[llvm] def2042 - [llvm][DiagnosticInfo] handle function pointer casts

[Nick Desaulniers via llvm-commits]

Author: Nick Desaulniers
Date: 2023-01-24T13:59:34-08:00
New Revision: def20427b401a839210ff27b34dd31b929fa82ef

URL: https://github.com/llvm/llvm-project/commit/def20427b401a839210ff27b34dd31b929fa82ef
DIFF: https://github.com/llvm/llvm-project/commit/def20427b401a839210ff27b34dd31b929fa82ef.diff

LOG: [llvm][DiagnosticInfo] handle function pointer casts

As pointed out by @arsenm in https://reviews.llvm.org/D141451#4045099,
we don't handle ConstantExpressions for dontcall-{warn|error} IR Fn
Attrs.

Use CallBase::getCalledOperand() and Value::stripPointerCasts() should
the call to CallBase::getCalledFunction return nullptr.

I don't know how to express the IR test case in C, otherwise I'd add a
clang test, too.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D142058

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    llvm/lib/IR/DiagnosticInfo.cpp
    llvm/test/CodeGen/X86/attr-dontcall.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 84e1a397d3a2..0bdfdac6a65f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -8369,9 +8369,9 @@ void SelectionDAGBuilder::visitCall(const CallInst &I) {
     return;
   }
 
-  if (Function *F = I.getCalledFunction()) {
-    diagnoseDontCall(I);
+  diagnoseDontCall(I);
 
+  if (Function *F = I.getCalledFunction()) {
     if (F->isDeclaration()) {
       // Is this an LLVM intrinsic or a target-specific intrinsic?
       unsigned IID = F->getIntrinsicID();

diff  --git a/llvm/lib/IR/DiagnosticInfo.cpp b/llvm/lib/IR/DiagnosticInfo.cpp
index aed38b6927bd..fb238e2aac59 100644
--- a/llvm/lib/IR/DiagnosticInfo.cpp
+++ b/llvm/lib/IR/DiagnosticInfo.cpp
@@ -416,7 +416,9 @@ void OptimizationRemarkAnalysisFPCommute::anchor() {}
 void OptimizationRemarkAnalysisAliasing::anchor() {}
 
 void llvm::diagnoseDontCall(const CallInst &CI) {
-  auto *F = CI.getCalledFunction();
+  const auto *F =
+      dyn_cast<Function>(CI.getCalledOperand()->stripPointerCasts());
+
   if (!F)
     return;
 

diff  --git a/llvm/test/CodeGen/X86/attr-dontcall.ll b/llvm/test/CodeGen/X86/attr-dontcall.ll
index 4c2595f7d4ee..8b518aee6dce 100644
--- a/llvm/test/CodeGen/X86/attr-dontcall.ll
+++ b/llvm/test/CodeGen/X86/attr-dontcall.ll
@@ -20,6 +20,14 @@ define void @bar3() {
   ret void
 }
 
+declare void @foo4(i32) addrspace(1) "dontcall-warn"="cast"
+
+define void @bar4() {
+  call void addrspacecast (ptr addrspace(1) @foo4 to ptr)(i32 0)
+  ret void
+}
+
 ; CHECK: error: call to foo marked "dontcall-error": e
 ; CHECK: warning: call to foo2 marked "dontcall-warn": w
 ; CHECK: warning: call to foo3 marked "dontcall-warn"{{$}}
+; CHECK: warning: call to foo4 marked "dontcall-warn": cast