xref: /dragonfly/contrib/gcc-4.7/gcc/lto-opts.c (revision 25a2db75)
1 /* LTO IL options.
2 
3    Copyright 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
4    Contributed by Simon Baldwin <simonb@google.com>
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12 
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16 for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tree.h"
26 #include "hashtab.h"
27 #include "ggc.h"
28 #include "vec.h"
29 #include "bitmap.h"
30 #include "flags.h"
31 #include "opts.h"
32 #include "options.h"
33 #include "common/common-target.h"
34 #include "diagnostic.h"
35 #include "lto-streamer.h"
36 #include "toplev.h"
37 
38 /* Append the option piece OPT to the COLLECT_GCC_OPTIONS string
39    set up by OB, appropriately quoted and separated by spaces
40    (if !*FIRST_P).  */
41 
42 static void
43 append_to_collect_gcc_options (struct obstack *ob,
44 			       bool *first_p, const char *opt)
45 {
46   const char *p, *q = opt;
47   if (!first_p)
48     obstack_grow (ob, " ", 1);
49   obstack_grow (ob, "'", 1);
50   while ((p = strchr (q, '\'')))
51     {
52       obstack_grow (ob, q, p - q);
53       obstack_grow (ob, "'\\''", 4);
54       q = ++p;
55     }
56   obstack_grow (ob, q, strlen (q));
57   obstack_grow (ob, "'", 1);
58   *first_p = false;
59 }
60 
61 /* Write currently held options to an LTO IL section.  */
62 
63 void
64 lto_write_options (void)
65 {
66   struct lto_output_stream stream;
67   char *section_name;
68   struct obstack temporary_obstack;
69   unsigned int i, j;
70   char *args;
71   bool first_p = true;
72 
73   section_name = lto_get_section_name (LTO_section_opts, NULL, NULL);
74   lto_begin_section (section_name, false);
75   memset (&stream, 0, sizeof (stream));
76 
77   obstack_init (&temporary_obstack);
78 
79   /* Output options that affect GIMPLE IL semantics and are implicitely
80      enabled by the frontend.
81      This for now includes an explicit set of options that we also handle
82      explicitly in lto-wrapper.c.  In the end the effects on GIMPLE IL
83      semantics should be explicitely encoded in the IL or saved per
84      function rather than per compilation unit.  */
85   /* -fexceptions causes the EH machinery to be initialized, enabling
86      generation of unwind data so that explicit throw() calls work.  */
87   if (global_options.x_flag_exceptions)
88     append_to_collect_gcc_options (&temporary_obstack, &first_p,
89 				   "-fexceptions");
90 
91   /* Output explicitely passed options.  */
92   for (i = 1; i < save_decoded_options_count; ++i)
93     {
94       struct cl_decoded_option *option = &save_decoded_options[i];
95 
96       /* Skip frontend and driver specific options here.  */
97       if (!(cl_options[option->opt_index].flags & (CL_COMMON|CL_TARGET|CL_LTO)))
98 	continue;
99 
100       /* Drop options created from the gcc driver that will be rejected
101 	 when passed on to the driver again.  */
102       if (cl_options[option->opt_index].cl_reject_driver)
103 	continue;
104 
105       /* Also drop all options that are handled by the driver as well,
106          which includes things like -o and -v or -fhelp for example.
107 	 We do not need those.  Also drop all diagnostic options.  */
108       if (cl_options[option->opt_index].flags & (CL_DRIVER|CL_WARNING))
109 	continue;
110 
111       /* Skip explicitly some common options that we do not need.  */
112       switch (option->opt_index)
113 	{
114 	case OPT_dumpbase:
115 	case OPT_SPECIAL_input_file:
116 	  continue;
117 
118 	default:
119 	  break;
120 	}
121 
122       for (j = 0; j < option->canonical_option_num_elements; ++j)
123 	append_to_collect_gcc_options (&temporary_obstack, &first_p,
124 				       option->canonical_option[j]);
125     }
126   obstack_grow (&temporary_obstack, "\0", 1);
127   args = XOBFINISH (&temporary_obstack, char *);
128   lto_output_data_stream (&stream, args, strlen (args) + 1);
129 
130   lto_write_stream (&stream);
131   lto_end_section ();
132 
133   obstack_free (&temporary_obstack, NULL);
134   free (section_name);
135 }
136