gcc.c

gcc库的原代码,对编程有很大帮助.

		  if (arglen < optlen)
		    {
		      for (k = j + 1;
			   k < sizeof (option_map) / sizeof (option_map[0]);
			   k++)
			if (strlen (option_map[k].name) >= arglen
			    && !strncmp (argv[i], option_map[k].name, arglen))
			  {
			    error ("Ambiguous abbreviation %s", argv[i]);
			    break;
			  }

		      if (k != sizeof (option_map) / sizeof (option_map[0]))
			break;
		    }

		  if (arglen > optlen)
		    {
		      /* If the option has an argument, accept that.  */
		      if (argv[i][optlen] == '=')
			arg = argv[i] + optlen + 1;

		      /* If this mapping requires extra text at end of name,
			 accept that as "argument".  */
		      else if (index (arginfo, '*') != 0)
			arg = argv[i] + optlen;

		      /* Otherwise, extra text at end means mismatch.
			 Try other mappings.  */
		      else
			continue;
		    }

		  else if (index (arginfo, '*') != 0)
		    {
		      error ("Incomplete `%s' option", option_map[j].name);
		      break;
		    }

		  /* Handle arguments.  */
		  if (index (arginfo, 'a') != 0)
		    {
		      if (arg == 0)
			{
			  if (i + 1 == argc)
			    {
			      error ("Missing argument to `%s' option",
				     option_map[j].name);
			      break;
			    }

			  arg = argv[++i];
			}
		    }
		  else if (index (arginfo, '*') != 0)
		    ;
		  else if (index (arginfo, 'o') == 0)
		    {
		      if (arg != 0)
			error ("Extraneous argument to `%s' option",
			       option_map[j].name);
		      arg = 0;
		    }

		  /* Store the translation as one argv elt or as two.  */
		  if (arg != 0 && index (arginfo, 'j') != 0)
		    newv[newindex++] = concat (option_map[j].equivalent, arg);
		  else if (arg != 0)
		    {
		      newv[newindex++] = option_map[j].equivalent;
		      newv[newindex++] = arg;
		    }
		  else
		    newv[newindex++] = option_map[j].equivalent;

		  break;
		}
	    }
	  i++;
	}

      /* Handle old-fashioned options--just copy them through,
	 with their arguments.  */
      else if (argv[i][0] == '-')
	{
	  char *p = argv[i] + 1;
	  int c = *p;
	  int nskip = 1;

	  if (SWITCH_TAKES_ARG (c) > (p[1] != 0))
	    nskip += SWITCH_TAKES_ARG (c) - (p[1] != 0);
	  else if (WORD_SWITCH_TAKES_ARG (p))
	    nskip += WORD_SWITCH_TAKES_ARG (p);
	  else if ((c == 'B' || c == 'b' || c == 'V' || c == 'x')
		   && p[1] == 0)
	    nskip += 1;
	  else if (! strcmp (p, "Xlinker"))
	    nskip += 1;

	  /* Watch out for an option at the end of the command line that
	     is missing arguments, and avoid skipping past the end of the
	     command line.  */
	  if (nskip + i > argc)
	    nskip = argc - i;

	  while (nskip > 0)
	    {
	      newv[newindex++] = argv[i++];
	      nskip--;
	    }
	}
      else
	/* Ordinary operands, or +e options.  */
	newv[newindex++] = argv[i++];
    }

  newv[newindex] = 0;

  *argvp = newv;
  *argcp = newindex;
}

char *
my_strerror(e)
     int e;
{

#ifdef HAVE_STRERROR
  return strerror(e);

#else

  static char buffer[30];
  if (!e)
    return "";

  if (e > 0 && e < sys_nerr)
    return sys_errlist[e];

  sprintf (buffer, "Unknown error %d", e);
  return buffer;
#endif
}

/* Read compilation specs from a file named FILENAME,
   replacing the default ones.

   A suffix which starts with `*' is a definition for
   one of the machine-specific sub-specs.  The "suffix" should be
   *asm, *cc1, *cpp, *link, *startfile, *signed_char, etc.
   The corresponding spec is stored in asm_spec, etc.,
   rather than in the `compilers' vector.

