[PGO] Instrument only base constructors and destructors.

Constructors and destructors may be represented by several functions
in IR. Only base structors correspond to source code, others are
small pieces of code and eventually call the base variant. In this
case instrumentation of non-base structors has little sense, this
fix remove it. Now profile data of a declaration corresponds to
exactly one function in IR, it agrees with the current logic of the
profile data loading.

This change fixes PR24996.

Differential Revision: http://reviews.llvm.org/D15158

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@254876 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index 87165fe13a4022f9e5cc66acbc40d48f400971b7..ba2941e9df4ad496a86e56c063fa9d46c9e0ed3e 100644 (file)
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -1241,7 +1241,7 @@ CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
   if (IsLambdaConversionToBlock)
     EmitLambdaBlockInvokeBody();
   else {
-    PGO.assignRegionCounters(blockDecl, fn);
+    PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
     incrementProfileCounter(blockDecl->getBody());
     EmitStmt(blockDecl->getBody());
   }

diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index 6865f974fc2dd2aa37d73908389b6d7480757be6..2d5991b71fca801c9afc676bcd5ed93548084291 100644 (file)
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -557,7 +557,7 @@ static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
 /// its pointer, name, and types registered in the class struture.
 void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
   StartObjCMethod(OMD, OMD->getClassInterface());
-  PGO.assignRegionCounters(OMD, CurFn);
+  PGO.assignRegionCounters(GlobalDecl(OMD), CurFn);
   assert(isa<CompoundStmt>(OMD->getBody()));
   incrementProfileCounter(OMD->getBody());
   EmitCompoundStmtWithoutScope(*cast<CompoundStmt>(OMD->getBody()));

diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 5ebcdf654ab572d32c759b5c596b7d5f934cfa19..1cbdeffd7c4f12fd538eb80b64d857be35ef51b8 100644 (file)
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -2170,7 +2170,7 @@ CodeGenFunction::GenerateCapturedStmtFunction(const CapturedStmt &S) {
     CXXThisValue = EmitLoadOfLValue(ThisLValue, Loc).getScalarVal();
   }
 
-  PGO.assignRegionCounters(CD, F);
+  PGO.assignRegionCounters(GlobalDecl(CD), F);
   CapturedStmtInfo->EmitBody(*this, CD->getBody());
   FinishFunction(CD->getBodyRBrace());
 

diff --git a/lib/CodeGen/CGStmtOpenMP.cpp b/lib/CodeGen/CGStmtOpenMP.cpp
index a6099cabb59f184135f3377968c14e413a79134c..d86cdc7110e4fc1fa0e90a14f46f122c97d96ef3 100644 (file)
--- a/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/lib/CodeGen/CGStmtOpenMP.cpp
@@ -185,7 +185,7 @@ CodeGenFunction::GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S) {
     ++Cnt, ++I;
   }
 
-  PGO.assignRegionCounters(CD, F);
+  PGO.assignRegionCounters(GlobalDecl(CD), F);
   CapturedStmtInfo->EmitBody(*this, CD->getBody());
   FinishFunction(CD->getBodyRBrace());
 

diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 31a93e001f8705e3a264d5447b909feaa8838096..048a04328fc23c30d5219ed6b7cb5b342b360de1 100644 (file)
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -957,8 +957,7 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   StartFunction(GD, ResTy, Fn, FnInfo, Args, Loc, BodyRange.getBegin());
 
   // Generate the body of the function.
-  PGO.checkGlobalDecl(GD);
-  PGO.assignRegionCounters(GD.getDecl(), CurFn);
+  PGO.assignRegionCounters(GD, CurFn);
   if (isa<CXXDestructorDecl>(FD))
     EmitDestructorBody(Args);
   else if (isa<CXXConstructorDecl>(FD))

diff --git a/lib/CodeGen/CodeGenPGO.cpp b/lib/CodeGen/CodeGenPGO.cpp
index 403380efcb4637b65a485339a7ce5869557b7be5..38774332f31d687bb8817fb7640997640cc0366e 100644 (file)
--- a/lib/CodeGen/CodeGenPGO.cpp
+++ b/lib/CodeGen/CodeGenPGO.cpp
@@ -605,27 +605,24 @@ uint64_t PGOHash::finalize() {
   return endian::read<uint64_t, little, unaligned>(Result);
 }
 
-void CodeGenPGO::checkGlobalDecl(GlobalDecl GD) {
-  // Make sure we only emit coverage mapping for one constructor/destructor.
-  // Clang emits several functions for the constructor and the destructor of
-  // a class. Every function is instrumented, but we only want to provide
-  // coverage for one of them. Because of that we only emit the coverage mapping
-  // for the base constructor/destructor.
-  if ((isa<CXXConstructorDecl>(GD.getDecl()) &&
-       GD.getCtorType() != Ctor_Base) ||
-      (isa<CXXDestructorDecl>(GD.getDecl()) &&
-       GD.getDtorType() != Dtor_Base)) {
-    SkipCoverageMapping = true;
-  }
-}
-
-void CodeGenPGO::assignRegionCounters(const Decl *D, llvm::Function *Fn) {
+void CodeGenPGO::assignRegionCounters(GlobalDecl GD, llvm::Function *Fn) {
+  const Decl *D = GD.getDecl();
   bool InstrumentRegions = CGM.getCodeGenOpts().ProfileInstrGenerate;
   llvm::IndexedInstrProfReader *PGOReader = CGM.getPGOReader();
   if (!InstrumentRegions && !PGOReader)
     return;
   if (D->isImplicit())
     return;
+  // Constructors and destructors may be represented by several functions in IR.
+  // If so, instrument only base variant, others are implemented by delegation
+  // to the base one, it would be counted twice otherwise.
+  if (CGM.getTarget().getCXXABI().hasConstructorVariants() &&
+      ((isa<CXXConstructorDecl>(GD.getDecl()) &&
+        GD.getCtorType() != Ctor_Base) ||
+       (isa<CXXDestructorDecl>(GD.getDecl()) &&
+        GD.getDtorType() != Dtor_Base))) {
+      return;
+  }
   CGM.ClearUnusedCoverageMapping(D);
   setFuncName(Fn);
 

