Merge branch 'emekoi-dynlib-load'

closes #2598

lib/std/c.zig

@@ -226,3 +226,7 @@ pub extern "c" fn pthread_cond_destroy(cond: *pthread_cond_t) c_int;
 
 pub const pthread_t = *@OpaqueType();
 pub const FILE = @OpaqueType();
+
+pub extern "c" fn dlopen(path: [*:0]const u8, mode: c_int) ?*c_void;
+pub extern "c" fn dlclose(handle: *c_void) c_int;
+pub extern "c" fn dlsym(handle: ?*c_void, symbol: [*:0]const u8) ?*c_void;

lib/std/c/linux.zig

@@ -98,3 +98,10 @@ const __SIZEOF_PTHREAD_MUTEX_T = if (builtin.os == .fuchsia) 40 else switch (bui
     },
     else => unreachable,
 };
+
+pub const RTLD_LAZY = 1;
+pub const RTLD_NOW = 2;
+pub const RTLD_NOLOAD = 4;
+pub const RTLD_NODELETE = 4096;
+pub const RTLD_GLOBAL = 256;
+pub const RTLD_LOCAL = 0;

lib/std/dynamic_library.zig

@@ -7,11 +7,13 @@ const assert = std.debug.assert;
 const testing = std.testing;
 const elf = std.elf;
 const windows = std.os.windows;
+const system = std.os.system;
 const maxInt = std.math.maxInt;
 
 pub const DynLib = switch (builtin.os) {
-    .linux => LinuxDynLib,
+    .linux => if (builtin.link_libc) DlDynlib else LinuxDynLib,
     .windows => WindowsDynLib,
+    .macosx, .tvos, .watchos, .ios => DlDynlib,
     else => void,
 };
 
@@ -99,12 +101,14 @@ pub fn linkmap_iterator(phdrs: []elf.Phdr) !LinkMap.Iterator {
 }
 
 pub const LinuxDynLib = struct {
+    pub const Error = ElfLib.Error;
+
     elf_lib: ElfLib,
     fd: i32,
     memory: []align(mem.page_size) u8,
 
     /// Trusts the file
-    pub fn open(path: []const u8) !DynLib {
+    pub fn open(path: []const u8) !LinuxDynLib {
         const fd = try os.open(path, 0, os.O_RDONLY | os.O_CLOEXEC);
         errdefer os.close(fd);
 
@@ -121,25 +125,43 @@ pub const LinuxDynLib = struct {
         );
         errdefer os.munmap(bytes);
 
-        return DynLib{
+        return LinuxDynLib{
             .elf_lib = try ElfLib.init(bytes),
             .fd = fd,
             .memory = bytes,
         };
     }
 
-    pub fn close(self: *DynLib) void {
+    pub fn openC(path_c: [*:0]const u8) !LinuxDynLib {
+        return open(mem.toSlice(u8, path_c));
+    }
+
+    pub fn close(self: *LinuxDynLib) void {
         os.munmap(self.memory);
         os.close(self.fd);
         self.* = undefined;
     }
 
-    pub fn lookup(self: *DynLib, name: []const u8) ?usize {
-        return self.elf_lib.lookup("", name);
+    pub fn lookup(self: *LinuxDynLib, comptime T: type, name: [:0]const u8) ?T {
+        if (self.elf_lib.lookup("", name)) |symbol| {
+            return @intToPtr(T, symbol);
+        } else {
+            return null;
+        }
     }
 };
 
 pub const ElfLib = struct {
+    pub const Error = error{
+        NotElfFile,
+        NotDynamicLibrary,
+        MissingDynamicLinkingInformation,
+        BaseNotFound,
+        ElfStringSectionNotFound,
+        ElfSymSectionNotFound,
+        ElfHashTableNotFound,
+    };
+
     strings: [*:0]u8,
     syms: [*]elf.Sym,
     hashtab: [*]os.Elf_Symndx,
@@ -245,13 +267,24 @@ fn checkver(def_arg: *elf.Verdef, vsym_arg: i32, vername: []const u8, strings: [
 }
 
 pub const WindowsDynLib = struct {
+    pub const Error = error{FileNotFound};
+
     dll: windows.HMODULE,
 
     pub fn open(path: []const u8) !WindowsDynLib {
-        const wpath = try windows.sliceToPrefixedFileW(path);
+        const path_w = try windows.sliceToPrefixedFileW(path);
+        return openW(&path_w);
+    }
 
+    pub fn openC(path_c: [*:0]const u8) !WindowsDynLib {
+        const path_w = try windows.cStrToPrefixedFileW(path);
+        return openW(&path_w);
+    }
+
+    pub fn openW(path_w: [*:0]const u16) !WindowsDynLib {
         return WindowsDynLib{
-            .dll = try windows.LoadLibraryW(&wpath),
+            // + 4 to skip over the \??\
+            .dll = try windows.LoadLibraryW(path_w + 4),
         };
     }
 
@@ -260,8 +293,46 @@ pub const WindowsDynLib = struct {
         self.* = undefined;
     }
 
