+            .c_short,
+            .c_ushort,
+            .c_int,
+            .c_uint,
+            .c_long,
+            .c_ulong,
+            .c_longlong,
+            .c_ulonglong,
+            .bool,
+            .type,
+            .anyerror,
+            .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
+            .single_const_pointer_to_comptime_int,
+            .array_u8_sentinel_0,
+            .const_slice_u8,
+            => return false,
+
+            .c_void,
+            .void,
+            .noreturn,
+            => return true,
+
+            .int_unsigned => return ty.cast(Payload.IntUnsigned).?.bits == 0,
+            .int_signed => return ty.cast(Payload.IntSigned).?.bits == 0,
+            .array => {
+                const array = ty.cast(Payload.Array).?;
+                if (array.len == 0)
+                    return true;
+                ty = array.elem_type;
+                continue;
+            },
+            .single_const_pointer => {
+                const ptr = ty.cast(Payload.SingleConstPointer).?;
+                ty = ptr.pointee_type;
+                continue;
+            },
+        };
+    }
+
+    pub fn isCPtr(self: Type) bool {
+        return switch (self.tag()) {
+            .f16,
+            .f32,
+            .f64,
+            .f128,
+            .c_longdouble,
+            .comptime_int,
+            .comptime_float,
+            .u8,
+            .i8,
+            .usize,
+            .isize,
+            .c_short,
+            .c_ushort,
+            .c_int,
+            .c_uint,
+            .c_long,
+            .c_ulong,
+            .c_longlong,
+            .c_ulonglong,
+            .bool,
+            .type,
+            .anyerror,
+            .fn_naked_noreturn_no_args,
+            .fn_ccc_void_no_args,
+            .single_const_pointer_to_comptime_int,
+            .array_u8_sentinel_0,
+            .const_slice_u8,
+            .c_void,
+            .void,
+            .noreturn,
+            .int_unsigned,
+            .int_signed,
+            .array,
+            .single_const_pointer,
+            => return false,
+        };
+    }
+
     /// This enum does not directly correspond to `std.builtin.TypeId` because
     /// it has extra enum tags in it, as a way of using less memory. For example,
     /// even though Zig recognizes `*align(10) i32` and `*i32` both as Pointer types
@@ -667,6 +915,7 @@ pub const Type = extern union {
         comptime_float,
         noreturn,
         fn_naked_noreturn_no_args,
+        fn_ccc_void_no_args,
         single_const_pointer_to_comptime_int,
         const_slice_u8, // See last_no_payload_tag below.
         // After this, the tag requires a payload.
@@ -674,6 +923,8 @@ pub const Type = extern union {
         array_u8_sentinel_0,
         array,
         single_const_pointer,
+        int_signed,
+        int_unsigned,
 
         pub const last_no_payload_tag = Tag.const_slice_u8;
         pub const no_payload_count = @enumToInt(last_no_payload_tag) + 1;
@@ -700,10 +951,22 @@ pub const Type = extern union {
 
             pointee_type: Type,
         };
+
+        pub const IntSigned = struct {
+            base: Payload = Payload{ .tag = .int_signed },
+
+            bits: u16,
+        };
+
+        pub const IntUnsigned = struct {
+            base: Payload = Payload{ .tag = .int_unsigned },
+
+            bits: u16,
+        };
     };
 };
 
-pub const CInteger = enum {
+pub const CType = enum {
     short,
     ushort,
     int,
@@ -712,8 +975,9 @@ pub const CInteger = enum {
     ulong,
     longlong,
     ulonglong,
+    longdouble,
 
-    pub fn sizeInBits(self: CInteger, target: Target) u16 {
+    pub fn sizeInBits(self: CType, target: Target) u16 {
         const arch = target.cpu.arch;
         switch (target.os.tag) {
             .freestanding, .other => switch (target.cpu.arch) {
@@ -729,6 +993,7 @@ pub const CInteger = enum {
                     .longlong,
                     .ulonglong,
                     => return 64,
+                    .longdouble => @panic("TODO figure out what kind of float `long double` is on this target"),
                 },
                 else => switch (self) {
                     .short,
@@ -743,6 +1008,7 @@ pub const CInteger = enum {
                     .longlong,
                     .ulonglong,
                     => return 64,
+                    .longdouble => @panic("TODO figure out what kind of float `long double` is on this target"),
                 },
             },
 
@@ -767,6 +1033,7 @@ pub const CInteger = enum {
                 .longlong,
                 .ulonglong,
                 => return 64,
+                .longdouble => @panic("TODO figure out what kind of float `long double` is on this target"),
             },
 
             .windows, .uefi => switch (self) {
@@ -781,6 +1048,7 @@ pub const CInteger = enum {
                 .longlong,
                 .ulonglong,
                 => return 64,
+                .longdouble => @panic("TODO figure out what kind of float `long double` is on this target"),
             },
 
