motiejus/zig
1
Fork 0
Code Releases Activity

elf: streamline codepaths for different linker modes (object, ar, exe/dyn)

Browse Source
This commit is contained in:
Jakub Konka
2023-11-08 17:35:56 +01:00
parent a16e6706b3
commit 0b4d398c40
1 changed files with 358 additions and 249 deletions
Download Patch File Download Diff File Expand all files Collapse all files

607
src/link/Elf.zig
View File

@@ -959,6 +959,9 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
} else null;
const gc_sections = self.base.options.gc_sections orelse false;
// --verbose-link
if (self.base.options.verbose_link) try self.dumpArgv(comp);
var csu = try CsuObjects.init(arena, self.base.options, comp);
const compiler_rt_path: ?[]const u8 = blk: {
if (comp.compiler_rt_lib) |x| break :blk x.full_object_path;
@@ -966,247 +969,9 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
break :blk null;
};
// --verbose-link
if (self.base.options.verbose_link) {
var argv = std.ArrayList([]const u8).init(arena);
try argv.append("zig");
try argv.append("ld");
try argv.append("-o");
try argv.append(full_out_path);
if (self.base.options.entry) |entry| {
try argv.append("--entry");
try argv.append(entry);
}
if (self.base.options.dynamic_linker) |path| {
try argv.append("-dynamic-linker");
try argv.append(path);
}
if (self.base.options.soname) |name| {
try argv.append("-soname");
try argv.append(name);
}
for (self.base.options.rpath_list) |rpath| {
try argv.append("-rpath");
try argv.append(rpath);
}
if (self.base.options.each_lib_rpath) {
for (self.base.options.lib_dirs) |lib_dir_path| {
try argv.append("-rpath");
try argv.append(lib_dir_path);
}
for (self.base.options.objects) |obj| {
if (Compilation.classifyFileExt(obj.path) == .shared_library) {
const lib_dir_path = std.fs.path.dirname(obj.path) orelse continue;
if (obj.loption) continue;
try argv.append("-rpath");
try argv.append(lib_dir_path);
}
}
}
if (self.base.options.stack_size_override) |ss| {
try argv.append("-z");
try argv.append(try std.fmt.allocPrint(arena, "stack-size={d}", .{ss}));
}
if (self.base.options.image_base_override) |image_base| {
try argv.append(try std.fmt.allocPrint(arena, "--image-base={d}", .{image_base}));
}
if (gc_sections) {
try argv.append("--gc-sections");
}
if (self.base.options.print_gc_sections) {
try argv.append("--print-gc-sections");
}
if (self.base.options.eh_frame_hdr) {
try argv.append("--eh-frame-hdr");
}
if (self.base.options.rdynamic) {
try argv.append("--export-dynamic");
}
if (self.base.options.strip) {
try argv.append("-s");
}
if (self.base.options.z_notext) {
try argv.append("-z");
try argv.append("notext");
}
if (self.base.options.z_nocopyreloc) {
try argv.append("-z");
try argv.append("nocopyreloc");
}
if (self.base.options.z_now) {
try argv.append("-z");
try argv.append("now");
}
if (self.isStatic()) {
try argv.append("-static");
} else if (self.isDynLib()) {
try argv.append("-shared");
}
if (self.base.options.pie and self.isExe()) {
try argv.append("-pie");
}
// csu prelude
if (csu.crt0) |v| try argv.append(v);
if (csu.crti) |v| try argv.append(v);
if (csu.crtbegin) |v| try argv.append(v);
for (self.base.options.lib_dirs) |lib_dir| {
try argv.append("-L");
try argv.append(lib_dir);
}
if (self.base.options.link_libc) {
if (self.base.options.libc_installation) |libc_installation| {
try argv.append("-L");
try argv.append(libc_installation.crt_dir.?);
}
}
var whole_archive = false;
for (self.base.options.objects) |obj| {
if (obj.must_link and !whole_archive) {
try argv.append("-whole-archive");
whole_archive = true;
} else if (!obj.must_link and whole_archive) {
try argv.append("-no-whole-archive");
whole_archive = false;
}
if (obj.loption) {
assert(obj.path[0] == ':');
try argv.append("-l");
}
try argv.append(obj.path);
}
if (whole_archive) {
try argv.append("-no-whole-archive");
whole_archive = false;
}
for (comp.c_object_table.keys()) |key| {
try argv.append(key.status.success.object_path);
}
if (module_obj_path) |p| {
try argv.append(p);
}
// TSAN
if (self.base.options.tsan) {
try argv.append(comp.tsan_static_lib.?.full_object_path);
}
// libc
if (!self.base.options.skip_linker_dependencies and
!self.base.options.link_libc)
{
if (comp.libc_static_lib) |lib| {
try argv.append(lib.full_object_path);
}
}
// stack-protector.
