/* Specific flags and argument handling of the Fortran front-end.
   Copyright (C) 1997 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* This file contains a filter for the main `gcc' driver, which is
   replicated for the `g77' driver by adding this filter.  The purpose
   of this filter is to be basically identical to gcc (in that
   it faithfully passes all of the original arguments to gcc) but,
   unless explicitly overridden by the user in certain ways, ensure
   that the needs of the language supported by this wrapper are met.

   For GNU Fortran (g77), we do the following to the argument list
   before passing it to `gcc':

   1.  Make sure `-lg2c -lm' is at the end of the list.

   2.  Make sure each time `-lg2c' or `-lm' is seen, it forms
       part of the series `-lg2c -lm'.

   #1 and #2 are not done if `-nostdlib' or any option that disables
   the linking phase is present, or if `-xfoo' is in effect.  Note that
   a lack of source files or -l options disables linking.

   This program was originally made out of gcc/cp/g++spec.c, but the
   way it builds the new argument list was rewritten so it is much
   easier to maintain, improve the way it decides to add or not add
   extra arguments, etc.  And several improvements were made in the
   handling of arguments, primarily to make it more consistent with
   `gcc' itself.  */

#include "config.h"

#include <sys/types.h>
#include <stdio.h>

#include "gansidecl.h"

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#endif

#include <f/version.h>

#ifndef MATH_LIBRARY
#define MATH_LIBRARY "-lm"
#endif

#ifndef FORTRAN_LIBRARY
#define FORTRAN_LIBRARY "-lg2c"
#endif

/* Options this driver needs to recognize, not just know how to
   skip over.  */
typedef enum
{
  OPTION_b,			/* Aka --prefix. */
  OPTION_B,			/* Aka --target. */
  OPTION_c,			/* Aka --compile. */
  OPTION_driver,		/* Wrapper-specific option. */
  OPTION_E,			/* Aka --preprocess. */
  OPTION_help,			/* --help. */
  OPTION_i,			/* -imacros, -include, -include-*. */
  OPTION_l,
  OPTION_L,			/* Aka --library-directory. */
  OPTION_M,			/* Aka --dependencies. */
  OPTION_MM,			/* Aka --user-dependencies. */
  OPTION_nostdlib,		/* Aka --no-standard-libraries, or
				   -nodefaultlibs. */
  OPTION_o,			/* Aka --output. */
  OPTION_S,			/* Aka --assemble. */
  OPTION_syntax_only,		/* -fsyntax-only. */
  OPTION_v,			/* Aka --verbose. */
  OPTION_version,		/* --version. */
  OPTION_V,			/* Aka --use-version. */
  OPTION_x,			/* Aka --language. */
  OPTION_			/* Unrecognized or unimportant. */
} Option;

/* The original argument list and related info is copied here.  */
static int g77_xargc;
static char **g77_xargv;
static void (*g77_fn)();

/* The new argument list will be built here.  */
static int g77_newargc;
static char **g77_newargv;

extern char *xmalloc PROTO((size_t));

/* --- This comes from gcc.c (2.8.1) verbatim: */

/* This defines which switch letters take arguments.  */

#define DEFAULT_SWITCH_TAKES_ARG(CHAR)      \
  ((CHAR) == 'D' || (CHAR) == 'U' || (CHAR) == 'o' \
   || (CHAR) == 'e' || (CHAR) == 'T' || (CHAR) == 'u' \
   || (CHAR) == 'I' || (CHAR) == 'm' || (CHAR) == 'x' \
   || (CHAR) == 'L' || (CHAR) == 'A')

#ifndef SWITCH_TAKES_ARG
#define SWITCH_TAKES_ARG(CHAR) DEFAULT_SWITCH_TAKES_ARG(CHAR)
#endif

/* This defines which multi-letter switches take arguments.  */

#define DEFAULT_WORD_SWITCH_TAKES_ARG(STR)		\
 (!strcmp (STR, "Tdata") || !strcmp (STR, "Ttext")	\
  || !strcmp (STR, "Tbss") || !strcmp (STR, "include")	\
  || !strcmp (STR, "imacros") || !strcmp (STR, "aux-info") \
  || !strcmp (STR, "idirafter") || !strcmp (STR, "iprefix") \
  || !strcmp (STR, "iwithprefix") || !strcmp (STR, "iwithprefixbefore") \
  || !strcmp (STR, "isystem") || !strcmp (STR, "specs"))

#ifndef WORD_SWITCH_TAKES_ARG
#define WORD_SWITCH_TAKES_ARG(STR) DEFAULT_WORD_SWITCH_TAKES_ARG (STR)
#endif

/* --- End of verbatim.  */

/* Assumes text[0] == '-'.  Returns number of argv items that belong to
   (and follow) this one, an option id for options important to the
   caller, and a pointer to the first char of the arg, if embedded (else
   returns NULL, meaning no arg or it's the next argv).

