1 /* LTO IL options.
2 
3    Copyright (C) 2009-2020 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, 0, 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   /* If debug info is enabled append -g.  */
98   if (debug_info_level > DINFO_LEVEL_NONE)
99     append_to_collect_gcc_options (&temporary_obstack, &first_p, "-g");
100 
101   /* Append options from target hook and store them to offload_lto section.  */
102   if (lto_stream_offload_p)
103     {
104       char *offload_opts = targetm.offload_options ();
105       char *offload_ptr = offload_opts;
106       while (offload_ptr)
107        {
108 	 char *next = strchr (offload_ptr, ' ');
109 	 if (next)
110 	   *next++ = '\0';
111 	 append_to_collect_gcc_options (&temporary_obstack, &first_p,
112 					offload_ptr);
113 	 offload_ptr = next;
114        }
115       free (offload_opts);
116     }
117 
118   /* Output explicitly passed options.  */
119   for (i = 1; i < save_decoded_options_count; ++i)
120     {
121       struct cl_decoded_option *option = &save_decoded_options[i];
122 
123       /* Skip explicitly some common options that we do not need.  */
124       switch (option->opt_index)
125       {
126 	case OPT_dumpbase:
127 	case OPT_SPECIAL_unknown:
128 	case OPT_SPECIAL_ignore:
129 	case OPT_SPECIAL_warn_removed:
130 	case OPT_SPECIAL_program_name:
131 	case OPT_SPECIAL_input_file:
132 	case OPT_dumpdir:
133 	case OPT_fresolution_:
134 	case OPT_fdebug_prefix_map_:
135 	case OPT_ffile_prefix_map_:
136 	case OPT_fmacro_prefix_map_:
137 	  continue;
138 
139 	default:
140 	  break;
141       }
142 
143       /* Skip frontend and driver specific options here.  */
144       if (!(cl_options[option->opt_index].flags & (CL_COMMON|CL_TARGET|CL_LTO)))
145 	continue;
146 
147       /* Do not store target-specific options in offload_lto section.  */
148       if ((cl_options[option->opt_index].flags & CL_TARGET)
149 	  && lto_stream_offload_p)
150        continue;
151 
152       /* Drop options created from the gcc driver that will be rejected
153 	 when passed on to the driver again.  */
154       if (cl_options[option->opt_index].cl_reject_driver)
155 	continue;
156 
157       /* Also drop all options that are handled by the driver as well,
158 	 which includes things like -o and -v or -fhelp for example.
159 	 We do not need those.  The only exception is -foffload option, if we
160 	 write it in offload_lto section.  Also drop all diagnostic options.  */
161       if ((cl_options[option->opt_index].flags & (CL_DRIVER|CL_WARNING))
162 	  && (!lto_stream_offload_p || option->opt_index != OPT_foffload_))
163 	continue;
164 
165       for (j = 0; j < option->canonical_option_num_elements; ++j)
166 	append_to_collect_gcc_options (&temporary_obstack, &first_p,
167 				       option->canonical_option[j]);
168     }
169 
170   const char *collect_as_options = getenv ("COLLECT_AS_OPTIONS");
171   if (collect_as_options)
172     prepend_xassembler_to_collect_as_options (collect_as_options,
173 					      &temporary_obstack);
174 
175   obstack_grow (&temporary_obstack, "\0", 1);
176   args = XOBFINISH (&temporary_obstack, char *);
177   lto_write_data (args, strlen (args) + 1);
178   lto_end_section ();
179 
180   obstack_free (&temporary_obstack, NULL);
181   free (section_name);
182 }
183