Skip to content

Compilation: fix compiler_rt and ubsan_rt strategy logic #24866

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
andrewrk merged 1 commit into from
Aug 18, 2025
Merged

Compilation: fix compiler_rt and ubsan_rt strategy logic #24866

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
80 changes: 50 additions & 30 deletions src/Compilation.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1983,13 +1983,21 @@ pub fn create(gpa: Allocator, arena: Allocator, diag: *CreateDiagnostic, options
if (options.skip_linker_dependencies) break :s .none;
const want = options.want_compiler_rt orelse is_exe_or_dyn_lib;
if (!want) break :s .none;
if (have_zcu and target_util.canBuildLibCompilerRt(target, use_llvm, build_options.have_llvm and use_llvm)) {
const need_llvm = switch (target_util.canBuildLibCompilerRt(target)) {
.no => break :s .none, // impossible to build
.yes => false,
.llvm_only => true,
};
if (have_zcu and (!need_llvm or use_llvm)) {
if (output_mode == .Obj) break :s .zcu;
if (switch (target_util.zigBackend(target, use_llvm)) {
else => false,
.stage2_aarch64, .stage2_x86_64 => target.ofmt == .coff,
}) break :s if (is_exe_or_dyn_lib) .dyn_lib else .zcu;
switch (target_util.zigBackend(target, use_llvm)) {
else => {},
.stage2_aarch64, .stage2_x86_64 => if (target.ofmt == .coff) {
break :s if (is_exe_or_dyn_lib) .dyn_lib else .zcu;
},
}
}
if (need_llvm and !build_options.have_llvm) break :s .none; // impossible to build without llvm
if (is_exe_or_dyn_lib) break :s .lib;
break :s .obj;
};
Expand Down Expand Up @@ -2031,14 +2039,22 @@ pub fn create(gpa: Allocator, arena: Allocator, diag: *CreateDiagnostic, options
}

// unlike compiler_rt, we always want to go through the `_ = @import("ubsan-rt")`
// approach, since the ubsan runtime uses quite a lot of the standard library
// and this reduces unnecessary bloat.
// approach if possible, since the ubsan runtime uses quite a lot of the standard
// library and this reduces unnecessary bloat.
const ubsan_rt_strat: RtStrat = s: {
const can_build_ubsan_rt = target_util.canBuildLibUbsanRt(target, use_llvm, build_options.have_llvm);
const want_ubsan_rt = options.want_ubsan_rt orelse (can_build_ubsan_rt and any_sanitize_c == .full and is_exe_or_dyn_lib);
if (!want_ubsan_rt) break :s .none;
if (options.skip_linker_dependencies) break :s .none;
if (have_zcu and target_util.canBuildLibUbsanRt(target, use_llvm, build_options.have_llvm and use_llvm)) break :s .zcu;
const want = options.want_ubsan_rt orelse (any_sanitize_c == .full and is_exe_or_dyn_lib);
if (!want) break :s .none;
const need_llvm = switch (target_util.canBuildLibUbsanRt(target)) {
.no => break :s .none, // impossible to build
.yes => false,
.llvm_only => true,
.llvm_lld_only => if (!options.config.use_lld) {
break :s .none; // only LLD can handle ubsan-rt for this target
} else true,
};
if (have_zcu and (!need_llvm or use_llvm)) break :s .zcu;
if (need_llvm and !build_options.have_llvm) break :s .none; // impossible to build without llvm
if (is_exe_or_dyn_lib) break :s .lib;
break :s .obj;
};
Expand Down Expand Up @@ -2476,8 +2492,6 @@ pub fn create(gpa: Allocator, arena: Allocator, diag: *CreateDiagnostic, options
};
errdefer comp.destroy();

const can_build_compiler_rt = target_util.canBuildLibCompilerRt(target, use_llvm, build_options.have_llvm);

