gcc/config/sol2.c

   1 /* General Solaris system support.
   2    Copyright (C) 2004, 2005 , 2007, 2010, 2011, 2012
   3    Free Software Foundation, Inc.
   4    Contributed by CodeSourcery, LLC.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public 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 "tree.h"
  26 #include "output.h"
  27 #include "tm.h"
  28 #include "rtl.h"
  29 #include "target.h"
  30 #include "tm_p.h"
  31 #include "diagnostic-core.h"
  32 #include "ggc.h"
  33 #include "hashtab.h"
  34
  35 tree solaris_pending_aligns, solaris_pending_inits, solaris_pending_finis;
  36
  37 /* Attach any pending attributes for DECL to the list in *ATTRIBUTES.
  38    Pending attributes come from #pragma or _Pragma, so this code is
  39    only useful in the C family front ends, but it is included in
  40    all languages to avoid changing the target machine initializer
  41    depending on the language.  */
  42
  43 void
  44 solaris_insert_attributes (tree decl, tree *attributes)
  45 {
  46   tree *x, next;
  47
  48   if (solaris_pending_aligns != NULL && TREE_CODE (decl) == VAR_DECL)
  49     for (x = &solaris_pending_aligns; *x; x = &TREE_CHAIN (*x))
  50       {
  51         tree name = TREE_PURPOSE (*x);
  52         tree value = TREE_VALUE (*x);
  53         if (DECL_NAME (decl) == name)
  54           {
  55             if (lookup_attribute ("aligned", DECL_ATTRIBUTES (decl))
  56                 || lookup_attribute ("aligned", *attributes))
  57               warning (0, "ignoring %<#pragma align%> for explicitly "
  58                        "aligned %q+D", decl);
  59             else
  60               *attributes = tree_cons (get_identifier ("aligned"), value,
  61                                        *attributes);
  62             next = TREE_CHAIN (*x);
  63             ggc_free (*x);
  64             *x = next;
  65             break;
  66           }
  67       }
  68
  69   if (solaris_pending_inits != NULL && TREE_CODE (decl) == FUNCTION_DECL)
  70     for (x = &solaris_pending_inits; *x; x = &TREE_CHAIN (*x))
  71       {
  72         tree name = TREE_PURPOSE (*x);
  73         if (DECL_NAME (decl) == name)
  74           {
  75             *attributes = tree_cons (get_identifier ("init"), NULL,
  76                                      *attributes);
  77             TREE_USED (decl) = 1;
  78             DECL_PRESERVE_P (decl) = 1;
  79             next = TREE_CHAIN (*x);
  80             ggc_free (*x);
  81             *x = next;
  82             break;
  83           }
  84       }
  85
  86   if (solaris_pending_finis != NULL && TREE_CODE (decl) == FUNCTION_DECL)
  87     for (x = &solaris_pending_finis; *x; x = &TREE_CHAIN (*x))
  88       {
  89         tree name = TREE_PURPOSE (*x);
  90         if (DECL_NAME (decl) == name)
  91           {
  92             *attributes = tree_cons (get_identifier ("fini"), NULL,
  93                                      *attributes);
  94             TREE_USED (decl) = 1;
  95             DECL_PRESERVE_P (decl) = 1;
  96             next = TREE_CHAIN (*x);
  97             ggc_free (*x);
  98             *x = next;
  99             break;
 100           }
 101       }
 102 }
 103
 104 /* Output initializer or finalizer entries for DECL to FILE.  */
 105
 106 void
 107 solaris_output_init_fini (FILE *file, tree decl)
 108 {
 109   if (lookup_attribute ("init", DECL_ATTRIBUTES (decl)))
 110     {
 111       fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".init");
 112       ASM_OUTPUT_CALL (file, decl);
 113       fprintf (file, "\t.popsection\n");
 114     }
 115
 116   if (lookup_attribute ("fini", DECL_ATTRIBUTES (decl)))
 117     {
 118       fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".fini");
 119       ASM_OUTPUT_CALL (file, decl);
 120       fprintf (file, "\t.popsection\n");
 121     }
 122 }
 123
 124 /* Emit an assembler directive to set symbol for DECL visibility to
 125    the visibility type VIS, which must not be VISIBILITY_DEFAULT.  */
 126
 127 void
 128 solaris_assemble_visibility (tree decl ATTRIBUTE_UNUSED,
 129                              int vis ATTRIBUTE_UNUSED)
