gcc/config/sol2.c

   1 /* General Solaris system support.
   2    Copyright (C) 2004-2017 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 "memmodel.h"
  28 #include "tm_p.h"
  29 #include "stringpool.h"
  30 #include "diagnostic-core.h"
  31 #include "varasm.h"
  32 #include "output.h"
  33
  34 tree solaris_pending_aligns, solaris_pending_inits, solaris_pending_finis;
  35
  36 /* Attach any pending attributes for DECL to the list in *ATTRIBUTES.
  37    Pending attributes come from #pragma or _Pragma, so this code is
  38    only useful in the C family front ends, but it is included in
  39    all languages to avoid changing the target machine initializer
  40    depending on the language.  */
  41
  42 void
  43 solaris_insert_attributes (tree decl, tree *attributes)
  44 {
  45   tree *x, next;
  46
  47   if (solaris_pending_aligns != NULL && TREE_CODE (decl) == VAR_DECL)
  48     for (x = &solaris_pending_aligns; *x; x = &TREE_CHAIN (*x))
  49       {
  50         tree name = TREE_PURPOSE (*x);
  51         tree value = TREE_VALUE (*x);
  52         if (DECL_NAME (decl) == name)
  53           {
  54             if (lookup_attribute ("aligned", DECL_ATTRIBUTES (decl))
  55                 || lookup_attribute ("aligned", *attributes))
  56               warning (0, "ignoring %<#pragma align%> for explicitly "
  57                        "aligned %q+D", decl);
  58             else
  59               *attributes = tree_cons (get_identifier ("aligned"), value,
  60                                        *attributes);
  61             next = TREE_CHAIN (*x);
  62             ggc_free (*x);
  63             *x = next;
  64             break;
  65           }
  66       }
  67
  68   if (solaris_pending_inits != NULL && TREE_CODE (decl) == FUNCTION_DECL)
  69     for (x = &solaris_pending_inits; *x; x = &TREE_CHAIN (*x))
  70       {
  71         tree name = TREE_PURPOSE (*x);
  72         if (DECL_NAME (decl) == name)
  73           {
  74             *attributes = tree_cons (get_identifier ("init"), NULL,
  75                                      *attributes);
  76             TREE_USED (decl) = 1;
  77             DECL_PRESERVE_P (decl) = 1;
  78             next = TREE_CHAIN (*x);
  79             ggc_free (*x);
  80             *x = next;
  81             break;
  82           }
  83       }
  84
  85   if (solaris_pending_finis != NULL && TREE_CODE (decl) == FUNCTION_DECL)
  86     for (x = &solaris_pending_finis; *x; x = &TREE_CHAIN (*x))
  87       {
  88         tree name = TREE_PURPOSE (*x);
  89         if (DECL_NAME (decl) == name)
  90           {
  91             *attributes = tree_cons (get_identifier ("fini"), NULL,
  92                                      *attributes);
  93             TREE_USED (decl) = 1;
  94             DECL_PRESERVE_P (decl) = 1;
  95             next = TREE_CHAIN (*x);
  96             ggc_free (*x);
  97             *x = next;
  98             break;
  99           }
 100       }
 101 }
 102
 103 /* Output initializer or finalizer entries for DECL to FILE.  */
 104
 105 void
 106 solaris_output_init_fini (FILE *file, tree decl)
 107 {
 108   if (lookup_attribute ("init", DECL_ATTRIBUTES (decl)))
 109     {
 110       fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".init");
 111       ASM_OUTPUT_CALL (file, decl);
 112       fprintf (file, "\t.popsection\n");
 113     }
 114
 115   if (lookup_attribute ("fini", DECL_ATTRIBUTES (decl)))
 116     {
 117       fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".fini");
 118       ASM_OUTPUT_CALL (file, decl);
 119       fprintf (file, "\t.popsection\n");
 120     }
 121 }
 122
 123 /* Emit an assembler directive to set symbol for DECL visibility to
 124    the visibility type VIS, which must not be VISIBILITY_DEFAULT.  */
 125
 126 void
 127 solaris_assemble_visibility (tree decl, int vis ATTRIBUTE_UNUSED)
