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 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 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 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 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 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