// Related: https://github.com/ziglang/zig/issues/7265
if (comp.libssp_static_lib) |ssp| {
try argv.append(ssp.full_object_path);
}
// Shared libraries.
// Worst-case, we need an --as-needed argument for every lib, as well
// as one before and one after.
try argv.ensureUnusedCapacity(self.base.options.system_libs.keys().len * 2 + 2);
argv.appendAssumeCapacity("--as-needed");
var as_needed = true;
for (self.base.options.system_libs.values()) |lib_info| {
const lib_as_needed = !lib_info.needed;
switch ((@as(u2, @intFromBool(lib_as_needed)) << 1) | @intFromBool(as_needed)) {
0b00, 0b11 => {},
0b01 => {
argv.appendAssumeCapacity("--no-as-needed");
as_needed = false;
},
0b10 => {
argv.appendAssumeCapacity("--as-needed");
as_needed = true;
},
}
argv.appendAssumeCapacity(lib_info.path.?);
}
if (!as_needed) {
argv.appendAssumeCapacity("--as-needed");
as_needed = true;
}
// libc++ dep
if (self.base.options.link_libcpp) {
try argv.append(comp.libcxxabi_static_lib.?.full_object_path);
try argv.append(comp.libcxx_static_lib.?.full_object_path);
}
// libunwind dep
if (self.base.options.link_libunwind) {
try argv.append(comp.libunwind_static_lib.?.full_object_path);
}
// libc dep
if (self.base.options.link_libc) {
if (self.base.options.libc_installation != null) {
const needs_grouping = self.base.options.link_mode == .Static;
if (needs_grouping) try argv.append("--start-group");
try argv.appendSlice(target_util.libcFullLinkFlags(target));
if (needs_grouping) try argv.append("--end-group");
} else if (target.isGnuLibC()) {
for (glibc.libs) |lib| {
const lib_path = try std.fmt.allocPrint(arena, "{s}{c}lib{s}.so.{d}", .{
comp.glibc_so_files.?.dir_path, fs.path.sep, lib.name, lib.sover,
});
try argv.append(lib_path);
}
try argv.append(try comp.get_libc_crt_file(arena, "libc_nonshared.a"));
} else if (target.isMusl()) {
try argv.append(try comp.get_libc_crt_file(arena, switch (self.base.options.link_mode) {
.Static => "libc.a",
.Dynamic => "libc.so",
}));
}
}
// compiler-rt
if (compiler_rt_path) |p| {
try argv.append(p);
}
// crt postlude
if (csu.crtend) |v| try argv.append(v);
if (csu.crtn) |v| try argv.append(v);
Compilation.dump_argv(argv.items);
}
if (self.zigObjectPtr()) |zig_object| try zig_object.flushModule(self);
if (self.isStaticLib()) return self.flushStaticLib(comp, module_obj_path);
if (self.isObject()) return self.flushObject(comp, module_obj_path);
// Here we will parse input positional and library files (if referenced).
// This will roughly match in any linker backend we support.
