gcc/file-prefix-map.cc

   1 /* Implementation of file prefix remapping support (-f*-prefix-map options).
   2    Copyright (C) 2017-2022 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify it
   5    under the terms of the GNU General Public License as published by the
   6    Free Software Foundation; either version 3, or (at your option) any
   7    later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; see the file COPYING3.  If not see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include "config.h"
  19 #include "system.h"
  20 #include "coretypes.h"
  21 #include "diagnostic.h"
  22 #include "file-prefix-map.h"
  23
  24 /* Structure recording the mapping from source file and directory names at
  25    compile time to those to be embedded in the compilation result (debug
  26    information, the __FILE__ macro expansion, etc).  */
  27 struct file_prefix_map
  28 {
  29   const char *old_prefix;
  30   const char *new_prefix;
  31   size_t old_len;
  32   size_t new_len;
  33   struct file_prefix_map *next;
  34 };
  35
  36 /* Record a file prefix mapping in the specified map.  ARG is the argument to
  37    -f*-prefix-map and must be of the form OLD=NEW.  OPT is the option name
  38    for diagnostics.  */
  39 static void
  40 add_prefix_map (file_prefix_map *&maps, const char *arg, const char *opt)
  41 {
  42   file_prefix_map *map;
  43   const char *p;
  44
  45   /* Note: looking for the last '='. The thinking is we can control the paths
  46      inside our projects but not where the users build them.  */
  47   p = strrchr (arg, '=');
  48   if (!p)
  49     {
  50       error ("invalid argument %qs to %qs", arg, opt);
  51       return;
  52     }
  53   map = XNEW (file_prefix_map);
  54   map->old_prefix = xstrndup (arg, p - arg);
  55   map->old_len = p - arg;
  56   p++;
  57   map->new_prefix = xstrdup (p);
  58   map->new_len = strlen (p);
  59   map->next = maps;
  60   maps = map;
  61 }
  62
  63 /* Perform user-specified mapping of filename prefixes.  Return the
  64    GC-allocated new name corresponding to FILENAME or FILENAME if no
  65    remapping was performed.  */
  66
  67 static const char *
  68 remap_filename (file_prefix_map *maps, const char *filename)
  69 {
  70   file_prefix_map *map;
  71   char *s;
  72   const char *name;
  73   char *realname;
  74   size_t name_len;
  75
  76   if (!filename || lbasename (filename) == filename)
  77     return filename;
  78
  79   realname = lrealpath (filename);
  80
  81   for (map = maps; map; map = map->next)
  82     if (filename_ncmp (realname, map->old_prefix, map->old_len) == 0)
  83       break;
  84   if (!map)
  85     {
  86       free (realname);
  87       return filename;
  88     }
  89   name = realname + map->old_len;
  90   name_len = strlen (name) + 1;
  91
  92   s = (char *) ggc_alloc_atomic (name_len + map->new_len);
  93   memcpy (s, map->new_prefix, map->new_len);
  94   memcpy (s + map->new_len, name, name_len);
  95   free (realname);
  96   return s;
  97 }
  98
  99 /* NOTE: if adding another -f*-prefix-map option then don't forget to
 100    ignore it in DW_AT_producer (dwarf2out.cc).  */
 101
 102 /* Linked lists of file_prefix_map structures.  */
 103 static file_prefix_map *macro_prefix_maps; /* -fmacro-prefix-map  */
 104 static file_prefix_map *debug_prefix_maps; /* -fdebug-prefix-map  */
 105 static file_prefix_map *profile_prefix_maps; /* -fprofile-prefix-map  */
 106
 107 /* Record a file prefix mapping for -fmacro-prefix-map.  */
 108 void
 109 add_macro_prefix_map (const char *arg)
 110 {
 111   add_prefix_map (macro_prefix_maps, arg, "-fmacro-prefix-map");
 112 }
 113
 114 /* Record a file prefix mapping for -fdebug-prefix-map.  */
 115 void
 116 add_debug_prefix_map (const char *arg)
 117 {
 118   add_prefix_map (debug_prefix_maps, arg, "-fdebug-prefix-map");
 119 }
 120
 121 /* Record a file prefix mapping for all -f*-prefix-map.  */
 122 void
 123 add_file_prefix_map (const char *arg)
 124 {
 125   add_prefix_map (macro_prefix_maps, arg, "-ffile-prefix-map");
 126   add_prefix_map (debug_prefix_maps, arg, "-ffile-prefix-map");
 127   add_prefix_map (profile_prefix_maps, arg, "-ffile-prefix-map");
 128 }
 129
 130 /* Record a file prefix mapping for -fprofile-prefix-map.  */
 131 void
 132 add_profile_prefix_map (const char *arg)
 133 {
 134   add_prefix_map (profile_prefix_maps, arg, "-fprofile-prefix-map");
 135 }
 136
 137 /* Remap using -fmacro-prefix-map.  Return the GC-allocated new name
 138    corresponding to FILENAME or FILENAME if no remapping was performed.  */
 139 const char *
 140 remap_macro_filename (const char *filename)
 141 {
 142   return remap_filename (macro_prefix_maps, filename);
 143 }
 144
 145 /* Remap using -fdebug-prefix-map.  Return the GC-allocated new name
 146    corresponding to FILENAME or FILENAME if no remapping was performed.  */
 147 const char *
 148 remap_debug_filename (const char *filename)
 149 {
 150   return remap_filename (debug_prefix_maps, filename);
 151 }
 152
 153 /* Remap using -fprofile-prefix-map.  Return the GC-allocated new name
 154    corresponding to FILENAME or FILENAME if no remapping was performed.  */
 155 const char *
 156 remap_profile_filename (const char *filename)
 157 {
 158   return remap_filename (profile_prefix_maps, filename);
 159 }