From 12bdcc3d7970860b9d66ed4dea203bde8fd68d4d Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Thu, 12 Sep 2024 12:45:03 -0400 Subject: c++: decltype(auto) deduction of statement-expression [PR116418] r8-7538 for PR84968 made strip_typedefs_expr diagnose STATEMENT_LIST so that we reject statement-expressions in noexcept-specifiers to match our behavior in template arguments (which the parser diagnoses directly). Later r11-7452 made decltype(auto) deduction canonicalize the expression (as an implementation detail) which in turn calls strip_typedefs_expr, and so ever since we inadvertently reject decltype(auto) deduction of a statement-expression. This patch just removes the diagnostic in strip_typedefs_expr and instead treats statement-expressions similar to lambda-expressions. The function doesn't seem like the right place for such a diagnostic and so it seems easier to just accept rather than try to reject them in a suitable place. PR c++/116418 gcc/cp/ChangeLog: * tree.cc (strip_typedefs_expr) : Replace this error path with ... : ... this, returning the original tree. gcc/testsuite/ChangeLog: * g++.dg/eh/pr84968.C: No longer expect an ahead of time diagnostic for the statement-expresssion. Instantiate the template and expect an incomplete type error instead. * g++.dg/ext/stmtexpr26.C: New test. Reviewed-by: Jason Merrill --- gcc/cp/tree.cc | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'gcc/cp/tree.cc') diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc index c3a38de..99088da 100644 --- a/gcc/cp/tree.cc +++ b/gcc/cp/tree.cc @@ -2009,12 +2009,9 @@ strip_typedefs_expr (tree t, bool *remove_attributes, unsigned int flags) } case LAMBDA_EXPR: + case STMT_EXPR: return t; - case STATEMENT_LIST: - error ("statement-expression in a constant expression"); - return error_mark_node; - default: break; } -- cgit v1.1