[AMDGPU] Do not internalize ASan device library functions.

[hsmhsm]

Summary

ASan device library functions (those starts with the prefix __asan_)
are at the moment undergoing through undesired optimizations due to
internalization. Hence, in order to avoid such undesired optimizations
on ASan device library functions, do not internalize them in the first
place.

[pvellien]

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

520–522

there are two asan device functions that don't start with "__asan_*" prefix, they are the following:

1. __sanitizer_ptr_cmp
2. __sanitizer_ptr_sub

@b-sumner do we want to not internalize those functions?

llvm/test/CodeGen/AMDGPU/internalize.ll

3 ↗

(On Diff #375013)

Since, this is a asan related change, I think it would be beneficial if we have a lit test with -fgpu-sanitize option.
Eg : https://reviews.llvm.org/D99071
please correct me if it is not needed here.

[b-sumner]

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

520–522

Yes, I think sanitizer_* should be handled similarly to asan_*

[b-sumner]

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

520–522

Sorry I forgot about the markup. I meant __sanitizer_* should be handled similarly to __asan_*

[hsmhsm]

Fix review comments by Praveen and Brian, and rebase.

[yaxunl]

LGTM. Thanks.

[DavidSpickett]

I've marked this test folder as needing AMDGPU in https://reviews.llvm.org/rG8f9f959b99e1.

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

StringRef AMDGPUTargetMachine::getFeatureString(const Function &F) const {
 
   return FSAttr.isValid() ? FSAttr.getValueAsString()
                           : getTargetFeatureString();
 }
 
 /// Predicate for Internalize pass.
 static bool mustPreserveGV(const GlobalValue &GV) {
   if (const Function *F = dyn_cast<Function>(&GV))
-    return F->isDeclaration() || AMDGPU::isEntryFunctionCC(F->getCallingConv());
+    return F->isDeclaration() || F->getName().startswith("__asan_") ||
+           F->getName().startswith("__sanitizer_") ||
+           AMDGPU::isEntryFunctionCC(F->getCallingConv());
 
   GV.removeDeadConstantUsers();
   return !GV.use_empty();
 }
 
 void AMDGPUTargetMachine::adjustPassManager(PassManagerBuilder &Builder) {
   Builder.DivergentTarget = true;
 

llvm/test/Instrumentation/AddressSanitizer/AMDGPU/asan_do_not_internalize.ll

+; RUN: opt -O0 -S -mtriple=amdgcn-unknown-amdhsa -amdgpu-internalize-symbols < %s | FileCheck -check-prefix=OPTNONE %s
+; RUN: opt -passes='default<O0>' -S -mtriple=amdgcn-unknown-amdhsa -amdgpu-internalize-symbols < %s | FileCheck -check-prefix=OPTNONE %s
+; RUN: opt -O1 -S -mtriple=amdgcn-unknown-amdhsa -amdgpu-internalize-symbols < %s | FileCheck -check-prefix=ASAN_NO_INTERNALIZE %s
+; RUN: opt -passes='default<O1>' -S -mtriple=amdgcn-unknown-amdhsa -amdgpu-internalize-symbols < %s | FileCheck -check-prefix=ASAN_NO_INTERNALIZE %s
+
+; OPTNONE: define void @__asan_no_explicit_linkage(
+; ASAN_NO_INTERNALIZE: define void @__asan_no_explicit_linkage(
+define void @__asan_no_explicit_linkage() {
+entry:
+  ret void
+}
+
+; OPTNONE: define weak void @__asan_weak_linkage(
+; ASAN_NO_INTERNALIZE: define weak void @__asan_weak_linkage(
+define weak void @__asan_weak_linkage() {
+entry:
+  ret void
+}
+
+; OPTNONE: define void @__sanitizer_no_explicit_linkage(
+; ASAN_NO_INTERNALIZE: define void @__sanitizer_no_explicit_linkage(
+define void @__sanitizer_no_explicit_linkage() {
+entry:
+  ret void
+}
+
+; OPTNONE: define weak void @__sanitizer_weak_linkage(
+; ASAN_NO_INTERNALIZE: define weak void @__sanitizer_weak_linkage(
+define weak void @__sanitizer_weak_linkage() {
+entry:
+  ret void
+}