1 /* Target support for C++ classes on Windows. 2 Contributed by Danny Smith (dannysmith@users.sourceforge.net) 3 Copyright (C) 2005, 2007, 2009 Free Software Foundation, 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 "tm.h" 25 #include "rtl.h" 26 #include "regs.h" 27 #include "hard-reg-set.h" 28 #include "output.h" 29 #include "tree.h" 30 #include "cp/cp-tree.h" /* This is why we're a separate module. */ 31 #include "flags.h" 32 #include "tm_p.h" 33 #include "toplev.h" 34 #include "hashtab.h" 35 36 bool 37 i386_pe_type_dllimport_p (tree decl) 38 { 39 gcc_assert (TREE_CODE (decl) == VAR_DECL 40 || TREE_CODE (decl) == FUNCTION_DECL); 41 42 if (TARGET_NOP_FUN_DLLIMPORT && TREE_CODE (decl) == FUNCTION_DECL) 43 return false; 44 45 /* We ignore the dllimport attribute for inline member functions. 46 This differs from MSVC behavior which treats it like GNUC 47 'extern inline' extension. Also ignore for template 48 instantiations with linkonce semantics and artificial methods. */ 49 if (TREE_CODE (decl) == FUNCTION_DECL 50 && (DECL_DECLARED_INLINE_P (decl) 51 || DECL_TEMPLATE_INSTANTIATION (decl) 52 || DECL_ARTIFICIAL (decl))) 53 return false; 54 55 /* Overrides of the class dllimport decls by out-of-class definitions are 56 handled by tree.c:merge_dllimport_decl_attributes. */ 57 return true; 58 } 59 60 bool 61 i386_pe_type_dllexport_p (tree decl) 62 { 63 gcc_assert (TREE_CODE (decl) == VAR_DECL 64 || TREE_CODE (decl) == FUNCTION_DECL); 65 66 /* Avoid exporting compiler-generated default dtors and copy ctors. 67 The only artificial methods that need to be exported are virtual 68 and non-virtual thunks. */ 69 if (TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE 70 && DECL_ARTIFICIAL (decl) && !DECL_THUNK_P (decl)) 71 return false; 72 return true; 73 } 74 75 static inline void maybe_add_dllimport (tree decl) 76 { 77 if (i386_pe_type_dllimport_p (decl)) 78 DECL_DLLIMPORT_P (decl) = 1; 79 } 80 81 static inline void maybe_add_dllexport (tree decl) 82 { 83 if (i386_pe_type_dllexport_p (decl)) 84 { 85 tree decl_attrs = DECL_ATTRIBUTES (decl); 86 if (lookup_attribute ("dllexport", decl_attrs) != NULL_TREE) 87 /* Already done. */ 88 return; 89 DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("dllexport"), 90 NULL_TREE, decl_attrs); 91 } 92 } 93 94 void 95 i386_pe_adjust_class_at_definition (tree t) 96 { 97 tree member; 98 99 gcc_assert (CLASS_TYPE_P (t)); 100 101 102 if (lookup_attribute ("dllexport", TYPE_ATTRIBUTES (t)) != NULL_TREE) 103 { 104 tree tmv = TYPE_MAIN_VARIANT (t); 105 106 /* Make sure that we set dllexport attribute to typeinfo's 107 base declaration, as otherwise it would fail to be exported as 108 it isn't a class-member. */ 109 if (tmv != NULL_TREE 110 && CLASSTYPE_TYPEINFO_VAR (tmv) != NULL_TREE) 111 { 112 tree na, ti_decl = CLASSTYPE_TYPEINFO_VAR (tmv); 113 na = tree_cons (get_identifier ("dllexport"), NULL_TREE, 114 NULL_TREE); 115 decl_attributes (&ti_decl, na, 0); 116 } 117 118 /* Check static VAR_DECL's. */ 119 for (member = TYPE_FIELDS (t); member; member = TREE_CHAIN (member)) 120 if (TREE_CODE (member) == VAR_DECL) 121 maybe_add_dllexport (member); 122 123 /* Check FUNCTION_DECL's. */ 124 for (member = TYPE_METHODS (t); member; member = TREE_CHAIN (member)) 125 if (TREE_CODE (member) == FUNCTION_DECL) 126 { 127 tree thunk; 128 maybe_add_dllexport (member); 129 130 /* Also add the attribute to its thunks. */ 131 for (thunk = DECL_THUNKS (member); thunk; 132 thunk = TREE_CHAIN (thunk)) 133 maybe_add_dllexport (thunk); 134 } 135 /* Check vtables */ 136 for (member = CLASSTYPE_VTABLES (t); member; member = TREE_CHAIN (member)) 137 if (TREE_CODE (member) == VAR_DECL) 138 maybe_add_dllexport (member); 139 } 140 141 else if (lookup_attribute ("dllimport", TYPE_ATTRIBUTES (t)) != NULL_TREE) 142 { 143 /* We don't actually add the attribute to the decl, just set the flag 144 that signals that the address of this symbol is not a compile-time 145 constant. Any subsequent out-of-class declaration of members wil 146 cause the DECL_DLLIMPORT_P flag to be unset. 147 (See tree.c: merge_dllimport_decl_attributes). 148 That is just right since out-of class declarations can only be a 149 definition. */ 150 151 /* Check static VAR_DECL's. */ 152 for (member = TYPE_FIELDS (t); member; member = TREE_CHAIN (member)) 153 if (TREE_CODE (member) == VAR_DECL) 154 maybe_add_dllimport (member); 155 156 /* Check FUNCTION_DECL's. */ 157 for (member = TYPE_METHODS (t); member; member = TREE_CHAIN (member)) 158 if (TREE_CODE (member) == FUNCTION_DECL) 159 { 160 tree thunk; 161 maybe_add_dllimport (member); 162 163 /* Also add the attribute to its thunks. */ 164 for (thunk = DECL_THUNKS (member); thunk; 165 thunk = TREE_CHAIN (thunk)) 166 maybe_add_dllimport (thunk); 167 } 168 169 /* Check vtables */ 170 for (member = CLASSTYPE_VTABLES (t); member; member = TREE_CHAIN (member)) 171 if (TREE_CODE (member) == VAR_DECL) 172 maybe_add_dllimport (member); 173 174 /* We leave typeinfo tables alone. We can't mark TI objects as 175 dllimport, since the address of a secondary VTT may be needed 176 for static initialization of a primary VTT. VTT's of 177 dllimport'd classes should always be link-once COMDAT. */ 178 } 179 } 180