             .ios => switch (self) {
@@ -795,6 +1063,7 @@ pub const CInteger = enum {
                 .longlong,
                 .ulonglong,
                 => return 64,
+                .longdouble => @panic("TODO figure out what kind of float `long double` is on this target"),
             },
 
             .ananas,
@@ -821,7 +1090,7 @@ pub const CInteger = enum {
             .amdpal,
             .hermit,
             .hurd,
-            => @panic("TODO specify the C integer type sizes for this OS"),
+            => @panic("TODO specify the C integer and float type sizes for this OS"),
         }
     }
 };

src-self-hosted/value.zig

@@ -2,7 +2,8 @@ const std = @import("std");
 const Type = @import("type.zig").Type;
 const log2 = std.math.log2;
 const assert = std.debug.assert;
-const BigInt = std.math.big.Int;
+const BigIntConst = std.math.big.int.Const;
+const BigIntMutable = std.math.big.int.Mutable;
 const Target = std.Target;
 const Allocator = std.mem.Allocator;
 
@@ -45,12 +46,14 @@ pub const Value = extern union {
         comptime_float_type,
         noreturn_type,
         fn_naked_noreturn_no_args_type,
+        fn_ccc_void_no_args_type,
         single_const_pointer_to_comptime_int_type,
         const_slice_u8_type,
 
+        undef,
         zero,
-        void_value,
-        noreturn_value,
+        the_one_possible_value, // when the type only has one possible value
+        null_value,
         bool_true,
         bool_false, // See last_no_payload_tag below.
         // After this, the tag requires a payload.
@@ -58,11 +61,13 @@ pub const Value = extern union {
         ty,
         int_u64,
         int_i64,
-        int_big,
+        int_big_positive,
+        int_big_negative,
         function,
         ref,
         ref_val,
         bytes,
+        repeated, // the value is a value repeated some number of times
 
         pub const last_no_payload_tag = Tag.bool_false;
         pub const no_payload_count = @enumToInt(last_no_payload_tag) + 1;
@@ -132,18 +137,21 @@ pub const Value = extern union {
             .comptime_float_type => return out_stream.writeAll("comptime_float"),
             .noreturn_type => return out_stream.writeAll("noreturn"),
             .fn_naked_noreturn_no_args_type => return out_stream.writeAll("fn() callconv(.Naked) noreturn"),
+            .fn_ccc_void_no_args_type => return out_stream.writeAll("fn() callconv(.C) void"),
             .single_const_pointer_to_comptime_int_type => return out_stream.writeAll("*const comptime_int"),
             .const_slice_u8_type => return out_stream.writeAll("[]const u8"),
 
+            .null_value => return out_stream.writeAll("null"),
+            .undef => return out_stream.writeAll("undefined"),
             .zero => return out_stream.writeAll("0"),
-            .void_value => return out_stream.writeAll("{}"),
-            .noreturn_value => return out_stream.writeAll("unreachable"),
+            .the_one_possible_value => return out_stream.writeAll("(one possible value)"),
             .bool_true => return out_stream.writeAll("true"),
             .bool_false => return out_stream.writeAll("false"),
             .ty => return val.cast(Payload.Ty).?.ty.format("", options, out_stream),
             .int_u64 => return std.fmt.formatIntValue(val.cast(Payload.Int_u64).?.int, "", options, out_stream),
             .int_i64 => return std.fmt.formatIntValue(val.cast(Payload.Int_i64).?.int, "", options, out_stream),
-            .int_big => return out_stream.print("{}", .{val.cast(Payload.IntBig).?.big_int}),
+            .int_big_positive => return out_stream.print("{}", .{val.cast(Payload.IntBigPositive).?.asBigInt()}),
+            .int_big_negative => return out_stream.print("{}", .{val.cast(Payload.IntBigNegative).?.asBigInt()}),
             .function => return out_stream.writeAll("(function)"),
             .ref => return out_stream.writeAll("(ref)"),
             .ref_val => {
@@ -152,6 +160,10 @@ pub const Value = extern union {
                 continue;
             },
             .bytes => return std.zig.renderStringLiteral(self.cast(Payload.Bytes).?.data, out_stream),
+            .repeated => {
+                try out_stream.writeAll("(repeated) ");
+                val = val.cast(Payload.Repeated).?.val;
+            },
         };
     }
 
@@ -195,27 +207,31 @@ pub const Value = extern union {
             .comptime_float_type => Type.initTag(.@"comptime_float"),
             .noreturn_type => Type.initTag(.@"noreturn"),
             .fn_naked_noreturn_no_args_type => Type.initTag(.fn_naked_noreturn_no_args),
+            .fn_ccc_void_no_args_type => Type.initTag(.fn_ccc_void_no_args),
             .single_const_pointer_to_comptime_int_type => Type.initTag(.single_const_pointer_to_comptime_int),
             .const_slice_u8_type => Type.initTag(.const_slice_u8),
 
