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Re: Can I build gcc so -Wall option is always on ?


On Sat, 9 Jan 2010, Joel Dice wrote:

On Sun, 10 Jan 2010, Dr. David Kirkby wrote:

Ralf Wildenhues wrote:
> Hello David,
> > * Dr. David Kirkby wrote on Thu, Dec 24, 2009 at 05:38:23PM CET:
> > I'm helping on the Sage maths project
> > > > http://www.sagemath.org/
> > > > where there are a large number of packages built, most of which > > ignore CFLAGS. (Quite a few ignore CC and CXX too!) I'd like to > > display all the warnings, but its hard when people overwrite CFLAGS.
> > > > Is there a way I can build gcc such that effectively "-Wall" is > > enabled all the time?
> > I hate to be stating the obvious, but why not use a wrapper script?
> > mv gcc gcc.real
> cat >gcc <<\EOF
> #! /bin/sh
> exec gcc.real -Wall "$@"
> EOF
> > or just put one early in your $PATH. Depending on your needs, it might
> have to be a bit more complex (put -Wall at the end if you care about
> overriding -Wno-all and some other flags, for example; or only add > -Wall
> if -c is also seen, or similarly).
> > Cheers,
> Ralf
>
I've tried this, and it works in 90% of cases, but not all. 'sqlite' is
once such package which always gives errors if I try to build like this.
The errors are like "no newline" or something like that. So I stuck a new
line in, but it still does not work.


Here's one such error, where

 make[2]: Entering directory
 `/export/home/drkirkby/sage-4.3.1.alpha1/spkg/build/sqlite-3.6.19.p0/src'
 if /bin/sh ./libtool --tag=CC --mode=compile gcc -DPACKAGE_NAME=\"sqlite\"
 -DPACKAGE_TARNAME=\"sqlite\" -DPACKAGE_VERSION=\"3.6.19\"
 -DPACKAGE_STRING=\"sqlite\ 3.6.19\"
 -DPACKAGE_BUGREPORT=\"http://www.sqlite.org\"; -DPACKAGE=\"sqlite\"
 -DVERSION=\"3.6.19\" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1
 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1
 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1
 -DHAVE_DLFCN_H=1 -DHAVE_FDATASYNC=1 -DHAVE_USLEEP=1 -DHAVE_LOCALTIME_R=1
 -DHAVE_GMTIME_R=1 -DHAVE_READLINE=1 -I. -I.   -I
 /export/home/drkirkby/sage-4.3.1.alpha1/local/include
 -DSQLITE_THREADSAFE=1 -Wall -g -m64 -m64  -g  -O2  -MT sqlite3.lo -MD -MP
 -MF ".deps/sqlite3.Tpo" -c -o sqlite3.lo sqlite3.c; \
 	then mv -f ".deps/sqlite3.Tpo" ".deps/sqlite3.Plo"; else rm -f
 ".deps/sqlite3.Tpo"; exit 1; fi
 mkdir .libs
 gcc "-DPACKAGE_NAME=\"sqlite\"" "-DPACKAGE_TARNAME=\"sqlite\""
 "-DPACKAGE_VERSION=\"3.6.19\"" "-DPACKAGE_STRING=\"sqlite 3.6.19\""
 "-DPACKAGE_BUGREPORT=\"http://www.sqlite.org\""; "-DPACKAGE=\"sqlite\""
 "-DVERSION=\"3.6.19\"" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1
 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1
 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1
 -DHAVE_DLFCN_H=1 -DHAVE_FDATASYNC=1 -DHAVE_USLEEP=1 -DHAVE_LOCALTIME_R=1
 -DHAVE_GMTIME_R=1 -DHAVE_READLINE=1 -I. -I. -I
 /export/home/drkirkby/sage-4.3.1.alpha1/local/include
 -DSQLITE_THREADSAFE=1 -Wall -g -m64 -m64 -g -O2 -MT sqlite3.lo -MD -MP -MF
 .deps/sqlite3.Tpo -c sqlite3.c  -fPIC -DPIC -o .libs/sqlite3.o
 gcc: 3.6.19": No such file or directory
 make[2]: *** [sqlite3.lo] Error 1
 make[2]: Leaving directory
 `/export/home/drkirkby/sage-4.3.1.alpha1/spkg/build/sqlite-3.6.19.p0/src'
 Error making sqlite

Try replacing the "$@" in your script with ${1+"$@"}. That should ensure "-DPACKAGE_STRING=\"sqlite 3.6.19\"" appears as a single argument to gcc.real.

Replying to my own suggestion, I'll mention that the ${1+"$@"} syntax is something I found in a script written by someone else, and I suggest it because I've used it with success in similar situations.


However, despite having studied the man pages for several shells, I have never actually figured out what ${1+"$@"} means and how it differs from just "$@". Indeed, the "$@" syntax seems perfectly adequate for this case, so I can't explain why Ralf's suggestion isn't working. I've just run a few simple tests, each of which behaves the same regardless of which syntax I use, so perhaps they're interchangeable.

Perhaps a shell programming expert can enlighten us.

 (The two -m64's are a result of it being added elsewhere too, but
 generally I've not found a wrapper suitable.)

Dave






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