Re: [libvirt] Compiler warnings
On 10/18/2011 10:02 AM, Wen Congyang wrote:
At 10/18/2011 01:03 AM, Eric Blake Write:
On 10/17/2011 10:17 AM, Alex Jia wrote:
Eric,
It's latest libvirt upstream, current commit id is commit 0a71c79.
# rpm -q glibc
glibc-2.12-1.42.el6.x86_64
430 if (strchr(toescape, *cur))
CC libvirt_util_la-buf.lo
util/buf.c: In function 'virBufferEscape':
util/buf.c:430: warning: logical '' with non-zero constant will
always
evaluate as true [-Wlogical-op]
Something's screwy. There's no in that line, unless strchr() is a
macro based on your particular compilation flags. I'm suspecting that
this is a case of -D_FORTIFY_SOURCE going awry. I don't see how this
could possibly be a libvirt issue; more likely, it is an issue with the
choice of compiler flags you are using, coupled with an issue in the
system headers causing the preprocessor to expand strchr() into
something that tickles a spurious gcc warning.
Yes, strchr() is a macro, I use -E, and get the following:
while (*cur != 0) {
if ((__extension__ (__builtin_constant_p (*cur) !__builtin_constant_p
(toescape) (*cur) == '\0' ? (char *) __rawmemchr (toescape, *cur) : __builtin_strchr
(toescape, *cur
*out++ = '\\';
*out++ = *cur;
cur++;
}
*out = 0;
I reproduce this problem on RHEL6.
Hmm, I test it on Fedora15, and the problem does not happen.
I check the output with -E, and the macro strchr()'s expansion
is the same as its expansion on RHEL6.
I think it maybe gcc's problem.
Thanks
Wen Congyang
Thanks
Wen Congyang
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Re: [libvirt] Compiler warnings
On 10/17/2011 11:35 PM, Alex Jia wrote: Hi all, I meet the following compiler warnings today: .. CC libvirt_util_la-buf.lo util/buf.c: In function 'virBufferEscape': util/buf.c:430: warning: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] CC libvirt_util_la-command.lo .. CC libvirt_lxc-buf.o util/buf.c: In function 'virBufferEscape': util/buf.c:430: warning: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] CC libvirt_lxc-command.o .. Has anybody the same experience? I meet another warnings, but it does not break the buildings: CCLD libvirt_driver_remote.la CCLD libvirt.la CCLD libvirt_test.la *** Warning: Linking the shared library libvirt_test.la against the non-libtool *** objects probes.o is not portable! *** Warning: Linking the shared library libvirt.la against the non-libtool *** objects probes.o is not portable! CCLD libvirt-qemu.la make[3]: Leaving directory `/home/wency/rpmbuild/BUILD/libvirt-0.9.6/src' Thanks Wen Congyang Thanks, Alex -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] Compiler warnings
On 10/18/2011 07:21 AM, Wen Congyang wrote: I meet another warnings, but it does not break the buildings: CCLD libvirt_driver_remote.la CCLD libvirt.la CCLD libvirt_test.la *** Warning: Linking the shared library libvirt_test.la against the non-libtool *** objects probes.o is not portable! Yes, that warning is present if you are compiling on Linux and have the dtrace tool enabled for systemtap probe points. It is harmless, because we aren't trying to link against probes.o on any platform except Linux, but we have no way to tell libtool to shut up. It would only be worth worrying about if we tried to use probes.o on other platforms. -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] Compiler warnings
On 10/17/2011 09:35 AM, Alex Jia wrote: Hi all, I meet the following compiler warnings today: .. CC libvirt_util_la-buf.lo util/buf.c: In function 'virBufferEscape': util/buf.c:430: warning: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] Which version of gcc? Has anybody the same experience? Not with gcc 4.5.1 (Fedora 14), but not the first time that newer gcc has become smarter. I'll patch it if I can reproduce it (I'll try a rawhide build shortly). -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] Compiler warnings
Eric, # rpm -q gcc gcc-4.4.6-3.el6.x86_64 Regards, Alex - Original Message - From: Eric Blake ebl...@redhat.com To: Alex Jia a...@redhat.com Cc: libvir-list@redhat.com Sent: Monday, October 17, 2011 11:38:50 PM Subject: Re: [libvirt] Compiler warnings On 10/17/2011 09:35 AM, Alex Jia wrote: Hi all, I meet the following compiler warnings today: .. CC libvirt_util_la-buf.lo util/buf.c: In function 'virBufferEscape': util/buf.c:430: warning: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] Which version of gcc? Has anybody the same experience? Not with gcc 4.5.1 (Fedora 14), but not the first time that newer gcc has become smarter. I'll patch it if I can reproduce it (I'll try a rawhide build shortly). -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] Compiler warnings
On 10/17/2011 09:51 AM, Alex Jia wrote: Eric, # rpm -q gcc gcc-4.4.6-3.el6.x86_64 I'm still not seeing it on my RHEL 6 host. What version of glibc (in case it's a header problem), and is this the latest libvirt.git or a particular source rpm rebuild? What's on line 430 of the file in question? CC libvirt_util_la-buf.lo util/buf.c: In function 'virBufferEscape': util/buf.c:430: warning: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] Compiler warnings
Eric,
It's latest libvirt upstream, current commit id is commit 0a71c79.
