[clang] [llvm][Stmt]:Fix musttail attribute on a function with not_tail_called attribute has no warning/error (PR #134465)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: None (MillePlateaux)

<details>
<summary>Changes</summary>

Added judgment statements and accurately reported errors.Closes #<!-- -->133509

---
Full diff: https://github.com/llvm/llvm-project/pull/134465.diff


1 Files Affected:

- (modified) clang/lib/Sema/SemaStmt.cpp (+8) 


``````````diff
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index e1b9ccc693bd5..c8354198a5614 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -717,6 +717,14 @@ bool Sema::checkMustTailAttr(const Stmt *St, const Attr &MTA) {
     return false;
   }
 
+  if (const FunctionDecl *CalleeDecl = CE->getDirectCallee()) {
+    if (CalleeDecl->hasAttr<NotTailCalledAttr>()) {
+      Diag(St->getBeginLoc(), diag::err_musttail_conflicts_with_not_tail_called)
+          << &MTA;
+      return false;
+    }
+  }
+
   if (const auto *EWC = dyn_cast<ExprWithCleanups>(E)) {
     if (EWC->cleanupsHaveSideEffects()) {
       Diag(St->getBeginLoc(), diag::err_musttail_needs_trivial_args) << &MTA;

``````````

</details>


https://github.com/llvm/llvm-project/pull/134465