zig/src-self-hosted/link.zig

581 lines
20 KiB
Zig

const std = @import("std");
const mem = std.mem;
const c = @import("c.zig");
const Compilation = @import("compilation.zig").Compilation;
const Target = std.Target;
const ObjectFormat = Target.ObjectFormat;
const LibCInstallation = @import("libc_installation.zig").LibCInstallation;
const assert = std.debug.assert;
const util = @import("util.zig");
const Context = struct {
comp: *Compilation,
arena: std.heap.ArenaAllocator,
args: std.ArrayList([*:0]const u8),
link_in_crt: bool,
link_err: error{OutOfMemory}!void,
link_msg: std.Buffer,
libc: *LibCInstallation,
out_file_path: std.Buffer,
};
pub fn link(comp: *Compilation) !void {
var ctx = Context{
.comp = comp,
.arena = std.heap.ArenaAllocator.init(comp.gpa()),
.args = undefined,
.link_in_crt = comp.haveLibC() and comp.kind == .Exe,
.link_err = {},
.link_msg = undefined,
.libc = undefined,
.out_file_path = undefined,
};
defer ctx.arena.deinit();
ctx.args = std.ArrayList([*:0]const u8).init(&ctx.arena.allocator);
ctx.link_msg = std.Buffer.initNull(&ctx.arena.allocator);
ctx.out_file_path = try std.Buffer.init(&ctx.arena.allocator, comp.name.toSliceConst());
switch (comp.kind) {
.Exe => {
try ctx.out_file_path.append(comp.target.exeFileExt());
},
.Lib => {
try ctx.out_file_path.append(if (comp.is_static) comp.target.staticLibSuffix() else comp.target.dynamicLibSuffix());
},
.Obj => {
try ctx.out_file_path.append(comp.target.oFileExt());
},
}
// even though we're calling LLD as a library it thinks the first
// argument is its own exe name
try ctx.args.append("lld");
if (comp.haveLibC()) {
// TODO https://github.com/ziglang/zig/issues/3190
var libc = ctx.comp.override_libc orelse blk: {
switch (comp.target) {
Target.Native => {
break :blk comp.zig_compiler.getNativeLibC() catch return error.LibCRequiredButNotProvidedOrFound;
},
else => return error.LibCRequiredButNotProvidedOrFound,
}
};
ctx.libc = libc;
}
try constructLinkerArgs(&ctx);
if (comp.verbose_link) {
for (ctx.args.toSliceConst()) |arg, i| {
const space = if (i == 0) "" else " ";
std.debug.warn("{}{s}", .{ space, arg });
}
std.debug.warn("\n", .{});
}
const extern_ofmt = toExternObjectFormatType(util.getObjectFormat(comp.target));
const args_slice = ctx.args.toSlice();
{
// LLD is not thread-safe, so we grab a global lock.
const held = comp.zig_compiler.lld_lock.acquire();
defer held.release();
// Not evented I/O. LLD does its own multithreading internally.
if (!ZigLLDLink(extern_ofmt, args_slice.ptr, args_slice.len, linkDiagCallback, @ptrCast(*c_void, &ctx))) {
if (!ctx.link_msg.isNull()) {
// TODO capture these messages and pass them through the system, reporting them through the
// event system instead of printing them directly here.
// perhaps try to parse and understand them.