   Note that this also assumes gcc.c's pass converting long options
   to short ones, where available, has already been run.  */

static void
lookup_option (xopt, xskip, xarg, text)
     Option *xopt;
     int *xskip;
     char **xarg;
     char *text;
{
  Option opt = OPTION_;
  int skip;
  char *arg = NULL;

  if ((skip = SWITCH_TAKES_ARG (text[1])))
    skip -= (text[2] != '\0');	/* See gcc.c. */

  if (text[1] == 'B')
    opt = OPTION_B, skip = (text[2] == '\0'), arg = text + 2;
  else if (text[1] == 'b')
    opt = OPTION_b, skip = (text[2] == '\0'), arg = text + 2;
  else if ((text[1] == 'c') && (text[2] == '\0'))
    opt = OPTION_c, skip = 0;
  else if ((text[1] == 'E') && (text[2] == '\0'))
    opt = OPTION_E, skip = 0;
  else if (text[1] == 'i')
    opt = OPTION_i, skip = 0;
  else if (text[1] == 'l')
    opt = OPTION_l;
  else if (text[1] == 'L')
    opt = OPTION_L, arg = text + 2;
  else if (text[1] == 'o')
    opt = OPTION_o;
  else if ((text[1] == 'S') && (text[2] == '\0'))
    opt = OPTION_S, skip = 0;
  else if (text[1] == 'V')
    opt = OPTION_V, skip = (text[2] == '\0');
  else if ((text[1] == 'v') && (text[2] == '\0'))
    opt = OPTION_v, skip = 0;
  else if (text[1] == 'x')
    opt = OPTION_x, arg = text + 2;
  else
    {
      if ((skip = WORD_SWITCH_TAKES_ARG (text + 1)) != 0)  /* See gcc.c. */
	;
      else if (! strncmp (text, "-fdriver", 8))  /* Really --driver!! */
	opt = OPTION_driver;	/* Never mind arg, this is unsupported. */
      else if (! strcmp (text, "-fhelp"))  /* Really --help!! */
	opt = OPTION_help;
      else if (! strcmp (text, "-M"))
	opt = OPTION_M;
      else if (! strcmp (text, "-MM"))
	opt = OPTION_MM;
      else if (! strcmp (text, "-nostdlib")
	       || ! strcmp (text, "-nodefaultlibs"))
	opt = OPTION_nostdlib;
      else if (! strcmp (text, "-fsyntax-only"))
	opt = OPTION_syntax_only;
      else if (! strcmp (text, "-dumpversion"))
	opt = OPTION_version;
      else if (! strcmp (text, "-Xlinker")
	       || ! strcmp (text, "-specs"))
	skip = 1;
      else
	skip = 0;
    }

  if (xopt != NULL)
    *xopt = opt;
  if (xskip != NULL)
    *xskip = skip;
  if (xarg != NULL)
    {
      if ((arg != NULL)
	  && (arg[0] == '\0'))
	*xarg = NULL;
      else
	*xarg = arg;
    }
}

/* Append another argument to the list being built.  As long as it is
   identical to the corresponding arg in the original list, just increment
   the new arg count.  Otherwise allocate a new list, etc.  */

static void
append_arg (arg)
     char *arg;
{
  static int newargsize;

#if 0
  fprintf (stderr, "`%s'\n", arg);
#endif

  if (g77_newargv == g77_xargv
      && g77_newargc < g77_xargc
      && (arg == g77_xargv[g77_newargc]
	  || ! strcmp (arg, g77_xargv[g77_newargc])))
    {
      ++g77_newargc;
      return;			/* Nothing new here. */
    }

  if (g77_newargv == g77_xargv)
    {				/* Make new arglist. */
      int i;

      newargsize = (g77_xargc << 2) + 20;	/* This should handle all. */
      g77_newargv = (char **) xmalloc (newargsize * sizeof (char *));