   Anything invalid in the file is a fatal error.  */

static void
read_specs (filename)
     char *filename;
{
  int desc;
  int readlen;
  struct stat statbuf;
  char *buffer;
  register char *p;

  if (verbose_flag)
    fprintf (stderr, "Reading specs from %s\n", filename);

  /* Open and stat the file.  */
  desc = open (filename, O_RDONLY, 0);
  if (desc < 0)
    pfatal_with_name (filename);
  if (stat (filename, &statbuf) < 0)
    pfatal_with_name (filename);

  /* Read contents of file into BUFFER.  */
  buffer = xmalloc ((unsigned) statbuf.st_size + 1);
  readlen = read (desc, buffer, (unsigned) statbuf.st_size);
  if (readlen < 0)
    pfatal_with_name (filename);
  buffer[readlen] = 0;
  close (desc);

  /* Scan BUFFER for specs, putting them in the vector.  */
  p = buffer;
  while (1)
    {
      char *suffix;
      char *spec;
      char *in, *out, *p1, *p2;

      /* Advance P in BUFFER to the next nonblank nocomment line.  */
      p = skip_whitespace (p);
      if (*p == 0)
	break;

      /* Find the colon that should end the suffix.  */
      p1 = p;
      while (*p1 && *p1 != ':' && *p1 != '\n') p1++;
      /* The colon shouldn't be missing.  */
      if (*p1 != ':')
	fatal ("specs file malformed after %d characters", p1 - buffer);
      /* Skip back over trailing whitespace.  */
      p2 = p1;
      while (p2 > buffer && (p2[-1] == ' ' || p2[-1] == '\t')) p2--;
      /* Copy the suffix to a string.  */
      suffix = save_string (p, p2 - p);
      /* Find the next line.  */
      p = skip_whitespace (p1 + 1);
      if (p[1] == 0)
	fatal ("specs file malformed after %d characters", p - buffer);
      p1 = p;
      /* Find next blank line.  */
      while (*p1 && !(*p1 == '\n' && p1[1] == '\n')) p1++;
      /* Specs end at the blank line and do not include the newline.  */
      spec = save_string (p, p1 - p);
      p = p1;

      /* Delete backslash-newline sequences from the spec.  */
      in = spec;
      out = spec;
      while (*in != 0)
	{
	  if (in[0] == '\\' && in[1] == '\n')
	    in += 2;
	  else if (in[0] == '#')
	    {
	      while (*in && *in != '\n') in++;
	    }
	  else
	    *out++ = *in++;
	}
      *out = 0;

      if (suffix[0] == '*')
	{
	  if (! strcmp (suffix, "*link_command"))
	    link_command_spec = spec;
	  else
	    set_spec (suffix + 1, spec);
	}
      else
	{
	  /* Add this pair to the vector.  */
	  compilers
	    = ((struct compiler *)
	       xrealloc (compilers, (n_compilers + 2) * sizeof (struct compiler)));
	  compilers[n_compilers].suffix = suffix;
	  bzero ((char *) compilers[n_compilers].spec,
		 sizeof compilers[n_compilers].spec);
	  compilers[n_compilers].spec[0] = spec;
	  n_compilers++;
	  bzero ((char *) &compilers[n_compilers],
		 sizeof compilers[n_compilers]);
	}

      if (*suffix == 0)
	link_command_spec = spec;
    }

  if (link_command_spec == 0)
    fatal ("spec file has no spec for linking");
}

static char *
skip_whitespace (p)
     char *p;
{
  while (1)
    {
      /* A fully-blank line is a delimiter in the SPEC file and shouldn't
	 be considered whitespace.  */
      if (p[0] == '\n' && p[1] == '\n' && p[2] == '\n')
	return p + 1;
      else if (*p == '\n' || *p == ' ' || *p == '\t')
	p++;
      else if (*p == '#')
	{
	  while (*p != '\n') p++;
	  p++;
	}
      else
	break;
    }

  return p;
}

/* Structure to keep track of the specs that have been defined so far.  These
   are accessed using %(specname) or %[specname] in a compiler or link spec. */

struct spec_list
{
  char *name;                 /* Name of the spec. */
  char *spec;                 /* The spec itself. */
  struct spec_list *next;     /* Next spec in linked list. */
};

/* List of specs that have been defined so far. */

static struct spec_list *specs = (struct spec_list *) 0;

/* Change the value of spec NAME to SPEC.  If SPEC is empty, then the spec is
   removed; If the spec starts with a + then SPEC is added to the end of the
   current spec. */

static void
set_spec (name, spec)
     char *name;
     char *spec;
{
  struct spec_list *sl;
  char *old_spec;

