1 /* LTO IL options.
2 
3    Copyright (C) 2009-2018 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 "backend.h"
26 #include "target.h"
27 #include "tree.h"
28 #include "gimple.h"
29 #include "cgraph.h"
30 #include "lto-streamer.h"
31 #include "opts.h"
32 #include "toplev.h"
33 
34 /* Append the option piece OPT to the COLLECT_GCC_OPTIONS string
35    set up by OB, appropriately quoted and separated by spaces
36    (if !*FIRST_P).  */
37 
38 static void
append_to_collect_gcc_options(struct obstack * ob,bool * first_p,const char * opt)39 append_to_collect_gcc_options (struct obstack *ob,
40 			       bool *first_p, const char *opt)
41 {
42   const char *p, *q = opt;
43   if (!*first_p)
44     obstack_grow (ob, " ", 1);
45   obstack_grow (ob, "'", 1);
46   while ((p = strchr (q, '\'')))
47     {
48       obstack_grow (ob, q, p - q);
49       obstack_grow (ob, "'\\''", 4);
50       q = ++p;
51     }
52   obstack_grow (ob, q, strlen (q));
53   obstack_grow (ob, "'", 1);
54   *first_p = false;
55 }
56 
57 /* Write currently held options to an LTO IL section.  */
58 
59 void
lto_write_options(void)60 lto_write_options (void)
61 {
62   char *section_name;
63   struct obstack temporary_obstack;
64   unsigned int i, j;
65   char *args;
66   bool first_p = true;
67 
68   section_name = lto_get_section_name (LTO_section_opts, NULL, NULL);
69   lto_begin_section (section_name, false);
70 
71   obstack_init (&temporary_obstack);
72 
73   if (!global_options_set.x_flag_openmp
74       && !global_options.x_flag_openmp)
75     append_to_collect_gcc_options (&temporary_obstack, &first_p,
76 				   "-fno-openmp");
77   if (!global_options_set.x_flag_openacc
78       && !global_options.x_flag_openacc)
79     append_to_collect_gcc_options (&temporary_obstack, &first_p,
80 				   "-fno-openacc");
81   /* Append PIC/PIE mode because its default depends on target and it is
82      subject of merging in lto-wrapper.  */
83   if (!global_options_set.x_flag_pic && !global_options_set.x_flag_pie)
84     {
85        append_to_collect_gcc_options (&temporary_obstack, &first_p,
86 				      global_options.x_flag_pic == 2
87 				      ? "-fPIC"
88 				      : global_options.x_flag_pic == 1
89 				      ? "-fpic"
90 				      : global_options.x_flag_pie == 2
91 				      ? "-fPIE"
92 				      : global_options.x_flag_pie == 1
93 				      ? "-fpie"
94 				      : "-fno-pie");
95     }
96 
97   /* Append options from target hook and store them to offload_lto section.  */
98   if (lto_stream_offload_p)
99     {
100       char *offload_opts = targetm.offload_options ();
101       char *offload_ptr = offload_opts;
102       while (offload_ptr)
103        {
104 	 char *next = strchr (offload_ptr, ' ');
105 	 if (next)
106 	   *next++ = '\0';
107 	 append_to_collect_gcc_options (&temporary_obstack, &first_p,
108 					offload_ptr);
109 	 offload_ptr = next;
110        }
111       free (offload_opts);
112     }
113 
114   /* Output explicitly passed options.  */
115   for (i = 1; i < save_decoded_options_count; ++i)
116     {
117       struct cl_decoded_option *option = &save_decoded_options[i];
118 
119       /* Skip explicitly some common options that we do not need.  */
120       switch (option->opt_index)
121       {
122 	case OPT_dumpbase:
123 	case OPT_SPECIAL_unknown:
124 	case OPT_SPECIAL_ignore:
125 	case OPT_SPECIAL_program_name:
126 	case OPT_SPECIAL_input_file:
127 	  continue;
128 
129 	default:
130 	  break;
131       }
132 
133       /* Skip frontend and driver specific options here.  */
134       if (!(cl_options[option->opt_index].flags & (CL_COMMON|CL_TARGET|CL_LTO)))
135 	continue;
136 
137       /* Do not store target-specific options in offload_lto section.  */
138       if ((cl_options[option->opt_index].flags & CL_TARGET)
139 	  && lto_stream_offload_p)
140        continue;
141 
142       /* Drop options created from the gcc driver that will be rejected
143 	 when passed on to the driver again.  */
144       if (cl_options[option->opt_index].cl_reject_driver)
145 	continue;
146 
147       /* Also drop all options that are handled by the driver as well,
148 	 which includes things like -o and -v or -fhelp for example.
149 	 We do not need those.  The only exception is -foffload option, if we
150 	 write it in offload_lto section.  Also drop all diagnostic options.  */
151       if ((cl_options[option->opt_index].flags & (CL_DRIVER|CL_WARNING))
152 	  && (!lto_stream_offload_p || option->opt_index != OPT_foffload_))
153 	continue;
154 
155       for (j = 0; j < option->canonical_option_num_elements; ++j)
156 	append_to_collect_gcc_options (&temporary_obstack, &first_p,
157 				       option->canonical_option[j]);
158     }
159   obstack_grow (&temporary_obstack, "\0", 1);
160   args = XOBFINISH (&temporary_obstack, char *);
161   lto_write_data (args, strlen (args) + 1);
162   lto_end_section ();
163 
164   obstack_free (&temporary_obstack, NULL);
165   free (section_name);
166 }
167