[[clang::always_destroy]] attribute silences warn-exit-time-destructor

[ycdtosa]

user wants the warning silenced by the attribute so no warning should be issued.

Fixes #68686

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[llvmbot]

@llvm/pr-subscribers-clang

Author: None (ycdtosa)

Changes

user wants the warning silenced by the attribute
so no warning should be issued.

---

Full diff: https://github.com/llvm/llvm-project/pull/86486.diff

2 Files Affected:

• (modified) clang/lib/Sema/SemaDeclCXX.cpp (+2-1)
• (modified) clang/test/SemaCXX/warn-exit-time-destructors.cpp (+6)

diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index ee732679417e37..7070ea00cff275 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -16202,7 +16202,8 @@ void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
 
   // Emit warning for non-trivial dtor in global scope (a real global,
   // class-static, function-static).
-  Diag(VD->getLocation(), diag::warn_exit_time_destructor);
+  if (!VD->hasAttr<AlwaysDestroyAttr>())
+    Diag(VD->getLocation(), diag::warn_exit_time_destructor);
 
   // TODO: this should be re-enabled for static locals by !CXAAtExit
   if (!VD->isStaticLocal())
diff --git a/clang/test/SemaCXX/warn-exit-time-destructors.cpp b/clang/test/SemaCXX/warn-exit-time-destructors.cpp
index 2f14243cb48c47..8bd798c036333e 100644
--- a/clang/test/SemaCXX/warn-exit-time-destructors.cpp
+++ b/clang/test/SemaCXX/warn-exit-time-destructors.cpp
@@ -51,6 +51,11 @@ struct A { ~A(); };
 }
 
 namespace test5 {
+struct A { ~A(); };
+[[clang::always_destroy]] A a; // no warning
+}
+
+namespace test6 {
 #if __cplusplus >= 202002L
 #define CPP20_CONSTEXPR constexpr
 #else
@@ -68,3 +73,4 @@ namespace test5 {
   T t; // expected-warning {{exit-time destructor}}
 #undef CPP20_CONSTEXPR
 }
+

[ycdtosa]

this was lightly discussed in #68686

[ycdtosa]

@AaronBallman I finally got some time to prepare this PR, but I am not familiar with the approval process.
It also seems that you have commit rights, so there!

Still, I fell the test might be incomplete.

[AaronBallman]

Thank you for the fix! I have another suggested test case, and please be sure to add a release note to clang/docs/ReleaseNotes.rst so users know about the fix. Also, I think AttrDocs.td should be updated to document the fact that always_destroy will silence this diagnostic.

[ycdtosa]

Mind my English. I hope the wording for the docs is correct.

[AaronBallman]

LGTM aside from a few minor nits, thank you for the improvement! I'm assuming you need me to land this on your behalf, so I'll go ahead and apply the fixes myself and then land the changes.

[AaronBallman]

Suggesting a typo fix to my previous suggested edits

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