gcc/config/arm/pe.c

   1 /* Routines for GCC for ARM/pe.
   2    Copyright (C) 1995, 1996, 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2010
   3    Free Software Foundation, Inc.
   4    Contributed by Doug Evans (dje@cygnus.com).
   5
   6    This file is part of GCC.
   7
   8    GCC is free software; you can redistribute it and/or modify it
   9    under the terms of the GNU General Public License as published
  10    by the Free Software Foundation; either version 3, or (at your
  11    option) any later version.
  12
  13    GCC is distributed in the hope that it will be useful, but WITHOUT
  14    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  16    License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with GCC; see the file COPYING3.  If not see
  20    <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "rtl.h"
  27 #include "output.h"
  28 #include "flags.h"
  29 #include "tree.h"
  30 #include "expr.h"
  31 #include "diagnostic-core.h"
  32 #include "tm_p.h"
  33
  34 extern int current_function_anonymous_args;
  35
  36 \f
  37 /* Return nonzero if DECL is a dllexport'd object.  */
  38
  39 tree current_class_type; /* FIXME */
  40
  41 int
  42 arm_dllexport_p (tree decl)
  43 {
  44   tree exp;
  45
  46   if (TREE_CODE (decl) != VAR_DECL
  47       && TREE_CODE (decl) != FUNCTION_DECL)
  48     return 0;
  49   exp = lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl));
  50   if (exp)
  51     return 1;
  52
  53   return 0;
  54 }
  55
  56 /* Return nonzero if DECL is a dllimport'd object.  */
  57
  58 int
  59 arm_dllimport_p (tree decl)
  60 {
  61   tree imp;
  62
  63   if (TREE_CODE (decl) == FUNCTION_DECL
  64       && TARGET_NOP_FUN_DLLIMPORT)
  65     return 0;
  66
  67   if (TREE_CODE (decl) != VAR_DECL
  68       && TREE_CODE (decl) != FUNCTION_DECL)
  69     return 0;
  70   imp = lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl));
  71   if (imp)
  72     return 1;
  73
  74   return 0;
  75 }
  76
  77 /* Return nonzero if SYMBOL is marked as being dllexport'd.  */
  78
  79 int
  80 arm_dllexport_name_p (const char *symbol)
  81 {
  82   return symbol[0] == ARM_PE_FLAG_CHAR && symbol[1] == 'e' && symbol[2] == '.';
  83 }
  84
  85 /* Return nonzero if SYMBOL is marked as being dllimport'd.  */
  86
  87 int
  88 arm_dllimport_name_p (const char *symbol)
  89 {
  90   return symbol[0] == ARM_PE_FLAG_CHAR && symbol[1] == 'i' && symbol[2] == '.';
  91 }
  92
  93 /* Mark a DECL as being dllexport'd.
  94    Note that we override the previous setting (e.g.: dllimport).  */
  95
  96 void
  97 arm_mark_dllexport (tree decl)
  98 {
  99   const char * oldname;
 100   char * newname;
 101   rtx rtlname;
 102   tree idp;
 103
 104   rtlname = XEXP (DECL_RTL (decl), 0);
 105   if (GET_CODE (rtlname) == MEM)
 106     rtlname = XEXP (rtlname, 0);
 107   gcc_assert (GET_CODE (rtlname) == SYMBOL_REF);
 108   oldname = XSTR (rtlname, 0);
 109
 110   if (arm_dllimport_name_p (oldname))
 111     oldname += 9;
 112   else if (arm_dllexport_name_p (oldname))
 113     return; /* already done */
 114
 115   newname = XALLOCAVEC (char, strlen (oldname) + 4);
 116   sprintf (newname, "%ce.%s", ARM_PE_FLAG_CHAR, oldname);
 117
 118   /* We pass newname through get_identifier to ensure it has a unique
 119      address.  RTL processing can sometimes peek inside the symbol ref
 120      and compare the string's addresses to see if two symbols are
 121      identical.  */
 122   /* ??? At least I think that's why we do this.  */
 123   idp = get_identifier (newname);
 124
 125   XEXP (DECL_RTL (decl), 0) =
 126     gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));
 127 }
 128
 129 /* Mark a DECL as being dllimport'd.  */
 130
 131 void
 132 arm_mark_dllimport (tree decl)
 133 {
 134   const char * oldname;
 135   char * newname;
 136   tree idp;
 137   rtx rtlname, newrtl;
 138
 139   rtlname = XEXP (DECL_RTL (decl), 0);
 140
 141   if (GET_CODE (rtlname) == MEM)
 142     rtlname = XEXP (rtlname, 0);
 143   gcc_assert (GET_CODE (rtlname) == SYMBOL_REF);
 144   oldname = XSTR (rtlname, 0);
 145
 146   gcc_assert (!arm_dllexport_name_p (oldname));
 147   if (arm_dllimport_name_p (oldname))
 148     return; /* already done */
 149
 150   /* ??? One can well ask why we're making these checks here,
 151      and that would be a good question.  */
 152
 153   /* Imported variables can't be initialized.  */
 154   if (TREE_CODE (decl) == VAR_DECL
 155       && !DECL_VIRTUAL_P (decl)
 156       && DECL_INITIAL (decl))
 157     {
 158       error ("initialized variable %q+D is marked dllimport", decl);
 159       return;
 160     }
 161   /* Nor can they be static.  */
 162   if (TREE_CODE (decl) == VAR_DECL
 163       /* ??? Is this test for vtables needed?  */
 164       && !DECL_VIRTUAL_P (decl)
 165       && 0 /*???*/)
 166     {
 167       error ("static variable %q+D is marked dllimport", decl);
 168       return;
 169     }
 170
 171   /* `extern' needn't be specified with dllimport.
