1 /* depend.c - Handle dependency tracking. 2 Copyright (C) 1997-2016 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 #include "filenames.h" 23 24 /* The file to write to, or NULL if no dependencies being kept. */ 25 static char * dep_file = NULL; 26 27 struct dependency 28 { 29 char * file; 30 struct dependency * next; 31 }; 32 33 /* All the files we depend on. */ 34 static struct dependency * dep_chain = NULL; 35 36 /* Current column in output file. */ 37 static int column = 0; 38 39 static int quote_string_for_make (FILE *, const char *); 40 static void wrap_output (FILE *, const char *, int); 41 42 /* Number of columns allowable. */ 43 #define MAX_COLUMNS 72 44 45 /* Start saving dependencies, to be written to FILENAME. If this is 47 never called, then dependency tracking is simply skipped. */ 48 49 void 50 start_dependencies (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 (const char *filename) 59 { 60 struct dependency *dep; 61 62 if (dep_file == NULL) 63 return; 64 65 for (dep = dep_chain; dep != NULL; dep = dep->next) 66 { 67 if (!filename_cmp (filename, dep->file)) 68 return; 69 } 70 71 dep = XNEW (struct dependency); 72 dep->file = xstrdup (filename); 73 dep->next = dep_chain; 74 dep_chain = dep; 75 } 76 77 /* Quote a file name the way `make' wants it, and print it to FILE. 78 If FILE is NULL, do no printing, but return the length of the 79 quoted string. 80 81 This code is taken from gcc with only minor changes. */ 82 83 static int 84 quote_string_for_make (FILE *file, const char *src) 85 { 86 const char *p = src; 87 int i = 0; 88 89 for (;;) 90 { 91 char c = *p++; 92 93 switch (c) 94 { 95 case '\0': 96 case ' ': 97 case '\t': 98 { 99 /* GNU make uses a weird quoting scheme for white space. 100 A space or tab preceded by 2N+1 backslashes represents 101 N backslashes followed by space; a space or tab 102 preceded by 2N backslashes represents N backslashes at 103 the end of a file name; and backslashes in other 104 contexts should not be doubled. */ 105 const char *q; 106 107 for (q = p - 1; src < q && q[-1] == '\\'; q--) 108 { 109 if (file) 110 putc ('\\', file); 111 i++; 112 } 113 } 114 if (!c) 115 return i; 116 if (file) 117 putc ('\\', file); 118 i++; 119 goto ordinary_char; 120 121 case '$': 122 if (file) 123 putc (c, file); 124 i++; 125 /* Fall through. This can mishandle things like "$(" but 126 there's no easy fix. */ 127 default: 128 ordinary_char: 129 /* This can mishandle characters in the string "\0\n%*?[\\~"; 130 exactly which chars are mishandled depends on the `make' version. 131 We know of no portable solution for this; 132 even GNU make 3.76.1 doesn't solve the problem entirely. 133 (Also, '\0' is mishandled due to our calling conventions.) */ 134 if (file) 135 putc (c, file); 136 i++; 137 break; 138 } 139 } 140 } 141 142 /* Append some output to the file, keeping track of columns and doing 143 wrapping as necessary. */ 144 145 static void 146 wrap_output (FILE *f, const char *string, int spacer) 147 { 148 int len = quote_string_for_make (NULL, string); 149 150 if (len == 0) 151 return; 152 153 if (column 154 && (MAX_COLUMNS 155 - 1 /* spacer */ 156 - 2 /* ` \' */ 157 < column + len)) 158 { 159 fprintf (f, " \\\n "); 160 column = 0; 161 if (spacer == ' ') 162 spacer = '\0'; 163 } 164 165 if (spacer == ' ') 166 { 167 putc (spacer, f); 168 ++column; 169 } 170 171 quote_string_for_make (f, string); 172 column += len; 173 174 if (spacer == ':') 175 { 176 putc (spacer, f); 177 ++column; 178 } 179 } 180 181 /* Print dependency file. */ 182 183 void 184 print_dependencies (void) 185 { 186 FILE *f; 187 struct dependency *dep; 188 189 if (dep_file == NULL) 190 return; 191 192 f = fopen (dep_file, FOPEN_WT); 193 if (f == NULL) 194 { 195 as_warn (_("can't open `%s' for writing"), dep_file); 196 return; 197 } 198 199 column = 0; 200 wrap_output (f, out_file_name, ':'); 201 for (dep = dep_chain; dep != NULL; dep = dep->next) 202 wrap_output (f, dep->file, ' '); 203 204 putc ('\n', f); 205 206 if (fclose (f)) 207 as_warn (_("can't close `%s'"), dep_file); 208 } 209
