[Time-report] Add a flag -ftime-report={per-pass,per-pass-run} to control the pass timing aggregation

Currently, -ftime-report + new pass manager emits one line of report for each
pass run. This potentially causes huge output text especially with regular LTO
or large single file (Obeserved in private tests and was reported in D51276).
The behaviour of -ftime-report + legacy pass manager is
emitting one line of report for each pass object which has relatively reasonable
text output size. This patch adds a flag `-ftime-report=` to control time report
aggregation for new pass manager.

The flag is for new pass manager only. Using it with legacy pass manager gives
an error. It is a driver and cc1 flag. `per-pass` is the new default so
`-ftime-report` is aliased to `-ftime-report=per-pass`. Before this patch,
functionality-wise `-ftime-report` is aliased to `-ftime-report=per-pass-run`.

* Adds an boolean variable TimePassesHandler::PerRun to control per-pass vs per-pass-run.
* Adds a new clang CodeGen flag CodeGenOptions::TimePassesPerRun to work with the existing CodeGenOptions::TimePasses.
* Remove FrontendOptions::ShowTimers, its uses are replaced by the existing CodeGenOptions::TimePasses.
* Remove FrontendTimesIsEnabled (It was introduced in D45619 which was largely reverted.)

Differential Revision: https://reviews.llvm.org/D92436

1 files changed, 20 insertions, 18 deletions

diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
index 1e935bb..5b23b6d 100644
--- a/clang/lib/CodeGen/CodeGenAction.cpp
+++ b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -122,6 +122,8 @@ namespace clang {
     /// can happen when Clang plugins trigger additional AST deserialization.
     bool IRGenFinished = false;
 
+    bool TimerIsEnabled = false;
+
     std::unique_ptr<CodeGenerator> Gen;
 
     SmallVector<LinkModule, 4> LinkModules;
@@ -136,8 +138,7 @@ namespace clang {
                     const PreprocessorOptions &PPOpts,
                     const CodeGenOptions &CodeGenOpts,
                     const TargetOptions &TargetOpts,
-                    const LangOptions &LangOpts, bool TimePasses,
-                    const std::string &InFile,
+                    const LangOptions &LangOpts, const std::string &InFile,
                     SmallVector<LinkModule, 4> LinkModules,
                     std::unique_ptr<raw_pwrite_stream> OS, LLVMContext &C,
                     CoverageSourceInfo *CoverageInfo = nullptr)
@@ -149,8 +150,9 @@ namespace clang {
           Gen(CreateLLVMCodeGen(Diags, InFile, HeaderSearchOpts, PPOpts,
                                 CodeGenOpts, C, CoverageInfo)),
           LinkModules(std::move(LinkModules)) {
-      FrontendTimesIsEnabled = TimePasses;
-      llvm::TimePassesIsEnabled = TimePasses;
+      TimerIsEnabled = CodeGenOpts.TimePasses;
+      llvm::TimePassesIsEnabled = CodeGenOpts.TimePasses;
+      llvm::TimePassesPerRun = CodeGenOpts.TimePassesPerRun;
     }
 
     // This constructor is used in installing an empty BackendConsumer
@@ -161,7 +163,7 @@ namespace clang {
                     const PreprocessorOptions &PPOpts,
                     const CodeGenOptions &CodeGenOpts,
                     const TargetOptions &TargetOpts,
-                    const LangOptions &LangOpts, bool TimePasses,
+                    const LangOptions &LangOpts,
                     SmallVector<LinkModule, 4> LinkModules, LLVMContext &C,
                     CoverageSourceInfo *CoverageInfo = nullptr)
         : Diags(Diags), Action(Action), HeaderSearchOpts(HeaderSearchOpts),
@@ -172,8 +174,9 @@ namespace clang {
           Gen(CreateLLVMCodeGen(Diags, "", HeaderSearchOpts, PPOpts,
                                 CodeGenOpts, C, CoverageInfo)),
           LinkModules(std::move(LinkModules)) {
-      FrontendTimesIsEnabled = TimePasses;
-      llvm::TimePassesIsEnabled = TimePasses;
+      TimerIsEnabled = CodeGenOpts.TimePasses;
+      llvm::TimePassesIsEnabled = CodeGenOpts.TimePasses;
+      llvm::TimePassesPerRun = CodeGenOpts.TimePassesPerRun;
     }
     llvm::Module *getModule() const { return Gen->GetModule(); }
     std::unique_ptr<llvm::Module> takeModule() {
@@ -191,12 +194,12 @@ namespace clang {
 