std.debug.warn("{}\n", .{ctx.link_msg.toSliceConst()});
}
return error.LinkFailed;
}
}
}
extern fn ZigLLDLink(
oformat: c.ZigLLVM_ObjectFormatType,
args: [*]const [*]const u8,
arg_count: usize,
append_diagnostic: extern fn (*c_void, [*]const u8, usize) void,
context: *c_void,
) bool;
extern fn linkDiagCallback(context: *c_void, ptr: [*]const u8, len: usize) void {
const ctx = @ptrCast(*Context, @alignCast(@alignOf(Context), context));
ctx.link_err = linkDiagCallbackErrorable(ctx, ptr[0..len]);
}
fn linkDiagCallbackErrorable(ctx: *Context, msg: []const u8) !void {
if (ctx.link_msg.isNull()) {
try ctx.link_msg.resize(0);
}
try ctx.link_msg.append(msg);
}
fn toExternObjectFormatType(ofmt: ObjectFormat) c.ZigLLVM_ObjectFormatType {
return switch (ofmt) {
.unknown => .ZigLLVM_UnknownObjectFormat,
.coff => .ZigLLVM_COFF,
.elf => .ZigLLVM_ELF,
.macho => .ZigLLVM_MachO,
.wasm => .ZigLLVM_Wasm,
};
}
fn constructLinkerArgs(ctx: *Context) !void {
switch (util.getObjectFormat(ctx.comp.target)) {
.unknown => unreachable,
.coff => return constructLinkerArgsCoff(ctx),
.elf => return constructLinkerArgsElf(ctx),
.macho => return constructLinkerArgsMachO(ctx),
.wasm => return constructLinkerArgsWasm(ctx),
}
}
fn constructLinkerArgsElf(ctx: *Context) !void {
// TODO commented out code in this function
//if (g->linker_script) {
// lj->args.append("-T");
// lj->args.append(g->linker_script);
//}
try ctx.args.append("--gc-sections");
if (ctx.comp.link_eh_frame_hdr) {
try ctx.args.append("--eh-frame-hdr");
}
//lj->args.append("-m");
//lj->args.append(getLDMOption(&g->zig_target));
//bool is_lib = g->out_type == OutTypeLib;
//bool shared = !g->is_static && is_lib;
//Buf *soname = nullptr;
if (ctx.comp.is_static) {
if (util.isArmOrThumb(ctx.comp.target)) {
try ctx.args.append("-Bstatic");
} else {
try ctx.args.append("-static");
}
}
//} else if (shared) {
// lj->args.append("-shared");
// if (buf_len(&lj->out_file) == 0) {
// buf_appendf(&lj->out_file, "lib%s.so.%" ZIG_PRI_usize ".%" ZIG_PRI_usize ".%" ZIG_PRI_usize "",
// buf_ptr(g->root_out_name), g->version_major, g->version_minor, g->version_patch);
// }
// soname = buf_sprintf("lib%s.so.%" ZIG_PRI_usize "", buf_ptr(g->root_out_name), g->version_major);
//}
try ctx.args.append("-o");
try ctx.args.append(ctx.out_file_path.toSliceConst());
if (ctx.link_in_crt) {
const crt1o = if (ctx.comp.is_static) "crt1.o" else "Scrt1.o";
const crtbegino = if (ctx.comp.is_static) "crtbeginT.o" else "crtbegin.o";
try addPathJoin(ctx, ctx.libc.lib_dir.?, crt1o);
try addPathJoin(ctx, ctx.libc.lib_dir.?, "crti.o");
try addPathJoin(ctx, ctx.libc.static_lib_dir.?, crtbegino);
}
if (ctx.comp.haveLibC()) {
try ctx.args.append("-L");
// TODO addNullByte should probably return [:0]u8
try ctx.args.append(@ptrCast([*:0]const u8, (try std.cstr.addNullByte(&ctx.arena.allocator, ctx.libc.lib_dir.?)).ptr));
try ctx.args.append("-L");
try ctx.args.append(@ptrCast([*:0]const u8, (try std.cstr.addNullByte(&ctx.arena.allocator, ctx.libc.static_lib_dir.?)).ptr));
if (!ctx.comp.is_static) {
const dl = blk: {
if (ctx.libc.dynamic_linker_path) |dl| break :blk dl;
if (util.getDynamicLinkerPath(ctx.comp.target)) |dl| break :blk dl;
return error.LibCMissingDynamicLinker;
};
try ctx.args.append("-dynamic-linker");
try ctx.args.append(@ptrCast([*:0]const u8, (try std.cstr.addNullByte(&ctx.arena.allocator, dl)).ptr));
}
}
//if (shared) {
// lj->args.append("-soname");
// lj->args.append(buf_ptr(soname));
//}
// .o files
for (ctx.comp.link_objects) |link_object| {
const link_obj_with_null = try std.cstr.addNullByte(&ctx.arena.allocator, link_object);