      /* Copy what has been done so far.  */
      for (i = 0; i < g77_newargc; ++i)
	g77_newargv[i] = g77_xargv[i];
    }

  if (g77_newargc == newargsize)
    (*g77_fn) ("overflowed output arg list for `%s'", arg);

  g77_newargv[g77_newargc++] = arg;
}

void
lang_specific_driver (fn, in_argc, in_argv)
     void (*fn)();
     int *in_argc;
     char ***in_argv;
{
  int argc = *in_argc;
  char **argv = *in_argv;

  int i;
  int verbose = 0;
  Option opt;
  int skip;
  char *arg;

  /* This will be NULL if we encounter a situation where we should not
     link in libf2c.  */
  char *library = FORTRAN_LIBRARY;

  /* This will become 0 if anything other than -v and kin (like -V)
     is seen, meaning the user is trying to accomplish something.
     If it remains nonzero, and the user wants version info, add stuff to
     the command line to make gcc invoke all the appropriate phases
     to get all the version info.  */
  int add_version_magic = 1;

  /* 0 => -xnone in effect.
     1 => -xfoo in effect.  */
  int saw_speclang = 0;

  /* 0 => initial/reset state
     1 => last arg was -l<library>
     2 => last two args were -l<library> -lm.  */
  int saw_library = 0;

  /* The number of input and output files in the incoming arg list.  */
  int n_infiles = 0;
  int n_outfiles = 0;

#if 0
  fprintf (stderr, "Incoming:");
  for (i = 0; i < argc; i++)
    fprintf (stderr, " %s", argv[i]);
  fprintf (stderr, "\n");
#endif

  g77_xargc = argc;
  g77_xargv = argv;
  g77_newargc = 0;
  g77_newargv = argv;
  g77_fn = fn;

  /* First pass through arglist.

     If -nostdlib or a "turn-off-linking" option is anywhere in the
     command line, don't do any library-option processing (except
     relating to -x).  Also, if -v is specified, but no other options
     that do anything special (allowing -V version, etc.), remember
     to add special stuff to make gcc command actually invoke all
     the different phases of the compilation process so all the version
     numbers can be seen.

     Also, here is where all problems with missing arguments to options
     are caught.  If this loop is exited normally, it means all options
     have the appropriate number of arguments as far as the rest of this
     program is concerned.  */

  for (i = 1; i < argc; ++i)
    {
      if ((argv[i][0] == '+') && (argv[i][1] == 'e'))
	{
	  add_version_magic = 0;
	  continue;
	}

      if ((argv[i][0] != '-') || (argv[i][1] == '\0'))
	{
	  ++n_infiles;
	  add_version_magic = 0;
	  continue;
	}

      lookup_option (&opt, &skip, NULL, argv[i]);

      switch (opt)
	{
	case OPTION_nostdlib:
	case OPTION_c:
	case OPTION_S:
	case OPTION_syntax_only:
	case OPTION_E:
	case OPTION_M:
	case OPTION_MM:
	  /* These options disable linking entirely or linking of the
	     standard libraries.  */
	  library = 0;
	  add_version_magic = 0;
	  break;

	case OPTION_l:
	  ++n_infiles;
	  add_version_magic = 0;
	  break;

	case OPTION_o:
	  ++n_outfiles;
	  add_version_magic = 0;
	  break;

	case OPTION_v:
	  if (! verbose)
	    fprintf (stderr, "g77 version %s\n", ffe_version_string);
	  verbose = 1;
	  break;

	case OPTION_b:
	case OPTION_B:
	case OPTION_L:
	case OPTION_i:
	case OPTION_V:
	  /* These options are useful in conjunction with -v to get
	     appropriate version info.  */
	  break;

	case OPTION_version:
	  printf ("\
GNU Fortran %s\n\
Copyright (C) 1997 Free Software Foundation, Inc.\n\
For more version information on components of the GNU Fortran\n\
compilation system, especially useful when reporting bugs,\n\
type the command `g77 --verbose'.\n\
\n\
GNU Fortran comes with NO WARRANTY, to the extent permitted by law.\n\
You may redistribute copies of GNU Fortran\n\
under the terms of the GNU General Public License.\n\
For more information about these matters, see the file named COPYING\n\
or type the command `info -f g77 Copying'.\n\
", ffe_version_string);
	  exit (0);
	  break;