# rpm -q glibc
glibc-2.12-1.42.el6.x86_64
399 void
400 virBufferEscape(const virBufferPtr buf,
401 const char *toescape,
402 const char *format,
403 const char *str)
404 {
.
427 cur = str;
428 out = escaped;
429 while (*cur != 0) {
430 if (strchr(toescape, *cur))
431 *out++ = '\\';
432 *out++ = *cur;
433 cur++;
434 }
..
Regards,
Alex
- Original Message -
From: Eric Blake ebl...@redhat.com
To: Alex Jia a...@redhat.com
Cc: libvir-list@redhat.com
Sent: Tuesday, October 18, 2011 12:11:19 AM
Subject: Re: [libvirt] Compiler warnings
On 10/17/2011 09:51 AM, Alex Jia wrote:
Eric,
# rpm -q gcc
gcc-4.4.6-3.el6.x86_64
I'm still not seeing it on my RHEL 6 host. What version of glibc (in
case it's a header problem), and is this the latest libvirt.git or a
particular source rpm rebuild? What's on line 430 of the file in question?
CC libvirt_util_la-buf.lo
util/buf.c: In function 'virBufferEscape':
util/buf.c:430: warning: logical '' with non-zero constant will always
evaluate as true [-Wlogical-op]
--
Eric Blake ebl...@redhat.com+1-801-349-2682
Libvirt virtualization library http://libvirt.org
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Re: [libvirt] Compiler warnings
On 10/17/2011 11:03 AM, Eric Blake wrote: On 10/17/2011 10:17 AM, Alex Jia wrote: Eric, It's latest libvirt upstream, current commit id is commit 0a71c79. # rpm -q glibc glibc-2.12-1.42.el6.x86_64 430 if (strchr(toescape, *cur)) CC libvirt_util_la-buf.lo util/buf.c: In function 'virBufferEscape': util/buf.c:430: warning: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] Something's screwy. There's no in that line, unless strchr() is a macro based on your particular compilation flags. I'm suspecting that this is a case of -D_FORTIFY_SOURCE going awry. I don't see how this could possibly be a libvirt issue; more likely, it is an issue with the choice of compiler flags you are using, coupled with an issue in the system headers causing the preprocessor to expand strchr() into something that tickles a spurious gcc warning. Just to make sure, could you show 'make V=1' output, so we know exactly which compiler flags are in effect? -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] Compiler warnings
On 10/17/2011 10:17 AM, Alex Jia wrote: Eric, It's latest libvirt upstream, current commit id is commit 0a71c79. # rpm -q glibc glibc-2.12-1.42.el6.x86_64 430 if (strchr(toescape, *cur)) CC libvirt_util_la-buf.lo util/buf.c: In function 'virBufferEscape': util/buf.c:430: warning: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] Something's screwy. There's no in that line, unless strchr() is a macro based on your particular compilation flags. I'm suspecting that this is a case of -D_FORTIFY_SOURCE going awry. I don't see how this could possibly be a libvirt issue; more likely, it is an issue with the choice of compiler flags you are using, coupled with an issue in the system headers causing the preprocessor to expand strchr() into something that tickles a spurious gcc warning. -- Eric Blake ebl...@redhat.com+1-801-349-2682 Libvirt virtualization library http://libvirt.org -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] Compiler warnings