diff --git a/lib/CodeGen/CodeGenPGO.h b/lib/CodeGen/CodeGenPGO.h
index 350cdcce3e871c16ca16442257f0ffb5acf321c3..6bf29ecaa7c4d26ff98db70aa8407e34a740fdf5 100644 (file)
--- a/lib/CodeGen/CodeGenPGO.h
+++ b/lib/CodeGen/CodeGenPGO.h
@@ -78,13 +78,11 @@ public:
       setCurrentRegionCount(*Count);
   }
 
-  /// Check if we need to emit coverage mapping for a given declaration
-  void checkGlobalDecl(GlobalDecl GD);
   /// Assign counters to regions and configure them for PGO of a given
   /// function. Does nothing if instrumentation is not enabled and either
   /// generates global variables or associates PGO data with each of the
   /// counters depending on whether we are generating or using instrumentation.
-  void assignRegionCounters(const Decl *D, llvm::Function *Fn);
+  void assignRegionCounters(GlobalDecl GD, llvm::Function *Fn);
   /// Emit a coverage mapping range with a counter zero
   /// for an unused declaration.
   void emitEmptyCounterMapping(const Decl *D, StringRef FuncName,

diff --git a/test/Profile/cxx-structors.cpp b/test/Profile/cxx-structors.cpp
new file mode 100644 (file)
index 0000000..24c595b
--- /dev/null
+++ b/test/Profile/cxx-structors.cpp
@@ -0,0 +1,32 @@
+// Tests for instrumentation of C++ constructors and destructors.
+//
+// RUN: %clang_cc1 -triple x86_64-apple-macosx10.11.0 -x c++ %s -o - -emit-llvm -fprofile-instr-generate | FileCheck %s
+
+struct Foo {
+  Foo() {}
+  Foo(int) {}
+  ~Foo() {}
+};
+
+struct Bar : public Foo {
+  Bar() {}
+  Bar(int x) : Foo(x) {}
+  ~Bar();
+};
+
+Foo foo;
+Foo foo2(1);
+Bar bar;
+
+// Profile data for complete constructors and destructors must absent.
+
+// CHECK-NOT: @__llvm_profile_name__ZN3FooC1Ev
+// CHECK-NOT: @__llvm_profile_name__ZN3FooC1Ei
+// CHECK-NOT: @__llvm_profile_name__ZN3FooD1Ev
+// CHECK-NOT: @__llvm_profile_name__ZN3BarC1Ev
+// CHECK-NOT: @__llvm_profile_name__ZN3BarD1Ev
+// CHECK-NOT: @__llvm_profile_counters__ZN3FooD1Ev
+// CHECK-NOT: @__llvm_profile_data__ZN3FooD1Ev
+
+int main() {
+}

diff --git a/test/Profile/cxx-virtual-destructor-calls.cpp b/test/Profile/cxx-virtual-destructor-calls.cpp
index 35975c28533c22d9de32e15b8870e22300a337a8..d117c2114371b87fdee11fb58cc2afa84b0c1183 100644 (file)
--- a/test/Profile/cxx-virtual-destructor-calls.cpp
+++ b/test/Profile/cxx-virtual-destructor-calls.cpp
@@ -13,18 +13,25 @@ struct B : A {
   virtual ~B();
 };
 
-// Complete dtor
-// CHECK: @__llvm_profile_name__ZN1BD1Ev = private constant [9 x i8] c"_ZN1BD1Ev"
+// Base dtor
+// CHECK: @__llvm_profile_name__ZN1BD2Ev = private constant [9 x i8] c"_ZN1BD2Ev"
 
-// Deleting dtor
-// CHECK: @__llvm_profile_name__ZN1BD0Ev = private constant [9 x i8] c"_ZN1BD0Ev"
+// Complete dtor must not be instrumented
+// CHECK-NOT: @__llvm_profile_name__ZN1BD1Ev = private constant [9 x i8] c"_ZN1BD1Ev"
 
-// Complete dtor counters and profile data
-// CHECK: @__llvm_profile_counters__ZN1BD1Ev = private global [1 x i64] zeroinitializer
-// CHECK: @__llvm_profile_data__ZN1BD1Ev =
+// Deleting dtor must not be instrumented
+// CHECK-NOT: @__llvm_profile_name__ZN1BD0Ev = private constant [9 x i8] c"_ZN1BD0Ev"
 
-// Deleting dtor counters and profile data
-// CHECK: @__llvm_profile_counters__ZN1BD0Ev = private global [1 x i64] zeroinitializer
-// CHECK: @__llvm_profile_data__ZN1BD0Ev =
+// Base dtor counters and profile data
+// CHECK: @__llvm_profile_counters__ZN1BD2Ev = private global [1 x i64] zeroinitializer
+// CHECK: @__llvm_profile_data__ZN1BD2Ev =
+
+// Complete dtor counters and profile data must absent
+// CHECK-NOT: @__llvm_profile_counters__ZN1BD1Ev = private global [1 x i64] zeroinitializer
+// CHECK-NOT: @__llvm_profile_data__ZN1BD1Ev =
+
+// Deleting dtor counters and profile data must absent
+// CHECK-NOT: @__llvm_profile_counters__ZN1BD0Ev = private global [1 x i64] zeroinitializer
+// CHECK-NOT: @__llvm_profile_data__ZN1BD0Ev =
 
 B::~B() { }