	case OPTION_help:
	  printf ("\
Usage: g77 [OPTION]... FORTRAN-SOURCE...\n\
\n\
Compile and link Fortran source code to produce an executable program,\n\
which by default is named `a.out', and can be invoked with the UNIX\n\
command `./a.out'.\n\
\n\
Options:\n\
--debug                include debugging information in executable.\n\
--help                 display this help and exit.\n\
--optimize[=LEVEL]     take extra time and memory to make generated\n\
                         executable run faster.  LEVEL is 0 for no\n\
                         optimization, 1 for normal optimization, and\n\
                         increases through 3 for more optimization.\n\
--output=PROGRAM       name the executable PROGRAM instead of a.out;\n\
                         invoke with the command `./PROGRAM'.\n\
--version              display version information and exit.\n\
\n\
Many other options exist to tailor the compilation process, specify\n\
the dialect of the Fortran source code, specify details of the\n\
code-generation methodology, and so on.\n\
\n\
For more information on g77 and gcc, type the commands `info -f g77'\n\
and `info -f gcc' to read the Info documentation.\n\
\n\
Report bugs to <fortran@gnu.org>.\n");
	  exit (0);
	  break;

	case OPTION_driver:
	  (*fn) ("--driver no longer supported", argv[i]);
	  break;

	default:
	  add_version_magic = 0;
	  break;
	}

      /* This is the one place we check for missing arguments in the
	 program.  */

      if (i + skip < argc)
	i += skip;
      else
	(*fn) ("argument to `%s' missing", argv[i]);
    }

  if ((n_outfiles != 0) && (n_infiles == 0))
    (*fn) ("No input files; unwilling to write output files");

  /* Second pass through arglist, transforming arguments as appropriate.  */

  append_arg (argv[0]);	/* Start with command name, of course. */

  for (i = 1; i < argc; ++i)
    {
      if (argv[i][0] == '\0')
	{
	  append_arg (argv[i]);	/* Interesting.  Just append as is. */
	  continue;
	}

      if ((argv[i][0] == '-') && (argv[i][1] != 'l'))
	{
	  /* Not a filename or library. */

	  if (saw_library == 1)	/* -l<library>. */
	    append_arg (MATH_LIBRARY);

	  saw_library = 0;

	  lookup_option (&opt, &skip, &arg, argv[i]);

	  if (argv[i][1] == '\0')
	    {
	      append_arg (argv[i]);	/* "-" == Standard input. */
	      continue;
	    }

	  if (opt == OPTION_x)
	    {
	      /* Track input language. */
	      char *lang;

	      if (arg == NULL)
		lang = argv[i+1];
	      else
		lang = arg;

	      saw_speclang = (strcmp (lang, "none") != 0);
	    }

	  append_arg (argv[i]);

	  for (; skip != 0; --skip)
	    append_arg (argv[++i]);

	  continue;
	}

      /* A filename/library, not an option. */

      if (saw_speclang)
	saw_library = 0;	/* -xfoo currently active. */
      else
	{			/* -lfoo or filename. */
	  if (strcmp (argv[i], MATH_LIBRARY) == 0
#ifdef ALT_LIBM
	      || strcmp (argv[i], ALT_LIBM) == 0
#endif
	      )
	    {
	      if (saw_library == 1)
		saw_library = 2;	/* -l<library> -lm. */
	    }
	  else if (strcmp (argv[i], FORTRAN_LIBRARY) == 0)
	    saw_library = 1;	/* -l<library>. */
	  else
	    {		/* Other library, or filename. */
	      if (saw_library == 1)
		append_arg (MATH_LIBRARY);
	      saw_library = 0;
	    }
	}
      append_arg (argv[i]);
    }

  /* Append `-lg2c -lm' as necessary.  */

  if (! add_version_magic && library)
    {				/* Doing a link and no -nostdlib. */
      if (saw_speclang)
	append_arg ("-xnone");

      switch (saw_library)
	{
	case 0:
	  append_arg (library);
	case 1:
	  append_arg (MATH_LIBRARY);
	default:
	  break;
	}
    }
  else if (add_version_magic && verbose)
    {
      append_arg ("-c");
      append_arg ("-xf77-version");
      append_arg ("/dev/null");
      append_arg ("-xnone");
    }

  if (verbose
      && g77_newargv != g77_xargv)
    {
      fprintf (stderr, "Driving:");
      for (i = 0; i < g77_newargc; i++)
	fprintf (stderr, " %s", g77_newargv[i]);
      fprintf (stderr, "\n");
    }

  *in_argc = g77_newargc;
  *in_argv = g77_newargv;
}