At 10/18/2011 01:04 AM, Eric Blake Write: On 10/17/2011 11:03 AM, Eric Blake wrote: On 10/17/2011 10:17 AM, Alex Jia wrote: Eric, It's latest libvirt upstream, current commit id is commit 0a71c79. # rpm -q glibc glibc-2.12-1.42.el6.x86_64 430 if (strchr(toescape, *cur)) CC libvirt_util_la-buf.lo util/buf.c: In function 'virBufferEscape': util/buf.c:430: warning: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] Something's screwy. There's no in that line, unless strchr() is a macro based on your particular compilation flags. I'm suspecting that this is a case of -D_FORTIFY_SOURCE going awry. I don't see how this could possibly be a libvirt issue; more likely, it is an issue with the choice of compiler flags you are using, coupled with an issue in the system headers causing the preprocessor to expand strchr() into something that tickles a spurious gcc warning. Just to make sure, could you show 'make V=1' output, so we know exactly which compiler flags are in effect? I can reproduce this problem, here is 'make V=1' output: = make[3]: Entering directory `/root/rpmbuild/BUILD/libvirt-0.9.6/src' /bin/sh ../libtool --tag=CC --mode=compile gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -I../gnulib/lib -I../gnulib/lib -I../include -I../src/util -I../include -DIN_LIBVIRT-I/usr/include/libxml2 -Wall -W -Wformat-y2k -Wformat-security -Winit-self -Wmissing-include-dirs -Wunused -Wunknown-pragmas -Wstrict-aliasing -Wshadow -Wpointer-arith -Wbad-function-cast -Wcast-align -Wwrite-strings -Wlogical-op -Waggregate-return -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-declarations -Wmissing-noreturn -Wmissing-format-attribute -Wredundant-decls -Wnested-externs -Winline -Winvalid-pch -Wvolatile-register-var -Wdisabled-optimization -Wbuiltin-macro-redefined -Wmudflap -Wpacked-bitfield-compat -Wsync-nand -Wattributes -Wcoverage-mismatch -Wmultichar -Wno-missing-field-initializers -Wno-sign-compare -Wframe-larger-than=4096 -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-all --param=ssp-buffer-size=4 -fexceptions -fasynchronous-unwind-tables -fdiagnostics-s how-option -funit-at-a-time -Werror -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -MT libvirt_util_la-buf.lo -MD -MP -MF .deps/libvirt_util_la-buf.Tpo -c -o libvirt_util_la-buf.lo `test -f 'util/buf.c' || echo './'`util/buf.c libtool: compile: gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -I../gnulib/lib -I../gnulib/lib -I../include -I../src/util -I../include -DIN_LIBVIRT -I/usr/include/libxml2 -Wall -W -Wformat-y2k -Wformat-security -Winit-self -Wmissing-include-dirs -Wunused -Wunknown-pragmas -Wstrict-aliasing -Wshadow -Wpointer-arith -Wbad-function-cast -Wcast-align -Wwrite-strings -Wlogical-op -Waggregate-return -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-declarations -Wmissing-noreturn -Wmissing-format-attribute -Wredundant-decls -Wnested-externs -Winline -Winvalid-pch -Wvolatile-register-var -Wdisabled-optimization -Wbuiltin-macro-redefined -Wmudflap -Wpacked-bitfield-compat -Wsync-nand -Wattributes -Wcoverage-mismatch -Wmultichar -Wno-missing-field-initializers -Wno-sign-compare -Wframe-larger-than=4096 -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-all --param=ssp-buffer-size=4 -fexceptions -fasynchronous-unwind-tables -fdiagnostics-show-option -funit-at-a-time -Werror -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -MT libvirt_util_la-buf.lo -MD -MP -MF .deps/libvirt_util_la-buf.Tpo -c util/buf.c -fPIC -DPIC -o .libs/libvirt_util_la-buf.o cc1: warnings being treated as errors util/buf.c: In function 'virBufferEscape': util/buf.c:430: error: logical '' with non-zero constant will always evaluate as true [-Wlogical-op] make[3]: *** [libvirt_util_la-buf.lo] Error 1 = If I remove -O2, I can build util/buf.c. I am still investigating this problem. Thanks Wen Congyang -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] Compiler warnings
At 10/18/2011 01:03 AM, Eric Blake Write:
On 10/17/2011 10:17 AM, Alex Jia wrote:
Eric,
It's latest libvirt upstream, current commit id is commit 0a71c79.
