Re: Bug report: Compile with Microsoft and Intel compiler

[Eli Zaretskii]

> From: =?iso-8859-1?Q?Jerker_B=E4ck?= <address@hidden>
> Cc: <address@hidden>
> Date: Fri, 29 Apr 2005 05:31:40 +0200
> 
> You asked for the real prototypes - here they are:
> 
> These functions are defined in the runtime library and cannot be defined
> again unless EXACTLY identical stated. All local defines of these functions
> MUST therefore be disabled. Otherwise we get a fatal error 2373. How you
> previously got MSC by this is mysterious.

??? Sorry, I'm mightily confused.  What do you mean by ``defined in
the runtime library''?  A library does not, AFAIK, include any
declarations of function's prototypes.  It includes _their_code_.

Next, what do you mean by ``local defines'', and what is that "fatal
error 2373"?  E.g., can you compile, link, and run the following toy
program (which is a simplified replacement for the CHDIR command)?

-------------------------------------------
 _CRTIMP int __cdecl _chdir(const char *);

 int main(int argc, char *argv[])
 {
    if (argc > 1)
       _chdir(argv[1]);
    return 0;
 }
-------------------------------------------

If this compiles at the highest possible warning level and runs and
expected, why can't we throw together a unistd.h and use it?  What am
I missing?
> 
> List of redefines causing errors
> 
> Func      Microsoft     Borland
> --------------------------------
> chdir     <direct.h>    <dir.h>
> dup2      <io.h>        <io.h>
> environ   <stdlib.h>    <stdlib.h>
> execve    <process.h>   <process.h>
> _exit     <stdlib.h>    <stdlib.h>
> getcwd    <direct.h>    <dir.h>
> getenv    <stdlib.h>    <stdlib.h>
> getpid    <process.h>   <process.h>
> mktemp    <io.h>        <io.h>
> strerror  <string.h>    <string.h>
> 
> (Borland also have direct.h)
> 

> Microsoft default prototypes:
> ------------------------------
> _CRTIMP int __cdecl _chdir(const char *);
> _CRTIMP int __cdecl _dup2(int, int);
> _CRTIMP extern char ** _environ;
> _CRTIMP int __cdecl _execve(const char *, const char * const *, const char *
> const *);
> _CRTIMP __declspec(noreturn) void   __cdecl _exit(int);
> _CRTIMP char * __cdecl _getdcwd(int, char *, int);
> _CRTIMP int __cdecl _getpid(void);
> _CRTIMP char * __cdecl _mktemp(char *);
> _CRTIMP char *  __cdecl _strerror(const char *);
> _CRTIMP char *  __cdecl strerror(int);

I need to see how it defines chdir, dup2, environ, getpid, and mktemp,
without the leading underscores.

Also, what is the precise definition of _CRTIMP?

> there is also prototypes for oldnames.lib functions
> (no underscore function aliases)

Please show these aliases.

> Note: To make it even more complicated you're normally using the
> UNICODE/MBCS safe defines in tchar.h
> 
> Ex:
> MBCS defined:
> #define _tchdir     _chdir

But Make doesn't use _tchdir, does it?  So we could safely forget
about this complication.

> So, if you plan what I think you're planning - don't, it's not a good idea.

??? Please explain why.  Especially since MinGW, evidently, uses
similar techniques to create its version of unistd.h, as Earnie told
us just now.