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

llvm-svn: 357340

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/Serialization/GlobalModuleIndex.cpp b/clang/lib/Serialization/GlobalModuleIndex.cpp
index c5091bbbe49..ebcfa9f5067 100644
--- a/clang/lib/Serialization/GlobalModuleIndex.cpp
+++ b/clang/lib/Serialization/GlobalModuleIndex.cpp
@@ -10,6 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+
 #include "ASTReaderInternals.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Lex/HeaderSearch.h"
@@ -28,6 +29,7 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/OnDiskHashTable.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/TimeProfiler.h"
 #include <cstdio>
 using namespace clang;
 using namespace serialization;
@@ -126,6 +128,7 @@ GlobalModuleIndex::GlobalModuleIndex(std::unique_ptr<llvm::MemoryBuffer> Buffer,
                                      llvm::BitstreamCursor Cursor)
     : Buffer(std::move(Buffer)), IdentifierIndex(), NumIdentifierLookups(),
       NumIdentifierLookupHits() {
+  llvm::TimeTraceScope TimeScope("Module LoadIndex", StringRef(""));
   // Read the global index.
   bool InGlobalIndexBlock = false;
   bool Done = false;
@@ -739,6 +742,7 @@ bool GlobalModuleIndexBuilder::writeIndex(llvm::BitstreamWriter &Stream) {
   }
 
   using namespace llvm;
+  llvm::TimeTraceScope TimeScope("Module WriteIndex", StringRef(""));
 
   // Emit the file header.
   Stream.Emit((unsigned)'B', 8);