[ThinLTO] Leverage new in-place renaming support

Due to the new in-place renaming support added in r257174, we no
longer need to invoke ThinLTO global renaming from clang. It will be
invoked on the module in the FunctionImport pass (by an immediately
following llvm commit).

As a result, we don't need to load the FunctionInfoIndex as early,
so that is moved down into EmitAssemblyHelper::EmitAssembly.

llvm-svn: 257179

1 files changed, 33 insertions, 16 deletions

diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 7032d00386f..6d746c25eed 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -28,6 +28,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Object/FunctionIndexObjectFile.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/TargetRegistry.h"
@@ -54,7 +55,6 @@ class EmitAssemblyHelper {
   const clang::TargetOptions &TargetOpts;
   const LangOptions &LangOpts;
   Module *TheModule;
-  std::unique_ptr<FunctionInfoIndex> FunctionIndex;
 
   Timer CodeGenerationTime;
 
@@ -97,7 +97,7 @@ private:
     return PerFunctionPasses;
   }
 
-  void CreatePasses();
+  void CreatePasses(FunctionInfoIndex *FunctionIndex);
 
   /// Generates the TargetMachine.
   /// Returns Null if it is unable to create the target machine.
@@ -117,12 +117,11 @@ private:
 public:
   EmitAssemblyHelper(DiagnosticsEngine &_Diags, const CodeGenOptions &CGOpts,
                      const clang::TargetOptions &TOpts,
-                     const LangOptions &LOpts, Module *M,
-                     std::unique_ptr<FunctionInfoIndex> Index)
+                     const LangOptions &LOpts, Module *M)
       : Diags(_Diags), CodeGenOpts(CGOpts), TargetOpts(TOpts), LangOpts(LOpts),
-        TheModule(M), FunctionIndex(std::move(Index)),
-        CodeGenerationTime("Code Generation Time"), CodeGenPasses(nullptr),
-        PerModulePasses(nullptr), PerFunctionPasses(nullptr) {}
+        TheModule(M), CodeGenerationTime("Code Generation Time"),
+        CodeGenPasses(nullptr), PerModulePasses(nullptr),
+        PerFunctionPasses(nullptr) {}
 
   ~EmitAssemblyHelper() {
     delete CodeGenPasses;
@@ -278,7 +277,7 @@ static void addSymbolRewriterPass(const CodeGenOptions &Opts,
   MPM->add(createRewriteSymbolsPass(DL));
 }
 
-void EmitAssemblyHelper::CreatePasses() {
+void EmitAssemblyHelper::CreatePasses(FunctionInfoIndex *FunctionIndex) {
   if (CodeGenOpts.DisableLLVMPasses)
     return;
 
@@ -332,9 +331,8 @@ void EmitAssemblyHelper::CreatePasses() {
 
   // If we are performing a ThinLTO importing compile, invoke the LTO
   // pipeline and pass down the in-memory function index.
-  if (!CodeGenOpts.ThinLTOIndexFile.empty()) {
-    assert(FunctionIndex && "Expected non-empty function index");
-    PMBuilder.FunctionIndex = FunctionIndex.get();
+  if (FunctionIndex) {
+    PMBuilder.FunctionIndex = FunctionIndex;
     PMBuilder.populateLTOPassManager(*MPM);
     return;
   }
@@ -642,7 +640,28 @@ void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
     return;
   if (TM)
     TheModule->setDataLayout(TM->createDataLayout());
-  CreatePasses();
+
+  // If we are performing a ThinLTO importing compile, load the function
+  // index into memory and pass it into CreatePasses, which will add it
+  // to the PassManagerBuilder and invoke LTO passes.
+  std::unique_ptr<FunctionInfoIndex> FunctionIndex;
+  if (!CodeGenOpts.ThinLTOIndexFile.empty()) {
+    ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr =
+        llvm::getFunctionIndexForFile(CodeGenOpts.ThinLTOIndexFile,
+                                      [&](const DiagnosticInfo &DI) {
+                                        TheModule->getContext().diagnose(DI);
+                                      });
+    if (std::error_code EC = IndexOrErr.getError()) {
+      std::string Error = EC.message();
+      errs() << "Error loading index file '" << CodeGenOpts.ThinLTOIndexFile
+             << "': " << Error << "\n";
+      return;
+    }
+    FunctionIndex = std::move(IndexOrErr.get());
+    assert(FunctionIndex && "Expected non-empty function index");
+  }
+
+  CreatePasses(FunctionIndex.get());
 
   switch (Action) {
   case Backend_EmitNothing:
@@ -695,10 +714,8 @@ void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
                               const clang::TargetOptions &TOpts,
                               const LangOptions &LOpts, StringRef TDesc,
                               Module *M, BackendAction Action,
-                              raw_pwrite_stream *OS,
-                              std::unique_ptr<FunctionInfoIndex> Index) {
-  EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, LOpts, M,
-                               std::move(Index));
+                              raw_pwrite_stream *OS) {
+  EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, LOpts, M);
 
   AsmHelper.EmitAssembly(Action, OS);