Re: [PATCH] git-compat-util: Avoid strcasecmp() being inlined

From: Sebastian Schuberth <sschuberth@gmail.com>
Date: Sep 12, 2013, 09:36 UTC
Message-ID: <CAHGBnuP3iX9pqm5kK9_WjAXr5moDuJ1jxtUkXwKEt2jjLTcLkQ@mail.gmail.com>
In-Reply-To: <20130911214116.GA12235@sigill.intra.peff.net>

On Wed, Sep 11, 2013 at 11:41 PM, Jeff King <peff@peff.net> wrote:

Show 12 quoted lines

>> I'm on Windows using MSYS / MinGW. Since MinGW runtime version 4.0,
>> string.h contains the following code (see [1]):
>>
>> #ifndef __NO_INLINE__
>> __CRT_INLINE int __cdecl __MINGW_NOTHROW
>> strncasecmp (const char * __sz1, const char * __sz2, size_t __sizeMaxCompare)
>> {return _strnicmp (__sz1, __sz2, __sizeMaxCompare);}
>> #else
>> #define strncasecmp _strnicmp
>> #endif
>
> What is the error the compiler reports? Can it take the address of other

The error message of GCC 4.8.1 is:

    LINK git-credential-store.exe
libgit.a(mailmap.o): In function `read_mailmap':
C:\mingwGitDevEnv\git/mailmap.c:238: undefined reference to `strcasecmp'
collect2.exe: error: ld returned 1 exit status
make: *** [git-credential-store.exe] Error 1

So it's a linker error, not a compiler error.

Show 5 quoted lines

> inline functions? For example, can it compile:
>
>     inline int foo(void) { return 5; }
>     extern int bar(int (*cb)(void));
>     int call(void) { return bar(foo); }

I had to modify the example slightly to:

inline int foo(void) { return 5; } extern int bar(int (*cb)(void)) { return cb(); } int main(void) { return bar(foo); }

And this compiles.

> Just wondering if that is the root of the problem, or if maybe there is
> something else subtle going on. Also, does __CRT_INLINE just turn into
> "inline", or is there perhaps some other pre-processor magic going on?

This is the function definition from string.h after preprocessing:

extern __inline__ int __attribute__((__cdecl__)) __attribute__ ((__nothrow__))
strncasecmp (const char * __sz1, const char * __sz2, size_t __sizeMaxCompare)
  {return _strnicmp (__sz1, __sz2, __sizeMaxCompare);}

-- 
Sebastian Schuberth