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 "gcc.h"
25 #include "opts.h"
26 
27 /* The `cpp' executable installed in $(bindir) and $(cpp_install_dir)
28    is a customized version of the gcc driver.  It forces -E; -S and -c
29    are errors.  It defaults to -x c for files with unrecognized
30    extensions, unless -x options appear in argv, in which case we
31    assume the user knows what they're doing.  If no explicit input is
32    mentioned, it will read stdin.  */
33 
34 /* Suffixes for known sorts of input files.  Note that we do not list
35    files which are normally considered to have been preprocessed already,
36    since the user's expectation is that `cpp' always preprocesses.  */
37 static const char *const known_suffixes[] =
38 {
39   ".c",  ".C",   ".S",   ".m",
40   ".cc", ".cxx", ".cpp", ".cp",  ".c++",
41   ".sx",
42   NULL
43 };
44 
45 /* Filter the command line before processing by the gcc driver proper.  */
46 void
47 lang_specific_driver (struct cl_decoded_option **in_decoded_options,
48 		      unsigned int *in_decoded_options_count,
49 		      int *in_added_libraries ATTRIBUTE_UNUSED)
50 {
51   struct cl_decoded_option *decoded_options = *in_decoded_options;
52   unsigned int argc = *in_decoded_options_count;
53 
54   /* Do we need to read stdin? */
55   int read_stdin = 1;
56 
57   /* Do we need to insert -E? */
58   int need_E = 1;
59 
60   /* Have we seen an input file? */
61   int seen_input = 0;
62 
63   /* Positions to insert -xc, -xassembler-with-cpp, and -o, if necessary.
64      0 means unnecessary.  */
65   unsigned int lang_c_here = 0;
66   unsigned int lang_S_here = 0;
67   unsigned int o_here = 0;
68 
69   /* Do we need to fix up an input file with an unrecognized suffix? */
70   int need_fixups = 1;
71 
72   unsigned int i, j;
73   struct cl_decoded_option *new_decoded_options;
74   unsigned int new_argc;
75   extern int is_cpp_driver;
76 
77   is_cpp_driver = 1;
78 
79   /* First pass.  If we see an -S or -c, barf.  If we see an input file,
80      turn off read_stdin.  If we see a second input file, it is actually
81      the output file.  If we see a third input file, barf.  */
82   for (i = 1; i < argc; i++)
83     {
84       switch (decoded_options[i].opt_index)
85 	{
86 	case OPT_E:
87 	  need_E = 0;
88 	  break;
89 
90 	case OPT_S:
91 	case OPT_c:
92 	  fatal_error (input_location,
93 		       "%qs is not a valid option to the preprocessor",
94 		       decoded_options[i].orig_option_with_args_text);
95 	  return;
96 
97 	case OPT_x:
98 	  need_fixups = 0;
99 	  break;
100 
101 	case OPT_SPECIAL_input_file:
102 	  {
103 	    const char *file = decoded_options[i].arg;
104 
105 	    if (strcmp (file, "-") == 0)
106 	      read_stdin = 0;
107 	    else
108 	      {
109 		seen_input++;
110 		if (seen_input == 3)
111 		  {
112 		    fatal_error (input_location, "too many input files");
113 		    return;
114 		  }
115 		else if (seen_input == 2)
116 		  {
117 		    o_here = i;
118 		  }
119 		else
120 		  {
121 		    read_stdin = 0;
122 		    if (need_fixups)
123 		      {
124 			int l = strlen (file);
125 			int known = 0;
126 			const char *const *suff;
127 
128 			for (suff = known_suffixes; *suff; suff++)
129 			  if (!strcmp (*suff, &file[l - strlen(*suff)]))
130 			    {
131 			      known = 1;
132 			      break;
133 			    }
134 
135 			if (! known)
136 			  {
137 			    /* .s files are a special case; we have to
138 			       treat them like .S files so
139 			       -D__ASSEMBLER__ will be in effect.  */
140 			    if (!strcmp (".s", &file[l - 2]))
141 			      lang_S_here = i;
142 			    else
143 			      lang_c_here = i;
144 			  }
145 		      }
146 		  }
147 	      }
148 	  }
149 	  break;
150 	}
151     }
152 
153   /* If we don't need to edit the command line, we can bail early.  */
154 
155   new_argc = argc + need_E + read_stdin + !!lang_c_here + !!lang_S_here;
156 
157   if (new_argc == argc && !o_here)
158     return;
159 
160   new_decoded_options = XNEWVEC (struct cl_decoded_option, new_argc);
161 
162   new_decoded_options[0] = decoded_options[0];
163   j = 1;
164 
165   if (need_E)
166     generate_option (OPT_E, NULL, 1, CL_DRIVER, &new_decoded_options[j++]);
167 
168   for (i = 1; i < argc; i++, j++)
169     {
170       if (i == lang_c_here)
171 	generate_option (OPT_x, "c", 1, CL_DRIVER, &new_decoded_options[j++]);
172       else if (i == lang_S_here)
173 	generate_option (OPT_x, "assembler-with-cpp", 1, CL_DRIVER,
174 			 &new_decoded_options[j++]);
175       else if (i == o_here)
176 	{
177 	  generate_option (OPT_o, decoded_options[i].arg, 1, CL_DRIVER,
178 			   &new_decoded_options[j]);
179 	  continue;
180 	}
181 
182       new_decoded_options[j] = decoded_options[i];
183     }
184 
185   if (read_stdin)
186     generate_option_input_file ("-", &new_decoded_options[j++]);
187 
188   *in_decoded_options_count = new_argc;
189   *in_decoded_options = new_decoded_options;
190 }
191 
192 /* Called before linking.  Returns 0 on success and -1 on failure.  */
193 int lang_specific_pre_link (void)
194 {
195   return 0;  /* Not used for cpp.  */
196 }
197 
198 /* Number of extra output files that lang_specific_pre_link may generate.  */
199 int lang_specific_extra_outfiles = 0;  /* Not used for cpp.  */
200