From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2119) id 22B133858C66; Sun, 30 Apr 2023 18:30:18 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 22B133858C66 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1682879418; bh=9hu5aQCEesGVa0OaAnzwIEQvmwAxyKWcpezsRlVFsMk=; h=From:To:Subject:Date:From; b=HtAya43Hgfyuj2lCwbk9ob3P5wzvD/E6xBUTvvwLUr+TOLw7xoZqXTx5dIR9R5LHe RxVLxn+X+qFjSm8MhloEfy9XYVw3MFMwp05xI72r50G0h2K60IMrZCqEwqnZtXtXvU vkOlBGrQr60fy/iioYoFUzu9+ie1Ol58DBGIG8mc= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jeff Law To: gcc-cvs@gcc.gnu.org Subject: [gcc r14-358] [PATCH] libcpp: suppress builtin macro redefined warnings for __LINE__ X-Act-Checkin: gcc X-Git-Author: Longjun Luo X-Git-Refname: refs/heads/master X-Git-Oldrev: 2744dbb9ecf104a113da3a0f39115da4653bb676 X-Git-Newrev: e7ce7c4905fd254760b1cd187752a03bc0c148ba Message-Id: <20230430183018.22B133858C66@sourceware.org> Date: Sun, 30 Apr 2023 18:30:18 +0000 (GMT) List-Id: https://gcc.gnu.org/g:e7ce7c4905fd254760b1cd187752a03bc0c148ba commit r14-358-ge7ce7c4905fd254760b1cd187752a03bc0c148ba Author: Longjun Luo Date: Sun Apr 30 12:28:06 2023 -0600 [PATCH] libcpp: suppress builtin macro redefined warnings for __LINE__ From 0821df518b264e754d698d399f98be1a62945e32 Mon Sep 17 00:00:00 2001 From: Longjun Luo Date: Thu, 12 Jan 2023 23:59:54 +0800 Subject: [PATCH] libcpp: suppress builtin macro redefined warnings for __LINE__ 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. libcpp: * init.cc (builtin_array): Do not always warn for a redefinition of __LINE__. gcc/testsuite * gcc.dg/builtin-redefine.c: Test for redefintion warnings for __LINE__. * gcc.dg/builtin-redefine-1.c: New test. Diff: --- gcc/testsuite/gcc.dg/builtin-redefine-1.c | 49 +++++++++++++++++++++++++++++++ gcc/testsuite/gcc.dg/builtin-redefine.c | 24 ++++++++++++--- libcpp/init.cc | 2 +- 3 files changed, 70 insertions(+), 5 deletions(-) diff --git a/gcc/testsuite/gcc.dg/builtin-redefine-1.c b/gcc/testsuite/gcc.dg/builtin-redefine-1.c new file mode 100755 index 00000000000..c1e05b4fc7c --- /dev/null +++ b/gcc/testsuite/gcc.dg/builtin-redefine-1.c @@ -0,0 +1,49 @@ +/* Test default warnings for redefining builtin macros. */ + +/* { dg-do compile } */ +/* { dg-options "-D__TIMESTAMP__=x -D__TIME__=x -D__DATE__=x -D__FILE__=x -D__FILE_NAME__=x -D__BASE_FILE__=x -D__LINE__=0" } */ + +/* Check default behavior for builtin macros redefinition. */ + +/* { dg-message "\"__TIMESTAMP__\" redefined" "" {target "*-*-*"} 0 } */ +#ifndef __TIMESTAMP__ +#error "__TIMESTAMP__ builtin is not defined" +/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */ +#endif + +/* { dg-message "\"__TIME__\" redefined" "" {target "*-*-*"} 0 } */ +#ifndef __TIME__ +#error "__TIME__ builtin is not defined" +/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */ +#endif + +/* { dg-message "\"__DATE__\" redefined" "" {target "*-*-*"} 0 } */ +#ifndef __DATE__ +#error "__DATE__ builtin is not defined" +/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */ +#endif + +/* { dg-message "\"__FILE__\" redefined" "" {target "*-*-*"} 0 } */ +#ifndef __FILE__ +#error "__FILE__ builtin is not defined" +/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */ +#endif + +/* { dg-message "\"__FILE_NAME__\" redefined" "" {target "*-*-*"} 0 } */ +#ifndef __FILE_NAME__ +#error "__FILE_NAME__ builtin is not defined" +/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */ +#endif + +/* { dg-message "\"__BASE_FILE__\" redefined" "" {target "*-*-*"} 0 } */ +#ifndef __BASE_FILE__ +#error "__BASE_FILE__ builtin is not defined" +/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */ +#endif + +/* { dg-message "\"__LINE__\" redefined" "" {target "*-*-*"} 0 } */ +#ifndef __LINE__ +#error "__LINE__ builtin is not defined" +/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */ +#endif + diff --git a/gcc/testsuite/gcc.dg/builtin-redefine.c b/gcc/testsuite/gcc.dg/builtin-redefine.c index 882b2210992..fa27ee9aefc 100644 --- a/gcc/testsuite/gcc.dg/builtin-redefine.c +++ b/gcc/testsuite/gcc.dg/builtin-redefine.c @@ -1,9 +1,9 @@ /* Test -Wno-builtin-macro-redefined warnings. */ /* { dg-do compile } */ -/* { dg-options "-Wno-builtin-macro-redefined -U__DATE__ -D__TIME__=X" } */ +/* { dg-options "-Wno-builtin-macro-redefined -U__DATE__ -D__TIME__=X -D__LINE__=0" } */ -/* Check date, time, and datestamp built-ins warnings may be suppressed. */ +/* Check date, time, datestamp and line built-ins warnings may be suppressed. */ #if defined(__DATE__) #error "__DATE__ is defined, but should not be (-U command line error)" @@ -15,6 +15,11 @@ /* { dg-bogus "__TIME__ is not defined" "" { target *-*-* } .-1 } */ #endif +#if __LINE__ != 0 +#error "__LINE__ is not defined as expected (-D command line error)" +/* { dg-bogus "__LINE__ is not defined" "" { target *-*-* } .-1 } */ +#endif + #if !defined(__TIMESTAMP__) #error "__TIMESTAMP__ is not defined (built-in macro expectation error)" /* { dg-bogus "__TIMESTAMP__ is not defined" "" { target *-*-* } .-1 } */ @@ -53,6 +58,18 @@ #undef __TIMESTAMP__ /* Undefine while defined. */ +#undef __LINE__ /* Undefine while defined. */ +#undef __LINE__ /* Undefine while already undefined. */ + +#define __LINE__ "1" /* Define while undefined. */ +#define __LINE__ "1" /* Re-define while defined. */ /* { dg-line line_prev } */ + +#define __LINE__ "2" /* { dg-warning "-:\"__LINE__\" redefined" } */ +/* { dg-message "-:previous definition" "" { target *-*-* } line_prev } */ + +#undef __LINE__ /* Undefine while defined. */ + + /* Check other built-ins with warnings that may be suppressed. */ #if !defined(__FILE__) || !defined(__BASE_FILE__) @@ -66,12 +83,11 @@ /* Check selected built-ins not affected by warning suppression. */ -#if !defined(__LINE__) || !defined(__INCLUDE_LEVEL__) || !defined(__COUNTER__) +#if !defined(__INCLUDE_LEVEL__) || !defined(__COUNTER__) #error "Expected built-in is not defined (built-in macro expectation error)" /* { 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 c508f06112a..bdeccffa029 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