+            .undef,
             .zero,
-            .void_value,
-            .noreturn_value,
+            .the_one_possible_value,
             .bool_true,
             .bool_false,
+            .null_value,
             .int_u64,
             .int_i64,
-            .int_big,
+            .int_big_positive,
+            .int_big_negative,
             .function,
             .ref,
             .ref_val,
             .bytes,
+            .repeated,
             => unreachable,
         };
     }
 
     /// Asserts the value is an integer.
-    pub fn toBigInt(self: Value, allocator: *Allocator) Allocator.Error!BigInt {
+    pub fn toBigInt(self: Value, space: *BigIntSpace) BigIntConst {
         switch (self.tag()) {
             .ty,
             .u8_type,
@@ -244,23 +260,28 @@ pub const Value = extern union {
             .comptime_float_type,
             .noreturn_type,
             .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
             .single_const_pointer_to_comptime_int_type,
             .const_slice_u8_type,
-            .void_value,
-            .noreturn_value,
             .bool_true,
             .bool_false,
+            .null_value,
             .function,
             .ref,
             .ref_val,
             .bytes,
+            .undef,
+            .repeated,
             => unreachable,
 
-            .zero => return BigInt.initSet(allocator, 0),
+            .the_one_possible_value, // An integer with one possible value is always zero.
+            .zero,
+            => return BigIntMutable.init(&space.limbs, 0).toConst(),
 
-            .int_u64 => return BigInt.initSet(allocator, self.cast(Payload.Int_u64).?.int),
-            .int_i64 => return BigInt.initSet(allocator, self.cast(Payload.Int_i64).?.int),
-            .int_big => return self.cast(Payload.IntBig).?.big_int,
+            .int_u64 => return BigIntMutable.init(&space.limbs, self.cast(Payload.Int_u64).?.int).toConst(),
+            .int_i64 => return BigIntMutable.init(&space.limbs, self.cast(Payload.Int_i64).?.int).toConst(),
+            .int_big_positive => return self.cast(Payload.IntBigPositive).?.asBigInt(),
+            .int_big_negative => return self.cast(Payload.IntBigPositive).?.asBigInt(),
         }
     }
 
@@ -294,23 +315,90 @@ pub const Value = extern union {
             .comptime_float_type,
             .noreturn_type,
             .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
             .single_const_pointer_to_comptime_int_type,
             .const_slice_u8_type,
-            .void_value,
-            .noreturn_value,
             .bool_true,
             .bool_false,
+            .null_value,
             .function,
             .ref,
             .ref_val,
             .bytes,
+            .undef,
+            .repeated,
             => unreachable,
 
-            .zero => return 0,
+            .zero,
+            .the_one_possible_value, // an integer with one possible value is always zero
+            => return 0,
 
             .int_u64 => return self.cast(Payload.Int_u64).?.int,
             .int_i64 => return @intCast(u64, self.cast(Payload.Int_u64).?.int),
-            .int_big => return self.cast(Payload.IntBig).?.big_int.to(u64) catch unreachable,
+            .int_big_positive => return self.cast(Payload.IntBigPositive).?.asBigInt().to(u64) catch unreachable,
+            .int_big_negative => return self.cast(Payload.IntBigNegative).?.asBigInt().to(u64) catch unreachable,
+        }
+    }
+
+    /// Asserts the value is an integer and not undefined.
+    /// Returns the number of bits the value requires to represent stored in twos complement form.
+    pub fn intBitCountTwosComp(self: Value) usize {
+        switch (self.tag()) {
+            .ty,
+            .u8_type,
+            .i8_type,
+            .isize_type,
+            .usize_type,
+            .c_short_type,
+            .c_ushort_type,
+            .c_int_type,
+            .c_uint_type,
+            .c_long_type,
+            .c_ulong_type,
+            .c_longlong_type,
+            .c_ulonglong_type,
+            .c_longdouble_type,
+            .f16_type,
+            .f32_type,
+            .f64_type,
+            .f128_type,
+            .c_void_type,
+            .bool_type,
+            .void_type,
+            .type_type,
+            .anyerror_type,
+            .comptime_int_type,
+            .comptime_float_type,
+            .noreturn_type,
+            .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
+            .single_const_pointer_to_comptime_int_type,
+            .const_slice_u8_type,
+            .bool_true,
+            .bool_false,
+            .null_value,
+            .function,
+            .ref,
+            .ref_val,
+            .bytes,
+            .undef,
+            .repeated,
+            => unreachable,
+
+            .the_one_possible_value, // an integer with one possible value is always zero
+            .zero,
+            => return 0,
+
+            .int_u64 => {
+                const x = self.cast(Payload.Int_u64).?.int;
+                if (x == 0) return 0;
+                return std.math.log2(x) + 1;
+            },
+            .int_i64 => {
+                @panic("TODO implement i64 intBitCountTwosComp");
+            },
+            .int_big_positive => return self.cast(Payload.IntBigPositive).?.asBigInt().bitCountTwosComp(),
+            .int_big_negative => return self.cast(Payload.IntBigNegative).?.asBigInt().bitCountTwosComp(),
         }
     }
 
