Don't warn on returning the address of a label from a statement expression
Summary:
There isn't anything inherently wrong with returning a label from a
statement expression. In practice, the Linux kernel uses this pattern to
materialize PCs.
Fixes PR38569
Reviewers: niravd, rsmith, nickdesaulniers
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D50805
llvm-svn: 340101
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 766f23b..1f28056 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -6924,6 +6924,10 @@
} else if (isa<BlockExpr>(L)) {
Diag(DiagLoc, diag::err_ret_local_block) << DiagRange;
} else if (isa<AddrLabelExpr>(L)) {
+ // Don't warn when returning a label from a statement expression.
+ // Leaving the scope doesn't end its lifetime.
+ if (LK == LK_StmtExprResult)
+ return false;
Diag(DiagLoc, diag::warn_ret_addr_label) << DiagRange;
} else {
Diag(DiagLoc, diag::warn_ret_local_temp_addr_ref)