# rpm -q glibc
glibc-2.12-1.42.el6.x86_64
430 if (strchr(toescape, *cur))
CC libvirt_util_la-buf.lo
util/buf.c: In function 'virBufferEscape':
util/buf.c:430: warning: logical '' with non-zero constant will
always
evaluate as true [-Wlogical-op]
Something's screwy. There's no in that line, unless strchr() is a
macro based on your particular compilation flags. I'm suspecting that
this is a case of -D_FORTIFY_SOURCE going awry. I don't see how this
could possibly be a libvirt issue; more likely, it is an issue with the
choice of compiler flags you are using, coupled with an issue in the
system headers causing the preprocessor to expand strchr() into
something that tickles a spurious gcc warning.
Yes, strchr() is a macro, I use -E, and get the following:
while (*cur != 0) {
if ((__extension__ (__builtin_constant_p (*cur)
!__builtin_constant_p (toescape) (*cur) == '\0' ? (char *) __rawmemchr
(toescape, *cur) : __builtin_strchr (toescape, *cur
*out++ = '\\';
*out++ = *cur;
cur++;
}
*out = 0;
Thanks
Wen Congyang
--
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Re: [libvirt] Compiler warnings
At 10/18/2011 09:32 AM, Wen Congyang Write:
At 10/18/2011 01:04 AM, Eric Blake Write:
On 10/17/2011 11:03 AM, Eric Blake wrote:
On 10/17/2011 10:17 AM, Alex Jia wrote:
Eric,
It's latest libvirt upstream, current commit id is commit 0a71c79.
# rpm -q glibc
glibc-2.12-1.42.el6.x86_64
430 if (strchr(toescape, *cur))
CC libvirt_util_la-buf.lo
util/buf.c: In function 'virBufferEscape':
util/buf.c:430: warning: logical '' with non-zero constant will
always
evaluate as true [-Wlogical-op]
Something's screwy. There's no in that line, unless strchr() is a
macro based on your particular compilation flags. I'm suspecting that
this is a case of -D_FORTIFY_SOURCE going awry. I don't see how this
could possibly be a libvirt issue; more likely, it is an issue with the
choice of compiler flags you are using, coupled with an issue in the
system headers causing the preprocessor to expand strchr() into
something that tickles a spurious gcc warning.
Just to make sure, could you show 'make V=1' output, so we know exactly
which compiler flags are in effect?
I can reproduce this problem, here is 'make V=1' output:
=
make[3]: Entering directory `/root/rpmbuild/BUILD/libvirt-0.9.6/src'
/bin/sh ../libtool --tag=CC --mode=compile gcc -std=gnu99 -DHAVE_CONFIG_H
-I. -I.. -I../gnulib/lib -I../gnulib/lib -I../include -I../src/util
-I../include -DIN_LIBVIRT-I/usr/include/libxml2 -Wall -W
-Wformat-y2k -Wformat-security -Winit-self -Wmissing-include-dirs -Wunused
-Wunknown-pragmas -Wstrict-aliasing -Wshadow -Wpointer-arith
-Wbad-function-cast -Wcast-align -Wwrite-strings -Wlogical-op
-Waggregate-return -Wstrict-prototypes -Wold-style-definition
-Wmissing-prototypes -Wmissing-declarations -Wmissing-noreturn
-Wmissing-format-attribute -Wredundant-decls -Wnested-externs -Winline
-Winvalid-pch -Wvolatile-register-var -Wdisabled-optimization
-Wbuiltin-macro-redefined -Wmudflap -Wpacked-bitfield-compat -Wsync-nand
-Wattributes -Wcoverage-mismatch -Wmultichar -Wno-missing-field-initializers
-Wno-sign-compare -Wframe-larger-than=4096 -Wp,-D_FORTIFY_SOURCE=2
-fstack-protector-all --param=ssp-buffer-size=4 -fexceptions
-fasynchronous-unwind-tables -fdiagnostics
-s
how-option -funit-at-a-time -Werror -O2 -g -pipe -Wall
-Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector
--param=ssp-buffer-size=4 -m64 -mtune=generic -MT libvirt_util_la-buf.lo -MD
