[llvm] [CGProfile] Fix unhandled error crash on empty canonical function names (PR #201821)

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<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Arseniy Obolenskiy (aobolensk)

<details>
<summary>Changes</summary>

A function whose entire name is a strippable suffix  canonicalizes to an empty name, making InstrProfSymtab::create return an error

The current solution with `(void)(bool)` does not really suppress the error which leads to the crash

---
Full diff: https://github.com/llvm/llvm-project/pull/201821.diff


2 Files Affected:

- (modified) llvm/lib/Transforms/Instrumentation/CGProfile.cpp (+1-1) 
- (added) llvm/test/Instrumentation/cgprofile-empty-canonical-name.ll (+10) 


``````````diff
diff --git a/llvm/lib/Transforms/Instrumentation/CGProfile.cpp b/llvm/lib/Transforms/Instrumentation/CGProfile.cpp
index 60e7acc77ca29..07bbd2b8fccfd 100644
--- a/llvm/lib/Transforms/Instrumentation/CGProfile.cpp
+++ b/llvm/lib/Transforms/Instrumentation/CGProfile.cpp
@@ -60,7 +60,7 @@ static bool runCGProfilePass(Module &M, FunctionAnalysisManager &FAM,
     Count = SaturatingAdd(Count, NewCount);
   };
   // Ignore error here.  Indirect calls are ignored if this fails.
-  (void)(bool)Symtab.create(M, InLTO);
+  consumeError(Symtab.create(M, InLTO));
   for (auto &F : M) {
     // Avoid extra cost of running passes for BFI when the function doesn't have
     // entry count.
diff --git a/llvm/test/Instrumentation/cgprofile-empty-canonical-name.ll b/llvm/test/Instrumentation/cgprofile-empty-canonical-name.ll
new file mode 100644
index 0000000000000..a4fbf1d18ece0
--- /dev/null
+++ b/llvm/test/Instrumentation/cgprofile-empty-canonical-name.ll
@@ -0,0 +1,10 @@
+; RUN: opt < %s -passes='cg-profile' -S | FileCheck %s
+
+; A function whose entire name is a strippable suffix (e.g. ".llvm.123")
+; canonicalizes to an empty name. Building the InstrProfSymtab
+; for such a name returns an error that cg-profile intentionally ignores.
+
+; CHECK: define void @.llvm.123()
+define void @.llvm.123() {
+  ret void
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/201821