try ctx.args.append(@ptrCast([*:0]const u8, link_obj_with_null.ptr));
}
try addFnObjects(ctx);
//if (g->out_type == OutTypeExe || g->out_type == OutTypeLib) {
// if (g->libc_link_lib == nullptr) {
// Buf *builtin_o_path = build_o(g, "builtin");
// lj->args.append(buf_ptr(builtin_o_path));
// }
// // sometimes libgcc is missing stuff, so we still build compiler_rt and rely on weak linkage
// Buf *compiler_rt_o_path = build_compiler_rt(g);
// lj->args.append(buf_ptr(compiler_rt_o_path));
//}
//for (size_t i = 0; i < g->link_libs_list.length; i += 1) {
// LinkLib *link_lib = g->link_libs_list.at(i);
// if (buf_eql_str(link_lib->name, "c")) {
// continue;
// }
// Buf *arg;
// if (buf_starts_with_str(link_lib->name, "/") || buf_ends_with_str(link_lib->name, ".a") ||
// buf_ends_with_str(link_lib->name, ".so"))
// {
// arg = link_lib->name;
// } else {
// arg = buf_sprintf("-l%s", buf_ptr(link_lib->name));
// }
// lj->args.append(buf_ptr(arg));
//}
// libc dep
if (ctx.comp.haveLibC()) {
if (ctx.comp.is_static) {
try ctx.args.append("--start-group");
try ctx.args.append("-lgcc");
try ctx.args.append("-lgcc_eh");
try ctx.args.append("-lc");
try ctx.args.append("-lm");
try ctx.args.append("--end-group");
} else {
try ctx.args.append("-lgcc");
try ctx.args.append("--as-needed");
try ctx.args.append("-lgcc_s");
try ctx.args.append("--no-as-needed");
try ctx.args.append("-lc");
try ctx.args.append("-lm");
try ctx.args.append("-lgcc");
try ctx.args.append("--as-needed");
try ctx.args.append("-lgcc_s");
try ctx.args.append("--no-as-needed");
}
}
// crt end
if (ctx.link_in_crt) {
try addPathJoin(ctx, ctx.libc.static_lib_dir.?, "crtend.o");
try addPathJoin(ctx, ctx.libc.lib_dir.?, "crtn.o");
}
if (ctx.comp.target != Target.Native) {
try ctx.args.append("--allow-shlib-undefined");
}
}
fn addPathJoin(ctx: *Context, dirname: []const u8, basename: []const u8) !void {
const full_path = try std.fs.path.join(&ctx.arena.allocator, &[_][]const u8{ dirname, basename });
const full_path_with_null = try std.cstr.addNullByte(&ctx.arena.allocator, full_path);
try ctx.args.append(@ptrCast([*:0]const u8, full_path_with_null.ptr));
}
fn constructLinkerArgsCoff(ctx: *Context) !void {
try ctx.args.append("-NOLOGO");
if (!ctx.comp.strip) {
try ctx.args.append("-DEBUG");
}
switch (ctx.comp.target.getArch()) {
.i386 => try ctx.args.append("-MACHINE:X86"),
.x86_64 => try ctx.args.append("-MACHINE:X64"),
.aarch64 => try ctx.args.append("-MACHINE:ARM"),
else => return error.UnsupportedLinkArchitecture,
}
const is_library = ctx.comp.kind == .Lib;
const out_arg = try std.fmt.allocPrint(&ctx.arena.allocator, "-OUT:{}\x00", .{ctx.out_file_path.toSliceConst()});
try ctx.args.append(@ptrCast([*:0]const u8, out_arg.ptr));
if (ctx.comp.haveLibC()) {
try ctx.args.append(@ptrCast([*:0]const u8, (try std.fmt.allocPrint(&ctx.arena.allocator, "-LIBPATH:{}\x00", .{ctx.libc.msvc_lib_dir.?})).ptr));
try ctx.args.append(@ptrCast([*:0]const u8, (try std.fmt.allocPrint(&ctx.arena.allocator, "-LIBPATH:{}\x00", .{ctx.libc.kernel32_lib_dir.?})).ptr));
try ctx.args.append(@ptrCast([*:0]const u8, (try std.fmt.allocPrint(&ctx.arena.allocator, "-LIBPATH:{}\x00", .{ctx.libc.lib_dir.?})).ptr));
}
if (ctx.link_in_crt) {
const lib_str = if (ctx.comp.is_static) "lib" else "";
const d_str = if (ctx.comp.build_mode == .Debug) "d" else "";
if (ctx.comp.is_static) {
const cmt_lib_name = try std.fmt.allocPrint(&ctx.arena.allocator, "libcmt{}.lib\x00", .{d_str});
try ctx.args.append(@ptrCast([*:0]const u8, cmt_lib_name.ptr));
} else {
const msvcrt_lib_name = try std.fmt.allocPrint(&ctx.arena.allocator, "msvcrt{}.lib\x00", .{d_str});
