gcc/config/sol2.c

   1 /* General Solaris system support.
   2    Copyright (C) 2004-2016 Free Software Foundation, Inc.
   3    Contributed by CodeSourcery, LLC.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License 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 "rtl.h"
  26 #include "tree.h"
  27 #include "tm_p.h"
  28 #include "stringpool.h"
  29 #include "diagnostic-core.h"
  30 #include "varasm.h"
  31 #include "output.h"
  32
  33 tree solaris_pending_aligns, solaris_pending_inits, solaris_pending_finis;
  34
  35 /* Attach any pending attributes for DECL to the list in *ATTRIBUTES.
  36    Pending attributes come from #pragma or _Pragma, so this code is
  37    only useful in the C family front ends, but it is included in
  38    all languages to avoid changing the target machine initializer
  39    depending on the language.  */
  40
  41 void
  42 solaris_insert_attributes (tree decl, tree *attributes)
  43 {
  44   tree *x, next;
  45
  46   if (solaris_pending_aligns != NULL && TREE_CODE (decl) == VAR_DECL)
  47     for (x = &solaris_pending_aligns; *x; x = &TREE_CHAIN (*x))
  48       {
  49         tree name = TREE_PURPOSE (*x);
  50         tree value = TREE_VALUE (*x);
  51         if (DECL_NAME (decl) == name)
  52           {
  53             if (lookup_attribute ("aligned", DECL_ATTRIBUTES (decl))
  54                 || lookup_attribute ("aligned", *attributes))
  55               warning (0, "ignoring %<#pragma align%> for explicitly "
  56                        "aligned %q+D", decl);
  57             else
  58               *attributes = tree_cons (get_identifier ("aligned"), value,
  59                                        *attributes);
  60             next = TREE_CHAIN (*x);
  61             ggc_free (*x);
  62             *x = next;
  63             break;
  64           }
  65       }
  66
  67   if (solaris_pending_inits != NULL && TREE_CODE (decl) == FUNCTION_DECL)
  68     for (x = &solaris_pending_inits; *x; x = &TREE_CHAIN (*x))
  69       {
  70         tree name = TREE_PURPOSE (*x);
  71         if (DECL_NAME (decl) == name)
  72           {
  73             *attributes = tree_cons (get_identifier ("init"), NULL,
  74                                      *attributes);
  75             TREE_USED (decl) = 1;
  76             DECL_PRESERVE_P (decl) = 1;
  77             next = TREE_CHAIN (*x);
  78             ggc_free (*x);
  79             *x = next;
  80             break;
  81           }
  82       }
  83
  84   if (solaris_pending_finis != NULL && TREE_CODE (decl) == FUNCTION_DECL)
  85     for (x = &solaris_pending_finis; *x; x = &TREE_CHAIN (*x))
  86       {
  87         tree name = TREE_PURPOSE (*x);
  88         if (DECL_NAME (decl) == name)
  89           {
  90             *attributes = tree_cons (get_identifier ("fini"), NULL,
  91                                      *attributes);
  92             TREE_USED (decl) = 1;
  93             DECL_PRESERVE_P (decl) = 1;
  94             next = TREE_CHAIN (*x);
  95             ggc_free (*x);
  96             *x = next;
  97             break;
  98           }
  99       }
 100 }
 101
 102 /* Output initializer or finalizer entries for DECL to FILE.  */
 103
 104 void
 105 solaris_output_init_fini (FILE *file, tree decl)
 106 {
 107   if (lookup_attribute ("init", DECL_ATTRIBUTES (decl)))
 108     {
 109       fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".init");
 110       ASM_OUTPUT_CALL (file, decl);
 111       fprintf (file, "\t.popsection\n");
 112     }
 113
 114   if (lookup_attribute ("fini", DECL_ATTRIBUTES (decl)))
 115     {
 116       fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".fini");
 117       ASM_OUTPUT_CALL (file, decl);
 118       fprintf (file, "\t.popsection\n");
 119     }
 120 }
 121
 122 /* Emit an assembler directive to set symbol for DECL visibility to
 123    the visibility type VIS, which must not be VISIBILITY_DEFAULT.  */
 124
 125 void
 126 solaris_assemble_visibility (tree decl, int vis ATTRIBUTE_UNUSED)
