1 /* depend.c - Handle dependency tracking. 2 Copyright 1997, 1998, 2000, 2001, 2003, 2007 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 3, 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, 51 Franklin Street - Fifth Floor, Boston, MA 19 02110-1301, 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 int quote_string_for_make (FILE *, char *); 39 static void wrap_output (FILE *, char *, int); 40 41 /* Number of columns allowable. */ 42 #define MAX_COLUMNS 72 43 44 /* Start saving dependencies, to be written to FILENAME. If this is 45 never called, then dependency tracking is simply skipped. */ 46 47 void 48 start_dependencies (char *filename) 49 { 50 dep_file = filename; 51 } 52 53 /* Noticed a new filename, so try to register it. */ 54 55 void 56 register_dependency (char *filename) 57 { 58 struct dependency *dep; 59 60 if (dep_file == NULL) 61 return; 62 63 for (dep = dep_chain; dep != NULL; dep = dep->next) 64 { 65 if (!strcmp (filename, dep->file)) 66 return; 67 } 68 69 dep = (struct dependency *) xmalloc (sizeof (struct dependency)); 70 dep->file = xstrdup (filename); 71 dep->next = dep_chain; 72 dep_chain = dep; 73 } 74 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. 78 79 This code is taken from gcc with only minor changes. */ 80 81 static int 82 quote_string_for_make (FILE *file, char *src) 83 { 84 char *p = src; 85 int i = 0; 86 87 for (;;) 88 { 89 char c = *p++; 90 91 switch (c) 92 { 93 case '\0': 94 case ' ': 95 case '\t': 96 { 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; 104 105 for (q = p - 1; src < q && q[-1] == '\\'; q--) 106 { 107 if (file) 108 putc ('\\', file); 109 i++; 110 } 111 } 112 if (!c) 113 return i; 114 if (file) 115 putc ('\\', file); 116 i++; 117 goto ordinary_char; 118 119 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; 136 } 137 } 138 } 139 140 /* Append some output to the file, keeping track of columns and doing 141 wrapping as necessary. */ 142 143 static void 144 wrap_output (FILE *f, char *string, int spacer) 145 { 146 int len = quote_string_for_make (NULL, string); 147 148 if (len == 0) 149 return; 150 151 if (column 152 && (MAX_COLUMNS 153 - 1 /* spacer */ 154 - 2 /* ` \' */ 155 < column + len)) 156 { 157 fprintf (f, " \\\n "); 158 column = 0; 159 if (spacer == ' ') 160 spacer = '\0'; 161 } 162 163 if (spacer == ' ') 164 { 165 putc (spacer, f); 166 ++column; 167 } 168 169 quote_string_for_make (f, string); 170 column += len; 171 172 if (spacer == ':') 173 { 174 putc (spacer, f); 175 ++column; 176 } 177 } 178 179 /* Print dependency file. */ 180 181 void 182 print_dependencies (void) 183 { 184 FILE *f; 185 struct dependency *dep; 186 187 if (dep_file == NULL) 188 return; 189 190 f = fopen (dep_file, FOPEN_WT); 191 if (f == NULL) 192 { 193 as_warn (_("can't open `%s' for writing"), dep_file); 194 return; 195 } 196 197 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, ' '); 201 202 putc ('\n', f); 203 204 if (fclose (f)) 205 as_warn (_("can't close `%s'"), dep_file); 206 } 207