try ctx.args.append(@ptrCast([*:0]const u8, msvcrt_lib_name.ptr));
}
const vcruntime_lib_name = try std.fmt.allocPrint(&ctx.arena.allocator, "{}vcruntime{}.lib\x00", .{
lib_str,
d_str,
});
try ctx.args.append(@ptrCast([*:0]const u8, vcruntime_lib_name.ptr));
const crt_lib_name = try std.fmt.allocPrint(&ctx.arena.allocator, "{}ucrt{}.lib\x00", .{ lib_str, d_str });
try ctx.args.append(@ptrCast([*:0]const u8, crt_lib_name.ptr));
// Visual C++ 2015 Conformance Changes
// https://msdn.microsoft.com/en-us/library/bb531344.aspx
try ctx.args.append("legacy_stdio_definitions.lib");
// msvcrt depends on kernel32
try ctx.args.append("kernel32.lib");
} else {
try ctx.args.append("-NODEFAULTLIB");
if (!is_library) {
try ctx.args.append("-ENTRY:WinMainCRTStartup");
}
}
if (is_library and !ctx.comp.is_static) {
try ctx.args.append("-DLL");
}
for (ctx.comp.link_objects) |link_object| {
const link_obj_with_null = try std.cstr.addNullByte(&ctx.arena.allocator, link_object);
try ctx.args.append(@ptrCast([*:0]const u8, link_obj_with_null.ptr));
}
try addFnObjects(ctx);
switch (ctx.comp.kind) {
.Exe, .Lib => {
if (!ctx.comp.haveLibC()) {
@panic("TODO");
}
},
.Obj => {},
}
}
fn constructLinkerArgsMachO(ctx: *Context) !void {
try ctx.args.append("-demangle");
if (ctx.comp.linker_rdynamic) {
try ctx.args.append("-export_dynamic");
}
const is_lib = ctx.comp.kind == .Lib;
const shared = !ctx.comp.is_static and is_lib;
if (ctx.comp.is_static) {
try ctx.args.append("-static");
} else {
try ctx.args.append("-dynamic");
}
try ctx.args.append("-arch");
try ctx.args.append(util.getDarwinArchString(ctx.comp.target));
const platform = try DarwinPlatform.get(ctx.comp);
switch (platform.kind) {
.MacOS => try ctx.args.append("-macosx_version_min"),
.IPhoneOS => try ctx.args.append("-iphoneos_version_min"),
.IPhoneOSSimulator => try ctx.args.append("-ios_simulator_version_min"),
}
const ver_str = try std.fmt.allocPrint(&ctx.arena.allocator, "{}.{}.{}\x00", .{
platform.major,
platform.minor,
platform.micro,
});
try ctx.args.append(@ptrCast([*:0]const u8, ver_str.ptr));
if (ctx.comp.kind == .Exe) {
if (ctx.comp.is_static) {
try ctx.args.append("-no_pie");
} else {
try ctx.args.append("-pie");
}
}
try ctx.args.append("-o");
try ctx.args.append(ctx.out_file_path.toSliceConst());
if (shared) {
try ctx.args.append("-headerpad_max_install_names");
} else if (ctx.comp.is_static) {
try ctx.args.append("-lcrt0.o");
} else {
switch (platform.kind) {
.MacOS => {
if (platform.versionLessThan(10, 5)) {
try ctx.args.append("-lcrt1.o");
} else if (platform.versionLessThan(10, 6)) {
try ctx.args.append("-lcrt1.10.5.o");
} else if (platform.versionLessThan(10, 8)) {
try ctx.args.append("-lcrt1.10.6.o");
}
},
.IPhoneOS => {
if (ctx.comp.target.getArch() == .aarch64) {
// iOS does not need any crt1 files for arm64
} else if (platform.versionLessThan(3, 1)) {
try ctx.args.append("-lcrt1.o");
} else if (platform.versionLessThan(6, 0)) {
try ctx.args.append("-lcrt1.3.1.o");
}
},
.IPhoneOSSimulator => {}, // no crt1.o needed
}
}
for (ctx.comp.link_objects) |link_object| {
const link_obj_with_null = try std.cstr.addNullByte(&ctx.arena.allocator, link_object);
try ctx.args.append(@ptrCast([*:0]const u8, link_obj_with_null.ptr));
}
try addFnObjects(ctx);
if (ctx.comp.target == Target.Native) {
for (ctx.comp.link_libs_list.toSliceConst()) |lib| {
if (mem.eql(u8, lib.name, "c")) {
// on Darwin, libSystem has libc in it, but also you have to use it
// to make syscalls because the syscall numbers are not documented
// and change between versions.