@@ -1232,6 +997,7 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
// rpaths
var rpath_table = std.StringArrayHashMap(void).init(self.base.allocator);
defer rpath_table.deinit();
for (self.base.options.rpath_list) |rpath| {
_ = try rpath_table.put(rpath, {});
}
@@ -1380,8 +1146,6 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
try self.handleAndReportParseError(obj.path, err, &parse_ctx);
}
if (self.isStaticLib()) return self.flushStaticLib();
// Init all objects
for (self.objects.items) |index| {
try self.file(index).?.object.init(self);
@@ -1410,7 +1174,7 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
// If we haven't already, create a linker-generated input file comprising of
// linker-defined synthetic symbols only such as `_DYNAMIC`, etc.
if (self.linker_defined_index == null and !self.isRelocatable()) {
if (self.linker_defined_index == null) {
const index = @as(File.Index, @intCast(try self.files.addOne(gpa)));
self.files.set(index, .{ .linker_defined = .{ .index = index } });
self.linker_defined_index = index;
@@ -1424,8 +1188,6 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
self.resolveSymbols();
self.markEhFrameAtomsDead();
if (self.isObject()) return self.flushObject();
try self.convertCommonSymbols();
self.markImportsExports();
@@ -1519,9 +1281,30 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
}
}
pub fn flushStaticLib(self: *Elf) link.File.FlushError!void {
pub fn flushStaticLib(self: *Elf, comp: *Compilation, module_obj_path: ?[]const u8) link.File.FlushError!void {
const gpa = self.base.allocator;
var positionals = std.ArrayList(Compilation.LinkObject).init(gpa);
defer positionals.deinit();
try positionals.ensureUnusedCapacity(self.base.options.objects.len);
positionals.appendSliceAssumeCapacity(self.base.options.objects);
// This is a set of object files emitted by clang in a single `build-exe` invocation.
// For instance, the implicit `a.o` as compiled by `zig build-exe a.c` will end up
// in this set.
for (comp.c_object_table.keys()) |key| {
try positionals.append(.{ .path = key.status.success.object_path });
}
if (module_obj_path) |path| try positionals.append(.{ .path = path });
for (positionals.items) |obj| {
var parse_ctx: ParseErrorCtx = .{ .detected_cpu_arch = undefined };
self.parsePositional(obj.path, obj.must_link, &parse_ctx) catch |err|
try self.handleAndReportParseError(obj.path, err, &parse_ctx);
}
// First, we flush relocatable object file generated with our backends.
if (self.zigObjectPtr()) |zig_object| {
zig_object.resolveSymbols(self);
@@ -1631,7 +1414,41 @@ pub fn flushStaticLib(self: *Elf) link.File.FlushError!void {
try self.base.file.?.pwriteAll(buffer.items, 0);
}
pub fn flushObject(self: *Elf) link.File.FlushError!void {
pub fn flushObject(self: *Elf, comp: *Compilation, module_obj_path: ?[]const u8) link.File.FlushError!void {
const gpa = self.base.allocator;
var positionals = std.ArrayList(Compilation.LinkObject).init(gpa);
defer positionals.deinit();
try positionals.ensureUnusedCapacity(self.base.options.objects.len);
positionals.appendSliceAssumeCapacity(self.base.options.objects);
// This is a set of object files emitted by clang in a single `build-exe` invocation.
// For instance, the implicit `a.o` as compiled by `zig build-exe a.c` will end up
// in this set.
for (comp.c_object_table.keys()) |key| {
try positionals.append(.{ .path = key.status.success.object_path });
}
if (module_obj_path) |path| try positionals.append(.{ .path = path });
for (positionals.items) |obj| {
var parse_ctx: ParseErrorCtx = .{ .detected_cpu_arch = undefined };
self.parsePositional(obj.path, obj.must_link, &parse_ctx) catch |err|
try self.handleAndReportParseError(obj.path, err, &parse_ctx);
}
// Init all objects
for (self.objects.items) |index| {
try self.file(index).?.object.init(self);
}
// Now, we are ready to resolve the symbols across all input files.
// We will first resolve the files in the ZigObject, next in the parsed
// input Object files.
// Any qualifing unresolved symbol will be upgraded to an absolute, weak
// symbol for potential resolution at load-time.
self.resolveSymbols();
self.markEhFrameAtomsDead();
self.claimUnresolvedObject();
try self.initSectionsObject();
@@ -1660,6 +1477,296 @@ pub fn flushObject(self: *Elf) link.File.FlushError!void {
try self.writeElfHeader();
}
/// --verbose-link output
fn dumpArgv(self: *Elf, comp: *Compilation) !void {
var arena_allocator = std.heap.ArenaAllocator.init(self.base.allocator);
defer arena_allocator.deinit();
const arena = arena_allocator.allocator();
const target = self.base.options.target;
const directory = self.base.options.emit.?.directory; // Just an alias to make it shorter to type.
