[clang] [clang] Output an error when [[lifetimebound]] attribute is applied on a function parameter while the function returns void (PR #113460)

[Boaz Brickner via cfe-commits]

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@@ -6970,6 +6970,18 @@ static void checkAttributesAfterMerging(Sema &S, NamedDecl &ND) {
         }
       }
     }
+
+    for (unsigned int I = 0; I < FD->getNumParams(); ++I) {
+      const ParmVarDecl *P = FD->getParamDecl(I);
+
+      // The [[lifetimebound]] attribute can be applied to a function parameter
+      // only if the function returns a value.
+      if (auto *A = P->getAttr<LifetimeBoundAttr>()) {
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bricknerb wrote:

Added a test to demonstrate that.

https://github.com/llvm/llvm-project/pull/113460