       Context = &Ctx;
 
-      if (FrontendTimesIsEnabled)
+      if (TimerIsEnabled)
         LLVMIRGeneration.startTimer();
 
       Gen->Initialize(Ctx);
 
-      if (FrontendTimesIsEnabled)
+      if (TimerIsEnabled)
         LLVMIRGeneration.stopTimer();
     }
 
@@ -206,7 +209,7 @@ namespace clang {
                                      "LLVM IR generation of declaration");
 
       // Recurse.
-      if (FrontendTimesIsEnabled) {
+      if (TimerIsEnabled) {
         LLVMIRGenerationRefCount += 1;
         if (LLVMIRGenerationRefCount == 1)
           LLVMIRGeneration.startTimer();
@@ -214,7 +217,7 @@ namespace clang {
 
       Gen->HandleTopLevelDecl(D);
 
-      if (FrontendTimesIsEnabled) {
+      if (TimerIsEnabled) {
         LLVMIRGenerationRefCount -= 1;
         if (LLVMIRGenerationRefCount == 0)
           LLVMIRGeneration.stopTimer();
@@ -227,12 +230,12 @@ namespace clang {
       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
                                      Context->getSourceManager(),
                                      "LLVM IR generation of inline function");
-      if (FrontendTimesIsEnabled)
+      if (TimerIsEnabled)
         LLVMIRGeneration.startTimer();
 
       Gen->HandleInlineFunctionDefinition(D);
 
-      if (FrontendTimesIsEnabled)
+      if (TimerIsEnabled)
         LLVMIRGeneration.stopTimer();
     }
 
@@ -280,7 +283,7 @@ namespace clang {
       {
         llvm::TimeTraceScope TimeScope("Frontend");
         PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
-        if (FrontendTimesIsEnabled) {
+        if (TimerIsEnabled) {
           LLVMIRGenerationRefCount += 1;
           if (LLVMIRGenerationRefCount == 1)
             LLVMIRGeneration.startTimer();
@@ -288,7 +291,7 @@ namespace clang {
 
         Gen->HandleTranslationUnit(C);
 
-        if (FrontendTimesIsEnabled) {
+        if (TimerIsEnabled) {
           LLVMIRGenerationRefCount -= 1;
           if (LLVMIRGenerationRefCount == 0)
             LLVMIRGeneration.stopTimer();
@@ -967,8 +970,8 @@ CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
   std::unique_ptr<BackendConsumer> Result(new BackendConsumer(
       BA, CI.getDiagnostics(), CI.getHeaderSearchOpts(),
       CI.getPreprocessorOpts(), CI.getCodeGenOpts(), CI.getTargetOpts(),
-      CI.getLangOpts(), CI.getFrontendOpts().ShowTimers, std::string(InFile),
-      std::move(LinkModules), std::move(OS), *VMContext, CoverageInfo));
+      CI.getLangOpts(), std::string(InFile), std::move(LinkModules),
+      std::move(OS), *VMContext, CoverageInfo));
   BEConsumer = Result.get();
 
   // Enable generating macro debug info only when debug info is not disabled and
@@ -1115,7 +1118,6 @@ void CodeGenAction::ExecuteAction() {
     BackendConsumer Result(BA, CI.getDiagnostics(), CI.getHeaderSearchOpts(),
                            CI.getPreprocessorOpts(), CI.getCodeGenOpts(),
                            CI.getTargetOpts(), CI.getLangOpts(),
-                           CI.getFrontendOpts().ShowTimers,
                            std::move(LinkModules), *VMContext, nullptr);
     // PR44896: Force DiscardValueNames as false. DiscardValueNames cannot be
     // true here because the valued names are needed for reading textual IR.