[Bug bootstrap/56703] New: problems with strsignal and maybe strstr due to varying const on return type

[jay.krell at cornell dot edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56703

             Bug #: 56703
           Summary: problems with strsignal and maybe strstr due to
                    varying const on return type
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jay.krell@cornell.edu


The autoconf checks for strsignal and maybe strstr are overly strict or wrong
and fail due to varying const on the return.


gcc 4.8.0

 uname -a
SunOS unstable10s 5.10 Generic_147440-27 sun4v sparc
SUNW,SPARC-Enterprise-T5220


make[3]: Entering directory `/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/gcc'
/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/./prev-gcc/xg++
-B/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/./prev-gcc/
-B/home/jkrell/gcc480-sparc-sun-solaris2.10/sparc-sun-solaris2.10/bin/
-nostdinc++
-B/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/prev-sparc-sun-solaris2.10/libstdc++-v3/src/.libs
-B/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/prev-sparc-sun-solaris2.10/libstdc++-v3/libsupc++/.libs
-I/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/prev-sparc-sun-solaris2.10/libstdc++-v3/include/sparc-sun-solaris2.10
-I/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/prev-sparc-sun-solaris2.10/libstdc++-v3/include
-I/home/jkrell/src/gcc-4.8.0/libstdc++-v3/libsupc++
-L/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/prev-sparc-sun-solaris2.10/libstdc++-v3/src/.libs
-L/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/prev-sparc-sun-solaris2.10/libstdc++-v3/libsupc++/.libs
-c   -g -O2 -DIN_GCC   -fno-exceptions -fno-rtti -fasynchronous-unwind-tables
-W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute
-pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings  
-DHAVE_CONFIG_H -DGENERATOR_FILE -I. -Ibuild -I/home/jkrell/src/gcc-4.8.0/gcc
-I/home/jkrell/src/gcc-4.8.0/gcc/build
-I/home/jkrell/src/gcc-4.8.0/gcc/../include -I./../intl
-I/home/jkrell/src/gcc-4.8.0/gcc/../libcpp/include 
-I/home/jkrell/src/gcc-4.8.0/gcc/../libdecnumber
-I/home/jkrell/src/gcc-4.8.0/gcc/../libdecnumber/dpd -I../libdecnumber
-I/home/jkrell/src/gcc-4.8.0/gcc/../libbacktrace    \
        -o build/genconstants.o /home/jkrell/src/gcc-4.8.0/gcc/genconstants.c
In file included from ./bconfig.h:3:0,
                 from /home/jkrell/src/gcc-4.8.0/gcc/genconstants.c:27:
./auto-host.h:1994:16: error: declaration does not declare anything
[-fpermissive]
 #define rlim_t long
                ^
In file included from /home/jkrell/src/gcc-4.8.0/gcc/genconstants.c:28:0:
/home/jkrell/src/gcc-4.8.0/gcc/system.h:448:48: error: 'char* strstr(const
char*, const char*)' conflicts with previous using declaration 'const char*
std::strstr(const char*, const char*)'
 extern char *strstr (const char *, const char *);
                                                ^
In file included from /home/jkrell/src/gcc-4.8.0/gcc/genconstants.c:28:0:
/home/jkrell/src/gcc-4.8.0/gcc/system.h:500:34: error: declaration of C
function 'const char* strsignal(int)' conflicts with
 extern const char *strsignal (int);
                                  ^
In file included from
/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/prev-sparc-sun-solaris2.10/libstdc++-v3/include/cstring:42:0,
                 from /home/jkrell/src/gcc-4.8.0/gcc/system.h:205,
                 from /home/jkrell/src/gcc-4.8.0/gcc/genconstants.c:28:
/usr/include/string.h:79:14: error: previous declaration 'char* strsignal(int)'
here
 extern char *strsignal(int);
              ^
gmake[3]: *** [build/genconstants.o] Error 1
gmake[3]: Leaving directory `/home/jkrell/obj/gcc480-sparc-sun-solaris2.10/gcc'
gmake[2]: *** [all-stage2-gcc] Error 2
gmake[2]: Leaving directory `/home/jkrell/obj/gcc480-sparc-sun-solaris2.10'
gmake[1]: *** [stage2-bubble] Error 2
gmake[1]: Leaving directory `/home/jkrell/obj/gcc480-sparc-sun-solaris2.10'
gmake: *** [all] Error 2
jkrell@unstable10s [unstable10s]:~/obj/gcc480-sparc-sun-solaris2.10 > 


