gcc/config/darwin-sections.def

   1 /* Copyright (C) 2005-2018 Free Software Foundation, Inc.
   2
   3 This file is part of GCC.
   4
   5 GCC is free software; you can redistribute it and/or modify it under
   6 the terms of the GNU General Public License as published by the Free
   7 Software Foundation; either version 3, or (at your option) any later
   8 version.
   9
  10 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  11 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13 for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with GCC; see the file COPYING3.  If not see
  17 <http://www.gnu.org/licenses/>.  */
  18
  19 /* Since Darwin's ld will not allow zero-sized objects, and gcc wants them,
  20    we emit one byte (in darwin.c) when such an object is encountered.
  21
  22    This messes up section anchoring because the emitted byte is not counted
  23    outside the port.  To cope with this, we set aside sections for zero-sized
  24    objects and disallow those sections from  participating in section anchors
  25    ("zobj_" sections, below).
  26
  27    Items that might be coalesced by the linker are prevented from participating,
  28    (and those in mergeable sections are disallowed in varasm.c).  */
  29
  30 /* The .text section is generated in varasm.c  */
  31 DEF_SECTION (text_coal_section, SECTION_CODE|SECTION_NO_ANCHOR,
  32              ".section __TEXT,__textcoal_nt,coalesced,pure_instructions", 0)
  33
  34 /* We define a picbase thunks section separately, so that we can override the
  35    def to be '.text' for versions of ld64 that handle coalescing.  */
  36 DEF_SECTION (picbase_thunk_section, SECTION_CODE|SECTION_NO_ANCHOR,
  37              ".section __TEXT,__textcoal_nt,coalesced,pure_instructions", 0)
  38
  39 DEF_SECTION (text_hot_section, SECTION_CODE,
  40              ".section __TEXT,__text_hot,regular,pure_instructions", 0)
  41 DEF_SECTION (text_cold_section, SECTION_CODE,
  42              ".section __TEXT,__text_cold,regular,pure_instructions", 0)
  43 DEF_SECTION (text_startup_section, SECTION_CODE,
  44              ".section __TEXT,__text_startup,regular,pure_instructions", 0)
  45 DEF_SECTION (text_exit_section, SECTION_CODE,
  46              ".section __TEXT,__text_exit,regular,pure_instructions", 0)
  47
  48 DEF_SECTION (text_hot_coal_section, SECTION_CODE,
  49              ".section __TEXT,__text_hot_coal,coalesced,pure_instructions", 0)
  50 DEF_SECTION (text_cold_coal_section, SECTION_CODE,
  51              ".section __TEXT,__text_cold_coal,coalesced,pure_instructions", 0)
  52 DEF_SECTION (text_startup_coal_section, SECTION_CODE,
  53              ".section __TEXT,__text_stt_coal,coalesced,pure_instructions", 0)
  54 DEF_SECTION (text_exit_coal_section, SECTION_CODE,
  55              ".section __TEXT,__text_exit_coal,coalesced,pure_instructions", 0)
  56
  57 /* const */
  58 DEF_SECTION (const_section, 0, ".const", 0)
  59 DEF_SECTION (const_coal_section, SECTION_NO_ANCHOR,
  60              ".section __TEXT,__const_coal,coalesced", 0)
  61 /* Place to put zero-sized to avoid issues with section anchors.  */
  62 DEF_SECTION (zobj_const_section, SECTION_NO_ANCHOR,
  63              ".section\t__DATA,__zobj_const", 0)
  64
  65 /* Write-able data.  '.data'  handled in varasm.c  */
  66 DEF_SECTION (static_data_section, SECTION_WRITE, ".static_data", 0)
  67 DEF_SECTION (data_coal_section, SECTION_WRITE|SECTION_NO_ANCHOR,
  68              ".section __DATA,__datacoal_nt,coalesced", 0)
  69 /* Place to put zero-sized to avoid issues with section anchors.  */
  70 DEF_SECTION (zobj_data_section, SECTION_WRITE|SECTION_NO_ANCHOR,
  71              ".section\t__DATA,__zobj_data", 0)
  72
