aboutsummaryrefslogtreecommitdiff
path: root/src/build_settings.cpp
diff options
context:
space:
mode:
authorJesse Meyer <jesse.r.meyer@me.com>2026-02-01 09:04:53 -0500
committerJesse Meyer <jesse.r.meyer@me.com>2026-02-03 20:16:20 -0500
commit43ad4a1d9f18a89822e1b9f554adef1a228136db (patch)
treeca7a569d1e5adc6fa3f1d7eb6c1a5fe36b175715 /src/build_settings.cpp
parentf7901cffc9f4983259586241d5b336cdb6377b9c (diff)
Add ThinLTO support via -lto:thin and -lto:thin-files flags
- Add -lto:thin and -lto:thin-files CLI flags with validation - Emit LLVM bitcode (.bc) instead of object files when LTO is enabled - Pass -flto=thin and -flto-jobs to clang/lld linkers - Guard linkage corrections to skip declarations without definitions (required for LTO where declarations appear across modules) - Allow module-per-file with LTO even at higher optimization levels Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Diffstat (limited to 'src/build_settings.cpp')
-rw-r--r--src/build_settings.cpp30
1 files changed, 30 insertions, 0 deletions
diff --git a/src/build_settings.cpp b/src/build_settings.cpp
index 6b8fefa59..e0017baea 100644
--- a/src/build_settings.cpp
+++ b/src/build_settings.cpp
@@ -420,6 +420,12 @@ struct BuildCacheData {
};
+enum LTOKind : i32 {
+ LTO_None,
+ LTO_Thin,
+ LTO_Thin_Files,
+};
+
enum LinkerChoice : i32 {
Linker_Invalid = -1,
Linker_Default = 0,
@@ -560,6 +566,7 @@ struct BuildContext {
bool use_single_module;
bool use_separate_modules;
+ LTOKind lto_kind;
bool module_per_file;
bool cached;
BuildCacheData build_cache_data;
@@ -2030,6 +2037,29 @@ gb_internal void init_build_context(TargetMetrics *cross_target, Subtarget subta
bc->use_separate_modules = false;
}
+ if (bc->lto_kind == LTO_Thin || bc->lto_kind == LTO_Thin_Files) {
+#if LLVM_VERSION_MAJOR < 17
+ gb_printf_err("-lto:thin requires LLVM 17 or later\n");
+ gb_exit(1);
+#endif
+ if (bc->build_mode == BuildMode_Assembly || bc->build_mode == BuildMode_LLVM_IR) {
+ gb_printf_err("-lto:thin is incompatible with -build-mode:asm and -build-mode:llvm-ir\n");
+ gb_exit(1);
+ }
+#if defined(GB_SYSTEM_WINDOWS)
+ if (bc->linker_choice != Linker_lld) {
+ gb_printf_err("-lto:thin on Windows requires -linker:lld\n");
+ gb_exit(1);
+ }
+#endif
+ if (bc->use_single_module) {
+ gb_printf_err("Warning: -lto:thin overrides -use-single-module; separate modules will be used\n");
+ }
+ bc->use_separate_modules = true;
+ if (bc->lto_kind == LTO_Thin_Files) {
+ bc->module_per_file = true;
+ }
+ }
bc->ODIN_VALGRIND_SUPPORT = false;
if (build_context.metrics.os != TargetOs_windows) {