@@ -344,19 +432,23 @@ pub const Value = extern union {
             .comptime_float_type,
             .noreturn_type,
             .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
             .single_const_pointer_to_comptime_int_type,
             .const_slice_u8_type,
-            .void_value,
-            .noreturn_value,
             .bool_true,
             .bool_false,
+            .null_value,
             .function,
             .ref,
             .ref_val,
             .bytes,
+            .repeated,
             => unreachable,
 
-            .zero => return true,
+            .zero,
+            .undef,
+            .the_one_possible_value, // an integer with one possible value is always zero
+            => return true,
 
             .int_u64 => switch (ty.zigTypeTag()) {
                 .Int => {
@@ -381,10 +473,18 @@ pub const Value = extern union {
                 .ComptimeInt => return true,
                 else => unreachable,
             },
-            .int_big => switch (ty.zigTypeTag()) {
+            .int_big_positive => switch (ty.zigTypeTag()) {
                 .Int => {
                     const info = ty.intInfo(target);
-                    return self.cast(Payload.IntBig).?.big_int.fitsInTwosComp(info.signed, info.bits);
+                    return self.cast(Payload.IntBigPositive).?.asBigInt().fitsInTwosComp(info.signed, info.bits);
+                },
+                .ComptimeInt => return true,
+                else => unreachable,
+            },
+            .int_big_negative => switch (ty.zigTypeTag()) {
+                .Int => {
+                    const info = ty.intInfo(target);
+                    return self.cast(Payload.IntBigNegative).?.asBigInt().fitsInTwosComp(info.signed, info.bits);
                 },
                 .ComptimeInt => return true,
                 else => unreachable,
@@ -392,9 +492,9 @@ pub const Value = extern union {
         }
     }
 
-    /// Asserts the value is a pointer and dereferences it.
-    pub fn pointerDeref(self: Value) Value {
-        switch (self.tag()) {
+    /// Asserts the value is a float
+    pub fn floatHasFraction(self: Value) bool {
+        return switch (self.tag()) {
             .ty,
             .u8_type,
             .i8_type,
@@ -422,23 +522,170 @@ pub const Value = extern union {
             .comptime_float_type,
             .noreturn_type,
             .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
+            .single_const_pointer_to_comptime_int_type,
+            .const_slice_u8_type,
+            .bool_true,
+            .bool_false,
+            .null_value,
+            .function,
+            .ref,
+            .ref_val,
+            .bytes,
+            .repeated,
+            .undef,
+            .int_u64,
+            .int_i64,
+            .int_big_positive,
+            .int_big_negative,
+            .the_one_possible_value,
+            => unreachable,
+
+            .zero => false,
+        };
+    }
+
+    pub fn orderAgainstZero(lhs: Value) std.math.Order {
+        switch (lhs.tag()) {
+            .ty,
+            .u8_type,
+            .i8_type,
+            .isize_type,
+            .usize_type,
+            .c_short_type,
+            .c_ushort_type,
+            .c_int_type,
+            .c_uint_type,
+            .c_long_type,
+            .c_ulong_type,
+            .c_longlong_type,
+            .c_ulonglong_type,
+            .c_longdouble_type,
+            .f16_type,
+            .f32_type,
+            .f64_type,
+            .f128_type,
+            .c_void_type,
+            .bool_type,
+            .void_type,
+            .type_type,
+            .anyerror_type,
+            .comptime_int_type,
+            .comptime_float_type,
+            .noreturn_type,
+            .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
+            .single_const_pointer_to_comptime_int_type,
+            .const_slice_u8_type,
+            .bool_true,
+            .bool_false,
+            .null_value,
+            .function,
+            .ref,
+            .ref_val,
+            .bytes,
+            .repeated,
+            .undef,
+            => unreachable,
+
+            .zero,
+            .the_one_possible_value, // an integer with one possible value is always zero
+            => return .eq,
+
+            .int_u64 => return std.math.order(lhs.cast(Payload.Int_u64).?.int, 0),
+            .int_i64 => return std.math.order(lhs.cast(Payload.Int_i64).?.int, 0),
+            .int_big_positive => return lhs.cast(Payload.IntBigPositive).?.asBigInt().orderAgainstScalar(0),
+            .int_big_negative => return lhs.cast(Payload.IntBigNegative).?.asBigInt().orderAgainstScalar(0),
+        }
+    }
+
+    /// Asserts the value is comparable.
+    pub fn order(lhs: Value, rhs: Value) std.math.Order {
+        const lhs_tag = lhs.tag();
+        const rhs_tag = lhs.tag();
+        const lhs_is_zero = lhs_tag == .zero or lhs_tag == .the_one_possible_value;
+        const rhs_is_zero = rhs_tag == .zero or rhs_tag == .the_one_possible_value;
+        if (lhs_is_zero) return rhs.orderAgainstZero().invert();
+        if (rhs_is_zero) return lhs.orderAgainstZero();
+
+        // TODO floats
+
+        var lhs_bigint_space: BigIntSpace = undefined;
+        var rhs_bigint_space: BigIntSpace = undefined;
+        const lhs_bigint = lhs.toBigInt(&lhs_bigint_space);
+        const rhs_bigint = rhs.toBigInt(&rhs_bigint_space);
+        return lhs_bigint.order(rhs_bigint);
+    }
+
+    /// Asserts the value is comparable.
+    pub fn compare(lhs: Value, op: std.math.CompareOperator, rhs: Value) bool {
+        return order(lhs, rhs).compare(op);
+    }
+
+    /// Asserts the value is comparable.
+    pub fn compareWithZero(lhs: Value, op: std.math.CompareOperator) bool {
+        return orderAgainstZero(lhs).compare(op);
+    }
+
+    pub fn toBool(self: Value) bool {
+        return switch (self.tag()) {
+            .bool_true => true,
+            .bool_false => false,
+            else => unreachable,
+        };
+    }
+
+    /// Asserts the value is a pointer and dereferences it.
+    pub fn pointerDeref(self: Value) Value {
+        return switch (self.tag()) {
+            .ty,
+            .u8_type,
+            .i8_type,
+            .isize_type,
+            .usize_type,
+            .c_short_type,
+            .c_ushort_type,
+            .c_int_type,
+            .c_uint_type,
+            .c_long_type,
+            .c_ulong_type,
+            .c_longlong_type,
+            .c_ulonglong_type,
+            .c_longdouble_type,
+            .f16_type,
+            .f32_type,
+            .f64_type,
+            .f128_type,
+            .c_void_type,
+            .bool_type,
+            .void_type,
+            .type_type,
+            .anyerror_type,
+            .comptime_int_type,
+            .comptime_float_type,
+            .noreturn_type,
+            .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
             .single_const_pointer_to_comptime_int_type,
             .const_slice_u8_type,
             .zero,
-            .void_value,
-            .noreturn_value,
             .bool_true,
             .bool_false,
+            .null_value,
             .function,
             .int_u64,
             .int_i64,
-            .int_big,
+            .int_big_positive,
+            .int_big_negative,
             .bytes,
+            .undef,
+            .repeated,
             => unreachable,
 
