From 087253b9951766cbd93286b804ebb1ab59197aa8 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Tue, 8 Jun 2021 17:48:49 -0400 Subject: [PATCH] c++: remove redundant warning [PR100879] Before my r277864, build_new_op promoted enums to int before passing them on to cp_build_binary_op; after that commit, it doesn't, so warn_for_sign_compare sees the enum operands and gives a redundant warning. This warning dates back to 1995, and seems to have been dead code for a long time--likely since build_new_op was added in 1997--so let's just remove it. PR c++/100879 gcc/c-family/ChangeLog: * c-warn.c (warn_for_sign_compare): Remove C++ enum mismatch warning. gcc/testsuite/ChangeLog: * g++.dg/diagnostic/enum3.C: New test. --- gcc/c-family/c-warn.c | 12 ------------ gcc/testsuite/g++.dg/diagnostic/enum3.C | 9 +++++++++ 2 files changed, 9 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/g++.dg/diagnostic/enum3.C diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c index a587b99..cd3c99e 100644 --- a/gcc/c-family/c-warn.c +++ b/gcc/c-family/c-warn.c @@ -2240,18 +2240,6 @@ warn_for_sign_compare (location_t location, int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1)); int unsignedp0, unsignedp1; - /* In C++, check for comparison of different enum types. */ - if (c_dialect_cxx() - && TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE - && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE - && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0)) - != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1))) - { - warning_at (location, - OPT_Wsign_compare, "comparison between types %qT and %qT", - TREE_TYPE (orig_op0), TREE_TYPE (orig_op1)); - } - /* Do not warn if the comparison is being done in a signed type, since the signed type will only be chosen if it can represent all the values of the unsigned type. */ diff --git a/gcc/testsuite/g++.dg/diagnostic/enum3.C b/gcc/testsuite/g++.dg/diagnostic/enum3.C new file mode 100644 index 0000000..d51aa8a --- /dev/null +++ b/gcc/testsuite/g++.dg/diagnostic/enum3.C @@ -0,0 +1,9 @@ +// PR c++/100879 +// { dg-additional-options -Werror=sign-compare } + +enum e1 { e1val }; +enum e2 { e3val }; + +int main( int, char * [] ) { + if ( e1val == e3val ) return 1; // { dg-warning -Wenum-compare } +} -- 2.7.4