// so we always link against libSystem
try ctx.args.append("-lSystem");
} else {
if (mem.indexOfScalar(u8, lib.name, '/') == null) {
const arg = try std.fmt.allocPrint(&ctx.arena.allocator, "-l{}\x00", .{lib.name});
try ctx.args.append(@ptrCast([*:0]const u8, arg.ptr));
} else {
const arg = try std.cstr.addNullByte(&ctx.arena.allocator, lib.name);
try ctx.args.append(@ptrCast([*:0]const u8, arg.ptr));
}
}
}
} else {
try ctx.args.append("-undefined");
try ctx.args.append("dynamic_lookup");
}
if (platform.kind == .MacOS) {
if (platform.versionLessThan(10, 5)) {
try ctx.args.append("-lgcc_s.10.4");
} else if (platform.versionLessThan(10, 6)) {
try ctx.args.append("-lgcc_s.10.5");
}
} else {
@panic("TODO");
}
}
fn constructLinkerArgsWasm(ctx: *Context) void {
@panic("TODO");
}
fn addFnObjects(ctx: *Context) !void {
const held = ctx.comp.fn_link_set.acquire();
defer held.release();
var it = held.value.first;
while (it) |node| {
const fn_val = node.data orelse {
// handle the tombstone. See Value.Fn.destroy.
it = node.next;
held.value.remove(node);
ctx.comp.gpa().destroy(node);
continue;
};
try ctx.args.append(fn_val.containing_object.toSliceConst());
it = node.next;
}
}
const DarwinPlatform = struct {
kind: Kind,
major: u32,
minor: u32,
micro: u32,
const Kind = enum {
MacOS,
IPhoneOS,
IPhoneOSSimulator,
};
fn get(comp: *Compilation) !DarwinPlatform {
var result: DarwinPlatform = undefined;
const ver_str = switch (comp.darwin_version_min) {
.MacOS => |ver| blk: {
result.kind = .MacOS;
break :blk ver;
},
.Ios => |ver| blk: {
result.kind = .IPhoneOS;
break :blk ver;
},
.None => blk: {
assert(comp.target.getOs() == .macosx);
result.kind = .MacOS;
break :blk "10.14";
},
};
var had_extra: bool = undefined;
try darwinGetReleaseVersion(
ver_str,
&result.major,
&result.minor,
&result.micro,
&had_extra,
);
if (had_extra or result.major != 10 or result.minor >= 100 or result.micro >= 100) {
return error.InvalidDarwinVersionString;
}
if (result.kind == .IPhoneOS) {
switch (comp.target.getArch()) {
.i386,
.x86_64,
=> result.kind = .IPhoneOSSimulator,
else => {},
}
}
return result;
}
fn versionLessThan(self: DarwinPlatform, major: u32, minor: u32) bool {
if (self.major < major)
return true;
if (self.major > major)
return false;
if (self.minor < minor)
return true;
return false;
}
};
/// Parse (([0-9]+)(.([0-9]+)(.([0-9]+)?))?)? and return the
/// grouped values as integers. Numbers which are not provided are set to 0.
/// return true if the entire string was parsed (9.2), or all groups were
/// parsed (10.3.5extrastuff).
fn darwinGetReleaseVersion(str: []const u8, major: *u32, minor: *u32, micro: *u32, had_extra: *bool) !void {
major.* = 0;
minor.* = 0;
micro.* = 0;
had_extra.* = false;
if (str.len == 0)
return error.InvalidDarwinVersionString;
var start_pos: usize = 0;
for ([_]*u32{ major, minor, micro }) |v| {
const dot_pos = mem.indexOfScalarPos(u8, str, start_pos, '.');
const end_pos = dot_pos orelse str.len;
v.* = std.fmt.parseUnsigned(u32, str[start_pos..end_pos], 10) catch return error.InvalidDarwinVersionString;
start_pos = (dot_pos orelse return) + 1;
if (start_pos == str.len) return;
}
had_extra.* = true;
}