 127 {
 128 #ifdef HAVE_GAS_HIDDEN
 129   /* Sun as uses .symbolic for STV_PROTECTED.  STV_INTERNAL is marked as
 130      `currently reserved', but the linker treats it like STV_HIDDEN.  Sun
 131      Studio 12.1 cc emits .hidden instead.
 132
 133      There are 3 Sun extensions GCC doesn't yet know about: STV_EXPORTED,
 134      STV_SINGLETON, and STV_ELIMINATE.
 135
 136      See Linker and Libraries Guide, Ch. 2, Link-Editor, Defining
 137      Additional Symbols, and Ch. 7, Object-File Format, Symbol Table
 138      Section.  */
 139
 140   static const char * const visibility_types[] = {
 141     NULL, "symbolic", "hidden", "hidden"
 142   };
 143
 144   const char *name, *type;
 145   tree id = DECL_ASSEMBLER_NAME (decl);
 146
 147   while (IDENTIFIER_TRANSPARENT_ALIAS (id))
 148     id = TREE_CHAIN (id);
 149   name = IDENTIFIER_POINTER (id);
 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   if (!DECL_ARTIFICIAL (decl))
 157     warning (OPT_Wattributes, "visibility attribute not supported "
 158                               "in this configuration; ignored");
 159 #endif
 160 }
 161
 162 /* Group section information entry stored in solaris_comdat_htab.  */
 163
 164 typedef struct comdat_entry
 165 {
 166   const char *name;
 167   unsigned int flags;
 168   tree decl;
 169   const char *sig;
 170 } comdat_entry;
 171
 172 /* Helpers for maintaining solaris_comdat_htab.  */
 173
 174 struct comdat_entry_hasher : nofree_ptr_hash <comdat_entry>
 175 {
 176   static inline hashval_t hash (const comdat_entry *);
 177   static inline bool equal (const comdat_entry *, const comdat_entry *);
 178   static inline void remove (comdat_entry *);
 179 };
 180
 181 inline hashval_t
 182 comdat_entry_hasher::hash (const comdat_entry *entry)
 183 {
 184   return htab_hash_string (entry->sig);
 185 }
 186
 187 inline bool
 188 comdat_entry_hasher::equal (const comdat_entry *entry1,
 189                             const comdat_entry *entry2)
 190 {
 191   return strcmp (entry1->sig, entry2->sig) == 0;
 192 }
 193
 194 /* Hash table of group signature symbols.  */
 195
 196 static hash_table<comdat_entry_hasher> *solaris_comdat_htab;
 197
 198 /* Output assembly to switch to COMDAT group section NAME with attributes
 199    FLAGS and group signature symbol DECL, using Sun as syntax.  */
 200
 201 void
 202 solaris_elf_asm_comdat_section (const char *name, unsigned int flags, tree decl)
 203 {
 204   const char *signature;
 205   char *section;
 206   comdat_entry entry, **slot;
 207
 208   if (TREE_CODE (decl) == IDENTIFIER_NODE)
 209     signature = IDENTIFIER_POINTER (decl);
 210   else
 211     signature = IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl));
 212
 213   /* Sun as requires group sections to be fragmented, i.e. to have names of
 214      the form <section>%<fragment>.  Strictly speaking this is only
 215      necessary to support cc -xF, but is enforced globally in violation of
 216      the ELF gABI.  We keep the section names generated by GCC (generally
 217      of the form .text.<signature>) and append %<signature> to pacify as,
 218      despite the redundancy.  */
 219   section = concat (name, "%", signature, NULL);
 220
 221   /* Clear SECTION_LINKONCE flag so targetm.asm_out.named_section only
 222      emits this as a regular section.  Emit section before .group
 223      directive since Sun as treats undeclared sections as @progbits,
 224      which conflicts with .bss* sections which are @nobits.  */
 225   targetm.asm_out.named_section (section, flags & ~SECTION_LINKONCE, decl);
 226
 227   /* Sun as separates declaration of a group section and of the group
 228      itself, using the .group directive and the #comdat flag.  */
 229   fprintf (asm_out_file, "\t.group\t%s," SECTION_NAME_FORMAT ",#comdat\n",
 230            signature, section);
 231
 232   /* Unlike GNU as, group signature symbols need to be defined explicitly
 233      for Sun as.  With a few exceptions, this is already the case.  To
 234      identify the missing ones without changing the affected frontents,
 235      remember the signature symbols and emit those not marked
 236      TREE_SYMBOL_REFERENCED in solaris_file_end.  */
 237   if (!solaris_comdat_htab)
 238     solaris_comdat_htab = new hash_table<comdat_entry_hasher> (37);
 239
 240   entry.sig = signature;
 241   slot = solaris_comdat_htab->find_slot (&entry, INSERT);
 242
 243   if (*slot == NULL)
 244     {
 245       *slot = XCNEW (comdat_entry);
 246       /* Remember fragmented section name.  */
 247       (*slot)->name = section;
 248       /* Emit as regular section, .group declaration has already been done.  */
 249       (*slot)->flags = flags & ~SECTION_LINKONCE;
 250       (*slot)->decl = decl;
 251       (*slot)->sig = signature;
 252     }
 253 }
 254
 255 /* Define unreferenced COMDAT group signature symbol corresponding to SLOT.  */
 256
 257 int
 258 solaris_define_comdat_signature (comdat_entry **slot,
 259                                  void *aux ATTRIBUTE_UNUSED)
 260 {
 261   comdat_entry *entry = *slot;
 262   tree decl = entry->decl;
 263
 264   if (TREE_CODE (decl) != IDENTIFIER_NODE)
 265     decl = DECL_COMDAT_GROUP (decl);
 266
 267   if (!TREE_SYMBOL_REFERENCED (decl))
 268     {
 269       /* Switch to group section, otherwise Sun as complains
 270          `Group Id symbol defined outside of group'.  */
 271       switch_to_section (get_section (entry->name, entry->flags, entry->decl));
 272
 273       ASM_OUTPUT_LABEL (asm_out_file, entry->sig);
 274     }
 275
 276   /* Continue with scan.  */
 277   return 1;
 278 }
 279
 280 /* Emit unreferenced COMDAT group signature symbols for Sun as.  */
 281
 282 void
 283 solaris_file_end (void)
 284 {
 285   if (!solaris_comdat_htab)
 286     return;
 287
 288   solaris_comdat_htab->traverse <void *, solaris_define_comdat_signature>
 289     (NULL);
 290 }
 291
 292 void
 293 solaris_override_options (void)
 294 {
 295   /* Older versions of Solaris ld cannot handle CIE version 3 in .eh_frame.
 296      Don't emit DWARF3/4 unless specifically selected if so.  */
 297   if (!HAVE_LD_EH_FRAME_CIEV3 && !global_options_set.x_dwarf_version)
 298     dwarf_version = 2;
 299 }