  /* See if the spec already exists */
  for (sl = specs; sl; sl = sl->next)
    if (strcmp (sl->name, name) == 0)
      break;

  if (!sl)
    {
      /* Not found - make it */
      sl = (struct spec_list *) xmalloc (sizeof (struct spec_list));
      sl->name = save_string (name, strlen (name));
      sl->spec = save_string ("", 0);
      sl->next = specs;
      specs = sl;
    }

  old_spec = sl->spec;
  if (name && spec[0] == '+' && isspace (spec[1]))
    sl->spec = concat (old_spec, spec + 1);
  else
    sl->spec = save_string (spec, strlen (spec));

  if (! strcmp (name, "asm"))
    asm_spec = sl->spec;
  else if (! strcmp (name, "asm_final"))
    asm_final_spec = sl->spec;
  else if (! strcmp (name, "cc1"))
    cc1_spec = sl->spec;
  else if (! strcmp (name, "cc1plus"))
    cc1plus_spec = sl->spec;
  else if (! strcmp (name, "cpp"))
    cpp_spec = sl->spec;
  else if (! strcmp (name, "endfile"))
    endfile_spec = sl->spec;
  else if (! strcmp (name, "lib"))
    lib_spec = sl->spec;
  else if (! strcmp (name, "libgcc"))
    libgcc_spec = sl->spec;
  else if (! strcmp (name, "link"))
    link_spec = sl->spec;
  else if (! strcmp (name, "predefines"))
    cpp_predefines = sl->spec;
  else if (! strcmp (name, "signed_char"))
    signed_char_spec = sl->spec;
  else if (! strcmp (name, "startfile"))
    startfile_spec = sl->spec;
  else if (! strcmp (name, "switches_need_spaces"))
    switches_need_spaces = sl->spec;
  else if (! strcmp (name, "cross_compile"))
    cross_compile = atoi (sl->spec);
  else if (! strcmp (name, "multilib"))
    multilib_select = sl->spec;
  /* Free the old spec */
  if (old_spec)
    free (old_spec);
}

/* Accumulate a command (program name and args), and run it.  */

/* Vector of pointers to arguments in the current line of specifications.  */

static char **argbuf;

/* Number of elements allocated in argbuf.  */

static int argbuf_length;

/* Number of elements in argbuf currently in use (containing args).  */

static int argbuf_index;

/* This is the list of suffixes and codes (%g/%u/%U) and the associated
   temp file.  Used only if MKTEMP_EACH_FILE.  */

static struct temp_name {
  char *suffix;		/* suffix associated with the code.  */
  int length;		/* strlen (suffix).  */
  int unique;		/* Indicates whether %g or %u/%U was used.  */
  char *filename;	/* associated filename.  */
  int filename_length;	/* strlen (filename).  */
  struct temp_name *next;
} *temp_names;

/* Number of commands executed so far.  */

static int execution_count;

/* Number of commands that exited with a signal.  */

static int signal_count;

/* Name with which this program was invoked.  */

static char *programname;

/* Structures to keep track of prefixes to try when looking for files. */

struct prefix_list
{
  char *prefix;               /* String to prepend to the path. */
  struct prefix_list *next;   /* Next in linked list. */
  int require_machine_suffix; /* Don't use without machine_suffix.  */
  /* 2 means try both machine_suffix and just_machine_suffix.  */
  int *used_flag_ptr;	      /* 1 if a file was found with this prefix.  */
};

struct path_prefix
{
  struct prefix_list *plist;  /* List of prefixes to try */
  int max_len;                /* Max length of a prefix in PLIST */
  char *name;                 /* Name of this list (used in config stuff) */
};

/* List of prefixes to try when looking for executables. */

static struct path_prefix exec_prefixes = { 0, 0, "exec" };

/* List of prefixes to try when looking for startup (crt0) files. */

static struct path_prefix startfile_prefixes = { 0, 0, "startfile" };

/* List of prefixes to try when looking for include files.  */

static struct path_prefix include_prefixes = { 0, 0, "include" };

/* Suffix to attach to directories searched for commands.
   This looks like `MACHINE/VERSION/'.  */

static char *machine_suffix = 0;

/* Suffix to attach to directories searched for commands.