 172      Specify `extern' now and hope for the best.  Sigh.  */
 173   if (TREE_CODE (decl) == VAR_DECL
 174       /* ??? Is this test for vtables needed?  */
 175       && !DECL_VIRTUAL_P (decl))
 176     {
 177       DECL_EXTERNAL (decl) = 1;
 178       TREE_PUBLIC (decl) = 1;
 179     }
 180
 181   newname = XALLOCAVEC (char, strlen (oldname) + 11);
 182   sprintf (newname, "%ci.__imp_%s", ARM_PE_FLAG_CHAR, oldname);
 183
 184   /* We pass newname through get_identifier to ensure it has a unique
 185      address.  RTL processing can sometimes peek inside the symbol ref
 186      and compare the string's addresses to see if two symbols are
 187      identical.  */
 188   /* ??? At least I think that's why we do this.  */
 189   idp = get_identifier (newname);
 190
 191   newrtl = gen_rtx_MEM (Pmode,
 192                         gen_rtx_SYMBOL_REF (Pmode,
 193                                             IDENTIFIER_POINTER (idp)));
 194   XEXP (DECL_RTL (decl), 0) = newrtl;
 195 }
 196
 197 void
 198 arm_pe_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
 199 {
 200   /* This bit is copied from arm_encode_section_info.  */
 201   if (optimize > 0 && TREE_CONSTANT (decl))
 202     SYMBOL_REF_FLAG (XEXP (rtl, 0)) = 1;
 203
 204   /* Mark the decl so we can tell from the rtl whether the object is
 205      dllexport'd or dllimport'd.  */
 206   if (arm_dllexport_p (decl))
 207     arm_mark_dllexport (decl);
 208   else if (arm_dllimport_p (decl))
 209     arm_mark_dllimport (decl);
 210   /* It might be that DECL has already been marked as dllimport, but a
 211      subsequent definition nullified that.  The attribute is gone but
 212      DECL_RTL still has @i.__imp_foo.  We need to remove that.  */
 213   else if ((TREE_CODE (decl) == FUNCTION_DECL
 214             || TREE_CODE (decl) == VAR_DECL)
 215            && DECL_RTL (decl) != NULL_RTX
 216            && GET_CODE (DECL_RTL (decl)) == MEM
 217            && GET_CODE (XEXP (DECL_RTL (decl), 0)) == MEM
 218            && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == SYMBOL_REF
 219            && arm_dllimport_name_p (XSTR (XEXP (XEXP (DECL_RTL (decl), 0), 0), 0)))
 220     {
 221       const char *oldname = XSTR (XEXP (XEXP (DECL_RTL (decl), 0), 0), 0);
 222       tree idp = get_identifier (oldname + 9);
 223       rtx newrtl = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));
 224
 225       XEXP (DECL_RTL (decl), 0) = newrtl;
 226
 227       /* We previously set TREE_PUBLIC and DECL_EXTERNAL.
 228          ??? We leave these alone for now.  */
 229     }
 230 }
 231
 232 void
 233 arm_pe_unique_section (tree decl, int reloc)
 234 {
 235   int len;
 236   const char * name;
 237   char * string;
 238   const char * prefix;
 239
 240   name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 241   name = arm_strip_name_encoding (name);
 242
 243   /* The object is put in, for example, section .text$foo.
 244      The linker will then ultimately place them in .text
 245      (everything from the $ on is stripped).  */
 246   if (TREE_CODE (decl) == FUNCTION_DECL)
 247     prefix = ".text$";
 248   else if (decl_readonly_section (decl, reloc))
 249     prefix = ".rdata$";
 250   else
 251     prefix = ".data$";
 252   len = strlen (name) + strlen (prefix);
 253   string = XALLOCAVEC (char, len + 1);
 254   sprintf (string, "%s%s", prefix, name);
 255
 256   DECL_SECTION_NAME (decl) = build_string (len, string);
 257 }