Both the strstr and strsignal declarations in system.h have autoconf #if's
around them.
One wonders why they evaluate to true.


krell@unstable10s [unstable10s]:~/obj/gcc480-sparc-sun-solaris2.10 > grep STRS
*/*h
gcc/auto-host.h:#define HAVE_DECL_STRSIGNAL 0
gcc/auto-host.h:#define HAVE_DECL_STRSTR 0
gcc/auto-host.h:#define HAVE_STRSIGNAL 1
libiberty/config.h:#define HAVE_STRSIGNAL 1
libiberty/config.h:#define HAVE_STRSTR 1
prev-gcc/auto-host.h:#define HAVE_DECL_STRSIGNAL 1
prev-gcc/auto-host.h:#define HAVE_DECL_STRSTR 1
prev-gcc/auto-host.h:#define HAVE_STRSIGNAL 1


The mystery deepens...
cd gcc
vi config.log
...

| #undef HAVE_DECL_STRSIGNAL
| #define HAVE_DECL_STRSIGNAL 1
|
| #include "ansidecl.h"
| #include "system.h"
|
| int
| main ()
| {
| #ifndef strsignal
| char *(*pfn) = (char *(*)) strsignal ;
| #endif
|   ;
|   return 0;
| }
configure:10374: result: no
configure:10336: checking whether strstr is declared
configure:10359:  /home/jkrell/obj/gcc480-sparc-sun-solaris2.10/./prev-gcc/xgcc
-B/home/jkrell/obj/gcc4
80-sparc-sun-solaris2.10/./prev-gcc/
-B/home/jkrell/gcc480-sparc-sun-solaris2.10/sparc-sun-solaris2.10/
bin/ -B/home/jkrell/gcc480-sparc-sun-solaris2.10/sparc-sun-solaris2.10/bin/
-B/home/jkrell/gcc480-sparc
-sun-solaris2.10/sparc-sun-solaris2.10/lib/ -isystem
/home/jkrell/gcc480-sparc-sun-solaris2.10/sparc-su
n-solaris2.10/include -isystem
/home/jkrell/gcc480-sparc-sun-solaris2.10/sparc-sun-solaris2.10/sys-incl
ude    -c -g -O2 -I/home/jkrell/src/gcc-4.8.0/gcc
-I/home/jkrell/src/gcc-4.8.0/gcc/../include   conftes
t.c >&5
In file included from conftest.c:116:0:
/home/jkrell/src/gcc-4.8.0/gcc/system.h:500:20: error: conflicting types for
'strsignal'
 extern const char *strsignal (int);
                    ^
In file included from /home/jkrell/src/gcc-4.8.0/gcc/system.h:213:0,
                 from conftest.c:116:
/usr/include/string.h:79:14: note: previous declaration of 'strsignal' was here
 extern char *strsignal(int);
              ^
In file included from conftest.c:116:0:
/home/jkrell/src/gcc-4.8.0/gcc/system.h:641:17: fatal error: gmp.h: No such
file or directory
 #include <gmp.h>
                 ^
compilation terminated.
configure:10359: $? = 1
configure: failed program was:


so the checks for strstr and strsignal are too strict.

How about more like:

const char* a = strsignal(1);

on the matter of conflicting declarations:
conftest.c:77:6: warning: conflicting types for built-in function 'ldexp'
[enabled by default]
 char ldexp ();


 conftest.c:109:6: warning: conflicting types for built-in function
'fprintf_unlocked' [enabled by defau
lt]
 char fprintf_unlocked ();
      ^
Undefined                       first referenced
 symbol                             in file
fprintf_unlocked                    /home/jkrell/tmp/cc2gUNar.o
ld: fatal: symbol referencing errors. No output written to conftest


conftest.c:109:6: warning: conflicting types for built-in function
'fputc_unlocked' [enabled by default
]
 char fputc_unlocked ();
      ^
Undefined                       first referenced
 symbol                             in file
fputc_unlocked                      /home/jkrell/tmp/ccenrM6Q.o

more for *_unlocked, fork but I guess all that is ok..

I'm confused about strstr.
strsignal is definitely a problem, due to const mismatch on the return type.