Hi, building with compiler flags "-Wall -O2 -D_FORTIFY_SOURCE=2" throws some warnings:
[EMAIL PROTECTED]:~/projects/powermanagement/cvs/suspend> make CFLAGS='-Wall -O2 -D_FORTIFY_SOURCE=2' cc -Wall -O2 -D_FORTIFY_SOURCE=2 -c vt.c -o vt.o cc -Wall -O2 -D_FORTIFY_SOURCE=2 -DHAVE_INTTYPES_H -DHAVE_STDINT_H -c md5.c -o md5.o cc -Wall -O2 -D_FORTIFY_SOURCE=2 -DHAVE_INTTYPES_H -DHAVE_STDINT_H -I/usr/local/include -c encrypt.c -o encrypt.o cc -Wall -O2 -D_FORTIFY_SOURCE=2 -I/usr/local/include -c config.c -o config.o cc -g -Wall -O2 -D_FORTIFY_SOURCE=2 -I/usr/local/include -c bootsplash.c -o bootsplash.o cc -g -Wall -O2 -D_FORTIFY_SOURCE=2 -I/usr/local/include -c splash.c -o splash.o cc -g -Wall -O2 -D_FORTIFY_SOURCE=2 -I/usr/local/include vt.o md5.o encrypt.o config.o suspend.c -o s2disk splash.o bootsplash.o -L/usr/local/lib suspend.c: In function ‘prepare_console’: suspend.c:816: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result suspend.c: In function ‘get_kernel_console_loglevel’: suspend.c:886: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result suspend.c: In function ‘get_swappiness’: suspend.c:919: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result suspend.c: In function ‘main’: suspend.c:1192: warning: ignoring return value of ‘chdir’, declared with attribute warn_unused_result cc -Wall -O2 -D_FORTIFY_SOURCE=2 -c vbetool/lrmi.c -o vbetool/lrmi.o cc -Wall -O2 -D_FORTIFY_SOURCE=2 -c vbetool/x86-common.c -o vbetool/x86-common.o cc -Wall -O2 -D_FORTIFY_SOURCE=2 -DS2RAM -c vbetool/vbetool.c -o vbetool/vbetool.o vbetool/vbetool.c: In function ‘save_state’: vbetool/vbetool.c:347: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result cc -Wall -O2 -D_FORTIFY_SOURCE=2 -DS2RAM -c radeontool.c -o radeontool.o cc -Wall -O2 -D_FORTIFY_SOURCE=2 -DS2RAM -c dmidecode.c -o dmidecode.o cc -g -Wall -O2 -D_FORTIFY_SOURCE=2 -DCONFIG_BOTH -I/usr/local/include md5.o encrypt.o config.o suspend.c s2ram.c -o s2both vt.o vbetool/lrmi.o vbetool/x86-common.o vbetool/vbetool.o radeontool.o dmidecode.o splash.o bootsplash.o -L/usr/local/lib -lpci suspend.c: In function ‘prepare_console’: suspend.c:816: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result suspend.c: In function ‘get_kernel_console_loglevel’: suspend.c:886: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result suspend.c: In function ‘get_swappiness’: suspend.c:919: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result suspend.c: In function ‘main’: suspend.c:1192: warning: ignoring return value of ‘chdir’, declared with attribute warn_unused_result cc -Wall -O2 -D_FORTIFY_SOURCE=2 -I/usr/local/include md5.o encrypt.o config.o vt.o resume.c splash.o bootsplash.o -static -o resume -L/usr/local/lib resume.c: In function ‘main’: resume.c:737: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result cc -Wall -O2 -D_FORTIFY_SOURCE=2 -g s2ram.c vt.o vbetool/lrmi.o vbetool/x86-common.o vbetool/vbetool.o radeontool.o dmidecode.o -lpci -o s2ram In our build system, _FORTIFY_SOURCE=2 is mandatory and sooner or later those warnings will become errors. I can always work around them by casting to void, but as was pointed out to me by our toolchain team, some of them are probably real errors. If we _know_ that this write or fscanf cannot fail because we also _know_ what we are doing on the kernel side, then we should probably add a comment at the appropriate places and maybe just add a (void) cast. This is ugly to look at, but tells everybody else that we did not just forget to check for the values. Even leaving out the void cast, an comment like "this will throw a warning, but we know that this cannot fail" is better so i can defend my local patches against theevil overlords of the buildsystem :-) Thanks, -- Stefan Seyfried QA / R&D Team Mobile Devices | "Any ideas, John?" SUSE LINUX Products GmbH, Nürnberg | "Well, surrounding them's out." ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Suspend-devel mailing list Suspend-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/suspend-devel
