gas/depend.c

   1 /* depend.c - Handle dependency tracking.
   2    Copyright (C) 1997 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19    02111-1307, USA.  */
  20
  21 #include "as.h"
  22
  23 /* The file to write to, or NULL if no dependencies being kept.  */
  24 static char *dep_file = NULL;
  25
  26 struct dependency
  27 {
  28   char *file;
  29   struct dependency *next;
  30 };
  31
  32 /* All the files we depend on.  */
  33 static struct dependency *dep_chain = NULL;
  34
  35 /* Current column in output file.  */
  36 static int column = 0;
  37
  38 static void wrap_output PARAMS ((FILE *, char *, int));
  39
  40 /* Number of columns allowable.  */
  41 #define MAX_COLUMNS 72
  42
  43 \f
  44
  45 /* Start saving dependencies, to be written to FILENAME.  If this is
  46    never called, then dependency tracking is simply skipped.  */
  47
  48 void
  49 start_dependencies (filename)
  50      char *filename;
  51 {
  52   dep_file = filename;
  53 }
  54
  55 /* Noticed a new filename, so try to register it.  */
  56
  57 void
  58 register_dependency (filename)
  59      char *filename;
  60 {
  61   struct dependency *dep;
  62
  63   if (dep_file == NULL)
  64     return;
  65
  66   for (dep = dep_chain; dep != NULL; dep = dep->next)
  67     {
  68       if (! strcmp (filename, dep->file))
  69         return;
  70     }
  71
  72   dep = (struct dependency *) xmalloc (sizeof (struct dependency));
  73   dep->file = xstrdup (filename);
  74   dep->next = dep_chain;
  75   dep_chain = dep;
  76 }
  77
  78 /* Append some output to the file, keeping track of columns and doing
  79    wrapping as necessary.  */
  80
  81 static void
  82 wrap_output (f, string, spacer)
  83      FILE *f;
  84      char *string;
  85      int spacer;
  86 {
  87   int len = strlen (string);
  88
  89   if (len == 0)
  90     return;
  91
  92   if (column && MAX_COLUMNS - 1 /*spacer*/ - 2 /*` \'*/ < column + len)
  93     {
  94       fprintf (f, " \\\n ");
  95       column = 0;
  96       if (spacer == ' ')
  97         spacer = '\0';
  98     }
  99
 100   if (spacer == ' ')
 101     {
 102       putc (spacer, f);
 103       ++column;
 104     }
 105
 106   fputs (string, f);
 107   column += len;
 108
 109   if (spacer == ':')
 110     {
 111       putc (spacer, f);
 112       ++column;
 113     }
 114 }
 115
 116 /* Print dependency file.  */
 117
 118 void
 119 print_dependencies ()
 120 {
 121   FILE *f;
 122   struct dependency *dep;
 123
 124   if (dep_file == NULL)
 125     return;
 126
 127   f = fopen (dep_file, "w");
 128   if (f == NULL)
 129     {
 130       as_warn ("Can't open `%s' for writing", dep_file);
 131       return;
 132     }
 133
 134   column = 0;
 135   wrap_output (f, out_file_name, ':');
 136   for (dep = dep_chain; dep != NULL; dep = dep->next)
 137     wrap_output (f, dep->file, ' ');
 138
 139   putc ('\n', f);
 140
 141   if (fclose (f))
 142     as_warn ("Can't close %s", dep_file);
 143 }