[llvm-branch-commits] [clang] [analyzer] Only bind aggregate lifetime sources in LifetimeModeling for annotated functions (PR #214824)

[Benedek Kaibas via llvm-branch-commits]

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@@ -471,3 +471,35 @@ IntPtrArr return_array_field_not_yet_detected() {
   // expected-note at -2    {{Address of stack memory associated with local variable 'z' returned to caller}}
   // expected-warning at -3 {{address of stack memory associated with local variable 'z' returned}}
 }
+
+struct Hold {
+  int *ptr;
+};
+
+Hold retPtr(int &x) {
+  return Hold{&x};
+}
+// Even though there is a lifetime error in the function
+// UseAfterLifetimeEnd should not emit a warning for this
+// case since there is no annotation present in the code.
+// The warning present in the test comes from core.StackAddressEscape
+// checker.
+Hold return_by_val_no_ann() {
+  int num = 4;
+  return retPtr(num);
+  // expected-warning at -1 {{Address of stack memory associated with local variable 'num' returned to caller}}
+  // expected-note at -2    {{Address of stack memory associated with local variable 'num' returned to caller}}
+}
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benedekaibas wrote:

Applied changes here: [fbda2f3](https://github.com/llvm/llvm-project/pull/214824/commits/fbda2f34948493a657988e71fcc6b53ae7a8194c)

I have also corrected the comment to correctly display that there might be a lifetime error. Since `Hold takePtr(int &x);` is an opaque call `StackAddressEscape` has to stay silent to avoid FPs and it cannot claim that there is no lifetime error 100%.

https://github.com/llvm/llvm-project/pull/214824