1 /* Common VxWorks target definitions for GNU compiler.
2 Copyright (C) 2007-2020 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 #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
39 void
vxworks_asm_out_constructor(rtx symbol,int priority)40 vxworks_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
51 void
vxworks_asm_out_destructor(rtx symbol,int priority)52 vxworks_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
67 static tree
vxworks_emutls_var_fields(tree type,tree * name)68 vxworks_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
100 static tree
vxworks_emutls_var_init(tree var,tree decl,tree tmpl_addr)101 vxworks_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
127 void
vxworks_override_options(void)128 vxworks_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