Add two time-trace scope variables.

A time trace scope variable of `ParseDeclarationOrFunctionDefinition`
with the function's source location is added to record the time spent
parsing the function's declaration or definition. Another time trace
scope variable of `ParseFunctionDefinition` is also added to record the
name of the defined function. A release note is added as well.

Reviewed by: Aaron Ballman
Pull request: #65268

Author: MaggieYingYi

clang/docs/ReleaseNotes.rst

@@ -427,6 +427,14 @@ Improvements to Clang's diagnostics
   (or, more commonly, ``NULL`` when the platform defines it as ``__null``) to be more consistent
   with GCC.
 
+Improvements to Clang's time-trace
+----------------------------------
+- Two time-trace scope variables are added. A time trace scope variable of
+  ``ParseDeclarationOrFunctionDefinition`` with the function's source location
+  is added to record the time spent parsing the function's declaration or
+  definition. Another time trace scope variable of ``ParseFunctionDefinition``
+  is also added to record the name of the defined function.
+
 Bug Fixes in This Version
 -------------------------
 - Fixed an issue where a class template specialization whose declaration is

clang/lib/Parse/Parser.cpp

@@ -13,15 +13,16 @@
 #include "clang/Parse/Parser.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
-#include "clang/AST/DeclTemplate.h"
 #include "clang/AST/ASTLambda.h"
+#include "clang/AST/DeclTemplate.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Parse/ParseDiagnostic.h"
 #include "clang/Parse/RAIIObjectsForParser.h"
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/ParsedTemplate.h"
 #include "clang/Sema/Scope.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/TimeProfiler.h"
 using namespace clang;
 
 
@@ -1229,6 +1230,13 @@ Parser::DeclGroupPtrTy Parser::ParseDeclOrFunctionDefInternal(
 Parser::DeclGroupPtrTy Parser::ParseDeclarationOrFunctionDefinition(
     ParsedAttributes &Attrs, ParsedAttributes &DeclSpecAttrs,
     ParsingDeclSpec *DS, AccessSpecifier AS) {
+  // Add an enclosing time trace scope for a bunch of small scopes with
+  // "EvaluateAsConstExpr".
+  llvm::TimeTraceScope TimeScope(
+      "ParseDeclarationOrFunctionDefinition",
+      Tok.getLocation().printToString(
+          Actions.getASTContext().getSourceManager()));
+
   if (DS) {
     return ParseDeclOrFunctionDefInternal(Attrs, DeclSpecAttrs, *DS, AS);
   } else {
@@ -1259,6 +1267,10 @@ Parser::DeclGroupPtrTy Parser::ParseDeclarationOrFunctionDefinition(
 Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
                                       const ParsedTemplateInfo &TemplateInfo,
                                       LateParsedAttrList *LateParsedAttrs) {
+  llvm::TimeTraceScope TimeScope(
+      "ParseFunctionDefinition",
+      Actions.GetNameForDeclarator(D).getName().getAsString());
+
   // Poison SEH identifiers so they are flagged as illegal in function bodies.
   PoisonSEHIdentifiersRAIIObject PoisonSEHIdentifiers(*this, true);
   const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();

clang/test/Driver/check-time-trace-ParseDeclarationOrFunctionDefinition.cpp

@@ -0,0 +1,15 @@
+// RUN: %clangxx -S -ftime-trace -ftime-trace-granularity=0 -o %T/check-time-trace-ParseDeclarationOrFunctionDefinition %s
+// RUN: cat %T/check-time-trace-ParseDeclarationOrFunctionDefinition.json \
+// RUN:   | %python -c 'import json, sys; json.dump(json.loads(sys.stdin.read()), sys.stdout, sort_keys=True, indent=2)' \
+// RUN:   | FileCheck %s
+
+// CHECK-DAG: "name": "ParseDeclarationOrFunctionDefinition"
+// CHECK-DAG: "detail": "{{.*}}check-time-trace-ParseDeclarationOrFunctionDefinition.cpp:15:1"
+// CHECK-DAG: "name": "ParseFunctionDefinition"
+// CHECK-DAG: "detail": "foo"
+// CHECK-DAG: "name": "ParseFunctionDefinition"
+// CHECK-DAG: "detail": "bar"
+
+template <typename T>
+void foo(T) {}
+void bar() { foo(0); }