 128 {
 129 #ifdef HAVE_GAS_HIDDEN
 130   /* Sun as uses .symbolic for STV_PROTECTED.  STV_INTERNAL is marked as
 131      `currently reserved', but the linker treats it like STV_HIDDEN.  Sun
 132      Studio 12.1 cc emits .hidden instead.
 133
 134      There are 3 Sun extensions GCC doesn't yet know about: STV_EXPORTED,
 135      STV_SINGLETON, and STV_ELIMINATE.
 136
 137      See Linker and Libraries Guide, Ch. 2, Link-Editor, Defining
 138      Additional Symbols, and Ch. 7, Object-File Format, Symbol Table
 139      Section.  */
 140
 141   static const char * const visibility_types[] = {
 142     NULL, "symbolic", "hidden", "hidden"
 143   };
 144
 145   const char *name, *type;
 146   tree id = DECL_ASSEMBLER_NAME (decl);
 147
 148   while (IDENTIFIER_TRANSPARENT_ALIAS (id))
 149     id = TREE_CHAIN (id);
 150   name = IDENTIFIER_POINTER (id);
 151   type = visibility_types[vis];
 152
 153   fprintf (asm_out_file, "\t.%s\t", type);
 154   assemble_name (asm_out_file, name);
 155   fprintf (asm_out_file, "\n");
 156 #else
 157   if (!DECL_ARTIFICIAL (decl))
 158     warning (OPT_Wattributes, "visibility attribute not supported "
 159                               "in this configuration; ignored");
 160 #endif
 161 }
 162
 163 /* Group section information entry stored in solaris_comdat_htab.  */
 164
 165 typedef struct comdat_entry
 166 {
 167   const char *name;
 168   unsigned int flags;
 169   tree decl;
 170   const char *sig;
 171 } comdat_entry;
 172
 173 /* Helpers for maintaining solaris_comdat_htab.  */
 174
 175 struct comdat_entry_hasher : nofree_ptr_hash <comdat_entry>
 176 {
 177   static inline hashval_t hash (const comdat_entry *);
 178   static inline bool equal (const comdat_entry *, const comdat_entry *);
 179   static inline void remove (comdat_entry *);
 180 };
 181
 182 inline hashval_t
 183 comdat_entry_hasher::hash (const comdat_entry *entry)
 184 {
 185   return htab_hash_string (entry->sig);
 186 }
 187
 188 inline bool
 189 comdat_entry_hasher::equal (const comdat_entry *entry1,
 190                             const comdat_entry *entry2)
 191 {
 192   return strcmp (entry1->sig, entry2->sig) == 0;
 193 }
 194
 195 /* Hash table of group signature symbols.  */
 196
 197 static hash_table<comdat_entry_hasher> *solaris_comdat_htab;
 198
 199 /* Output assembly to switch to COMDAT group section NAME with attributes
 200    FLAGS and group signature symbol DECL, using Sun as syntax.  */
 201
 202 void
 203 solaris_elf_asm_comdat_section (const char *name, unsigned int flags, tree decl)
 204 {
 205   const char *signature;
 206   char *section;
 207   comdat_entry entry, **slot;
 208
 209   if (TREE_CODE (decl) == IDENTIFIER_NODE)
 210     signature = IDENTIFIER_POINTER (decl);
 211   else
 212     signature = IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl));
 213
 214   /* Sun as requires group sections to be fragmented, i.e. to have names of
 215      the form <section>%<fragment>.  Strictly speaking this is only
 216      necessary to support cc -xF, but is enforced globally in violation of
 217      the ELF gABI.  We keep the section names generated by GCC (generally
 218      of the form .text.<signature>) and append %<signature> to pacify as,
 219      despite the redundancy.  */
 220   section = concat (name, "%", signature, NULL);
 221
 222   /* Clear SECTION_LINKONCE flag so targetm.asm_out.named_section only
 223      emits this as a regular section.  Emit section before .group
 224      directive since Sun as treats undeclared sections as @progbits,
 225      which conflicts with .bss* sections which are @nobits.  */
 226   targetm.asm_out.named_section (section, flags & ~SECTION_LINKONCE, decl);
 227
 228   /* Sun as separates declaration of a group section and of the group
 229      itself, using the .group directive and the #comdat flag.  */
 230   fprintf (asm_out_file, "\t.group\t%s," SECTION_NAME_FORMAT ",#comdat\n",
 231            signature, section);
 232
 233   /* Unlike GNU as, group signature symbols need to be defined explicitly
 234      for Sun as.  With a few exceptions, this is already the case.  To
 235      identify the missing ones without changing the affected frontents,
 236      remember the signature symbols and emit those not marked
 237      TREE_SYMBOL_REFERENCED in solaris_file_end.  */
 238   if (!solaris_comdat_htab)
 239     solaris_comdat_htab = new hash_table<comdat_entry_hasher> (37);
 240
 241   entry.sig = signature;
 242   slot = solaris_comdat_htab->find_slot (&entry, INSERT);
 243
 244   if (*slot == NULL)
 245     {
 246       *slot = XCNEW (comdat_entry);
 247       /* Remember fragmented section name.  */
 248       (*slot)->name = section;
 249       /* Emit as regular section, .group declaration has already been done.  */
 250       (*slot)->flags = flags & ~SECTION_LINKONCE;
 251       (*slot)->decl = decl;
 252       (*slot)->sig = signature;
 253     }
 254 }
 255
 256 /* Define unreferenced COMDAT group signature symbol corresponding to SLOT.  */
 257
 258 int
 259 solaris_define_comdat_signature (comdat_entry **slot,
 260                                  void *aux ATTRIBUTE_UNUSED)
 261 {
 262   comdat_entry *entry = *slot;
 263   tree decl = entry->decl;
 264
 265   if (TREE_CODE (decl) != IDENTIFIER_NODE)
 266     decl = DECL_COMDAT_GROUP (decl);
 267
 268   if (!TREE_SYMBOL_REFERENCED (decl))
 269     {
 270       /* Switch to group section, otherwise Sun as complains
 271          `Group Id symbol defined outside of group'.  */
 272       switch_to_section (get_section (entry->name, entry->flags, entry->decl));
 273
 274       ASM_OUTPUT_LABEL (asm_out_file, entry->sig);
 275     }
 276
 277   /* Continue with scan.  */
 278   return 1;
 279 }
 280
 281 /* Emit unreferenced COMDAT group signature symbols for Sun as.  */
 282
 283 void
 284 solaris_file_end (void)
 285 {
 286   if (!solaris_comdat_htab)
 287     return;
 288
 289   solaris_comdat_htab->traverse <void *, solaris_define_comdat_signature>
 290     (NULL);
 291 }
 292
 293 void
 294 solaris_override_options (void)
 295 {
 296   /* Older versions of Solaris ld cannot handle CIE version 3 in .eh_frame.
 297      Don't emit DWARF3/4 unless specifically selected if so.  */
 298   if (!HAVE_LD_EH_FRAME_CIEV3 && !global_options_set.x_dwarf_version)
 299     dwarf_version = 2;
 300 }