-            .ref => return self.cast(Payload.Ref).?.cell.contents,
-            .ref_val => return self.cast(Payload.RefVal).?.val,
-        }
+            .the_one_possible_value => Value.initTag(.the_one_possible_value),
+            .ref => self.cast(Payload.Ref).?.cell.contents,
+            .ref_val => self.cast(Payload.RefVal).?.val,
+        };
     }
 
     /// Asserts the value is a single-item pointer to an array, or an array,
@@ -472,17 +719,20 @@ pub const Value = extern union {
             .comptime_float_type,
             .noreturn_type,
             .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
             .single_const_pointer_to_comptime_int_type,
             .const_slice_u8_type,
             .zero,
-            .void_value,
-            .noreturn_value,
+            .the_one_possible_value,
             .bool_true,
             .bool_false,
+            .null_value,
             .function,
             .int_u64,
             .int_i64,
-            .int_big,
+            .int_big_positive,
+            .int_big_negative,
+            .undef,
             => unreachable,
 
             .ref => @panic("TODO figure out how MemoryCell works"),
@@ -493,9 +743,70 @@ pub const Value = extern union {
                 int_payload.* = .{ .int = self.cast(Payload.Bytes).?.data[index] };
                 return Value.initPayload(&int_payload.base);
             },
+
+            // No matter the index; all the elements are the same!
+            .repeated => return self.cast(Payload.Repeated).?.val,
         }
     }
 
+    pub fn isUndef(self: Value) bool {
+        return self.tag() == .undef;
+    }
+
+    /// Valid for all types. Asserts the value is not undefined.
+    /// `.the_one_possible_value` is reported as not null.
+    pub fn isNull(self: Value) bool {
+        return switch (self.tag()) {
+            .ty,
+            .u8_type,
+            .i8_type,
+            .isize_type,
+            .usize_type,
+            .c_short_type,
+            .c_ushort_type,
+            .c_int_type,
+            .c_uint_type,
+            .c_long_type,
+            .c_ulong_type,
+            .c_longlong_type,
+            .c_ulonglong_type,
+            .c_longdouble_type,
+            .f16_type,
+            .f32_type,
+            .f64_type,
+            .f128_type,
+            .c_void_type,
+            .bool_type,
+            .void_type,
+            .type_type,
+            .anyerror_type,
+            .comptime_int_type,
+            .comptime_float_type,
+            .noreturn_type,
+            .fn_naked_noreturn_no_args_type,
+            .fn_ccc_void_no_args_type,
+            .single_const_pointer_to_comptime_int_type,
+            .const_slice_u8_type,
+            .zero,
+            .the_one_possible_value,
+            .bool_true,
+            .bool_false,
+            .function,
+            .int_u64,
+            .int_i64,
+            .int_big_positive,
+            .int_big_negative,
+            .ref,
+            .ref_val,
+            .bytes,
+            .repeated,
+            => false,
+
+            .undef => unreachable,
+            .null_value => true,
+        };
+    }
+
     /// This type is not copyable since it may contain pointers to its inner data.
     pub const Payload = struct {
         tag: Tag,
@@ -510,9 +821,22 @@ pub const Value = extern union {
             int: i64,
         };
 
