text: /* General Solaris system support.
     Copyright (C) 2004-2017 Free Software Foundation, Inc.
     Contributed by CodeSourcery, LLC.
  
  This file is part of GCC.
  
  GCC is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 3, or (at your option)
  any later version.
  
  GCC is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with GCC; see the file COPYING3.  If not see
  <http://www.gnu.org/licenses/>.  */
  
  #include "config.h"
  #include "system.h"
  #include "coretypes.h"
  #include "target.h"
  #include "rtl.h"
  #include "tree.h"
  #include "memmodel.h"
  #include "tm_p.h"
  #include "stringpool.h"
  #include "diagnostic-core.h"
  #include "varasm.h"
  #include "output.h"
  
  tree solaris_pending_aligns, solaris_pending_inits, solaris_pending_finis;
  
  /* Attach any pending attributes for DECL to the list in *ATTRIBUTES.
     Pending attributes come from #pragma or _Pragma, so this code is
     only useful in the C family front ends, but it is included in
     all languages to avoid changing the target machine initializer
     depending on the language.  */
  
  void
  solaris_insert_attributes (tree decl, tree *attributes)
  {
    tree *x, next;
  
    if (solaris_pending_aligns != NULL && TREE_CODE (decl) == VAR_DECL)
      for (x = &solaris_pending_aligns; *x; x = &TREE_CHAIN (*x))
        {
  	tree name = TREE_PURPOSE (*x);
  	tree value = TREE_VALUE (*x);
  	if (DECL_NAME (decl) == name)
  	  {
  	    if (lookup_attribute ("aligned", DECL_ATTRIBUTES (decl))
  		|| lookup_attribute ("aligned", *attributes))
  	      warning (0, "ignoring %<#pragma align%> for explicitly "
  		       "aligned %q+D", decl);
  	    else
  	      *attributes = tree_cons (get_identifier ("aligned"), value,
  				       *attributes);
  	    next = TREE_CHAIN (*x);
  	    ggc_free (*x);
  	    *x = next;
  	    break;
  	  }
        }
  
    if (solaris_pending_inits != NULL && TREE_CODE (decl) == FUNCTION_DECL)
      for (x = &solaris_pending_inits; *x; x = &TREE_CHAIN (*x))
        {
  	tree name = TREE_PURPOSE (*x);
  	if (DECL_NAME (decl) == name)
  	  {
  	    *attributes = tree_cons (get_identifier ("init"), NULL,
  				     *attributes);
  	    TREE_USED (decl) = 1;
  	    DECL_PRESERVE_P (decl) = 1;
  	    next = TREE_CHAIN (*x);
  	    ggc_free (*x);
  	    *x = next;
  	    break;
  	  }
        }
  
    if (solaris_pending_finis != NULL && TREE_CODE (decl) == FUNCTION_DECL)
      for (x = &solaris_pending_finis; *x; x = &TREE_CHAIN (*x))
        {
  	tree name = TREE_PURPOSE (*x);
  	if (DECL_NAME (decl) == name)
  	  {
  	    *attributes = tree_cons (get_identifier ("fini"), NULL,
  				     *attributes);
  	    TREE_USED (decl) = 1;
  	    DECL_PRESERVE_P (decl) = 1;
  	    next = TREE_CHAIN (*x);
  	    ggc_free (*x);
  	    *x = next;
  	    break;
  	  }
        }
  }
  
  /* Output initializer or finalizer entries for DECL to FILE.  */
  
  void
  solaris_output_init_fini (FILE *file, tree decl)
  {
    if (lookup_attribute ("init", DECL_ATTRIBUTES (decl)))
      {
        fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".init");
        ASM_OUTPUT_CALL (file, decl);
        fprintf (file, "\t.popsection\n");
      }
  
    if (lookup_attribute ("fini", DECL_ATTRIBUTES (decl)))
      {
        fprintf (file, "\t.pushsection\t" SECTION_NAME_FORMAT "\n", ".fini");
        ASM_OUTPUT_CALL (file, decl);
        fprintf (file, "\t.popsection\n");
      }
  }
  
  /* Emit an assembler directive to set symbol for DECL visibility to
     the visibility type VIS, which must not be VISIBILITY_DEFAULT.  */
  
  void
  solaris_assemble_visibility (tree decl, int vis ATTRIBUTE_UNUSED)
  {
  #ifdef HAVE_GAS_HIDDEN
    /* Sun as uses .symbolic for STV_PROTECTED.  STV_INTERNAL is marked as
       `currently reserved', but the linker treats it like STV_HIDDEN.  Sun
       Studio 12.1 cc emits .hidden instead.
  
       There are 3 Sun extensions GCC doesn't yet know about: STV_EXPORTED,
       STV_SINGLETON, and STV_ELIMINATE.
  
