1 /* go-backend.c -- Go frontend interface to gcc backend.
2 Copyright (C) 2010-2016 Free Software Foundation, Inc.
4 This file is part of GCC.
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
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
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/>. */
22 #include "coretypes.h"
26 #include "diagnostic.h"
27 #include "simple-object.h"
28 #include "stor-layout.h"
30 #include "output.h" /* for assemble_string */
31 #include "common/common-target.h"
34 /* The segment name we pass to simple_object_start_read to find Go
37 #ifndef GO_EXPORT_SEGMENT_NAME
38 #define GO_EXPORT_SEGMENT_NAME "__GNU_GO"
41 /* The section name we use when reading and writing export data. */
43 #ifndef GO_EXPORT_SECTION_NAME
44 #define GO_EXPORT_SECTION_NAME ".go_export"
47 /* This file holds all the cases where the Go frontend needs
48 information from gcc's backend. */
50 /* Return whether or not GCC has reported any errors. */
55 return errorcount
!= 0 || sorrycount
!= 0;
58 /* Return the alignment in bytes of a struct field of type T. */
61 go_field_alignment (tree t
)
67 #ifdef BIGGEST_FIELD_ALIGNMENT
68 if (v
> BIGGEST_FIELD_ALIGNMENT
)
69 v
= BIGGEST_FIELD_ALIGNMENT
;
72 #ifdef ADJUST_FIELD_ALIGN
74 tree field ATTRIBUTE_UNUSED
;
75 field
= build_decl (UNKNOWN_LOCATION
, FIELD_DECL
, NULL
, t
);
76 v
= ADJUST_FIELD_ALIGN (field
, v
);
80 return v
/ BITS_PER_UNIT
;
83 /* Return the size and alignment of a trampoline. */
86 go_trampoline_info (unsigned int *size
, unsigned int *alignment
)
88 *size
= TRAMPOLINE_SIZE
;
89 *alignment
= TRAMPOLINE_ALIGNMENT
;
92 /* This is called by the Go frontend proper if the unsafe package was
93 imported. When that happens we can not do type-based alias
97 go_imported_unsafe (void)
99 flag_strict_aliasing
= false;
101 /* Let the backend know that the options have changed. */
102 targetm
.override_options_after_change ();
105 /* This is called by the Go frontend proper to add data to the
106 section containing Go export data. */
109 go_write_export_data (const char *bytes
, unsigned int size
)
115 gcc_assert (targetm_common
.have_named_sections
);
116 sec
= get_section (GO_EXPORT_SECTION_NAME
, SECTION_DEBUG
, NULL
);
119 switch_to_section (sec
);
120 assemble_string (bytes
, size
);
123 /* The go_read_export_data function is called by the Go frontend
124 proper to read Go export data from an object file. FD is a file
125 descriptor open for reading. OFFSET is the offset within the file
126 where the object file starts; this will be 0 except when reading an
127 archive. On success this returns NULL and sets *PBUF to a buffer
128 allocated using malloc, of size *PLEN, holding the export data. If
129 the data is not found, this returns NULL and sets *PBUF to NULL and
130 *PLEN to 0. If some error occurs, this returns an error message
131 and sets *PERR to an errno value or 0 if there is no relevant
135 go_read_export_data (int fd
, off_t offset
, char **pbuf
, size_t *plen
,
138 simple_object_read
*sobj
;
149 sobj
= simple_object_start_read (fd
, offset
, GO_EXPORT_SEGMENT_NAME
,
153 /* If we get an error here, just pretend that we didn't find any
154 export data. This is the right thing to do if the error is
155 that the file was not recognized as an object file. This
156 will ignore file I/O errors, but it's not too big a deal
157 because we will wind up giving some other error later. */
161 found
= simple_object_find_section (sobj
, GO_EXPORT_SECTION_NAME
,
162 &sec_offset
, &sec_length
,
164 simple_object_release_read (sobj
);
168 if (lseek (fd
, offset
+ sec_offset
, SEEK_SET
) < 0)
171 return _("lseek failed while reading export data");
174 buf
= XNEWVEC (char, sec_length
);
178 return _("memory allocation failed while reading export data");
181 c
= read (fd
, buf
, sec_length
);
186 return _("read failed while reading export data");
192 return _("short read while reading export data");