const full_out_path = try directory.join(arena, &[_][]const u8{self.base.options.emit.?.sub_path});
const module_obj_path: ?[]const u8 = if (self.base.intermediary_basename) |path| blk: {
if (fs.path.dirname(full_out_path)) |dirname| {
break :blk try fs.path.join(arena, &.{ dirname, path });
} else {
break :blk path;
}
} else null;
const gc_sections = self.base.options.gc_sections orelse false;
var csu = try CsuObjects.init(arena, self.base.options, comp);
const compiler_rt_path: ?[]const u8 = blk: {
if (comp.compiler_rt_lib) |x| break :blk x.full_object_path;
if (comp.compiler_rt_obj) |x| break :blk x.full_object_path;
break :blk null;
};
var argv = std.ArrayList([]const u8).init(arena);
try argv.append("zig");
if (self.isStaticLib()) {
try argv.append("ar");
} else {
try argv.append("ld");
}
if (self.isObject()) {
try argv.append("-r");
}
try argv.append("-o");
try argv.append(full_out_path);
if (self.isRelocatable()) {
for (self.base.options.objects) |obj| {
try argv.append(obj.path);
}
for (comp.c_object_table.keys()) |key| {
try argv.append(key.status.success.object_path);
}
if (module_obj_path) |p| {
try argv.append(p);
}
} else {
if (!self.isStatic()) {
if (self.base.options.dynamic_linker) |path| {
try argv.append("-dynamic-linker");
try argv.append(path);
}
}
if (self.isDynLib()) {
if (self.base.options.soname) |name| {
try argv.append("-soname");
try argv.append(name);
}
}
if (self.base.options.entry) |entry| {
try argv.append("--entry");
try argv.append(entry);
}
for (self.base.options.rpath_list) |rpath| {
try argv.append("-rpath");
try argv.append(rpath);
}
if (self.base.options.each_lib_rpath) {
for (self.base.options.lib_dirs) |lib_dir_path| {
try argv.append("-rpath");
try argv.append(lib_dir_path);
}
for (self.base.options.objects) |obj| {
if (Compilation.classifyFileExt(obj.path) == .shared_library) {
const lib_dir_path = std.fs.path.dirname(obj.path) orelse continue;
if (obj.loption) continue;
try argv.append("-rpath");
try argv.append(lib_dir_path);
}
}
}
if (self.base.options.stack_size_override) |ss| {
try argv.append("-z");
try argv.append(try std.fmt.allocPrint(arena, "stack-size={d}", .{ss}));
}
if (self.base.options.image_base_override) |image_base| {
try argv.append(try std.fmt.allocPrint(arena, "--image-base={d}", .{image_base}));
}
if (gc_sections) {
try argv.append("--gc-sections");
}
if (self.base.options.print_gc_sections) {
try argv.append("--print-gc-sections");
}
if (self.base.options.eh_frame_hdr) {
try argv.append("--eh-frame-hdr");
}
if (self.base.options.rdynamic) {
try argv.append("--export-dynamic");
}
if (self.base.options.z_notext) {
try argv.append("-z");
try argv.append("notext");
}
if (self.base.options.z_nocopyreloc) {
try argv.append("-z");
try argv.append("nocopyreloc");
}
if (self.base.options.z_now) {
try argv.append("-z");
try argv.append("now");
}
if (self.isStatic()) {
try argv.append("-static");
} else if (self.isDynLib()) {
try argv.append("-shared");
}
if (self.base.options.pie and self.isExe()) {
try argv.append("-pie");
}
if (self.base.options.strip) {
try argv.append("-s");
}
// csu prelude
if (csu.crt0) |v| try argv.append(v);
if (csu.crti) |v| try argv.append(v);
if (csu.crtbegin) |v| try argv.append(v);
for (self.base.options.lib_dirs) |lib_dir| {
try argv.append("-L");
try argv.append(lib_dir);
}
if (self.base.options.link_libc) {
if (self.base.options.libc_installation) |libc_installation| {
try argv.append("-L");
try argv.append(libc_installation.crt_dir.?);
}
}
var whole_archive = false;
for (self.base.options.objects) |obj| {
if (obj.must_link and !whole_archive) {
try argv.append("-whole-archive");
whole_archive = true;
} else if (!obj.must_link and whole_archive) {
try argv.append("-no-whole-archive");
whole_archive = false;
}
if (obj.loption) {
assert(obj.path[0] == ':');
try argv.append("-l");
}
try argv.append(obj.path);
}
if (whole_archive) {
try argv.append("-no-whole-archive");
whole_archive = false;
}
for (comp.c_object_table.keys()) |key| {
try argv.append(key.status.success.object_path);
}
if (module_obj_path) |p| {
try argv.append(p);
}
// TSAN
if (self.base.options.tsan) {
try argv.append(comp.tsan_static_lib.?.full_object_path);
}
// libc
if (!self.base.options.skip_linker_dependencies and
!self.base.options.link_libc)
{
if (comp.libc_static_lib) |lib| {
try argv.append(lib.full_object_path);
}
}
// stack-protector.