-MP -MF .deps/libvirt_util_la-buf.Tpo -c -o libvirt_util_la-buf.lo `test -f
'util/buf.c' || echo './'`util/buf.c
libtool: compile: gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -I../gnulib/lib
-I../gnulib/lib -I../include -I../src/util -I../include -DIN_LIBVIRT
-I/usr/include/libxml2 -Wall -W -Wformat-y2k -Wformat-security -Winit-self
-Wmissing-include-dirs -Wunused -Wunknown-pragmas -Wstrict-aliasing -Wshadow
-Wpointer-arith -Wbad-function-cast -Wcast-align -Wwrite-strings -Wlogical-op
-Waggregate-return -Wstrict-prototypes -Wold-style-definition
-Wmissing-prototypes -Wmissing-declarations -Wmissing-noreturn
-Wmissing-format-attribute -Wredundant-decls -Wnested-externs -Winline
-Winvalid-pch -Wvolatile-register-var -Wdisabled-optimization
-Wbuiltin-macro-redefined -Wmudflap -Wpacked-bitfield-compat -Wsync-nand
-Wattributes -Wcoverage-mismatch -Wmultichar -Wno-missing-field-initializers
-Wno-sign-compare -Wframe-larger-than=4096 -Wp,-D_FORTIFY_SOURCE=2
-fstack-protector-all --param=ssp-buffer-size=4 -fexceptions
-fasynchronous-unwind-tables -fdiagnostics-show-option -funit-at-a-time -Werro
r
-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector
--param=ssp-buffer-size=4 -m64 -mtune=generic -MT libvirt_util_la-buf.lo -MD
-MP -MF .deps/libvirt_util_la-buf.Tpo -c util/buf.c -fPIC -DPIC -o
.libs/libvirt_util_la-buf.o
cc1: warnings being treated as errors
util/buf.c: In function 'virBufferEscape':
util/buf.c:430: error: logical '' with non-zero constant will always
evaluate as true [-Wlogical-op]
make[3]: *** [libvirt_util_la-buf.lo] Error 1
=
If I remove -O2, I can build util/buf.c.
I test strchr in a small program:
=
# cat test.c
#include stdio.h
#include string.h
int main() {
char *s = abcdefg;
int chr = (int)'d';
char *d;
d = strchr(s, chr);
if (d)
printf(%s\n, d);
return 0;
}
# gcc -std=c99 -Wall -o test test.c -Wlogical-op -Werror
# gcc -std=c99 -O2 -Wall -o test test.c -Wlogical-op -Werror
cc1: warnings being treated as errors
test.c: In function ‘main’:
test.c:9: error: logical ‘’ with non-zero constant will always evaluate as
true
# gcc -std=c99 -Wall -o test test.c -Wlogical-op -Werror
# gcc -std=c99 -Wall -o test test.c -Werror
=
The building failed only when '-O2' and '-Wlogical-op' are specified at the
Re: [libvirt] Compiler warnings
On 10/18/2011 10:09 AM, Wen Congyang wrote:
At 10/18/2011 09:32 AM, Wen Congyang Write:
At 10/18/2011 01:04 AM, Eric Blake Write:
On 10/17/2011 11:03 AM, Eric Blake wrote:
On 10/17/2011 10:17 AM, Alex Jia wrote:
Eric,
It's latest libvirt upstream, current commit id is commit 0a71c79.
# rpm -q glibc
glibc-2.12-1.42.el6.x86_64
430 if (strchr(toescape, *cur))
CC libvirt_util_la-buf.lo
util/buf.c: In function 'virBufferEscape':
util/buf.c:430: warning: logical '' with non-zero constant will
always
evaluate as true [-Wlogical-op]
Something's screwy. There's no in that line, unless strchr() is a
macro based on your particular compilation flags. I'm suspecting that
this is a case of -D_FORTIFY_SOURCE going awry. I don't see how this
could possibly be a libvirt issue; more likely, it is an issue with the
choice of compiler flags you are using, coupled with an issue in the
system headers causing the preprocessor to expand strchr() into
something that tickles a spurious gcc warning.
Just to make sure, could you show 'make V=1' output, so we know exactly
which compiler flags are in effect?
