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From: Eduardo =?iso-8859-1?Q?A=2E_Bustamante_L=F3pez?= <dualbus@gmail.com>
Newsgroups: gnu.bash.bug
Subject: Bash build issues in `devel' branch due to -Werror compiler flag
Date: Sat, 15 Dec 2018 23:35:49 -0800
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Approved: bug-bash@gnu.org
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Commit 9d80be9ab5cc17011c634e0348c64c15fcba95bf adds the following compiler=
 flag:

  dualbus@debian:~/src/gnu/bash$ cat -n configure.ac | grep Werror -C3
    1159		CFLAGS=3D"$CFLAGS -Wno-parentheses -Wno-format-security"
    1160		if test -n "$DEBUG"
    1161		then
  ~>1162			CFLAGS=3D"$CFLAGS -Werror"
    1163		fi
    1164	fi
    1165=09

During build (with gcc):

  dualbus@debian:~/src/gnu/bash$ make -j$(nproc) -s
  make[1]: warning: -j4 forced in submake: resetting jobserver mode.
  ./parse.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
  make[1]: warning: -j4 forced in submake: resetting jobserver mode.
  expr.c:217:17: error: conflicting types for built-in function =E2=80=98ex=
p2=E2=80=99 [-Werror=3Dbuiltin-declaration-mismatch]
   static intmax_t exp2 __P((void));
                   ^~~~
  cc1: all warnings being treated as errors


I know the `exp2' function here has nothing to do with the built-in exponen=
tial
function, and that it has had that name for a long time, but the build brea=
ks due to that.

To hack around it, I renamed it from `exp2' to `exp22', and then it broke h=
ere:

  dualbus@debian:~/src/gnu/bash$ make -j$(nproc) -s
  make[1]: warning: -j4 forced in submake: resetting jobserver mode.
 =20
        ***********************************************************
        *                                                         *
        * GNU bash, version 5.0.0(1)-rc1 (x86_64-pc-linux-gnu)
        *                                                         *
        ***********************************************************
 =20
  making lib/glob/libglob.a in ./lib/glob
  make[1]: warning: -j4 forced in submake: resetting jobserver mode.
  smatch.c: In function =E2=80=98_fnmatch_fallback_wc=E2=80=99:
  smatch.c:318:11: error: implicit declaration of function =E2=80=98fnmatch=
=E2=80=99; did you mean =E2=80=98gmatch=E2=80=99? [-Werror=3Dimplicit-funct=
ion-declaration]
     return (fnmatch ((const char *)w2, (const char *)w1, 0));
             ^~~~~~~
             gmatch


Which I believe is an actual issue and I assume the fix is along the lines =
of:

  dualbus@debian:~/src/gnu/bash$ git diff -- lib/
  diff --git a/lib/glob/smatch.c b/lib/glob/smatch.c
  index 3826c93e..9150a28e 100644
  --- a/lib/glob/smatch.c
  +++ b/lib/glob/smatch.c
  @@ -25,6 +25,7 @@
                                 =20
   #include "strmatch.h"
   #include <chartypes.h>
  +#include <fnmatch.h>
  =20
   #include "bashansi.h"
   #include "shmbutil.h"


I'm not sure what to do about `exp2' though. Personally, I'd love for these
functions to have slighly more meaningful names.


I also tried clang version 7.0.1-+rc3-2, which gives an additional error:

  making lib/sh/libsh.a in ./lib/sh
  (...)
  getenv.c:55:7: error: comparison of nonnull parameter 'name' equal to a n=
ull pointer is 'false' on first encounter [-Werror,-Wtautological-pointer-c=
ompare]
    if (name =3D=3D 0 || *name =3D=3D '\0')
        ^~~~    ~
  /usr/include/stdlib.h:631:50: note: declared 'nonnull' here
  extern char *getenv (const char *__name) __THROW __nonnull ((1)) __wur;
                                                   ^
  /usr/include/x86_64-linux-gnu/sys/cdefs.h:293:44: note: expanded from mac=
ro '__nonnull'
  # define __nonnull(params) __attribute__ ((__nonnull__ params))


This is due to the stdlib.h header being pulled by bashansi.h in
lib/sh/getenv.c, thus, providing a function signature that doesn't match Ba=
sh's
re-definition of getenv():

  dualbus@debian:~/src/gnu/bash$ grep bashansi.h lib/sh/getenv.c=20
  #include <bashansi.h>
 =20
  dualbus@debian:~/src/gnu/bash$ grep stdlib.h bashansi.h=20
  #  include <stdlib.h>
  #  include "ansi_stdlib.h"


~~~


Additional information:

gcc:

  dualbus@debian:~/src/gnu/bash$ cc -v
  Using built-in specs.
  COLLECT_GCC=3Dcc
  COLLECT_LTO_WRAPPER=3D/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
  OFFLOAD_TARGET_NAMES=3Dnvptx-none
  OFFLOAD_TARGET_DEFAULT=3D1
  Target: x86_64-linux-gnu
  Configured with: ../src/configure -v --with-pkgversion=3D'Debian 8.2.0-12=
' --with-bugurl=3Dfile:///usr/share/doc/gcc-8/README.Bugs --enable-language=
s=3Dc,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=3D/usr --with-gcc-maj=
or-version-only --program-suffix=3D-8 --program-prefix=3Dx86_64-linux-gnu- =
--enable-shared --enable-linker-build-id --libexecdir=3D/usr/lib --without-=
included-gettext --enable-threads=3Dposix --libdir=3D/usr/lib --enable-nls =
--with-sysroot=3D/ --enable-clocale=3Dgnu --enable-libstdcxx-debug --enable=
-libstdcxx-time=3Dyes --with-default-libstdcxx-abi=3Dnew --enable-gnu-uniqu=
e-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-d=
efault-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=3D=
auto --enable-multiarch --disable-werror --with-arch-32=3Di686 --with-abi=
=3Dm64 --with-multilib-list=3Dm32,m64,mx32 --enable-multilib --with-tune=3D=
generic --enable-offload-targets=3Dnvptx-none --without-cuda-driver --enabl=
e-checking=3Drelease --build=3Dx86_64-linux-gnu --host=3Dx86_64-linux-gnu -=
-target=3Dx86_64-linux-gnu
  Thread model: posix
  gcc version 8.2.0 (Debian 8.2.0-12)=20

clang:

  dualbus@debian:~/src/gnu/bash$ clang -v
  clang version 7.0.1-+rc3-2 (tags/RELEASE_701/rc3)
  Target: x86_64-pc-linux-gnu
  Thread model: posix
  InstalledDir: /usr/bin
  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7
  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.=
4.0
  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/8
  Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
  Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.4.0
  Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
  Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/8
  Candidate multilib: .;@m64
  Selected multilib: .;@m64