Problem with main routine during linking

[Martin Kahlert]

Hi,
thanks for the patch, this was in fact the thing i tried (see the thread
I need help for changing the java driver (gcj and libs with a main()) in 
the java-mailing list) except that i wanted that to go into gcc.c instead of
jvspec.c.

I tried your patch and it works for me, but i do not consider this patch
a nice one; it's some kind of a quick hack:
- it makes internal variables of the general build process public just for
  one specific language
- it does not solve David Billinghurst's Problem with main in cygwin libs

So my question is this: Should there be a general function 
(bryce suggested lang_specific_pre_compile()) for all languages,
which produces additional objects?

Does it do any harm, if we sort the -l options towards the end of outfiles 
*inside gcc.c* before linking?

Thanks,
Martin.



On Mon, May 07, 2001 at 11:20:49PM -0700, Per Bothner wrote:
> Could people try the following?
> 
> Index: gcc.c
> ===================================================================
> RCS file: /cvs/gcc/gcc/gcc/gcc.c,v
> retrieving revision 1.205.2.10
> diff -u -p -r1.205.2.10 gcc.c
> --- gcc.c	2001/05/01 18:56:21	1.205.2.10
> +++ gcc.c	2001/05/08 05:58:42
> @@ -2801,7 +2801,7 @@ struct infile
>  
>  static struct infile *infiles;
>  
> -static int n_infiles;
> +int n_infiles;
>  
>  /* This counts the number of libraries added by lang_specific_driver, so that
>     we can tell if there were any user supplied any files or libraries.  */
> @@ -2810,7 +2810,7 @@ static int added_libraries;
>  
>  /* And a vector of corresponding output files is made up later.  */
>  
> -static const char **outfiles;
> +const char **outfiles;
>  
>  /* Used to track if none of the -B paths are used.  */
>  static int warn_B;
> @@ -3871,7 +3871,7 @@ process_command (argc, argv)
>     of characters starting there excluding the suffix .c or whatever.  */
>  
>  const char *input_filename;
> -static int input_file_number;
> +int input_file_number;
>  size_t input_filename_length;
>  static int basename_length;
>  static int suffixed_basename_length;
> Index: gcc.h
> ===================================================================
> RCS file: /cvs/gcc/gcc/gcc/gcc.h,v
> retrieving revision 1.3.6.1
> diff -u -p -r1.3.6.1 gcc.h
> --- gcc.h	2001/03/17 19:56:09	1.3.6.1
> +++ gcc.h	2001/05/08 05:58:42
> @@ -42,7 +42,13 @@ extern void lang_specific_driver PARAMS 
>  /* Called before linking.  Returns 0 on success and -1 on failure. */
>  extern int lang_specific_pre_link PARAMS ((void));
>  
> +extern int n_infiles;
> +
>  /* Number of extra output files that lang_specific_pre_link may generate. */
>  extern int lang_specific_extra_outfiles;
> +
> +/* A vector of corresponding output files is made up later.  */
> +
> +extern const char **outfiles;
>  
>  #endif /* ! __GCC_H__ */
> Index: java/jvspec.c
> ===================================================================
> RCS file: /cvs/gcc/gcc/gcc/java/jvspec.c,v
> retrieving revision 1.35.2.4
> diff -u -p -r1.35.2.4 jvspec.c
> --- jvspec.c	2001/04/29 11:26:30	1.35.2.4
> +++ jvspec.c	2001/05/08 05:58:42
> @@ -524,9 +524,23 @@ lang_specific_driver (in_argc, in_argv, 
>  int
>  lang_specific_pre_link ()
>  {
> +  int err;
>    if (main_class_name == NULL)
>      return 0;
>    input_filename = main_class_name;
>    input_filename_length = strlen (main_class_name);
> -  return do_spec (jvgenmain_spec);
> +  err = do_spec (jvgenmain_spec);
> +  if (err == 0)
> +    {
> +      /* Shift the outfiles array so the generated main comes first.
> +	 This is important when linking against (non-shared) libraries,
> +	 since otherwise we risk (a) nothing getting linked or
> +	 (b) 'main' getting picked up from a library. */
> +      int i = n_infiles;
> +      const char *generated = outfiles[i];
> +      while (--i >= 0)
> +	outfiles[i + 1] = outfiles[i];
> +      outfiles[0] = generated;
> +    }
> +  return err;
>  }
> 

-- 
The early bird gets the worm. If you want something else for       
breakfast, get up later.