From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7814) id 7B1D53857C4A; Fri, 8 Oct 2021 01:44:21 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7B1D53857C4A Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Fangrui Song To: glibc-cvs@sourceware.org Subject: [glibc/maskray/clang] libc-symbols.h: Work around asm label issues with #pragma redefine_extname X-Act-Checkin: glibc X-Git-Author: Fangrui Song X-Git-Refname: refs/heads/maskray/clang X-Git-Oldrev: 46a1f512992264d017dc83fc2882400574eae964 X-Git-Newrev: 0881bdfb9179f78b4fd254eeb33ab5b24c7a213d Message-Id: <20211008014421.7B1D53857C4A@sourceware.org> Date: Fri, 8 Oct 2021 01:44:21 +0000 (GMT) X-BeenThere: glibc-cvs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Oct 2021 01:44:21 -0000 https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=0881bdfb9179f78b4fd254eeb33ab5b24c7a213d commit 0881bdfb9179f78b4fd254eeb33ab5b24c7a213d Author: Fangrui Song Date: Sat Sep 25 18:50:02 2021 -0700 libc-symbols.h: Work around asm label issues with #pragma redefine_extname Using asm labels can lead to `error: cannot apply asm label to function after its first use` in many places. `#pragma redefine_extname` has the same behavior with an asm label, but avoids the error. The symbol will not be properly renamed to a non-default version symbol. Diff: --- include/libc-symbols.h | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/include/libc-symbols.h b/include/libc-symbols.h index d41ecf4384..8a5a9ff0b3 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -534,9 +534,19 @@ for linking") __hidden_proto (name, , __GI_##name, ##attrs) # define hidden_tls_proto(name, attrs...) \ __hidden_proto (name, __thread, __GI_##name, ##attrs) -# define __hidden_proto(name, thread, internal, attrs...) \ +# ifdef __clang__ +# define __hidden_proto(name, thread, internal, attrs...) \ + extern thread __typeof (name) name \ + __hidden_proto_hiddenattr (attrs); \ + _Pragma (__redefine(name, internal)) +/* Note that this macro does not use __hidden_asmname, since it produces a string. */ +# define __redefine(name, internal) __stringize(redefine_extname name internal) +# define __stringize(X) #X +# else +# define __hidden_proto(name, thread, internal, attrs...) \ extern thread __typeof (name) name __asm__ (__hidden_asmname (#internal)) \ __hidden_proto_hiddenattr (attrs); +# endif # define __hidden_asmname(name) \ __hidden_asmname1 (__USER_LABEL_PREFIX__, name) # define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)