  73 /* BSS - .lcomm / .zerofill __DATA,__bss sections cannot be switched to
  74    explicitly (will create an assembler error).  */
  75 DEF_SECTION (zobj_bss_section, SECTION_WRITE|SECTION_BSS|SECTION_NO_ANCHOR,
  76              ".section\t__DATA,__zobj_bss", 0)
  77
  78 /* const data */
  79 DEF_SECTION (const_data_section, 0, ".const_data", 0)
  80 DEF_SECTION (const_data_coal_section, SECTION_NO_ANCHOR,
  81              ".section __DATA,__const_coal,coalesced", 0)
  82 /* Place to put zero-sized to avoid issues with section anchors.  */
  83 DEF_SECTION (zobj_const_data_section, SECTION_NO_ANCHOR,
  84              ".section\t__DATA,__zobj_cnst_data", 0)
  85
  86 /* Strings and other literals.  */
  87 DEF_SECTION (cstring_section, SECTION_MERGE | SECTION_STRINGS, ".cstring", 0)
  88 DEF_SECTION (literal4_section, SECTION_MERGE, ".literal4", 0)
  89 DEF_SECTION (literal8_section, SECTION_MERGE, ".literal8", 0)
  90 DEF_SECTION (literal16_section, SECTION_MERGE, ".literal16", 0)
  91 /* Unlike constant NSStrings, constant CFStrings do not live  in the
  92    __OBJC segment since they may also occur in pure C  or C++ programs.  */
  93 DEF_SECTION (cfstring_constant_object_section, 0,
  94              ".section __DATA, __cfstring", 0)
  95
  96 /* Module init, term, constructors & destructors.  */
  97 DEF_SECTION (mod_init_section, 0, ".mod_init_func", 0)
  98 DEF_SECTION (mod_term_section, 0, ".mod_term_func", 0)
  99 DEF_SECTION (constructor_section, 0, ".constructor", 0)
 100 DEF_SECTION (destructor_section, 0, ".destructor", 0)
 101
 102 /* Objective-C ABI=0 (Original version) sections.  */
 103 DEF_SECTION (objc_class_section, 0, ".objc_class", 1)
 104 DEF_SECTION (objc_meta_class_section, 0, ".objc_meta_class", 1)
 105 DEF_SECTION (objc_category_section, 0, ".objc_category", 1)
 106 DEF_SECTION (objc_class_vars_section, 0, ".objc_class_vars", 1)
 107 DEF_SECTION (objc_instance_vars_section, 0, ".objc_instance_vars", 1)
 108 DEF_SECTION (objc_cls_meth_section, 0, ".objc_cls_meth", 1)
 109 DEF_SECTION (objc_inst_meth_section, 0, ".objc_inst_meth", 1)
 110 DEF_SECTION (objc_cat_cls_meth_section, 0, ".objc_cat_cls_meth", 1)
 111 DEF_SECTION (objc_cat_inst_meth_section, 0, ".objc_cat_inst_meth", 1)
 112 DEF_SECTION (objc_selector_refs_section, SECTION_MERGE, ".objc_message_refs", 1)
 113 DEF_SECTION (objc_selector_fixup_section, 0,
 114             ".section __OBJC, __sel_fixup, regular, no_dead_strip", 1)
 115 DEF_SECTION (objc_symbols_section, 0, ".objc_symbols", 1)
 116 DEF_SECTION (objc_module_info_section, 0, ".objc_module_info", 1)
 117 DEF_SECTION (objc_protocol_section, 0, ".objc_protocol", 1)
 118 DEF_SECTION (objc_string_object_section, 0, ".objc_string_object", 1)
 119 DEF_SECTION (objc_constant_string_object_section, 0,
 120              ".section __OBJC, __cstring_object, regular, no_dead_strip", 0)
 121
 122 /* Fix-and-Continue image marker.  */
 123 DEF_SECTION (objc_image_info_section, 0,
 124              ".section __OBJC, __image_info, regular, no_dead_strip", 1)
 125 DEF_SECTION (objc_class_names_section, 0, ".objc_class_names", 1)
 126 DEF_SECTION (objc_meth_var_names_section, 0, ".objc_meth_var_names", 1)
 127 DEF_SECTION (objc_meth_var_types_section, 0, ".objc_meth_var_types", 1)
 128 DEF_SECTION (objc_cls_refs_section, SECTION_MERGE, ".objc_cls_refs", 1)
 129
 130 /* Stubs and symbol indirection sections.  */
 131 /* lazy symbol pointers.  */
 132 DEF_SECTION (machopic_lazy_symbol_ptr_section, SECTION_NO_ANCHOR,
 133              ".lazy_symbol_pointer", 0)
 134 DEF_SECTION (machopic_lazy_symbol_ptr2_section, SECTION_NO_ANCHOR,
 135              ".section __DATA, __la_sym_ptr2,lazy_symbol_pointers", 0)
 136 DEF_SECTION (machopic_lazy_symbol_ptr3_section, SECTION_NO_ANCHOR,