I can reproduce this problem, here is 'make V=1' output:
=
make[3]: Entering directory `/root/rpmbuild/BUILD/libvirt-0.9.6/src'
/bin/sh ../libtool --tag=CC --mode=compile gcc -std=gnu99 -DHAVE_CONFIG_H
-I. -I.. -I../gnulib/lib -I../gnulib/lib -I../include -I../src/util
-I../include -DIN_LIBVIRT-I/usr/include/libxml2 -Wall -W -Wformat-y2k
-Wformat-security -Winit-self -Wmissing-include-dirs -Wunused -Wunknown-pragmas
-Wstrict-aliasing -Wshadow -Wpointer-arith -Wbad-function-cast -Wcast-align
-Wwrite-strings -Wlogical-op -Waggregate-return -Wstrict-prototypes
-Wold-style-definition -Wmissing-prototypes -Wmissing-declarations
-Wmissing-noreturn -Wmissing-format-attribute -Wredundant-decls
-Wnested-externs -Winline -Winvalid-pch -Wvolatile-register-var
-Wdisabled-optimization -Wbuiltin-macro-redefined -Wmudflap
-Wpacked-bitfield-compat -Wsync-nand -Wattributes -Wcoverage-mismatch
-Wmultichar -Wno-missing-field-initializers -Wno-sign-compare
-Wframe-larger-than=4096 -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-all
--param=ssp-buffer-size=4 -fexceptions -fasynchronous-unwind-tables
-fdiagnostics
-s
how-option -funit-at-a-time -Werror -O2 -g -pipe -Wall
-Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector
--param=ssp-buffer-size=4 -m64 -mtune=generic -MT libvirt_util_la-buf.lo -MD
-MP -MF .deps/libvirt_util_la-buf.Tpo -c -o libvirt_util_la-buf.lo `test -f
'util/buf.c' || echo './'`util/buf.c
libtool: compile: gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -I../gnulib/lib
-I../gnulib/lib -I../include -I../src/util -I../include -DIN_LIBVIRT
-I/usr/include/libxml2 -Wall -W -Wformat-y2k -Wformat-security -Winit-self
-Wmissing-include-dirs -Wunused -Wunknown-pragmas -Wstrict-aliasing -Wshadow
-Wpointer-arith -Wbad-function-cast -Wcast-align -Wwrite-strings -Wlogical-op
-Waggregate-return -Wstrict-prototypes -Wold-style-definition
-Wmissing-prototypes -Wmissing-declarations -Wmissing-noreturn
-Wmissing-format-attribute -Wredundant-decls -Wnested-externs -Winline
-Winvalid-pch -Wvolatile-register-var -Wdisabled-optimization
-Wbuiltin-macro-redefined -Wmudflap -Wpacked-bitfield-compat -Wsync-nand
-Wattributes -Wcoverage-mismatch -Wmultichar -Wno-missing-field-initializers
-Wno-sign-compare -Wframe-larger-than=4096 -Wp,-D_FORTIFY_SOURCE=2
-fstack-protector-all --param=ssp-buffer-size=4 -fexceptions
-fasynchronous-unwind-tables -fdiagnostics-show-option -funit-at-a-time -Werro
r
-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector
--param=ssp-buffer-size=4 -m64 -mtune=generic -MT libvirt_util_la-buf.lo -MD
-MP -MF .deps/libvirt_util_la-buf.Tpo -c util/buf.c -fPIC -DPIC -o
.libs/libvirt_util_la-buf.o
cc1: warnings being treated as errors
util/buf.c: In function 'virBufferEscape':
util/buf.c:430: error: logical '' with non-zero constant will always evaluate
as true [-Wlogical-op]
make[3]: *** [libvirt_util_la-buf.lo] Error 1
=
If I remove -O2, I can build util/buf.c.
I test strchr in a small program:
=
# cat test.c
#includestdio.h
#includestring.h
int main() {
char *s = abcdefg;
int chr = (int)'d';
char *d;
d = strchr(s, chr);
if (d)
printf(%s\n, d);
return 0;
}
# gcc -std=c99 -Wall -o test test.c -Wlogical-op -Werror
# gcc -std=c99 -O2 -Wall -o test test.c -Wlogical-op -Werror
cc1: warnings being treated as errors
test.c: In function ‘main’:
test.c:9: error: logical ‘’ with non-zero constant will always evaluate as
true
# gcc -std=c99 -Wall -o test test.c -Wlogical-op -Werror
# gcc -std=c99 -Wall -o test test.c -Werror
=
The building failed only when '-O2' and '-Wlogical-op' are specified at the
same time.
