From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from longcc.localdomain (unknown [210.75.100.191]) by sourceware.org (Postfix) with ESMTPS id BE94F3858D37 for ; Thu, 1 Dec 2022 04:32:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org BE94F3858D37 Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=none smtp.mailfrom=longcc.localdomain Received: by longcc.localdomain (Postfix, from userid 1000) id E1554602805; Thu, 1 Dec 2022 12:32:10 +0800 (CST) From: Longjun Luo To: gcc-patches@gcc.gnu.org Cc: luolongjuna@gmail.com, sangyan@huawei.com Subject: [PATCH] libcpp: suppress builtin macro redefined warnings for __LINE__ Date: Thu, 1 Dec 2022 12:31:55 +0800 Message-Id: <20221201043155.9369-1-luolongjuna@gmail.com> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-10.5 required=5.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,GIT_PATCH_0,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_NONE,KAM_DMARC_STATUS,KAM_LAZY_DOMAIN_SECURITY,KAM_SHORT,NML_ADSP_CUSTOM_MED,NO_DNS_FOR_FROM,SPF_HELO_NONE,SPF_NONE,SPOOFED_FREEMAIL,SPOOFED_FREEMAIL_NO_RDNS,SPOOF_GMAIL_MID autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: As implied in gcc.gnu.org/legacy-ml/gcc-patches/2008-09/msg00076.html, gcc provides -Wno-builtin-macro-redefined to suppress warning when redefining builtin macro. However, at that time, there was no scenario for __LINE__ macro. But, when we try to build a live-patch, we compare sections by using -ffunction-sections. Some same functions are considered changed because of __LINE__ macro. At present, to detect such a changed caused by __LINE__ macro, we have to analyse code and maintain a function list. For example, in kpatch, check this commit github.com/dynup/kpatch/commit/0e1b95edeafa36edb7bcf11da6d1c00f76d7e03d. So, in this scenario, when we try to compared sections, it would be better to support suppress builtin macro redefined warnings for __LINE__ macro. Signed-off-by: Longjun Luo --- gcc/testsuite/gcc.dg/builtin-redefine.c | 1 - libcpp/init.cc | 2 +- 2 files changed, 1 insertion(+), 2 deletions(-) diff --git a/gcc/testsuite/gcc.dg/builtin-redefine.c b/gcc/testsuite/gcc.dg/builtin-redefine.c index 882b2210992..9d5b42252ee 100644 --- a/gcc/testsuite/gcc.dg/builtin-redefine.c +++ b/gcc/testsuite/gcc.dg/builtin-redefine.c @@ -71,7 +71,6 @@ /* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */ #endif -#define __LINE__ 0 /* { dg-warning "-:\"__LINE__\" redef" } */ #define __INCLUDE_LEVEL__ 0 /* { dg-warning "-:\"__INCLUDE_LEVEL__\" redef" } */ #define __COUNTER__ 0 /* { dg-warning "-:\"__COUNTER__\" redef" } */ diff --git a/libcpp/init.cc b/libcpp/init.cc index 5f34e3515d2..2765b9838b7 100644 --- a/libcpp/init.cc +++ b/libcpp/init.cc @@ -421,7 +421,7 @@ static const struct builtin_macro builtin_array[] = B("__FILE__", BT_FILE, false), B("__FILE_NAME__", BT_FILE_NAME, false), B("__BASE_FILE__", BT_BASE_FILE, false), - B("__LINE__", BT_SPECLINE, true), + B("__LINE__", BT_SPECLINE, false), B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true), B("__COUNTER__", BT_COUNTER, true), /* Make sure to update the list of built-in -- 2.38.1