-        pub const IntBig = struct {
-            base: Payload = Payload{ .tag = .int_big },
-            big_int: BigInt,
+        pub const IntBigPositive = struct {
+            base: Payload = Payload{ .tag = .int_big_positive },
+            limbs: []const std.math.big.Limb,
+
+            pub fn asBigInt(self: IntBigPositive) BigIntConst {
+                return BigIntConst{ .limbs = self.limbs, .positive = true };
+            }
+        };
+
+        pub const IntBigNegative = struct {
+            base: Payload = Payload{ .tag = .int_big_negative },
+            limbs: []const std.math.big.Limb,
+
+            pub fn asBigInt(self: IntBigNegative) BigIntConst {
+                return BigIntConst{ .limbs = self.limbs, .positive = false };
+            }
         };
 
         pub const Function = struct {
@@ -550,6 +874,20 @@ pub const Value = extern union {
             base: Payload = Payload{ .tag = .ty },
             ty: Type,
         };
+
+        pub const Repeated = struct {
+            base: Payload = Payload{ .tag = .ty },
+            /// This value is repeated some number of times. The amount of times to repeat
+            /// is stored externally.
+            val: Value,
+        };
+    };
+
+    /// Big enough to fit any non-BigInt value
+    pub const BigIntSpace = struct {
+        /// The +1 is headroom so that operations such as incrementing once or decrementing once
+        /// are possible without using an allocator.
+        limbs: [(@sizeOf(u64) / @sizeOf(std.math.big.Limb)) + 1]std.math.big.Limb,
     };
 };
 

test/stage2/compare_output.zig

@@ -2,24 +2,27 @@ const std = @import("std");
 const TestContext = @import("../../src-self-hosted/test.zig").TestContext;
 
 pub fn addCases(ctx: *TestContext) !void {
-    // hello world
-    try ctx.testCompareOutputLibC(
-        \\extern fn puts([*]const u8) void;
-        \\pub export fn main() c_int {
-        \\    puts("Hello, world!");
-        \\    return 0;
-        \\}
-    , "Hello, world!" ++ std.cstr.line_sep);
+    // TODO: re-enable these tests.
+    // https://github.com/ziglang/zig/issues/1364
 
-    // function calling another function
-    try ctx.testCompareOutputLibC(
-        \\extern fn puts(s: [*]const u8) void;
-        \\pub export fn main() c_int {
-        \\    return foo("OK");
-        \\}
-        \\fn foo(s: [*]const u8) c_int {
-        \\    puts(s);
-        \\    return 0;
-        \\}
-    , "OK" ++ std.cstr.line_sep);
+    //// hello world
+    //try ctx.testCompareOutputLibC(
+    //    \\extern fn puts([*]const u8) void;
+    //    \\pub export fn main() c_int {
+    //    \\    puts("Hello, world!");
+    //    \\    return 0;
+    //    \\}
+    //, "Hello, world!" ++ std.cstr.line_sep);
+
+    //// function calling another function
+    //try ctx.testCompareOutputLibC(
+    //    \\extern fn puts(s: [*]const u8) void;
+    //    \\pub export fn main() c_int {
+    //    \\    return foo("OK");
+    //    \\}
+    //    \\fn foo(s: [*]const u8) c_int {
+    //    \\    puts(s);
+    //    \\    return 0;
+    //    \\}
+    //, "OK" ++ std.cstr.line_sep);
 }

test/stage2/compile_errors.zig

@@ -1,54 +1,57 @@
 const TestContext = @import("../../src-self-hosted/test.zig").TestContext;
 
 pub fn addCases(ctx: *TestContext) !void {
-    try ctx.testCompileError(
-        \\export fn entry() void {}
-        \\export fn entry() void {}
-    , "1.zig", 2, 8, "exported symbol collision: 'entry'");
+    // TODO: re-enable these tests.
+    // https://github.com/ziglang/zig/issues/1364
 
-    try ctx.testCompileError(
-        \\fn() void {}
-    , "1.zig", 1, 1, "missing function name");
+    //try ctx.testCompileError(
+    //    \\export fn entry() void {}
+    //    \\export fn entry() void {}
+    //, "1.zig", 2, 8, "exported symbol collision: 'entry'");
 
-    try ctx.testCompileError(
-        \\comptime {
-        \\    return;
-        \\}
-    , "1.zig", 2, 5, "return expression outside function definition");
+    //try ctx.testCompileError(
+    //    \\fn() void {}
+    //, "1.zig", 1, 1, "missing function name");
 
