1 /* Common VxWorks target definitions for GNU compiler.
2 Copyright (C) 2007-2018 Free Software Foundation, Inc.
3 Contributed by CodeSourcery, Inc.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along 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 /* Like default_named_section_asm_out_constructor, except that even
32 constructors with DEFAULT_INIT_PRIORITY must go in a numbered
33 section on VxWorks. The VxWorks runtime uses a clever trick to get
34 the sentinel entry (-1) inserted at the beginning of the .ctors
35 segment. This trick will not work if we ever generate any entries
36 in plain .ctors sections; we must always use .ctors.PRIORITY. */
37
38 void
vxworks_asm_out_constructor(rtx symbol,int priority)39 vxworks_asm_out_constructor (rtx symbol, int priority)
40 {
41 section *sec;
42
43 sec = get_cdtor_priority_section (priority,
44 /*constructor_p=*/true);
45 assemble_addr_to_section (symbol, sec);
46 }
47
48 /* See comment for vxworks_asm_out_constructor. */
49
50 void
vxworks_asm_out_destructor(rtx symbol,int priority)51 vxworks_asm_out_destructor (rtx symbol, int priority)
52 {
53 section *sec;
54
55 sec = get_cdtor_priority_section (priority,
56 /*constructor_p=*/false);
57 assemble_addr_to_section (symbol, sec);
58 }
59
60 /* Return the list of FIELD_DECLs that make up an emulated TLS
61 variable's control object. TYPE is the structure these are fields
62 of and *NAME will be filled in with the structure tag that should
63 be used. */
64
65 static tree
vxworks_emutls_var_fields(tree type,tree * name)66 vxworks_emutls_var_fields (tree type, tree *name)
67 {
68 tree field, next_field;
69
70 *name = get_identifier ("__tls_var");
71
72 field = build_decl (BUILTINS_LOCATION, FIELD_DECL,
73 get_identifier ("size"), unsigned_type_node);
74 DECL_CONTEXT (field) = type;
75 next_field = field;
76
77 field = build_decl (BUILTINS_LOCATION, FIELD_DECL,
78 get_identifier ("module_id"), unsigned_type_node);
79 DECL_CONTEXT (field) = type;
80 DECL_CHAIN (field) = next_field;
81 next_field = field;
82
83 /* The offset field is declared as an unsigned int with pointer mode. */
84 field = build_decl (BUILTINS_LOCATION, FIELD_DECL,
85 get_identifier ("offset"), long_unsigned_type_node);
86
87 DECL_CONTEXT (field) = type;
88 DECL_CHAIN (field) = next_field;
89
90 return field;
91 }
92
93 /* Return the CONSTRUCTOR to initialize an emulated TLS control
94 object. VAR is the control object. DECL is the TLS object itself
95 and TMPL_ADDR is the address (an ADDR_EXPR) of the initializer for
96 that object. */
97
98 static tree
vxworks_emutls_var_init(tree var,tree decl,tree tmpl_addr)99 vxworks_emutls_var_init (tree var, tree decl, tree tmpl_addr)
100 {
101 vec<constructor_elt, va_gc> *v;
102 vec_alloc (v, 3);
103
104 tree type = TREE_TYPE (var);
105 tree field = TYPE_FIELDS (type);
106
107 constructor_elt elt = {field, fold_convert (TREE_TYPE (field), tmpl_addr)};
108 v->quick_push (elt);
109
110 field = DECL_CHAIN (field);
111 elt.index = field;
112 elt.value = build_int_cst (TREE_TYPE (field), 0);
113 v->quick_push (elt);
114
115 field = DECL_CHAIN (field);
116 elt.index = field;
117 elt.value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
118 v->quick_push (elt);
119
120 return build_constructor (type, v);
121 }
122
123 /* Do VxWorks-specific parts of TARGET_OPTION_OVERRIDE. */
124
125 void
vxworks_override_options(void)126 vxworks_override_options (void)
127 {
128 /* Setup the tls emulation bits if the OS misses proper
129 tls support. */
130 targetm.have_tls = VXWORKS_HAVE_TLS;
131
132 if (!VXWORKS_HAVE_TLS)
133 {
134 targetm.emutls.get_address = "__builtin___tls_lookup";
135 targetm.emutls.register_common = NULL;
136 targetm.emutls.var_section = ".tls_vars";
137 targetm.emutls.tmpl_section = ".tls_data";
138 targetm.emutls.var_prefix = "__tls__";
139 targetm.emutls.tmpl_prefix = "";
140 targetm.emutls.var_fields = vxworks_emutls_var_fields;
141 targetm.emutls.var_init = vxworks_emutls_var_init;
142 targetm.emutls.var_align_fixed = true;
143 targetm.emutls.debug_form_tls_address = true;
144 }
145
146 /* We can use .ctors/.dtors sections only in RTP mode. */
147 targetm.have_ctors_dtors = TARGET_VXWORKS_RTP;
148
149 /* PIC is only supported for RTPs. */
150 if (flag_pic && !TARGET_VXWORKS_RTP)
151 error ("PIC is only supported for RTPs");
152
153 /* VxWorks comes with non-gdb debuggers which only support strict
154 dwarf up to certain version. Default dwarf control to friendly
155 values for these. */
156
157 if (!global_options_set.x_dwarf_strict)
158 dwarf_strict = 1;
159
160 if (!global_options_set.x_dwarf_version)
161 dwarf_version = VXWORKS_DWARF_VERSION_DEFAULT;
162 }
163