[profiling] PR31992: Don't skip interesting non-base constructors

Fix the fact that we don't assign profile counters to constructors in
classes with virtual bases, or constructors with variadic parameters.

Differential Revision: https://reviews.llvm.org/D30131

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@296062 91177308-0d34-0410-b5e6-96231b3b80d8

Author: vedantk

Diff for: lib/CodeGen/CGClass.cpp

@@ -689,7 +689,8 @@ void CodeGenFunction::EmitInitializerForField(FieldDecl *Field, LValue LHS,
 /// complete-to-base constructor delegation optimization, i.e.
 /// emitting the complete constructor as a simple call to the base
 /// constructor.
-static bool IsConstructorDelegationValid(const CXXConstructorDecl *Ctor) {
+bool CodeGenFunction::IsConstructorDelegationValid(
+    const CXXConstructorDecl *Ctor) {
 
   // Currently we disable the optimization for classes with virtual
   // bases because (1) the addresses of parameter variables need to be

Diff for: lib/CodeGen/CodeGenFunction.h

@@ -1564,6 +1564,8 @@ class CodeGenFunction : public CodeGenTypeCache {
                      SourceLocation Loc = SourceLocation(),
                      SourceLocation StartLoc = SourceLocation());
 
+  static bool IsConstructorDelegationValid(const CXXConstructorDecl *Ctor);
+
   void EmitConstructorBody(FunctionArgList &Args);
   void EmitDestructorBody(FunctionArgList &Args);
   void emitImplicitAssignmentOperatorBody(FunctionArgList &Args);

Diff for: lib/CodeGen/CodeGenPGO.cpp

@@ -626,10 +626,14 @@ void CodeGenPGO::assignRegionCounters(GlobalDecl GD, llvm::Function *Fn) {
   // 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>(D) && GD.getCtorType() != Ctor_Base) ||
-       (isa<CXXDestructorDecl>(D) && GD.getDtorType() != Dtor_Base))) {
-    return;
+  if (CGM.getTarget().getCXXABI().hasConstructorVariants()) {
+    if (isa<CXXDestructorDecl>(D) && GD.getDtorType() != Dtor_Base)
+      return;
+
+    if (const auto *CCD = dyn_cast<CXXConstructorDecl>(D))
+      if (GD.getCtorType() != Ctor_Base &&
+          CodeGenFunction::IsConstructorDelegationValid(CCD))
+        return;
   }
   CGM.ClearUnusedCoverageMapping(D);
   setFuncName(Fn);

Diff for: test/Profile/Inputs/cxx-class.proftext

@@ -39,3 +39,14 @@ _ZN6SimpleC2Ei
 100
 99
 
+_ZN7DerivedC1Ev
+10
+2
+100
+99
+
+_ZN7DerivedD2Ev
+10
+2
+100
+99

Diff for: test/Profile/cxx-class.cpp

@@ -5,17 +5,21 @@
 // RUN: FileCheck --input-file=%tgen -check-prefix=DTRGEN %s
 // RUN: FileCheck --input-file=%tgen -check-prefix=MTHGEN %s
 // RUN: FileCheck --input-file=%tgen -check-prefix=WRPGEN %s
+// RUN: FileCheck --input-file=%tgen -check-prefix=VCTRGEN %s
+// RUN: FileCheck --input-file=%tgen -check-prefix=VDTRGEN %s
 
 // RUN: llvm-profdata merge %S/Inputs/cxx-class.proftext -o %t.profdata
 // RUN: %clang_cc1 %s -o - -emit-llvm -fprofile-instrument-use-path=%t.profdata -triple %itanium_abi_triple > %tuse
 // RUN: FileCheck --input-file=%tuse -check-prefix=CTRUSE %s
 // RUN: FileCheck --input-file=%tuse -check-prefix=DTRUSE %s
 // RUN: FileCheck --input-file=%tuse -check-prefix=MTHUSE %s
 // RUN: FileCheck --input-file=%tuse -check-prefix=WRPUSE %s
+// RUN: FileCheck --input-file=%tuse -check-prefix=VCTRUSE %s
+// RUN: FileCheck --input-file=%tuse -check-prefix=VDTRUSE %s
 
