From 86005fdbf40d6fc84d84c824d75c656e7c1398e3 Mon Sep 17 00:00:00 2001 From: "Paul E. Murphy" Date: Fri, 6 Mar 2020 09:41:03 -0600 Subject: ldbl-128ibm-compat: workaround GCC 9 C++ PR90731 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit GCC 9 has a bug (PR90731) whereby __typeof does not correctly copy exception specifiers[1]. Surprisingly, this can be quieted by declaring "#pragma system_header", or if the headers are installed in a system directory. Work around this by using the pragma for any gcc version between 9.0 and 9.2 to ensure tests continue to compile. [1] Example error from g++ 9.2.1: In file included from ../include/sys/cdefs.h:3, from ../include/features.h:465, from ../bits/libc-header-start.h:33, from ../math/math.h:27, from ../include/math.h:7, from test-math-isinff.cc:21: ../libio/bits/stdio-ldbl.h:25:20: error: declaration of ‘int sprintf(char*, const char*, ...)’ has a different exception specifier 25 | __LDBL_REDIR_DECL (sprintf) | ^~~~~~~ ../misc/sys/cdefs.h:461:26: note: in definition of macro ‘__LDBL_REDIR_DECL’ 461 | extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128")); | ^~~~ In file included from ../include/stdio.h:5, from test-math-isinff.cc:22: ../libio/stdio.h:334:12: note: from previous declaration ‘int sprintf(char*, const char*, ...) throw ()’ 334 | extern int sprintf (char *__restrict __s, | ^~~~~~~ Reviewed-by: Tulio Magno Quites Machado Filho --- include/stdio.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/stdio.h') diff --git a/include/stdio.h b/include/stdio.h index 6718af4108..1c09daf13a 100644 --- a/include/stdio.h +++ b/include/stdio.h @@ -2,8 +2,18 @@ # if !defined _ISOMAC && defined _IO_MTSAFE_IO # include # endif + +/* Workaround PR90731 with GCC 9 when using ldbl redirects in C++. */ +# include +# if defined __cplusplus && __LONG_DOUBLE_USES_FLOAT128 == 1 +# if __GNUC_PREREQ (9, 0) && !__GNUC_PREREQ (9, 3) +# pragma GCC system_header +# endif +# endif + # include # ifndef _ISOMAC + # define _LIBC_STDIO_H 1 # include -- cgit 1.4.1