Author: rnk Date: Fri Aug 17 15:11:31 2018 New Revision: 340101 URL: http://llvm.org/viewvc/llvm-project?rev=340101&view=rev Log: 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 Modified: cfe/trunk/lib/Sema/SemaInit.cpp cfe/trunk/test/Sema/statements.c Modified: cfe/trunk/lib/Sema/SemaInit.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=340101&r1=340100&r2=340101&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaInit.cpp (original) +++ cfe/trunk/lib/Sema/SemaInit.cpp Fri Aug 17 15:11:31 2018 @@ -6924,6 +6924,10 @@ void Sema::checkInitializerLifetime(cons } 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) Modified: cfe/trunk/test/Sema/statements.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/statements.c?rev=340101&r1=340100&r2=340101&view=diff ============================================================================== --- cfe/trunk/test/Sema/statements.c (original) +++ cfe/trunk/test/Sema/statements.c Fri Aug 17 15:11:31 2018 @@ -34,6 +34,15 @@ bar: return &&bar; // expected-warning {{returning address of label, which is local}} } +// PR38569: Don't warn when returning a label from a statement expression. +void test10_logpc(void*); +void test10a() { + test10_logpc(({ + my_pc: + &&my_pc; + })); +} + // PR6034 void test11(int bit) { switch (bit) _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
