merge from gcc
[binutils.git] / gas / depend.c
blob251458e987702fe92e8024ffe45c642a9ad65dc0
1 /* depend.c - Handle dependency tracking.
2 Copyright 1997, 1998, 2000, 2001, 2003, 2007 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
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 3, or (at your option)
9 any later version.
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.
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, 51 Franklin Street - Fifth Floor, Boston, MA
19 02110-1301, USA. */
21 #include "as.h"
23 /* The file to write to, or NULL if no dependencies being kept. */
24 static char * dep_file = NULL;
26 struct dependency
28 char * file;
29 struct dependency * next;
32 /* All the files we depend on. */
33 static struct dependency * dep_chain = NULL;
35 /* Current column in output file. */
36 static int column = 0;
38 static int quote_string_for_make (FILE *, char *);
39 static void wrap_output (FILE *, char *, int);
41 /* Number of columns allowable. */
42 #define MAX_COLUMNS 72
44 /* Start saving dependencies, to be written to FILENAME. If this is
45 never called, then dependency tracking is simply skipped. */
47 void
48 start_dependencies (char *filename)
50 dep_file = filename;
53 /* Noticed a new filename, so try to register it. */
55 void
56 register_dependency (char *filename)
58 struct dependency *dep;
60 if (dep_file == NULL)
61 return;
63 for (dep = dep_chain; dep != NULL; dep = dep->next)
65 if (!strcmp (filename, dep->file))
66 return;
69 dep = (struct dependency *) xmalloc (sizeof (struct dependency));
70 dep->file = xstrdup (filename);
71 dep->next = dep_chain;
72 dep_chain = dep;
75 /* Quote a file name the way `make' wants it, and print it to FILE.
76 If FILE is NULL, do no printing, but return the length of the
77 quoted string.
79 This code is taken from gcc with only minor changes. */
81 static int
82 quote_string_for_make (FILE *file, char *src)
84 char *p = src;
85 int i = 0;
87 for (;;)
89 char c = *p++;
91 switch (c)
93 case '\0':
94 case ' ':
95 case '\t':
97 /* GNU make uses a weird quoting scheme for white space.
98 A space or tab preceded by 2N+1 backslashes represents
99 N backslashes followed by space; a space or tab
100 preceded by 2N backslashes represents N backslashes at
101 the end of a file name; and backslashes in other
102 contexts should not be doubled. */
103 char *q;
105 for (q = p - 1; src < q && q[-1] == '\\'; q--)
107 if (file)
108 putc ('\\', file);
109 i++;
112 if (!c)
113 return i;
114 if (file)
115 putc ('\\', file);
116 i++;
117 goto ordinary_char;
119 case '$':
120 if (file)
121 putc (c, file);
122 i++;
123 /* Fall through. This can mishandle things like "$(" but
124 there's no easy fix. */
125 default:
126 ordinary_char:
127 /* This can mishandle characters in the string "\0\n%*?[\\~";
128 exactly which chars are mishandled depends on the `make' version.
129 We know of no portable solution for this;
130 even GNU make 3.76.1 doesn't solve the problem entirely.
131 (Also, '\0' is mishandled due to our calling conventions.) */
132 if (file)
133 putc (c, file);
134 i++;
135 break;
140 /* Append some output to the file, keeping track of columns and doing
141 wrapping as necessary. */
143 static void
144 wrap_output (FILE *f, char *string, int spacer)
146 int len = quote_string_for_make (NULL, string);
148 if (len == 0)
149 return;
151 if (column
152 && (MAX_COLUMNS
153 - 1 /* spacer */
154 - 2 /* ` \' */
155 < column + len))
157 fprintf (f, " \\\n ");
158 column = 0;
159 if (spacer == ' ')
160 spacer = '\0';
163 if (spacer == ' ')
165 putc (spacer, f);
166 ++column;
169 quote_string_for_make (f, string);
170 column += len;
172 if (spacer == ':')
174 putc (spacer, f);
175 ++column;
179 /* Print dependency file. */
181 void
182 print_dependencies (void)
184 FILE *f;
185 struct dependency *dep;
187 if (dep_file == NULL)
188 return;
190 f = fopen (dep_file, FOPEN_WT);
191 if (f == NULL)
193 as_warn (_("can't open `%s' for writing"), dep_file);
194 return;
197 column = 0;
198 wrap_output (f, out_file_name, ':');
199 for (dep = dep_chain; dep != NULL; dep = dep->next)
200 wrap_output (f, dep->file, ' ');
202 putc ('\n', f);
204 if (fclose (f))
205 as_warn (_("can't close `%s'"), dep_file);