 class Simple {
-  int Member;
 public:
+  int Member;
   // CTRGEN-LABEL: define {{.*}} @_ZN6SimpleC2Ei(
   // CTRUSE-LABEL: define {{.*}} @_ZN6SimpleC2Ei(
   // CTRGEN: store {{.*}} @[[SCC:__profc__ZN6SimpleC2Ei]], i64 0, i64 0
@@ -56,13 +60,43 @@ class Simple {
   // MTHUSE: ![[SM1]] = !{!"branch_weights", i32 100, i32 2}
 };
 
+class Derived : virtual public Simple {
+public:
+  // VCTRGEN-LABEL: define {{.*}} @_ZN7DerivedC1Ev(
+  // VCTRUSE-LABEL: define {{.*}} @_ZN7DerivedC1Ev(
+  // VCTRGEN: store {{.*}} @[[SCC:__profc__ZN7DerivedC1Ev]], i64 0, i64 0
+  Derived() : Simple(0) {
+    // VCTRGEN: store {{.*}} @[[SCC]], i64 0, i64 1
+    // VCTRUSE: br {{.*}} !prof ![[SC1:[0-9]+]]
+    if (Member) {}
+    // VCTRGEN-NOT: store {{.*}} @[[SCC]],
+    // VCTRUSE-NOT: br {{.*}} !prof ![0-9]+
+    // VCTRUSE: ret
+  }
+  // VCTRUSE: ![[SC1]] = !{!"branch_weights", i32 100, i32 2}
+
+  // VDTRGEN-LABEL: define {{.*}} @_ZN7DerivedD2Ev(
+  // VDTRUSE-LABEL: define {{.*}} @_ZN7DerivedD2Ev(
+  // VDTRGEN: store {{.*}} @[[SDC:__profc__ZN7DerivedD2Ev]], i64 0, i64 0
+  ~Derived() {
+    // VDTRGEN: store {{.*}} @[[SDC]], i64 0, i64 1
+    // VDTRUSE: br {{.*}} !prof ![[SD1:[0-9]+]]
+    if (Member) {}
+    // VDTRGEN-NOT: store {{.*}} @[[SDC]],
+    // VDTRUSE-NOT: br {{.*}} !prof ![0-9]+
+    // VDTRUSE: ret
+  }
+  // VDTRUSE: ![[SD1]] = !{!"branch_weights", i32 100, i32 2}
+};
+
 // WRPGEN-LABEL: define {{.*}} @_Z14simple_wrapperv(
 // WRPUSE-LABEL: define {{.*}} @_Z14simple_wrapperv(
 // WRPGEN: store {{.*}} @[[SWC:__profc__Z14simple_wrapperv]], i64 0, i64 0
 void simple_wrapper() {
   // WRPGEN: store {{.*}} @[[SWC]], i64 0, i64 1
   // WRPUSE: br {{.*}} !prof ![[SW1:[0-9]+]]
   for (int I = 0; I < 100; ++I) {
+    Derived d;
     Simple S(I);
     S.method();
   }

Diff for: test/Profile/cxx-structors.cpp

@@ -16,12 +16,28 @@ struct Bar : public Foo {
   ~Bar();
 };
 
+struct Baz : virtual public Foo {
+  Baz() {}
+  Baz(int x) : Foo(x) {}
+  ~Baz();
+};
+
+struct Quux : public Foo {
+  Quux(const char *y, ...) : Foo(0) {}
+};
+
 Foo foo;
 Foo foo2(1);
 Bar bar;
+Baz baz;
+Baz baz2(1);
+Quux qux("fi", "fo", "fum");
 
 // Profile data for complete constructors and destructors must absent.
 
+// INSTR: @__profc__ZN3BazC1Ev =
+// INSTR: @__profc__ZN3BazC1Ei =
+// INSTR: @__profc__ZN4QuuxC1EPKcz =
 // INSTR: @__profc_main =
 // INSTR: @__profc__ZN3FooC2Ev =
 // INSTR: @__profc__ZN3FooD2Ev =