-    pub fn lookup(self: *WindowsDynLib, name: []const u8) ?usize {
-        return @ptrToInt(windows.kernel32.GetProcAddress(self.dll, name.ptr));
+    pub fn lookup(self: *WindowsDynLib, comptime T: type, name: [:0]const u8) ?T {
+        if (windows.kernel32.GetProcAddress(self.dll, name.ptr)) |addr| {
+            return @ptrCast(T, addr);
+        } else {
+            return null;
+        }
+    }
+};
+
+pub const DlDynlib = struct {
+    pub const Error = error{FileNotFound};
+
+    handle: *c_void,
+
+    pub fn open(path: []const u8) !DlDynlib {
+        const path_c = try os.toPosixPath(path);
+        return openC(&path_c);
+    }
+
+    pub fn openC(path_c: [*:0]const u8) !DlDynlib {
+        return DlDynlib{
+            .handle = system.dlopen(path_c, system.RTLD_LAZY) orelse {
+                return error.FileNotFound;
+            },
+        };
+    }
+
+    pub fn close(self: *DlDynlib) void {
+        _ = system.dlclose(self.handle);
+        self.* = undefined;
+    }
+
+    pub fn lookup(self: *DlDynlib, comptime T: type, name: [:0]const u8) ?T {
+        // dlsym (and other dl-functions) secretly take shadow parameter - return address on stack
+        // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66826
+        if (@call(.{ .modifier = .never_tail }, system.dlsym, .{ self.handle, name.ptr })) |symbol| {
+            return @ptrCast(T, symbol);
+        } else {
+            return null;
+        }
     }
 };
 
@@ -269,12 +340,12 @@ test "dynamic_library" {
     const libname = switch (builtin.os) {
         .linux => "invalid_so.so",
         .windows => "invalid_dll.dll",
-        else => return,
+        .macosx, .tvos, .watchos, .ios => "invalid_dylib.dylib",
+        else => return error.SkipZigTest,
     };
 
     const dynlib = DynLib.open(libname) catch |err| {
         testing.expect(err == error.FileNotFound);
         return;
     };
-    @panic("Expected error from function");
 }

lib/std/os/bits/darwin.zig

@@ -1183,6 +1183,7 @@ pub fn S_ISSOCK(m: u32) bool {
 pub fn S_IWHT(m: u32) bool {
     return m & S_IFMT == S_IFWHT;
 }
+
 pub const HOST_NAME_MAX = 72;
 
 pub const AT_FDCWD = -2;
@@ -1209,3 +1210,16 @@ pub const addrinfo = extern struct {
     addr: ?*sockaddr,
     next: ?*addrinfo,
 };
+
+pub const RTLD_LAZY = 0x1;
+pub const RTLD_NOW = 0x2;
+pub const RTLD_LOCAL = 0x4;
+pub const RTLD_GLOBAL = 0x8;
+pub const RTLD_NOLOAD = 0x10;
+pub const RTLD_NODELETE = 0x80;
+pub const RTLD_FIRST = 0x100;
+
+pub const RTLD_NEXT = @intToPtr(*c_void, ~maxInt(usize));
+pub const RTLD_DEFAULT = @intToPtr(*c_void, ~maxInt(usize) - 1);
+pub const RTLD_SELF = @intToPtr(*c_void, ~maxInt(usize) - 2);
+pub const RTLD_MAIN_ONLY = @intToPtr(*c_void, ~maxInt(usize) - 4);

src/ir.cpp

@@ -6561,6 +6561,7 @@ static IrInstruction *ir_gen_prefix_op_id(IrBuilder *irb, Scope *scope, AstNode
 }
 
 static IrInstruction *ir_expr_wrap(IrBuilder *irb, Scope *scope, IrInstruction *inst, ResultLoc *result_loc) {
+    if (inst == irb->codegen->invalid_instruction) return inst;
     ir_build_end_expr(irb, scope, inst->source_node, inst, result_loc);
     return inst;
 }

test/standalone.zig

@@ -1,6 +1,5 @@
+const std = @import("std");
 const tests = @import("tests.zig");
-const builtin = @import("builtin");
-const is_windows = builtin.os == builtin.Os.windows;
 
 pub fn addCases(cases: *tests.StandaloneContext) void {
     cases.add("test/standalone/hello_world/hello.zig");
@@ -19,13 +18,10 @@ pub fn addCases(cases: *tests.StandaloneContext) void {
     cases.addBuildFile("test/standalone/use_alias/build.zig");
     cases.addBuildFile("test/standalone/brace_expansion/build.zig");
     cases.addBuildFile("test/standalone/empty_env/build.zig");
-    if (builtin.os == builtin.Os.linux) {
-        // TODO hook up the DynLib API for windows using LoadLibraryA
-        // TODO figure out how to make this work on darwin - probably libSystem has dlopen/dlsym in it
+    if (std.Target.current.getOs() != .wasi) {
         cases.addBuildFile("test/standalone/load_dynamic_library/build.zig");
     }
-
-    if (builtin.arch == builtin.Arch.x86_64) { // TODO add C ABI support for other architectures
+    if (std.Target.current.getArch() == .x86_64) { // TODO add C ABI support for other architectures
         cases.addBuildFile("test/stage1/c_abi/build.zig");
     }
 }

test/standalone/load_dynamic_library/main.zig

@@ -9,8 +9,7 @@ pub fn main() !void {
     var lib = try std.DynLib.open(dynlib_name);
     defer lib.close();
 
-    const addr = lib.lookup("add") orelse return error.SymbolNotFound;
-    const addFn = @intToPtr(extern fn (i32, i32) i32, addr);
+    const addFn = lib.lookup(extern fn (i32, i32) i32, "add") orelse return error.SymbolNotFound;
 
     const result = addFn(12, 34);
     std.debug.assert(result == 46);