wangbj@localhost ~/test $ ghci -v
GHCi, version 7.4.1: http://www.haskell.org/ghc/  :? for help
Glasgow Haskell Compiler, Version 7.4.1, stage 2 booted by GHC version 7.4.1
Using binary package database: /usr/lib64/ghc-7.4.1/package.conf.d/package.cache
hiding package time-1.4 to avoid conflict with later version time-1.4.0.1
wired-in package ghc-prim mapped to ghc-prim-0.2.0.0-c2ff696e5b8ec4d4b2bc2e42085fe471
wired-in package integer-gmp mapped to integer-gmp-0.4.0.0-3cccac07aef8e27023f605c1f45bdf74
wired-in package base mapped to base-4.5.0.0-40b99d05fae6a4eea95ea69e6e0c9702
wired-in package rts mapped to builtin_rts
wired-in package template-haskell mapped to template-haskell-2.7.0.0-8c8cd20e21666657195efabced685fe1
wired-in package dph-seq not found.
wired-in package dph-par not found.
Hsc static flags: -static
Loading package ghc-prim ... linking ... done.
*** gcc:
'gcc' '-fno-stack-protector' '-Wl,--hash-size=31' '-Wl,--reduce-memory-overheads' '-L/usr/lib64/ghc-7.4.1/integer-gmp-0.4.0.0' '--print-file-name' 'libgmp.so'
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... ghc: /usr/lib64/ghc-7.4.1/base-4.5.0.0/HSbase-4.5.0.0.o: unknown symbol `stat'
*** Deleting temp files:
Deleting:
*** Deleting temp dirs:
Deleting:
ghc: unable to load package `base'
wangbj@localhost ~/test $



I create a simple program for testing ``stat'':

$ cat ex98.c
#include <sys/types.h>
#include <sys/stat.h>

#include <stdio.h>

int main(int argc, char* argv[])
{
        struct stat st;

        stat (argv[0], &st);

        return 0;
}


$ readelf -s ex98 | grep stat
     4: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND __xstat@GLIBC_2.2.5 (2)
    39: 0000000000400670    16 FUNC    GLOBAL HIDDEN    13 __stat
    40: 0000000000400670    16 FUNC    WEAK   HIDDEN    13 stat
    43: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND __xstat@@GLIBC_2.2.5

GLIBC (2.15) don't have symbol for function ``stat'' (or __stat):

wangbj@localhost ~/test $ readelf -s /lib64/libc.so.6 | grep 'stat\>'
    65: 0000000000077730    16 FUNC    GLOBAL DEFAULT   12 _IO_file_stat@@GLIBC_2.2.5
   452: 00000000000dc8d0    69 FUNC    GLOBAL DEFAULT   12 __lxstat@@GLIBC_2.2.5
  1466: 00000000000dc880    69 FUNC    GLOBAL DEFAULT   12 __fxstat@@GLIBC_2.2.5
  1513: 00000000000ea300    69 FUNC    GLOBAL DEFAULT   12 ustat@@GLIBC_2.2.5
  1929: 00000000000dc830    69 FUNC    GLOBAL DEFAULT   12 __xstat@@GLIBC_2.2.5

If I objdump ex98:

0000000000400594 <main>:
  400594:       55                      push   %rbp
  400595:       48 89 e5                mov    %rsp,%rbp
  400598:       48 81 ec a0 00 00 00    sub    $0xa0,%rsp
  40059f:       89 bd 6c ff ff ff       mov    %edi,-0x94(%rbp)
  4005a5:       48 89 b5 60 ff ff ff    mov    %rsi,-0xa0(%rbp)
  4005ac:       48 8b 85 60 ff ff ff    mov    -0xa0(%rbp),%rax
  4005b3:       48 8b 00                mov    (%rax),%rax
  4005b6:       48 8d 95 70 ff ff ff    lea    -0x90(%rbp),%rdx
  4005bd:       48 89 d6                mov    %rdx,%rsi
  4005c0:       48 89 c7                mov    %rax,%rdi
  4005c3:       e8 a8 00 00 00          callq  400670 <__stat>
  4005c8:       b8 00 00 00 00          mov    $0x0,%eax
  4005cd:       c9                      leaveq
  4005ce:       c3                      retq
  4005cf:       90                      nop

...


0000000000400670 <__stat>:
  400670:       48 89 f2                mov    %rsi,%rdx
  400673:       48 89 fe                mov    %rdi,%rsi
  400676:       bf 01 00 00 00          mov    $0x1,%edi
  40067b:       e9 20 fe ff ff          jmpq   4004a0 <__xstat@plt>
  400680:       55                      push   %rbp
  400681:       48 89 e5                mov    %rsp,%rbp
  400684:       53                      push   %rbx
  400685:       48 83 ec 08             sub    $0x8,%rsp
  400689:       48 8b 05 58 07 20 00    mov    0x200758(%rip),%rax        # 600de8 <__init_array_end+0x4>
  400690:       48 83 f8 ff             cmp    $0xffffffffffffffff,%rax
  400694:       74 19                   je     4006af <__stat+0x3f>
  400696:       bb e8 0d 60 00          mov    $0x600de8,%ebx
  40069b:       0f 1f 44 00 00          nopl   0x0(%rax,%rax,1)
  4006a0:       48 83 eb 08             sub    $0x8,%rbx
  4006a4:       ff d0                   callq  *%rax
  4006a6:       48 8b 03                mov    (%rbx),%rax
  4006a9:       48 83 f8 ff             cmp    $0xffffffffffffffff,%rax
  4006ad:       75 f1                   jne    4006a0 <__stat+0x30>
  4006af:       48 83 c4 08             add    $0x8,%rsp
  4006b3:       5b                      pop    %rbx
  4006b4:       c9                      leaveq
  4006b5:       c3                      retq
  4006b6:       90                      nop
  4006b7:       90                      nop


So it seems GCC will create its own stat, and will call __xstat@plt from glibc, not the plain ``stat''.

in /usr/include/sys/stat.h:

#if defined __GNUC__ && __GNUC__ >= 2 && defined __USE_EXTERN_INLINES
/* Inlined versions of the real stat and mknod functions.  */

__extern_inline int
__NTH (stat (__const char *__path, struct stat *__statbuf))
{
  return __xstat (_STAT_VER, __path, __statbuf);
}

So it should be an error that HSbase.o linked agaist ``stat'' directly?