[ThinLTO] Clang support for emitting minimized bitcode for thin link
Summary:
Clang companion patch to LLVM patch D31027, which adds support
for emitting minimized bitcode file for use in the thin link step.
Add a cc1 option -fthin-link-bitcode=<file> to trigger this behavior.
Depends on D31027.
Reviewers: mehdi_amini, pcc
Subscribers: cfe-commits, Prazek
Differential Revision: https://reviews.llvm.org/D31050
llvm-svn: 298639
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 35c31a0..35de1a45 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -686,13 +686,28 @@
CodeGenPasses.add(
createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
+ std::unique_ptr<raw_fd_ostream> ThinLinkOS;
+
switch (Action) {
case Backend_EmitNothing:
break;
case Backend_EmitBC:
- if (CodeGenOpts.EmitSummaryIndex)
- PerModulePasses.add(createWriteThinLTOBitcodePass(*OS));
+ if (CodeGenOpts.EmitSummaryIndex) {
+ if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
+ std::error_code EC;
+ ThinLinkOS.reset(new llvm::raw_fd_ostream(
+ CodeGenOpts.ThinLinkBitcodeFile, EC,
+ llvm::sys::fs::F_None));
+ if (EC) {
+ Diags.Report(diag::err_fe_unable_to_open_output) << CodeGenOpts.ThinLinkBitcodeFile
+ << EC.message();
+ return;
+ }
+ }
+ PerModulePasses.add(
+ createWriteThinLTOBitcodePass(*OS, ThinLinkOS.get()));
+ }
else
PerModulePasses.add(
createBitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists));