[llvm] deec59b - [StackSafety] Skip a caller's callee operand typed GlobalVariable (#216565)

[via llvm-commits]

Author: Tomer Shafir
Date: 2026-08-27T09:59:08+03:00
New Revision: deec59b150d2346732ba59d155f1449447abd56d

URL: https://github.com/llvm/llvm-project/commit/deec59b150d2346732ba59d155f1449447abd56d
DIFF: https://github.com/llvm/llvm-project/commit/deec59b150d2346732ba59d155f1449447abd56d.diff

LOG: [StackSafety] Skip a caller's callee operand typed GlobalVariable (#216565)

The callee operand of a call can be a function pointer global. A
GlobalVariable is not analyzable locally. Otherwise the compiler could
crash.

Claude (Claude-Opus-5) noreply at anthropic.com

Added: 
    

Modified: 
    llvm/lib/Analysis/StackSafetyAnalysis.cpp
    llvm/test/Analysis/StackSafetyAnalysis/local.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/StackSafetyAnalysis.cpp b/llvm/lib/Analysis/StackSafetyAnalysis.cpp
index 9c20019677895..e6f17ff268155 100644
--- a/llvm/lib/Analysis/StackSafetyAnalysis.cpp
+++ b/llvm/lib/Analysis/StackSafetyAnalysis.cpp
@@ -527,7 +527,8 @@ void StackSafetyLocalAnalysis::analyzeAllUses(Value *Ptr,
         // dso_preemptable aliases or aliases with interposable linkage.
         const GlobalValue *Callee =
             dyn_cast<GlobalValue>(CB.getCalledOperand()->stripPointerCasts());
-        if (!Callee || isa<GlobalIFunc>(Callee)) {
+        if (!Callee || isa<GlobalIFunc>(Callee) ||
+            isa<GlobalVariable>(Callee)) {
           US.addRange(I, UnknownRange, /*IsSafe=*/false);
           break;
         }

diff  --git a/llvm/test/Analysis/StackSafetyAnalysis/local.ll b/llvm/test/Analysis/StackSafetyAnalysis/local.ll
index 6944f38411003..28c6172b8f61c 100644
--- a/llvm/test/Analysis/StackSafetyAnalysis/local.ll
+++ b/llvm/test/Analysis/StackSafetyAnalysis/local.ll
@@ -1136,5 +1136,32 @@ entry:
   ret ptr null
 }
 
+ at blob = external global [16 x i8]
+
+define dso_local void @CallGlobalVariable(ptr noundef %uaddr) local_unnamed_addr {
+; CHECK-LABEL: @CallGlobalVariable{{$}}
+; CHECK-NEXT: args uses:
+; CHECK-NEXT: uaddr[]: full-set{{$}}
+; CHECK-NEXT: allocas uses:
+; GLOBAL-NEXT: safe accesses:
+; CHECK-EMPTY:
+entry:
+  tail call i64 @blob(ptr noundef %uaddr)
+  ret void
+}
+
+define dso_local void @CallGlobalVariableAlloca() local_unnamed_addr {
+; CHECK-LABEL: @CallGlobalVariableAlloca{{$}}
+; CHECK-NEXT: args uses:
+; CHECK-NEXT: allocas uses:
+; CHECK-NEXT: x[4]: full-set{{$}}
+; GLOBAL-NEXT: safe accesses:
+; CHECK-EMPTY:
+entry:
+  %x = alloca i32, align 4
+  call i64 @blob(ptr noundef %x)
+  ret void
+}
+
 declare void @llvm.lifetime.start.p0(ptr nocapture)
 declare void @llvm.lifetime.end.p0(ptr nocapture)