[clang] [clang] Lifetime of locals must end before musttail call (PR #109255)

[Haojian Wu via cfe-commits]

================
@@ -267,3 +267,30 @@ namespace ns {}
 void TestCallNonValue() {
   [[clang::musttail]] return ns; // expected-error {{unexpected namespace name 'ns': expected expression}}
 }
+
+// Test diagnostics for lifetimes of local variables, which end earlier for a
+// musttail call than for a nowmal one.
+
+void TakesIntAndPtr(int, int *);
+void PassAddressOfLocal(int a, int *b) {
+  int c;
+  [[clang::musttail]] return TakesIntAndPtr(0, &c); // expected-warning {{address of stack memory associated with local variable 'c' passed to musttail function}}
----------------
hokein wrote:

can you add a test where a function call is used in the argument? something like

```
int foo();
void test(int a, const int &b) {
  int c;
  [[clang::musttail]] return test(0, foo()); 
}
```


https://github.com/llvm/llvm-project/pull/109255