 130 {
 131 #ifdef HAVE_GAS_HIDDEN
 132   /* Sun as uses .symbolic for STV_PROTECTED.  STV_INTERNAL is marked as
 133      `currently reserved', but the linker treats it like STV_HIDDEN.  Sun
 134      Studio 12.1 cc emits .hidden instead.
 135
 136      There are 3 Sun extensions GCC doesn't yet know about: STV_EXPORTED,
 137      STV_SINGLETON, and STV_ELIMINATE.
 138
 139      See Linker and Libraries Guide, Ch. 2, Link-Editor, Defining
 140      Additional Symbols, and Ch. 7, Object-File Format, Symbol Table
 141      Section.  */
 142
 143   static const char * const visibility_types[] = {
 144     NULL, "symbolic", "hidden", "hidden"
 145   };
 146
 147   const char *name, *type;
 148
 149   name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 150   type = visibility_types[vis];
 151
 152   fprintf (asm_out_file, "\t.%s\t", type);
 153   assemble_name (asm_out_file, name);
 154   fprintf (asm_out_file, "\n");
 155 #else
 156   warning (OPT_Wattributes, "visibility attribute not supported "
 157            "in this configuration; ignored");
 158 #endif
 159 }
 160
 161 /* Hash table of group signature symbols.  */
 162
 163 static htab_t solaris_comdat_htab;
 164
 165 /* Group section information entry stored in solaris_comdat_htab.  */
 166
 167 typedef struct comdat_entry
 168 {
 169   const char *name;
 170   unsigned int flags;
 171   tree decl;
 172   const char *sig;
 173 } comdat_entry;
 174
 175 /* Helper routines for maintaining solaris_comdat_htab.  */
 176
 177 static hashval_t
 178 comdat_hash (const void *p)
 179 {
 180   const comdat_entry *entry = (const comdat_entry *) p;
 181
 182   return htab_hash_string (entry->sig);
 183 }
 184
 185 static int
 186 comdat_eq (const void *p1, const void *p2)
 187 {
 188   const comdat_entry *entry1 = (const comdat_entry *) p1;
 189   const comdat_entry *entry2 = (const comdat_entry *) p2;
 190
 191   return strcmp (entry1->sig, entry2->sig) == 0;
 192 }
 193
 194 /* Output assembly to switch to COMDAT group section NAME with attributes
 195    FLAGS and group signature symbol DECL, using Sun as syntax.  */
 196
 197 void
 198 solaris_elf_asm_comdat_section (const char *name, unsigned int flags, tree decl)
 199 {
 200   const char *signature;
 201   char *section;
 202   comdat_entry entry, **slot;
 203
 204   if (TREE_CODE (decl) == IDENTIFIER_NODE)
 205     signature = IDENTIFIER_POINTER (decl);
 206   else
 207     signature = IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl));
 208
 209   /* Sun as requires group sections to be fragmented, i.e. to have names of
 210      the form <section>%<fragment>.  Strictly speaking this is only
 211      necessary to support cc -xF, but is enforced globally in violation of
 212      the ELF gABI.  We keep the section names generated by GCC (generally
 213      of the form .text.<signature>) and append %<signature> to pacify as,
 214      despite the redundancy.  */
 215   section = concat (name, "%", signature, NULL);
 216
 217   /* Clear SECTION_LINKONCE flag so targetm.asm_out.named_section only
 218      emits this as a regular section.  Emit section before .group
 219      directive since Sun as treats undeclared sections as @progbits,
 220      which conflicts with .bss* sections which are @nobits.  */
 221   targetm.asm_out.named_section (section, flags & ~SECTION_LINKONCE, decl);
 222
 223   /* Sun as separates declaration of a group section and of the group
 224      itself, using the .group directive and the #comdat flag.  */
 225   fprintf (asm_out_file, "\t.group\t%s," SECTION_NAME_FORMAT ",#comdat\n",
 226            signature, section);
 227
 228   /* Unlike GNU as, group signature symbols need to be defined explicitly
 229      for Sun as.  With a few exceptions, this is already the case.  To
 230      identify the missing ones without changing the affected frontents,
 231      remember the signature symbols and emit those not marked
 232      TREE_SYMBOL_REFERENCED in solaris_file_end.  */
 233   if (solaris_comdat_htab == NULL)
 234     solaris_comdat_htab = htab_create_alloc (37, comdat_hash, comdat_eq, NULL,
 235                                              xcalloc, free);
 236
 237   entry.sig = signature;
 238   slot = (comdat_entry **) htab_find_slot (solaris_comdat_htab, &entry, INSERT);
 239
 240   if (*slot == NULL)
 241     {
 242       *slot = XCNEW (comdat_entry);
 243       /* Remember fragmented section name.  */
 244       (*slot)->name = section;
 245       /* Emit as regular section, .group declaration has already been done.  */
 246       (*slot)->flags = flags & ~SECTION_LINKONCE;
 247       (*slot)->decl = decl;
 248       (*slot)->sig = signature;
 249     }
 250 }
 251
 252 /* Define unreferenced COMDAT group signature symbol corresponding to SLOT.  */
 253
 254 static int
 255 solaris_define_comdat_signature (void **slot, void *aux ATTRIBUTE_UNUSED)
 256 {
 257   comdat_entry *entry = *(comdat_entry **) slot;
 258   tree decl = entry->decl;
 259
 260   if (TREE_CODE (decl) != IDENTIFIER_NODE)
 261     decl = DECL_COMDAT_GROUP (decl);
 262
 263   if (!TREE_SYMBOL_REFERENCED (decl))
 264     {
 265       /* Switch to group section, otherwise Sun as complains
 266          `Group Id symbol defined outside of group'.  */
 267       switch_to_section (get_section (entry->name, entry->flags, entry->decl));
 268
 269       ASM_OUTPUT_LABEL (asm_out_file, entry->sig);
 270     }
 271
 272   /* Continue with scan.  */
 273   return 1;
 274 }
 275
 276 /* Emit unreferenced COMDAT group signature symbols for Sun as.  */
 277
 278 void
 279 solaris_file_end (void)
 280 {
 281   if (solaris_comdat_htab == NULL)
 282     return;
 283
 284   htab_traverse (solaris_comdat_htab, solaris_define_comdat_signature, NULL);
 285 }
 286
 287 void
 288 solaris_override_options (void)
 289 {
 290   /* Don't emit DWARF3/4 unless specifically selected.  Solaris ld cannot
 291      handle CIE version 3 in .eh_frame.  */
 292   if (!global_options_set.x_dwarf_version)
 293     dwarf_version = 2;
 294 }