gcc/config/sol2.c

   1 /* General Solaris system support.
   2    Copyright (C) 2004-2015 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 "input.h"
  25 #include "alias.h"
  26 #include "symtab.h"
  27 #include "options.h"
  28 #include "tree.h"
  29 #include "stringpool.h"
  30 #include "varasm.h"
  31 #include "output.h"
  32 #include "tm.h"
  33 #include "rtl.h"
  34 #include "target.h"
  35 #include "tm_p.h"
  36 #include "diagnostic-core.h"
  37
  38 tree solaris_pending_aligns, solaris_pending_inits, solaris_pending_finis;
  39
  40 /* Attach any pending attributes for DECL to the list in *ATTRIBUTES.
  41    Pending attributes come from #pragma or _Pragma, so this code is
  42    only useful in the C family front ends, but it is included in
  43    all languages to avoid changing the target machine initializer
  44    depending on the language.  */
  45
  46 void
  47 solaris_insert_attributes (tree decl, tree *attributes)
  48 {
  49   tree *x, next;
  50
  51   if (solaris_pending_aligns != NULL && TREE_CODE (decl) == VAR_DECL)
  52     for (x = &solaris_pending_aligns; *x; x = &TREE_CHAIN (*x))
  53       {
  54         tree name = TREE_PURPOSE (*x);
  55         tree value = TREE_VALUE (*x);
  56         if (DECL_NAME (decl) == name)
  57           {
  58             if (lookup_attribute ("aligned", DECL_ATTRIBUTES (decl))
  59                 || lookup_attribute ("aligned", *attributes))
  60               warning (0, "ignoring %<#pragma align%> for explicitly "
  61                        "aligned %q+D", decl);
  62             else
  63               *attributes = tree_cons (get_identifier ("aligned"), value,
  64                                        *attributes);
  65             next = TREE_CHAIN (*x);
  66             ggc_free (*x);
  67             *x = next;
  68             break;
  69           }
  70       }
  71
  72   if (solaris_pending_inits != NULL && TREE_CODE (decl) == FUNCTION_DECL)
  73     for (x = &solaris_pending_inits; *x; x = &TREE_CHAIN (*x))
  74       {
  75         tree name = TREE_PURPOSE (*x);
  76         if (DECL_NAME (decl) == name)
  77           {
  78             *attributes = tree_cons (get_identifier ("init"), NULL,
  79                                      *attributes);
  80             TREE_USED (decl) = 1;
  81             DECL_PRESERVE_P (decl) = 1;
  82             next = TREE_CHAIN (*x);
  83             ggc_free (*x);
  84             *x = next;
  85             break;
  86           }
  87       }
  88
  89   if (solaris_pending_finis != NULL && TREE_CODE (decl) == FUNCTION_DECL)
  90     for (x = &solaris_pending_finis; *x; x = &TREE_CHAIN (*x))
  91       {
  92         tree name = TREE_PURPOSE (*x);
  93         if (DECL_NAME (decl) == name)
  94           {
  95             *attributes = tree_cons (get_identifier ("fini"), NULL,
  96                                      *attributes);
  97             TREE_USED (decl) = 1;
  98             DECL_PRESERVE_P (decl) = 1;
  99             next = TREE_CHAIN (*x);
 100             ggc_free (*x);
 101             *x = next;
 102             break;
 103           }
 104       }
 105 }
 106
 107 /* Output initializer or finalizer entries for DECL to FILE.  */
 108
 109 void
 110 solaris_output_init_fini (FILE *file, tree decl)
 111 {
 112   if (lookup_attribute ("init", DECL_ATTRIBUTES (decl)))
 113     {
 114       fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".init");
 115       ASM_OUTPUT_CALL (file, decl);
 116       fprintf (file, "\t.popsection\n");
 117     }
 118
 119   if (lookup_attribute ("fini", DECL_ATTRIBUTES (decl)))
 120     {
 121       fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".fini");
 122       ASM_OUTPUT_CALL (file, decl);
 123       fprintf (file, "\t.popsection\n");
 124     }
 125 }
 126
 127 /* Emit an assembler directive to set symbol for DECL visibility to
 128    the visibility type VIS, which must not be VISIBILITY_DEFAULT.  */
 129
 130 void
 131 solaris_assemble_visibility (tree decl, int vis ATTRIBUTE_UNUSED)
