[clang] [Sema] Fix crash on invalid operator template-id (PR #181404)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Neha  (nehaGautam07)

<details>
<summary>Changes</summary>

Add checks in GetNameFromUnqualifiedId to handle invalid
TemplateId cases safely. This avoids a crash when parsing
malformed code like 'operator | <>' and allows normal
error reporting to continue.

Fixes #<!-- -->177549 

---
Full diff: https://github.com/llvm/llvm-project/pull/181404.diff


2 Files Affected:

- (modified) clang/lib/Sema/SemaDecl.cpp (+10) 
- (added) clang/test/SemaCXX/crash-invalid-operator-template.cpp (+3) 


``````````diff
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 7af6ce62d08dd..369a5f11ef5aa 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6101,7 +6101,17 @@ Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) {
   }
 
   case UnqualifiedIdKind::IK_TemplateId: {
+    if (!Name.TemplateId)
+      return DeclarationNameInfo();
+
+    if (Name.TemplateId->isInvalid())
+      return DeclarationNameInfo();
+
     TemplateName TName = Name.TemplateId->Template.get();
+
+    if (TName.isNull())
+      return DeclarationNameInfo();
+
     SourceLocation TNameLoc = Name.TemplateId->TemplateNameLoc;
     return Context.getNameForTemplate(TName, TNameLoc);
   }
diff --git a/clang/test/SemaCXX/crash-invalid-operator-template.cpp b/clang/test/SemaCXX/crash-invalid-operator-template.cpp
new file mode 100644
index 0000000000000..d383b5f26d8e9
--- /dev/null
+++ b/clang/test/SemaCXX/crash-invalid-operator-template.cpp
@@ -0,0 +1,3 @@
+// RUN: not %clang_cc1 -fsyntax-only  %s
+
+typedef(( operator | <> ) ) ( class { private: });
\ No newline at end of file

``````````

</details>


https://github.com/llvm/llvm-project/pull/181404