gcc/c-family/cppspec.c

   1 /* Specific flags and argument handling of the C preprocessor.
   2    Copyright (C) 1999-2018 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "tm.h"
  24 #include "opt-suggestions.h"
  25 #include "gcc.h"
  26 #include "opts.h"
  27
  28 /* The `cpp' executable installed in $(bindir) and $(cpp_install_dir)
  29    is a customized version of the gcc driver.  It forces -E; -S and -c
  30    are errors.  It defaults to -x c for files with unrecognized
  31    extensions, unless -x options appear in argv, in which case we
  32    assume the user knows what they're doing.  If no explicit input is
  33    mentioned, it will read stdin.  */
  34
  35 /* Suffixes for known sorts of input files.  Note that we do not list
  36    files which are normally considered to have been preprocessed already,
  37    since the user's expectation is that `cpp' always preprocesses.  */
  38 static const char *const known_suffixes[] =
  39 {
  40   ".c",  ".C",   ".S",   ".m",
  41   ".cc", ".cxx", ".cpp", ".cp",  ".c++",
  42   ".sx",
  43   NULL
  44 };
  45
  46 /* Filter the command line before processing by the gcc driver proper.  */
  47 void
  48 lang_specific_driver (struct cl_decoded_option **in_decoded_options,
  49                       unsigned int *in_decoded_options_count,
  50                       int *in_added_libraries ATTRIBUTE_UNUSED)
  51 {
  52   struct cl_decoded_option *decoded_options = *in_decoded_options;
  53   unsigned int argc = *in_decoded_options_count;
  54
  55   /* Do we need to read stdin? */
  56   int read_stdin = 1;
  57
  58   /* Do we need to insert -E? */
  59   int need_E = 1;
  60
  61   /* Have we seen an input file? */
  62   int seen_input = 0;
  63
  64   /* Positions to insert -xc, -xassembler-with-cpp, and -o, if necessary.
  65      0 means unnecessary.  */
  66   unsigned int lang_c_here = 0;
  67   unsigned int lang_S_here = 0;
  68   unsigned int o_here = 0;
  69
  70   /* Do we need to fix up an input file with an unrecognized suffix? */
  71   int need_fixups = 1;
  72
  73   unsigned int i, j;
  74   struct cl_decoded_option *new_decoded_options;
  75   unsigned int new_argc;
  76   extern int is_cpp_driver;
  77
  78   is_cpp_driver = 1;
  79
  80   /* First pass.  If we see an -S or -c, barf.  If we see an input file,
  81      turn off read_stdin.  If we see a second input file, it is actually
  82      the output file.  If we see a third input file, barf.  */
  83   for (i = 1; i < argc; i++)
  84     {
  85       switch (decoded_options[i].opt_index)
  86         {
  87         case OPT_E:
  88           need_E = 0;
  89           break;
  90
  91         case OPT_S:
  92         case OPT_c:
  93           fatal_error (input_location,
  94                        "%qs is not a valid option to the preprocessor",
  95                        decoded_options[i].orig_option_with_args_text);
  96           return;
  97
  98         case OPT_x:
  99           need_fixups = 0;
 100           break;
 101
 102         case OPT_SPECIAL_input_file:
 103           {
 104             const char *file = decoded_options[i].arg;
 105
 106             if (strcmp (file, "-") == 0)
 107               read_stdin = 0;
 108             else
 109               {
 110                 seen_input++;
 111                 if (seen_input == 3)
 112                   {
 113                     fatal_error (input_location, "too many input files");
 114                     return;
 115                   }
 116                 else if (seen_input == 2)
 117                   {
 118                     o_here = i;
 119                   }
 120                 else
 121                   {
 122                     read_stdin = 0;
 123                     if (need_fixups)
 124                       {
 125                         int l = strlen (file);
 126                         int known = 0;
 127                         const char *const *suff;
 128
 129                         for (suff = known_suffixes; *suff; suff++)
 130                           if (!strcmp (*suff, &file[l - strlen(*suff)]))
 131                             {
 132                               known = 1;
 133                               break;
 134                             }
 135
 136                         if (! known)
 137                           {
 138                             /* .s files are a special case; we have to
 139                                treat them like .S files so
 140                                -D__ASSEMBLER__ will be in effect.  */
 141                             if (!strcmp (".s", &file[l - 2]))
 142                               lang_S_here = i;
 143                             else
 144                               lang_c_here = i;
 145                           }
 146                       }
 147                   }
 148               }
 149           }
 150           break;
 151         }
 152     }
 153
 154   /* If we don't need to edit the command line, we can bail early.  */
 155
 156   new_argc = argc + need_E + read_stdin + !!lang_c_here + !!lang_S_here;
 157
 158   if (new_argc == argc && !o_here)
 159     return;
 160
 161   new_decoded_options = XNEWVEC (struct cl_decoded_option, new_argc);
 162
 163   new_decoded_options[0] = decoded_options[0];
 164   j = 1;
 165
 166   if (need_E)
 167     generate_option (OPT_E, NULL, 1, CL_DRIVER, &new_decoded_options[j++]);
 168
 169   for (i = 1; i < argc; i++, j++)
 170     {
 171       if (i == lang_c_here)
 172         generate_option (OPT_x, "c", 1, CL_DRIVER, &new_decoded_options[j++]);
 173       else if (i == lang_S_here)
 174         generate_option (OPT_x, "assembler-with-cpp", 1, CL_DRIVER,
 175                          &new_decoded_options[j++]);
 176       else if (i == o_here)
 177         {
 178           generate_option (OPT_o, decoded_options[i].arg, 1, CL_DRIVER,
 179                            &new_decoded_options[j]);
 180           continue;
 181         }
 182
 183       new_decoded_options[j] = decoded_options[i];
 184     }
 185
 186   if (read_stdin)
 187     generate_option_input_file ("-", &new_decoded_options[j++]);
 188
 189   *in_decoded_options_count = new_argc;
 190   *in_decoded_options = new_decoded_options;
 191 }
 192
 193 /* Called before linking.  Returns 0 on success and -1 on failure.  */
 194 int lang_specific_pre_link (void)
 195 {
 196   return 0;  /* Not used for cpp.  */
 197 }
 198
 199 /* Number of extra output files that lang_specific_pre_link may generate.  */
 200 int lang_specific_extra_outfiles = 0;  /* Not used for cpp.  */