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
diff --git a/clang/lib/Serialization/GlobalModuleIndex.cpp b/clang/lib/Serialization/GlobalModuleIndex.cpp
index c5091bb..ebcfa9f 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 @@
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 @@
}
using namespace llvm;
+ llvm::TimeTraceScope TimeScope("Module WriteIndex", StringRef(""));
// Emit the file header.
Stream.Emit((unsigned)'B', 8);