[clang] [UBSAN] Preserve ubsan code with ubsan-unique-traps (PR #83470)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-codegen

Author: Vitaly Buka (vitalybuka)

<details>
<summary>Changes</summary>

Removing `TrapBB->getParent()->size()` added with #<!-- -->65972. Counter as-is
is not very unique after inlining https://godbolt.org/z/4KfEKq7zb (see
m()).


---
Full diff: https://github.com/llvm/llvm-project/pull/83470.diff


2 Files Affected:

- (modified) clang/lib/CodeGen/CGExpr.cpp (+3-5) 
- (modified) clang/test/CodeGen/bounds-checking.c (+2-2) 


``````````diff
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 59a7fe8925001c..ee5f3a2786a627 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -3826,11 +3826,9 @@ void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked,
     Builder.CreateCondBr(Checked, Cont, TrapBB);
     EmitBlock(TrapBB);
 
-    llvm::CallInst *TrapCall = Builder.CreateCall(
-        CGM.getIntrinsic(llvm::Intrinsic::ubsantrap),
-        llvm::ConstantInt::get(CGM.Int8Ty, ClSanitizeDebugDeoptimization
-                                               ? TrapBB->getParent()->size()
-                                               : CheckHandlerID));
+    llvm::CallInst *TrapCall =
+        Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::ubsantrap),
+                           llvm::ConstantInt::get(CGM.Int8Ty, CheckHandlerID));
 
     if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
       auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
diff --git a/clang/test/CodeGen/bounds-checking.c b/clang/test/CodeGen/bounds-checking.c
index 8100e30d0650ad..f6c4880e70a150 100644
--- a/clang/test/CodeGen/bounds-checking.c
+++ b/clang/test/CodeGen/bounds-checking.c
@@ -74,11 +74,11 @@ char B2[10];
 // CHECK-LABEL: @f8
 void f8(int i, int k) {
   // NOOPTLOCAL: call void @llvm.ubsantrap(i8 3)
-  // NOOPTARRAY: call void @llvm.ubsantrap(i8 2)
+  // NOOPTARRAY: call void @llvm.ubsantrap(i8 18)
   B[i] = '\0';
 
   // NOOPTLOCAL: call void @llvm.ubsantrap(i8 5)
-  // NOOPTARRAY: call void @llvm.ubsantrap(i8 4)
+  // NOOPTARRAY: call void @llvm.ubsantrap(i8 18)
   B2[k] = '\0';
 }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/83470