clang/unittests/Support/TimeProfilerTest.cpp

@@ -177,22 +177,29 @@ constexpr int slow_init_list[] = {1, 1, 2, 3, 5, 8, 13, 21}; // 25th line
   std::string TraceGraph = buildTraceGraph(Json);
   ASSERT_TRUE(TraceGraph == R"(
 Frontend
-| EvaluateAsRValue (<test.cc:8:21>)
-| EvaluateForOverflow (<test.cc:8:21, col:25>)
-| EvaluateForOverflow (<test.cc:8:30, col:32>)
-| EvaluateAsRValue (<test.cc:9:14>)
-| EvaluateForOverflow (<test.cc:9:9, col:14>)
-| isPotentialConstantExpr (slow_namespace::slow_func)
-| EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
-| | EvaluateAsRValue (<test.cc:8:21, col:25>)
-| EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
-| | EvaluateAsRValue (<test.cc:8:21, col:25>)
-| EvaluateAsInitializer (slow_value)
-| EvaluateAsConstantExpr (<test.cc:17:33, col:59>)
-| EvaluateAsConstantExpr (<test.cc:18:11, col:37>)
-| EvaluateAsConstantExpr (<test.cc:23:31, col:57>)
-| EvaluateAsRValue (<test.cc:22:14, line:23:58>)
-| EvaluateAsInitializer (slow_init_list)
+| ParseDeclarationOrFunctionDefinition (test.cc:2:1)
+| ParseDeclarationOrFunctionDefinition (test.cc:6:1)
+| | ParseFunctionDefinition (slow_func)
+| | | EvaluateAsRValue (<test.cc:8:21>)
+| | | EvaluateForOverflow (<test.cc:8:21, col:25>)
+| | | EvaluateForOverflow (<test.cc:8:30, col:32>)
+| | | EvaluateAsRValue (<test.cc:9:14>)
+| | | EvaluateForOverflow (<test.cc:9:9, col:14>)
+| | | isPotentialConstantExpr (slow_namespace::slow_func)
+| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
+| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
+| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
+| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
+| ParseDeclarationOrFunctionDefinition (test.cc:16:1)
+| | ParseFunctionDefinition (slow_test)
+| | | EvaluateAsInitializer (slow_value)
+| | | EvaluateAsConstantExpr (<test.cc:17:33, col:59>)
+| | | EvaluateAsConstantExpr (<test.cc:18:11, col:37>)
+| ParseDeclarationOrFunctionDefinition (test.cc:22:1)
+| | EvaluateAsConstantExpr (<test.cc:23:31, col:57>)
+| | EvaluateAsRValue (<test.cc:22:14, line:23:58>)
+| ParseDeclarationOrFunctionDefinition (test.cc:25:1)
+| | EvaluateAsInitializer (slow_init_list)
 | PerformPendingInstantiations
 )");
 
@@ -213,8 +220,9 @@ struct {
   std::string TraceGraph = buildTraceGraph(Json);
   ASSERT_TRUE(TraceGraph == R"(
 Frontend
-| isIntegerConstantExpr (<test.c:3:18>)
-| EvaluateKnownConstIntCheckOverflow (<test.c:3:18>)
+| ParseDeclarationOrFunctionDefinition (test.c:2:1)
+| | isIntegerConstantExpr (<test.c:3:18>)
+| | EvaluateKnownConstIntCheckOverflow (<test.c:3:18>)
 | PerformPendingInstantiations
 )");