-    try ctx.testCompileError(
-        \\export fn entry() void {
-        \\    defer return;
-        \\}
-    , "1.zig", 2, 11, "cannot return from defer expression");
+    //try ctx.testCompileError(
+    //    \\comptime {
+    //    \\    return;
+    //    \\}
+    //, "1.zig", 2, 5, "return expression outside function definition");
 
-    try ctx.testCompileError(
-        \\export fn entry() c_int {
-        \\    return 36893488147419103232;
-        \\}
-    , "1.zig", 2, 12, "integer value '36893488147419103232' cannot be stored in type 'c_int'");
+    //try ctx.testCompileError(
+    //    \\export fn entry() void {
+    //    \\    defer return;
+    //    \\}
+    //, "1.zig", 2, 11, "cannot return from defer expression");
 
-    try ctx.testCompileError(
-        \\comptime {
-        \\    var a: *align(4) align(4) i32 = 0;
-        \\}
-    , "1.zig", 2, 22, "Extra align qualifier");
+    //try ctx.testCompileError(
+    //    \\export fn entry() c_int {
+    //    \\    return 36893488147419103232;
+    //    \\}
+    //, "1.zig", 2, 12, "integer value '36893488147419103232' cannot be stored in type 'c_int'");
 
-    try ctx.testCompileError(
-        \\comptime {
-        \\    var b: *const const i32 = 0;
-        \\}
-    , "1.zig", 2, 19, "Extra align qualifier");
+    //try ctx.testCompileError(
+    //    \\comptime {
+    //    \\    var a: *align(4) align(4) i32 = 0;
+    //    \\}
+    //, "1.zig", 2, 22, "Extra align qualifier");
 
-    try ctx.testCompileError(
-        \\comptime {
-        \\    var c: *volatile volatile i32 = 0;
-        \\}
-    , "1.zig", 2, 22, "Extra align qualifier");
+    //try ctx.testCompileError(
+    //    \\comptime {
+    //    \\    var b: *const const i32 = 0;
+    //    \\}
+    //, "1.zig", 2, 19, "Extra align qualifier");
 
-    try ctx.testCompileError(
-        \\comptime {
-        \\    var d: *allowzero allowzero i32 = 0;
-        \\}
-    , "1.zig", 2, 23, "Extra align qualifier");
+    //try ctx.testCompileError(
+    //    \\comptime {
+    //    \\    var c: *volatile volatile i32 = 0;
+    //    \\}
+    //, "1.zig", 2, 22, "Extra align qualifier");
+
+    //try ctx.testCompileError(
+    //    \\comptime {
+    //    \\    var d: *allowzero allowzero i32 = 0;
+    //    \\}
+    //, "1.zig", 2, 23, "Extra align qualifier");
 }

test/stage2/ir.zig

@@ -1,54 +0,0 @@
-test "hello world IR" {
-    exeCmp(
-        \\@0 = str("Hello, world!\n")
-        \\@1 = primitive(void)
-        \\@2 = primitive(usize)
-        \\@3 = fntype([], @1, cc=Naked)
-        \\@4 = int(0)
-        \\@5 = int(1)
-        \\@6 = int(231)
-        \\@7 = str("len")
-        \\
-        \\@8 = fn(@3, {
-        \\  %0 = as(@2, @5) ; SYS_write
-        \\  %1 = as(@2, @5) ; STDOUT_FILENO
-        \\  %2 = ptrtoint(@0) ; msg ptr
-        \\  %3 = fieldptr(@0, @7) ; msg len ptr
-        \\  %4 = deref(%3) ; msg len
-        \\  %sysoutreg = str("={rax}")
-        \\  %rax = str("{rax}")
-        \\  %rdi = str("{rdi}")
-        \\  %rsi = str("{rsi}")
-        \\  %rdx = str("{rdx}")
-        \\  %rcx = str("rcx")
-        \\  %r11 = str("r11")
-        \\  %memory = str("memory")
-        \\  %syscall = str("syscall")
-        \\  %5 = asm(%syscall, @2,
-        \\    volatile=1,
-        \\    output=%sysoutreg,
-        \\    inputs=[%rax, %rdi, %rsi, %rdx],
-        \\    clobbers=[%rcx, %r11, %memory],
-        \\    args=[%0, %1, %2, %4])
-        \\
-        \\  %6 = as(@2, @6) ;SYS_exit_group
-        \\  %7 = as(@2, @4) ;exit code
-        \\  %8 = asm(%syscall, @2,
-        \\    volatile=1,
-        \\    output=%sysoutreg,
-        \\    inputs=[%rax, %rdi],
-        \\    clobbers=[%rcx, %r11, %memory],
-        \\    args=[%6, %7])
-        \\
-        \\  %9 = unreachable()
-        \\})
-        \\
-        \\@9 = str("_start")
-        \\@10 = export(@9, @8)
-    ,
-        \\Hello, world!
-        \\
-    );
-}
-
-fn exeCmp(src: []const u8, expected_stdout: []const u8) void {}