       See Linker and Libraries Guide, Ch. 2, Link-Editor, Defining
       Additional Symbols, and Ch. 7, Object-File Format, Symbol Table
       Section.  */
  
    static const char * const visibility_types[] = {
      NULL, "symbolic", "hidden", "hidden"
    };
  
    const char *name, *type;
    tree id = DECL_ASSEMBLER_NAME (decl);
  
    while (IDENTIFIER_TRANSPARENT_ALIAS (id))
      id = TREE_CHAIN (id);
    name = IDENTIFIER_POINTER (id);
    type = visibility_types[vis];
  
    fprintf (asm_out_file, "\t.%s\t", type);
    assemble_name (asm_out_file, name);
    fprintf (asm_out_file, "\n");
  #else
    if (!DECL_ARTIFICIAL (decl))
      warning (OPT_Wattributes, "visibility attribute not supported "
  			      "in this configuration; ignored");
  #endif
  }
  
  /* Group section information entry stored in solaris_comdat_htab.  */
  
  typedef struct comdat_entry
  {
    const char *name;
    unsigned int flags;
    tree decl;
    const char *sig;
  } comdat_entry;
  
  /* Helpers for maintaining solaris_comdat_htab.  */
  
  struct comdat_entry_hasher : nofree_ptr_hash <comdat_entry>
  {
    static inline hashval_t hash (const comdat_entry *);
    static inline bool equal (const comdat_entry *, const comdat_entry *);
    static inline void remove (comdat_entry *);
  };
  
  inline hashval_t
  comdat_entry_hasher::hash (const comdat_entry *entry)
  {
    return htab_hash_string (entry->sig);
  }
  
  inline bool
  comdat_entry_hasher::equal (const comdat_entry *entry1,
  			    const comdat_entry *entry2)
  {
    return strcmp (entry1->sig, entry2->sig) == 0;
  }
  
  /* Hash table of group signature symbols.  */
  
  static hash_table<comdat_entry_hasher> *solaris_comdat_htab;
  
  /* Output assembly to switch to COMDAT group section NAME with attributes
     FLAGS and group signature symbol DECL, using Sun as syntax.  */
  
  void
  solaris_elf_asm_comdat_section (const char *name, unsigned int flags, tree decl)
  {
    const char *signature;
    char *section;
    comdat_entry entry, **slot;
  
    if (TREE_CODE (decl) == IDENTIFIER_NODE)
      signature = IDENTIFIER_POINTER (decl);
    else
      signature = IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl));
  
    /* Sun as requires group sections to be fragmented, i.e. to have names of
       the form <section>%<fragment>.  Strictly speaking this is only
       necessary to support cc -xF, but is enforced globally in violation of
       the ELF gABI.  We keep the section names generated by GCC (generally
       of the form .text.<signature>) and append %<signature> to pacify as,
       despite the redundancy.  */
    section = concat (name, "%", signature, NULL);
  
    /* Clear SECTION_LINKONCE flag so targetm.asm_out.named_section only
       emits this as a regular section.  Emit section before .group
       directive since Sun as treats undeclared sections as @progbits,
       which conflicts with .bss* sections which are @nobits.  */
    targetm.asm_out.named_section (section, flags & ~SECTION_LINKONCE, decl);
    
    /* Sun as separates declaration of a group section and of the group
       itself, using the .group directive and the #comdat flag.  */
    fprintf (asm_out_file, "\t.group\t%s," SECTION_NAME_FORMAT ",#comdat\n",
  	   signature, section);
  
    /* Unlike GNU as, group signature symbols need to be defined explicitly
       for Sun as.  With a few exceptions, this is already the case.  To
       identify the missing ones without changing the affected frontents,
       remember the signature symbols and emit those not marked
       TREE_SYMBOL_REFERENCED in solaris_file_end.  */
    if (!solaris_comdat_htab)
      solaris_comdat_htab = new hash_table<comdat_entry_hasher> (37);
  
    entry.sig = signature;
    slot = solaris_comdat_htab->find_slot (&entry, INSERT);
  
    if (*slot == NULL)
      {
        *slot = XCNEW (comdat_entry);
        /* Remember fragmented section name.  */
        (*slot)->name = section;
        /* Emit as regular section, .group declaration has already been done.  */
        (*slot)->flags = flags & ~SECTION_LINKONCE;
        (*slot)->decl = decl;
        (*slot)->sig = signature;
      }
  }
  
  /* Define unreferenced COMDAT group signature symbol corresponding to SLOT.  */
  
  int
  solaris_define_comdat_signature (comdat_entry **slot,
  				 void *aux ATTRIBUTE_UNUSED)
  {
    comdat_entry *entry = *slot;
    tree decl = entry->decl;
  
    if (TREE_CODE (decl) != IDENTIFIER_NODE)
      decl = DECL_COMDAT_GROUP (decl);
  
    if (!TREE_SYMBOL_REFERENCED (decl))
      {
        /* Switch to group section, otherwise Sun as complains
  	 `Group Id symbol defined outside of group'.  */
        switch_to_section (get_section (entry->name, entry->flags, entry->decl));
  
        ASM_OUTPUT_LABEL (asm_out_file, entry->sig);
      }
  
    /* Continue with scan.  */
    return 1;
  }
  
  /* Emit unreferenced COMDAT group signature symbols for Sun as.  */
  
  void
  solaris_file_end (void)
  {
    if (!solaris_comdat_htab)
      return;
  
    solaris_comdat_htab->traverse <void *, solaris_define_comdat_signature>
      (NULL);
  }
  
  void
  solaris_override_options (void)
  {
    /* Older versions of Solaris ld cannot handle CIE version 3 in .eh_frame.
       Don't emit DWARF3/4 unless specifically selected if so.  */
    if (!HAVE_LD_EH_FRAME_CIEV3 && !global_options_set.x_dwarf_version)
      dwarf_version = 2;
  }
  