 132 {
 133 #ifdef HAVE_GAS_HIDDEN
 134   /* Sun as uses .symbolic for STV_PROTECTED.  STV_INTERNAL is marked as
 135      `currently reserved', but the linker treats it like STV_HIDDEN.  Sun
 136      Studio 12.1 cc emits .hidden instead.
 137
 138      There are 3 Sun extensions GCC doesn't yet know about: STV_EXPORTED,
 139      STV_SINGLETON, and STV_ELIMINATE.
 140
 141      See Linker and Libraries Guide, Ch. 2, Link-Editor, Defining
 142      Additional Symbols, and Ch. 7, Object-File Format, Symbol Table
 143      Section.  */
 144
 145   static const char * const visibility_types[] = {
 146     NULL, "symbolic", "hidden", "hidden"
 147   };
 148
 149   const char *name, *type;
 150
 151   name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 152   type = visibility_types[vis];
 153
 154   fprintf (asm_out_file, "\t.%s\t", type);
 155   assemble_name (asm_out_file, name);
 156   fprintf (asm_out_file, "\n");
 157 #else
 158   if (!DECL_ARTIFICIAL (decl))
 159     warning (OPT_Wattributes, "visibility attribute not supported "
 160                               "in this configuration; ignored");
 161 #endif
 162 }
 163
 164 /* Group section information entry stored in solaris_comdat_htab.  */
 165
 166 typedef struct comdat_entry
 167 {
 168   const char *name;
 169   unsigned int flags;
 170   tree decl;
 171   const char *sig;
 172 } comdat_entry;
 173
 174 /* Helpers for maintaining solaris_comdat_htab.  */
 175
 176 struct comdat_entry_hasher : typed_noop_remove <comdat_entry>
 177 {
 178   typedef comdat_entry *value_type;
 179   typedef comdat_entry *compare_type;
 180   static inline hashval_t hash (const comdat_entry *);
 181   static inline bool equal (const comdat_entry *, const comdat_entry *);
 182   static inline void remove (comdat_entry *);
 183 };
 184
 185 inline hashval_t
 186 comdat_entry_hasher::hash (const comdat_entry *entry)
 187 {
 188   return htab_hash_string (entry->sig);
 189 }
 190
 191 inline bool
 192 comdat_entry_hasher::equal (const comdat_entry *entry1,
 193                             const comdat_entry *entry2)
 194 {
 195   return strcmp (entry1->sig, entry2->sig) == 0;
 196 }
 197
 198 /* Hash table of group signature symbols.  */
 199
 200 static hash_table<comdat_entry_hasher> *solaris_comdat_htab;
 201
 202 /* Output assembly to switch to COMDAT group section NAME with attributes
 203    FLAGS and group signature symbol DECL, using Sun as syntax.  */
 204
 205 void
 206 solaris_elf_asm_comdat_section (const char *name, unsigned int flags, tree decl)
 207 {
 208   const char *signature;
 209   char *section;
 210   comdat_entry entry, **slot;
 211
 212   if (TREE_CODE (decl) == IDENTIFIER_NODE)
 213     signature = IDENTIFIER_POINTER (decl);
 214   else
 215     signature = IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl));
 216
 217   /* Sun as requires group sections to be fragmented, i.e. to have names of
 218      the form <section>%<fragment>.  Strictly speaking this is only
 219      necessary to support cc -xF, but is enforced globally in violation of
 220      the ELF gABI.  We keep the section names generated by GCC (generally
 221      of the form .text.<signature>) and append %<signature> to pacify as,
 222      despite the redundancy.  */
 223   section = concat (name, "%", signature, NULL);
 224
 225   /* Clear SECTION_LINKONCE flag so targetm.asm_out.named_section only
 226      emits this as a regular section.  Emit section before .group
 227      directive since Sun as treats undeclared sections as @progbits,
 228      which conflicts with .bss* sections which are @nobits.  */
 229   targetm.asm_out.named_section (section, flags & ~SECTION_LINKONCE, decl);
 230
 231   /* Sun as separates declaration of a group section and of the group
 232      itself, using the .group directive and the #comdat flag.  */
 233   fprintf (asm_out_file, "\t.group\t%s," SECTION_NAME_FORMAT ",#comdat\n",
 234            signature, section);
 235
 236   /* Unlike GNU as, group signature symbols need to be defined explicitly
 237      for Sun as.  With a few exceptions, this is already the case.  To
 238      identify the missing ones without changing the affected frontents,
 239      remember the signature symbols and emit those not marked
 240      TREE_SYMBOL_REFERENCED in solaris_file_end.  */
 241   if (!solaris_comdat_htab)
 242     solaris_comdat_htab = new hash_table<comdat_entry_hasher> (37);
 243
 244   entry.sig = signature;
 245   slot = solaris_comdat_htab->find_slot (&entry, INSERT);
 246
 247   if (*slot == NULL)
 248     {
 249       *slot = XCNEW (comdat_entry);
 250       /* Remember fragmented section name.  */
 251       (*slot)->name = section;
 252       /* Emit as regular section, .group declaration has already been done.  */
 253       (*slot)->flags = flags & ~SECTION_LINKONCE;
 254       (*slot)->decl = decl;
 255       (*slot)->sig = signature;
 256     }
 257 }
 258
 259 /* Define unreferenced COMDAT group signature symbol corresponding to SLOT.  */
 260
 261 int
 262 solaris_define_comdat_signature (comdat_entry **slot,
 263                                  void *aux ATTRIBUTE_UNUSED)
 264 {
 265   comdat_entry *entry = *slot;
 266   tree decl = entry->decl;
 267
 268   if (TREE_CODE (decl) != IDENTIFIER_NODE)
 269     decl = DECL_COMDAT_GROUP (decl);
 270
 271   if (!TREE_SYMBOL_REFERENCED (decl))
 272     {
 273       /* Switch to group section, otherwise Sun as complains
 274          `Group Id symbol defined outside of group'.  */
 275       switch_to_section (get_section (entry->name, entry->flags, entry->decl));
 276
 277       ASM_OUTPUT_LABEL (asm_out_file, entry->sig);
 278     }
 279
 280   /* Continue with scan.  */
 281   return 1;
 282 }
 283
 284 /* Emit unreferenced COMDAT group signature symbols for Sun as.  */
 285
 286 void
 287 solaris_file_end (void)
 288 {
 289   if (!solaris_comdat_htab)
 290     return;
 291
 292   solaris_comdat_htab->traverse <void *, solaris_define_comdat_signature>
 293     (NULL);
 294 }
 295
 296 void
 297 solaris_override_options (void)
 298 {
 299   /* Older versions of Solaris ld cannot handle CIE version 3 in .eh_frame.
 300      Don't emit DWARF3/4 unless specifically selected if so.  */
 301   if (!HAVE_LD_EH_FRAME_CIEV3 && !global_options_set.x_dwarf_version)
 302     dwarf_version = 2;
 303 }