Index: include/clang/Driver/CC1Options.td =================================================================== --- include/clang/Driver/CC1Options.td +++ include/clang/Driver/CC1Options.td @@ -312,6 +312,8 @@ def flto_unit: Flag<["-"], "flto-unit">, HelpText<"Emit IR to support LTO unit features (CFI, whole program vtable opt)">; def fno_lto_unit: Flag<["-"], "fno-lto-unit">; +def fthin_link_bitcode_EQ : Joined<["-"], "fthin-link-bitcode=">, + HelpText<"Write minimized bitcode to for the ThinLTO thin link only">; //===----------------------------------------------------------------------===// // Dependency Output Options Index: include/clang/Frontend/CodeGenOptions.h =================================================================== --- include/clang/Frontend/CodeGenOptions.h +++ include/clang/Frontend/CodeGenOptions.h @@ -186,6 +186,11 @@ /// importing. std::string ThinLTOIndexFile; + /// Name of a file that can optionally be written with minimized bitcode + /// to be used as input for the ThinLTO thin link step, which only needs + /// the summary and module symbol table (and not, e.g. any debug metadata). + std::string ThinLinkBitcodeFile; + /// A list of file names passed with -fcuda-include-gpubinary options to /// forward to CUDA runtime back-end for incorporating them into host-side /// object file. Index: lib/CodeGen/BackendUtil.cpp =================================================================== --- lib/CodeGen/BackendUtil.cpp +++ lib/CodeGen/BackendUtil.cpp @@ -688,7 +688,8 @@ case Backend_EmitBC: if (CodeGenOpts.EmitSummaryIndex) - PerModulePasses.add(createWriteThinLTOBitcodePass(*OS)); + PerModulePasses.add( + createWriteThinLTOBitcodePass(*OS, CodeGenOpts.ThinLinkBitcodeFile)); else PerModulePasses.add( createBitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists)); Index: lib/Frontend/CompilerInvocation.cpp =================================================================== --- lib/Frontend/CompilerInvocation.cpp +++ lib/Frontend/CompilerInvocation.cpp @@ -641,6 +641,7 @@ << A->getAsString(Args) << "-x ir"; Opts.ThinLTOIndexFile = Args.getLastArgValue(OPT_fthinlto_index_EQ); } + Opts.ThinLinkBitcodeFile = Args.getLastArgValue(OPT_fthin_link_bitcode_EQ); Opts.MSVolatile = Args.hasArg(OPT_fms_volatile); Index: test/CodeGen/thin_link_bitcode.c =================================================================== --- /dev/null +++ test/CodeGen/thin_link_bitcode.c @@ -0,0 +1,9 @@ +// RUN: %clang_cc1 -o %t -flto=thin -fthin-link-bitcode=%t.nodebug -triple x86_64-unknown-linux-gnu -emit-llvm-bc -debug-info-kind=limited %s +// RUN: llvm-bcanalyzer -dump %t | FileCheck %s +// RUN: llvm-bcanalyzer -dump %t.nodebug | FileCheck %s --check-prefix=NO_DEBUG +int main (void) { + return 0; +} + +// CHECK: COMPILE_UNIT +// NO_DEBUG-NOT: COMPILE_UNIT