[InstrProf] Allow compiler generated functions in SCL

[ellis]

Summary

Allow compiler generated functions like __clang_call_terminate to be
blocked in the special case list (SCL) passed by the -fprofile-list= option.

[phosek]

clang/lib/CodeGen/CodeGenModule.cpp

3894–3896

Do we still need https://github.com/llvm/llvm-project/blob/759e5e0096f650515799805828f9ac5b7d4a7303/clang/lib/CodeGen/CodeGenFunction.cpp#L856 if we set the attribute here?

[ellis]

clang/lib/CodeGen/CodeGenModule.cpp

3894–3896

Both are needed. Here the attribute is added in GetOrCreateLLVMFunction() which I believe only creates compiler generated functions. Where you linked is called when normal functions are generated.

[phosek]

LGTM

[ellis]

clang/lib/CodeGen/CodeGenModule.cpp

3894–3896

Oh sorry, I was mistaken. I'd like to figure out how to only have this code in one location.

[ellis]

The function __clang_call_terminate seems to be a special case that clang builds itself. This diff might be too much for this rare specific case. Closing.

clang/lib/CodeGen/CodeGenModule.cpp

llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
   assert(F->getName() == MangledName && "name was uniqued!");
   if (D)
     SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
   if (ExtraAttrs.hasFnAttrs()) {
     llvm::AttrBuilder B(F->getContext(), ExtraAttrs.getFnAttrs());
     F->addFnAttrs(B);
   }
 
+  if (getCodeGenOpts().getProfileInstr() != CodeGenOptions::ProfileNone)
+    if (isProfileInstrExcluded(F, SourceLocation()))
+      F->addFnAttr(llvm::Attribute::NoProfile);
+
   if (!DontDefer) {
     // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
     // each other bottoming out with the base dtor.  Therefore we emit non-base
     // dtors on usage, even if there is no dtor definition in the TU.
     if (D && isa<CXXDestructorDecl>(D) &&
         getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
                                            GD.getDtorType()))
       addDeferredDeclToEmit(GD);

clang/test/CodeGen/profile-filter-compiler-generated.cpp

+// RUN: echo "!fun:__clang_call_terminate" > %t.list
+// RUN: %clang -fprofile-generate -fprofile-list=%t.list -Wno-exceptions -emit-llvm -S %s -o - | FileCheck %s
+
+// CHECK-NOT: noprofile
+// CHECK-LABEL: define {{.*}} i32 @_Z3foov()
+int foo() noexcept { throw 0; }
+
+// CHECK: noprofile
+// CHECK-LABEL: define {{.*}} void @__clang_call_terminate(