1/* LTO IL options.
2
3   Copyright (C) 2009-2022 Free Software Foundation, Inc.
4   Contributed by Simon Baldwin <simonb@google.com>
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 3, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along 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
38static void
39append_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
59void
60lto_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, 0, NULL);
69  lto_begin_section (section_name, false);
70
71  obstack_init (&temporary_obstack);
72
73  if (!OPTION_SET_P (flag_openmp)
74      && !global_options.x_flag_openmp)
75    append_to_collect_gcc_options (&temporary_obstack, &first_p,
76				   "-fno-openmp");
77  if (!OPTION_SET_P (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 (!OPTION_SET_P (flag_pic) && !OPTION_SET_P (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  if (!OPTION_SET_P (flag_cf_protection))
98    {
99      append_to_collect_gcc_options (
100	&temporary_obstack, &first_p,
101	global_options.x_flag_cf_protection == CF_NONE
102	? "-fcf-protection=none"
103	: global_options.x_flag_cf_protection == CF_FULL
104	? "-fcf-protection=full"
105	: global_options.x_flag_cf_protection == CF_BRANCH
106	? "-fcf-protection=branch"
107	: global_options.x_flag_cf_protection == CF_RETURN
108	? "-fcf-protection=return"
109	: "");
110    }
111
112  /* If debug info is enabled append -g.  */
113  if (debug_info_level > DINFO_LEVEL_NONE)
114    append_to_collect_gcc_options (&temporary_obstack, &first_p, "-g");
115
116  /* Append options from target hook and store them to offload_lto section.  */
117  if (lto_stream_offload_p)
118    {
119      char *offload_opts = targetm.offload_options ();
120      char *offload_ptr = offload_opts;
121      while (offload_ptr)
122       {
123	 char *next = strchr (offload_ptr, ' ');
124	 if (next)
125	   *next++ = '\0';
126	 append_to_collect_gcc_options (&temporary_obstack, &first_p,
127					offload_ptr);
128	 offload_ptr = next;
129       }
130      free (offload_opts);
131    }
132
133  /* Output explicitly passed options.  */
134  for (i = 1; i < save_decoded_options_count; ++i)
135    {
136      struct cl_decoded_option *option = &save_decoded_options[i];
137
138      /* Skip explicitly some common options that we do not need.  */
139      switch (option->opt_index)
140      {
141	case OPT_dumpbase:
142	case OPT_SPECIAL_unknown:
143	case OPT_SPECIAL_ignore:
144	case OPT_SPECIAL_warn_removed:
145	case OPT_SPECIAL_program_name:
146	case OPT_SPECIAL_input_file:
147	case OPT_dumpdir:
148	case OPT_fresolution_:
149	case OPT_fdebug_prefix_map_:
150	case OPT_ffile_prefix_map_:
151	case OPT_fmacro_prefix_map_:
152	case OPT_fprofile_prefix_map_:
153	  continue;
154
155	default:
156	  break;
157      }
158
159      /* Skip frontend and driver specific options here.  */
160      if (!(cl_options[option->opt_index].flags & (CL_COMMON|CL_TARGET|CL_LTO)))
161	continue;
162
163      /* Do not store target-specific options in offload_lto section.  */
164      if ((cl_options[option->opt_index].flags & CL_TARGET)
165	  && lto_stream_offload_p)
166       continue;
167
168      /* Drop options created from the gcc driver that will be rejected
169	 when passed on to the driver again.  */
170      if (cl_options[option->opt_index].cl_reject_driver)
171	continue;
172
173      /* Also drop all options that are handled by the driver as well,
174	 which includes things like -o and -v or -fhelp for example.
175	 We do not need those.  The only exception is -foffload option, if we
176	 write it in offload_lto section.  Also drop all diagnostic options.  */
177      if ((cl_options[option->opt_index].flags & (CL_DRIVER|CL_WARNING))
178	  && (!lto_stream_offload_p
179	      || option->opt_index != OPT_foffload_options_))
180	continue;
181
182      for (j = 0; j < option->canonical_option_num_elements; ++j)
183	append_to_collect_gcc_options (&temporary_obstack, &first_p,
184				       option->canonical_option[j]);
185    }
186
187  const char *collect_as_options = getenv ("COLLECT_AS_OPTIONS");
188  if (collect_as_options)
189    prepend_xassembler_to_collect_as_options (collect_as_options,
190					      &temporary_obstack);
191
192  obstack_grow (&temporary_obstack, "\0", 1);
193  args = XOBFINISH (&temporary_obstack, char *);
194  lto_write_data (args, strlen (args) + 1);
195  lto_end_section ();
196
197  obstack_free (&temporary_obstack, NULL);
198  free (section_name);
199}
200