Adds `-ftime-trace` option to clang that produces Chrome `chrome://tracing` compatible JSON profiling output dumps.

This change adds hierarchical "time trace" profiling blocks that can be visualized in Chrome, in a "flame chart" style. Each profiling block can have a "detail" string that for example indicates the file being processed, template name being instantiated, function being optimized etc.

This is taken from GitHub PR: https://github.com/aras-p/llvm-project-20170507/pull/2

Patch by Aras Pranckevičius.

Differential Revision: https://reviews.llvm.org/D58675

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@357340 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 16 insertions, 0 deletions

diff --git a/lib/Parse/ParseAST.cpp b/lib/Parse/ParseAST.cpp
index 5ecfc7d66f..3efd893e49 100644
--- a/lib/Parse/ParseAST.cpp
+++ b/lib/Parse/ParseAST.cpp
@@ -22,6 +22,7 @@
 #include "clang/Sema/SemaConsumer.h"
 #include "clang/Sema/TemplateInstCallback.h"
 #include "llvm/Support/CrashRecoveryContext.h"
+#include "llvm/Support/TimeProfiler.h"
 #include <cstdio>
 #include <memory>
 
@@ -150,6 +151,7 @@ void clang::ParseAST(Sema &S, bool PrintStats, bool SkipFunctionBodies) {
   bool HaveLexer = S.getPreprocessor().getCurrentLexer();
 
   if (HaveLexer) {
+    llvm::TimeTraceScope TimeScope("Frontend", StringRef(""));
     P.Initialize();
     Parser::DeclGroupPtrTy ADecl;
     for (bool AtEOF = P.ParseFirstTopLevelDecl(ADecl); !AtEOF;
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index fe9fa1059a..de481e8879 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -24,6 +24,7 @@
 #include "clang/Sema/ParsedTemplate.h"
 #include "clang/Sema/Scope.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/Support/TimeProfiler.h"
 
 using namespace clang;
 
@@ -3114,6 +3115,12 @@ void Parser::ParseCXXMemberSpecification(SourceLocation RecordLoc,
          TagType == DeclSpec::TST_union  ||
          TagType == DeclSpec::TST_class) && "Invalid TagType!");
 
+  llvm::TimeTraceScope TimeScope("ParseClass", [&]() {
+    if (auto *TD = dyn_cast_or_null<NamedDecl>(TagDecl))
+      return TD->getQualifiedNameAsString();
+    return std::string("<anonymous>");
+  });
+
   PrettyDeclStackTraceEntry CrashInfo(Actions.Context, TagDecl, RecordLoc,
                                       "parsing struct/union/class body");
 
diff --git a/lib/Parse/ParseTemplate.cpp b/lib/Parse/ParseTemplate.cpp
index 97826695e2..d028c8f4c3 100644
--- a/lib/Parse/ParseTemplate.cpp
+++ b/lib/Parse/ParseTemplate.cpp
@@ -18,6 +18,7 @@
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/ParsedTemplate.h"
 #include "clang/Sema/Scope.h"
+#include "llvm/Support/TimeProfiler.h"
 using namespace clang;
 
 /// Parse a template declaration, explicit instantiation, or
@@ -231,6 +232,12 @@ Decl *Parser::ParseSingleDeclarationAfterTemplate(
     return nullptr;
   }
 
+  llvm::TimeTraceScope TimeScope("ParseTemplate", [&]() {
+    return DeclaratorInfo.getIdentifier() != nullptr
+               ? DeclaratorInfo.getIdentifier()->getName()
+               : "<unknown>";
+  });
+
   LateParsedAttrList LateParsedAttrs(true);
   if (DeclaratorInfo.isFunctionDeclarator())
     MaybeParseGNUAttributes(DeclaratorInfo, &LateParsedAttrs);