// Related: https://github.com/ziglang/zig/issues/7265
if (comp.libssp_static_lib) |ssp| {
try argv.append(ssp.full_object_path);
}
// Shared libraries.
// Worst-case, we need an --as-needed argument for every lib, as well
// as one before and one after.
try argv.ensureUnusedCapacity(self.base.options.system_libs.keys().len * 2 + 2);
argv.appendAssumeCapacity("--as-needed");
var as_needed = true;
for (self.base.options.system_libs.values()) |lib_info| {
const lib_as_needed = !lib_info.needed;
switch ((@as(u2, @intFromBool(lib_as_needed)) << 1) | @intFromBool(as_needed)) {
0b00, 0b11 => {},
0b01 => {
argv.appendAssumeCapacity("--no-as-needed");
as_needed = false;
},
0b10 => {
argv.appendAssumeCapacity("--as-needed");
as_needed = true;
},
}
argv.appendAssumeCapacity(lib_info.path.?);
}
if (!as_needed) {
argv.appendAssumeCapacity("--as-needed");
as_needed = true;
}
// libc++ dep
if (self.base.options.link_libcpp) {
try argv.append(comp.libcxxabi_static_lib.?.full_object_path);
try argv.append(comp.libcxx_static_lib.?.full_object_path);
}
// libunwind dep
if (self.base.options.link_libunwind) {
try argv.append(comp.libunwind_static_lib.?.full_object_path);
}
// libc dep
if (self.base.options.link_libc) {
if (self.base.options.libc_installation != null) {
const needs_grouping = self.base.options.link_mode == .Static;
if (needs_grouping) try argv.append("--start-group");
try argv.appendSlice(target_util.libcFullLinkFlags(target));
if (needs_grouping) try argv.append("--end-group");
} else if (target.isGnuLibC()) {
for (glibc.libs) |lib| {
const lib_path = try std.fmt.allocPrint(arena, "{s}{c}lib{s}.so.{d}", .{
comp.glibc_so_files.?.dir_path, fs.path.sep, lib.name, lib.sover,
});
try argv.append(lib_path);
}
try argv.append(try comp.get_libc_crt_file(arena, "libc_nonshared.a"));
} else if (target.isMusl()) {
try argv.append(try comp.get_libc_crt_file(arena, switch (self.base.options.link_mode) {
.Static => "libc.a",
.Dynamic => "libc.so",
}));
}
}
// compiler-rt
if (compiler_rt_path) |p| {
try argv.append(p);
}
// crt postlude
if (csu.crtend) |v| try argv.append(v);
if (csu.crtn) |v| try argv.append(v);
}
Compilation.dump_argv(argv.items);
}
const ParseError = error{
UnknownFileType,
InvalidCpuArch,
@@ -3651,8 +3758,10 @@ fn setDynamicSection(self: *Elf, rpaths: []const []const u8) !void {
try self.dynamic.addNeeded(shared_object, self);
}
if (self.base.options.soname) |soname| {
try self.dynamic.setSoname(soname, self);
if (self.isDynLib()) {
if (self.base.options.soname) |soname| {
try self.dynamic.setSoname(soname, self);
}
}
try self.dynamic.setRpath(rpaths, self);