1/* Common VxWorks target definitions for GNU compiler.
2   Copyright (C) 2007-2020 Free Software Foundation, Inc.
3   Contributed by CodeSourcery, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 3, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3.  If not see
19<http://www.gnu.org/licenses/>.  */
20
21#include "config.h"
22#include "system.h"
23#include "coretypes.h"
24#include "target.h"
25#include "tree.h"
26#include "stringpool.h"
27#include "diagnostic-core.h"
28#include "output.h"
29#include "fold-const.h"
30
31#if !HAVE_INITFINI_ARRAY_SUPPORT
32/* Like default_named_section_asm_out_constructor, except that even
33   constructors with DEFAULT_INIT_PRIORITY must go in a numbered
34   section on VxWorks.  The VxWorks runtime uses a clever trick to get
35   the sentinel entry (-1) inserted at the beginning of the .ctors
36   segment.  This trick will not work if we ever generate any entries
37   in plain .ctors sections; we must always use .ctors.PRIORITY.  */
38
39void
40vxworks_asm_out_constructor (rtx symbol, int priority)
41{
42  section *sec;
43
44  sec = get_cdtor_priority_section (priority,
45				    /*constructor_p=*/true);
46  assemble_addr_to_section (symbol, sec);
47}
48
49/* See comment for vxworks_asm_out_constructor.  */
50
51void
52vxworks_asm_out_destructor (rtx symbol, int priority)
53{
54  section *sec;
55
56  sec = get_cdtor_priority_section (priority,
57				    /*constructor_p=*/false);
58  assemble_addr_to_section (symbol, sec);
59}
60#endif
61
62/* Return the list of FIELD_DECLs that make up an emulated TLS
63   variable's control object.  TYPE is the structure these are fields
64   of and *NAME will be filled in with the structure tag that should
65   be used.  */
66
67static tree
68vxworks_emutls_var_fields (tree type, tree *name)
69{
70  tree field, next_field;
71
72  *name = get_identifier ("__tls_var");
73
74  field = build_decl (BUILTINS_LOCATION, FIELD_DECL,
75		      get_identifier ("size"), unsigned_type_node);
76  DECL_CONTEXT (field) = type;
77  next_field = field;
78
79  field = build_decl (BUILTINS_LOCATION, FIELD_DECL,
80		      get_identifier ("module_id"), unsigned_type_node);
81  DECL_CONTEXT (field) = type;
82  DECL_CHAIN (field) = next_field;
83  next_field = field;
84
85  /* The offset field is declared as an unsigned int with pointer mode.  */
86  field = build_decl (BUILTINS_LOCATION, FIELD_DECL,
87		      get_identifier ("offset"), long_unsigned_type_node);
88
89  DECL_CONTEXT (field) = type;
90  DECL_CHAIN (field) = next_field;
91
92  return field;
93}
94
95/* Return the CONSTRUCTOR to initialize an emulated TLS control
96   object.  VAR is the control object.  DECL is the TLS object itself
97   and TMPL_ADDR is the address (an ADDR_EXPR) of the initializer for
98   that object.  */
99
100static tree
101vxworks_emutls_var_init (tree var, tree decl, tree tmpl_addr)
102{
103  vec<constructor_elt, va_gc> *v;
104  vec_alloc (v, 3);
105
106  tree type = TREE_TYPE (var);
107  tree field = TYPE_FIELDS (type);
108
109  constructor_elt elt = {field, fold_convert (TREE_TYPE (field), tmpl_addr)};
110  v->quick_push (elt);
111
112  field = DECL_CHAIN (field);
113  elt.index = field;
114  elt.value = build_int_cst (TREE_TYPE (field), 0);
115  v->quick_push (elt);
116
117  field = DECL_CHAIN (field);
118  elt.index = field;
119  elt.value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
120  v->quick_push (elt);
121
122  return build_constructor (type, v);
123}
124
125/* Do VxWorks-specific parts of TARGET_OPTION_OVERRIDE.  */
126
127void
128vxworks_override_options (void)
129{
130  /* Setup the tls emulation bits if the OS misses proper
131     tls support.  */
132  targetm.have_tls = VXWORKS_HAVE_TLS;
133
134  if (!VXWORKS_HAVE_TLS)
135    {
136      targetm.emutls.get_address = "__builtin___tls_lookup";
137      targetm.emutls.register_common = NULL;
138      targetm.emutls.var_section = ".tls_vars";
139      targetm.emutls.tmpl_section = ".tls_data";
140      targetm.emutls.var_prefix = "__tls__";
141      targetm.emutls.tmpl_prefix = "";
142      targetm.emutls.var_fields = vxworks_emutls_var_fields;
143      targetm.emutls.var_init = vxworks_emutls_var_init;
144      targetm.emutls.var_align_fixed = true;
145      targetm.emutls.debug_form_tls_address = true;
146    }
147
148  /* Arrange to use .ctors/.dtors sections if the target VxWorks configuration
149     and mode supports it, or the init/fini_array sections if we were
150     configured with --enable-initfini-array explicitly.  In the latter case,
151     the toolchain user is expected to provide whatever linker level glue is
152     required to get things to operate properly.  */
153
154  targetm.have_ctors_dtors =
155    TARGET_VXWORKS_HAVE_CTORS_DTORS || HAVE_INITFINI_ARRAY_SUPPORT;
156
157  /* PIC is only supported for RTPs.  */
158  if (flag_pic && !TARGET_VXWORKS_RTP)
159    error ("PIC is only supported for RTPs");
160
161  /* VxWorks comes with non-gdb debuggers which only support strict
162     dwarf up to certain version.  Default dwarf control to friendly
163     values for these.  */
164
165  if (!global_options_set.x_dwarf_strict)
166    dwarf_strict = 1;
167
168  if (!global_options_set.x_dwarf_version)
169    dwarf_version = VXWORKS_DWARF_VERSION_DEFAULT;
170}
171