[Bug c/56647] New: use return value of malloc() as initializer

["zhabgyuan1993 at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56647

             Bug #: 56647
           Summary: use return value of  malloc() as initializer
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zhabgyuan1993@gmail.com


Created attachment 29687
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29687
the preprocessed file for r.c

$:cat r.c
------------------------------------------------------
#include<stdio.h>
#include<stdlib.h>
int *c;
c = (int *)malloc(sizeof(int));
int main(void)
{
return 0;
}

error or warning
-------------------------------------------------------
r.c:4:1: warning: data definition has no type or storage class [enabled by
default]
r.c:4:1: error: conflicting types for âcâ
r.c:3:6: note: previous declaration of âcâ was here
r.c:4:5: warning: initialization makes integer from pointer without a cast
[enabled by default]
r.c:4:1: error: initializer element is not constant


$: gcc -v -save-temps r.c
-------------------------------------------------------
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.7.2-2ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object
--enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/4.7/cc1 -E -quiet -v -imultiarch
x86_64-linux-gnu r.c -mtune=generic -march=x86-64 -fpch-preprocess
-fstack-protector -o r.i
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-linux-gnu/4.7/include
 /usr/local/include
 /usr/lib/gcc/x86_64-linux-gnu/4.7/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/4.7/cc1 -fpreprocessed r.i -quiet -dumpbase r.c
-mtune=generic -march=x86-64 -auxbase r -version -fstack-protector -o r.s
GNU C (Ubuntu/Linaro 4.7.2-2ubuntu1) version 4.7.2 (x86_64-linux-gnu)
    compiled by GNU C version 4.7.2, GMP version 5.0.2, MPFR version 3.1.0-p3,
MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C (Ubuntu/Linaro 4.7.2-2ubuntu1) version 4.7.2 (x86_64-linux-gnu)
    compiled by GNU C version 4.7.2, GMP version 5.0.2, MPFR version 3.1.0-p3,
MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: efa32fef7aa241fa03ac6d7ad2a4a2cf
r.c:4:1: warning: data definition has no type or storage class [enabled by
default]
r.c:4:1: error: conflicting types for âcâ
r.c:3:6: note: previous declaration of âcâ was here
r.c:4:5: warning: initialization makes integer from pointer without a cast
[enabled by default]
r.c:4:1: error: initializer element is not constant