test/stage2/test.zig

@@ -3,4 +3,5 @@ const TestContext = @import("../../src-self-hosted/test.zig").TestContext;
 pub fn addCases(ctx: *TestContext) !void {
     try @import("compile_errors.zig").addCases(ctx);
     try @import("compare_output.zig").addCases(ctx);
+    @import("zir.zig").addCases(ctx);
 }

test/stage2/zir.zig

@@ -0,0 +1,107 @@
+const TestContext = @import("../../src-self-hosted/test.zig").TestContext;
+
+pub fn addCases(ctx: *TestContext) void {
+    ctx.addZIRTransform("elemptr, add, cmp, condbr, return, breakpoint",
+        \\@void = primitive(void)
+        \\@usize = primitive(usize)
+        \\@fnty = fntype([], @void, cc=C)
+        \\@0 = int(0)
+        \\@1 = int(1)
+        \\@2 = int(2)
+        \\@3 = int(3)
+        \\
+        \\@entry = fn(@fnty, {
+        \\  %a = str("\x32\x08\x01\x0a")
+        \\  %eptr0 = elemptr(%a, @0)
+        \\  %eptr1 = elemptr(%a, @1)
+        \\  %eptr2 = elemptr(%a, @2)
+        \\  %eptr3 = elemptr(%a, @3)
+        \\  %v0 = deref(%eptr0)
+        \\  %v1 = deref(%eptr1)
+        \\  %v2 = deref(%eptr2)
+        \\  %v3 = deref(%eptr3)
+        \\  %x0 = add(%v0, %v1)
+        \\  %x1 = add(%v2, %v3)
+        \\  %result = add(%x0, %x1)
+        \\
+        \\  %expected = int(69)
+        \\  %ok = cmp(%result, eq, %expected)
+        \\  %10 = condbr(%ok, {
+        \\    %11 = return()
+        \\  }, {
+        \\    %12 = breakpoint()
+        \\  })
+        \\})
+        \\
+        \\@9 = str("entry")
+        \\@10 = export(@9, @entry)
+    ,
+        \\@0 = primitive(void)
+        \\@1 = fntype([], @0, cc=C)
+        \\@2 = fn(@1, {
+        \\  %0 = return()
+        \\})
+        \\@3 = str("entry")
+        \\@4 = export(@3, @2)
+        \\
+    );
+
+    if (@import("std").Target.current.os.tag != .linux or
+        @import("std").Target.current.cpu.arch != .x86_64)
+    {
+        // TODO implement self-hosted PE (.exe file) linking
+        // TODO implement more ZIR so we don't depend on x86_64-linux
+        return;
+    }
+
+    ctx.addZIRCompareOutput("hello world ZIR",
+        \\@0 = str("Hello, world!\n")
+        \\@1 = primitive(noreturn)
+        \\@2 = primitive(usize)
+        \\@3 = fntype([], @1, cc=Naked)
+        \\@4 = int(0)
+        \\@5 = int(1)
+        \\@6 = int(231)
+        \\@7 = str("len")
+        \\
+        \\@8 = fn(@3, {
+        \\  %0 = as(@2, @5) ; SYS_write
+        \\  %1 = as(@2, @5) ; STDOUT_FILENO
+        \\  %2 = ptrtoint(@0) ; msg ptr
+        \\  %3 = fieldptr(@0, @7) ; msg len ptr
+        \\  %4 = deref(%3) ; msg len
+        \\  %sysoutreg = str("={rax}")
+        \\  %rax = str("{rax}")
+        \\  %rdi = str("{rdi}")
+        \\  %rsi = str("{rsi}")
+        \\  %rdx = str("{rdx}")
+        \\  %rcx = str("rcx")
+        \\  %r11 = str("r11")
+        \\  %memory = str("memory")
+        \\  %syscall = str("syscall")
+        \\  %5 = asm(%syscall, @2,
+        \\    volatile=1,
+        \\    output=%sysoutreg,
+        \\    inputs=[%rax, %rdi, %rsi, %rdx],
+        \\    clobbers=[%rcx, %r11, %memory],
+        \\    args=[%0, %1, %2, %4])
+        \\
+        \\  %6 = as(@2, @6) ;SYS_exit_group
+        \\  %7 = as(@2, @4) ;exit code
+        \\  %8 = asm(%syscall, @2,
+        \\    volatile=1,
+        \\    output=%sysoutreg,
+        \\    inputs=[%rax, %rdi],
+        \\    clobbers=[%rcx, %r11, %memory],
+        \\    args=[%6, %7])
+        \\
+        \\  %9 = unreachable()
+        \\})
+        \\
+        \\@9 = str("_start")
+        \\@10 = export(@9, @8)
+    ,
+        \\Hello, world!
+        \\
+    );
+}