 137              ".section __DATA, __la_sym_ptr3,lazy_symbol_pointers", 0)
 138 /* non-lazy symbol pointers.  */
 139 DEF_SECTION (machopic_nl_symbol_ptr_section, SECTION_NO_ANCHOR,
 140              MACHOPIC_NL_SYMBOL_PTR_SECTION, 0)
 141 /* Symbol stubs.  */
 142 DEF_SECTION (machopic_symbol_stub_section, SECTION_NO_ANCHOR,
 143              ".symbol_stub", 0)
 144 DEF_SECTION (machopic_symbol_stub1_section, SECTION_NO_ANCHOR,
 145              ".section __TEXT,__symbol_stub1,symbol_stubs,"
 146              "pure_instructions,16", 0)
 147 /* PIC symbol stubs.  */
 148 DEF_SECTION (machopic_picsymbol_stub_section, SECTION_NO_ANCHOR,
 149              ".picsymbol_stub", 0)
 150 DEF_SECTION (machopic_picsymbol_stub1_section, SECTION_NO_ANCHOR,
 151              ".section __TEXT,__picsymbolstub1,symbol_stubs,"
 152              "pure_instructions,32", 0)
 153 DEF_SECTION (machopic_picsymbol_stub2_section, SECTION_NO_ANCHOR,
 154              ".section __TEXT,__picsymbolstub2,symbol_stubs,pure_instructions,25", 0)
 155 DEF_SECTION (machopic_picsymbol_stub3_section, SECTION_NO_ANCHOR,
 156              ".section __IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5", 0)
 157
 158 /* Exception-related.  */
 159 DEF_SECTION (darwin_exception_section, SECTION_NO_ANCHOR,
 160              ".section __DATA,__gcc_except_tab", 0)
 161 DEF_SECTION (darwin_eh_frame_section, SECTION_NO_ANCHOR,
 162              ".section " EH_FRAME_SECTION_NAME ",__eh_frame"
 163              EH_FRAME_SECTION_ATTR, 0)
 164
 165 /* Sections for ObjC ABI=1 (ObjC 'V1' extensions) */
 166 DEF_SECTION (objc1_class_ext_section, 0,
 167             ".section __OBJC, __class_ext, regular, no_dead_strip", 1)
 168 DEF_SECTION (objc1_prop_list_section, 0,
 169             ".section __OBJC, __property, regular, no_dead_strip", 1)
 170 DEF_SECTION (objc1_protocol_ext_section, 0,
 171             ".section __OBJC, __protocol_ext, regular, no_dead_strip", 1)
 172
 173 /* Sections for ObjC ABI=2 (m64).  */
 174 DEF_SECTION (objc2_message_refs_section, 0,
 175              ".section __DATA, __objc_msgrefs, regular, no_dead_strip", 1)
 176 DEF_SECTION (objc2_classdefs_section, 0, ".section __DATA, __objc_data", 1)
 177 DEF_SECTION (objc2_metadata_section, 0, ".section __DATA, __objc_const", 1)
 178
 179 DEF_SECTION (objc2_classrefs_section, 0,
 180              ".section __DATA, __objc_classrefs, regular, no_dead_strip", 1)
 181 DEF_SECTION (objc2_classlist_section, 0,
 182              ".section __DATA, __objc_classlist, regular, no_dead_strip", 1)
 183 DEF_SECTION (objc2_categorylist_section, 0,
 184              ".section __DATA, __objc_catlist, regular, no_dead_strip", 1)
 185 DEF_SECTION (objc2_selector_refs_section, 0,
 186              ".section __DATA, __objc_selrefs, literal_pointers, no_dead_strip", 1)
 187 DEF_SECTION (objc2_nonlazy_class_section, 0,
 188              ".section __DATA, __objc_nlclslist, regular, no_dead_strip", 1)
 189 DEF_SECTION (objc2_nonlazy_category_section, 0,
 190              ".section __DATA, __objc_nlcatlist, regular, no_dead_strip", 1)
 191 DEF_SECTION (objc2_protocollist_section, 0,
 192              ".section __DATA, __objc_protolist, regular, no_dead_strip", 1)
 193 DEF_SECTION (objc2_protocolrefs_section, 0,
 194              ".section __DATA, __objc_protorefs, regular, no_dead_strip", 1)
 195 DEF_SECTION (objc2_super_classrefs_section, 0,
 196              ".section __DATA, __objc_superrefs, regular, no_dead_strip", 1)
 197 DEF_SECTION (objc2_image_info_section, 0,
 198              ".section __DATA, __objc_imageinfo, regular, no_dead_strip", 1)
 199 DEF_SECTION (objc2_constant_string_object_section, 0,
 200              ".section __DATA, __objc_stringobj, regular, no_dead_strip", 1)