From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1791) id 5F6EF385842C; Wed, 7 Feb 2024 14:04:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5F6EF385842C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1707314680; bh=xHqFOxcsTvinFhZeOJu+xgFZ13FZzc24gOfqu/FseK8=; h=From:To:Subject:Date:From; b=P9gExh26+ddxlG1IMn0XZhweIG3RGqbbRoQGBJYvceUCundXgoTnW+hzA//FsBF5W MjPVODQQXQhODWY134QCOx+apufZiwWQab1mLGRTcCVBTpP7GKjsJzT1YBOorMI36G GtinNXgzTvVE4Xlj6fgUXsHAkMRpXkRlBGI4vnQg= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Adhemerval Zanella To: glibc-cvs@sourceware.org Subject: [glibc/azanella/clang] elf: Suppress unused function clang for __ifunc_resolver X-Act-Checkin: glibc X-Git-Author: Adhemerval Zanella X-Git-Refname: refs/heads/azanella/clang X-Git-Oldrev: df3a2ca675447f8afda450ff0e31d8ad42028dd8 X-Git-Newrev: cc2dc55feb1324caec6dd5dfb522c958a558ae18 Message-Id: <20240207140440.5F6EF385842C@sourceware.org> Date: Wed, 7 Feb 2024 14:04:40 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=cc2dc55feb1324caec6dd5dfb522c958a558ae18 commit cc2dc55feb1324caec6dd5dfb522c958a558ae18 Author: Adhemerval Zanella Date: Thu Aug 4 09:43:18 2022 -0300 elf: Suppress unused function clang for __ifunc_resolver The __ifunc_resolver macro expands to: extern __typeof (__redirect_name) name __attribute__ ((ifunc ("iname_ifunc"))); static __typeof (__redirect_name) *name_ifunc (void) { [...] }; And although NAME_IFUNC is and alias for NAME, clang still emits an 'unused function 'name_ifunc' [-Werror,-Wunused-function]' warning. The static is used to avoid name pollution on static linkage. Diff: --- elf/ifuncmain9.c | 4 ++++ elf/tst-ifunc-fault-lazy.c | 4 ++++ include/libc-symbols.h | 6 +++++- 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/elf/ifuncmain9.c b/elf/ifuncmain9.c index 43011452b7..a13020dc6d 100644 --- a/elf/ifuncmain9.c +++ b/elf/ifuncmain9.c @@ -22,6 +22,7 @@ # include # include +# include /* Do not use the test framework, so that the process setup is not disturbed. */ @@ -40,6 +41,8 @@ implementation (void) return random_constant; } +DIAG_PUSH_NEEDS_COMMENT_CLANG; +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); static __typeof__ (implementation) * inhibit_stack_protector resolver (void) @@ -49,6 +52,7 @@ resolver (void) } static int magic (void) __attribute__ ((ifunc ("resolver"))); +DIAG_POP_NEEDS_COMMENT_CLANG; int main (void) diff --git a/elf/tst-ifunc-fault-lazy.c b/elf/tst-ifunc-fault-lazy.c index 5157c6cc6c..04448b2b15 100644 --- a/elf/tst-ifunc-fault-lazy.c +++ b/elf/tst-ifunc-fault-lazy.c @@ -21,6 +21,7 @@ relocations. */ #include +#include #ifdef HAVE_GCC_IFUNC @@ -34,6 +35,8 @@ implementation (void) *p = 0; } +DIAG_PUSH_NEEDS_COMMENT_CLANG; +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); static __typeof__ (implementation) * resolver (void) { @@ -42,6 +45,7 @@ resolver (void) *p = 0; return implementation; } +DIAG_POP_NEEDS_COMMENT_CLANG; static void magic (void) __attribute__ ((ifunc ("resolver"))); diff --git a/include/libc-symbols.h b/include/libc-symbols.h index d14837631b..1387525484 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -86,6 +86,7 @@ /* Obtain the definition of symbol_version_reference. */ #include +#include /* When PIC is defined and SHARED isn't defined, we are building PIE by default. */ @@ -685,7 +686,10 @@ for linking") # define __ifunc(type_name, name, expr, arg, init) \ extern __typeof (type_name) name __attribute__ \ ((ifunc (#name "_ifunc"))); \ - __ifunc_resolver (type_name, name, expr, arg, init, static) + DIAG_PUSH_NEEDS_COMMENT_CLANG; \ + DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); \ + __ifunc_resolver (type_name, name, expr, arg, init, static); \ + DIAG_POP_NEEDS_COMMENT_CLANG; # define __ifunc_hidden(type_name, name, expr, arg, init) \ __ifunc (type_name, name, expr, arg, init)