From 43ad4a1d9f18a89822e1b9f554adef1a228136db Mon Sep 17 00:00:00 2001 From: Jesse Meyer Date: Sun, 1 Feb 2026 09:04:53 -0500 Subject: 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 --- src/main.cpp | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'src/main.cpp') diff --git a/src/main.cpp b/src/main.cpp index 624869e65..feaf55f4b 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -413,6 +413,7 @@ enum BuildFlagKind { BuildFlag_Tilde, BuildFlag_Sanitize, + BuildFlag_LTO, #if defined(GB_SYSTEM_WINDOWS) BuildFlag_IgnoreVsSearch, @@ -643,6 +644,7 @@ gb_internal bool parse_build_flags(Array args) { #endif add_flag(&build_flags, BuildFlag_Sanitize, str_lit("sanitize"), BuildFlagParam_String, Command__does_build, true); + add_flag(&build_flags, BuildFlag_LTO, str_lit("lto"), BuildFlagParam_String, Command__does_build); #if defined(GB_SYSTEM_WINDOWS) @@ -1636,6 +1638,18 @@ gb_internal bool parse_build_flags(Array args) { } break; + case BuildFlag_LTO: + GB_ASSERT(value.kind == ExactValue_String); + if (str_eq_ignore_case(value.value_string, str_lit("thin"))) { + build_context.lto_kind = LTO_Thin; + } else if (str_eq_ignore_case(value.value_string, str_lit("thin-files"))) { + build_context.lto_kind = LTO_Thin_Files; + } else { + gb_printf_err("-lto: options are 'thin' and 'thin-files'\n"); + bad_flags = true; + } + break; + #if defined(GB_SYSTEM_WINDOWS) case BuildFlag_IgnoreVsSearch: { -- cgit v1.2.3