// Add a `CObject` for each `c_source_files`.
try comp.c_object_table.ensureTotalCapacity(gpa, options.c_source_files.len);
for (options.c_source_files) |c_source_file| {
Expand Down Expand Up @@ -2637,33 +2651,39 @@ pub fn create(gpa: Allocator, arena: Allocator, diag: *CreateDiagnostic, options
comp.queued_jobs.libtsan = true;
}

if (can_build_compiler_rt) {
if (comp.compiler_rt_strat == .lib) {
switch (comp.compiler_rt_strat) {
.none, .zcu => {},
.lib => {
log.debug("queuing a job to build compiler_rt_lib", .{});
comp.queued_jobs.compiler_rt_lib = true;
} else if (comp.compiler_rt_strat == .obj) {
},
.obj => {
log.debug("queuing a job to build compiler_rt_obj", .{});
// In this case we are making a static library, so we ask
// for a compiler-rt object to put in it.
comp.queued_jobs.compiler_rt_obj = true;
} else if (comp.compiler_rt_strat == .dyn_lib) {
},
.dyn_lib => {
// hack for stage2_x86_64 + coff
log.debug("queuing a job to build compiler_rt_dyn_lib", .{});
comp.queued_jobs.compiler_rt_dyn_lib = true;
}
},
}

if (comp.ubsan_rt_strat == .lib) {
switch (comp.ubsan_rt_strat) {
.none, .zcu => {},
.lib => {
log.debug("queuing a job to build ubsan_rt_lib", .{});
comp.queued_jobs.ubsan_rt_lib = true;
} else if (comp.ubsan_rt_strat == .obj) {
},
.obj => {
log.debug("queuing a job to build ubsan_rt_obj", .{});
comp.queued_jobs.ubsan_rt_obj = true;
}
},
.dyn_lib => unreachable, // hack for compiler_rt only
}

if (is_exe_or_dyn_lib and comp.config.any_fuzz) {
log.debug("queuing a job to build libfuzzer", .{});
comp.queued_jobs.fuzzer_lib = true;
}
if (is_exe_or_dyn_lib and comp.config.any_fuzz) {
log.debug("queuing a job to build libfuzzer", .{});
comp.queued_jobs.fuzzer_lib = true;
}
}

Expand Down Expand Up @@ -7638,11 +7658,11 @@ pub fn dump_argv(argv: []const []const u8) void {
const stderr = std.debug.lockStderrWriter(&buffer);
defer std.debug.unlockStderrWriter();
nosuspend {
for (argv) |arg| {
for (argv, 0..) |arg, i| {
if (i != 0) stderr.writeByte(' ') catch return;
stderr.writeAll(arg) catch return;
(stderr.writableArray(1) catch return)[0] = ' ';
}
stderr.buffer[stderr.end - 1] = '\n';
stderr.writeByte('\n') catch return;
}
}

Expand Down
36 changes: 17 additions & 19 deletions src/target.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -351,43 +351,41 @@ pub fn defaultCompilerRtOptimizeMode(target: *const std.Target) std.builtin.Opti
}
}

pub fn canBuildLibCompilerRt(target: *const std.Target, use_llvm: bool, have_llvm: bool) bool {
pub fn canBuildLibCompilerRt(target: *const std.Target) enum { no, yes, llvm_only } {
switch (target.os.tag) {
.plan9 => return false,
.plan9 => return .no,
else => {},
}
switch (target.cpu.arch) {
.spirv32, .spirv64 => return false,
.spirv32, .spirv64 => return .no,
// Remove this once https://github.com/ziglang/zig/issues/23714 is fixed
.amdgcn => return false,
.amdgcn => return .no,
else => {},
}
return switch (zigBackend(target, use_llvm)) {
.stage2_aarch64 => true,
.stage2_llvm => true,
return switch (zigBackend(target, false)) {
.stage2_aarch64 => .yes,
.stage2_x86_64 => switch (target.ofmt) {
.elf, .macho => true,
else => have_llvm,
.elf, .macho => .yes,
else => .llvm_only,
},
else => have_llvm,
else => .llvm_only,
};
}

pub fn canBuildLibUbsanRt(target: *const std.Target, use_llvm: bool, have_llvm: bool) bool {
pub fn canBuildLibUbsanRt(target: *const std.Target) enum { no, yes, llvm_only, llvm_lld_only } {
switch (target.cpu.arch) {
.spirv32, .spirv64 => return false,
.spirv32, .spirv64 => return .no,
// Remove this once https://github.com/ziglang/zig/issues/23715 is fixed
.nvptx, .nvptx64 => return false,
.nvptx, .nvptx64 => return .no,
else => {},
}
return switch (zigBackend(target, use_llvm)) {
.stage2_llvm => true,
.stage2_wasm => false,
return switch (zigBackend(target, false)) {
.stage2_wasm => .llvm_lld_only,
.stage2_x86_64 => switch (target.ofmt) {
.elf, .macho => true,
else => have_llvm,
.elf, .macho => .yes,
else => .llvm_only,
},
else => have_llvm,
else => .llvm_only,
};
}

Expand Down