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/* Subroutines for insn-output.c for Windows NT.

   Contributed by Douglas Rupp (drupp@cs.washington.edu)

   Copyright (C) 1995, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,

   2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.

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 "tm.h"

#include "rtl.h"

#include "regs.h"

#include "hard-reg-set.h"

#include "output.h"

#include "tree.h"

#include "flags.h"

#include "tm_p.h"

#include "toplev.h"

#include "hashtab.h"

#include "langhooks.h"

#include "ggc.h"

#include "target.h"

#include "lto-streamer.h"

/* i386/PE specific attribute support.

   i386/PE has two new attributes:

   dllexport - for exporting a function/variable that will live in a dll

   dllimport - for importing a function/variable from a dll

   Microsoft allows multiple declspecs in one __declspec, separating

   them with spaces.  We do NOT support this.  Instead, use __declspec

   multiple times.

*/

/* Handle a "shared" attribute;

   arguments as in struct attribute_spec.handler.  */

tree

ix86_handle_shared_attribute (tree *node, tree name,

                              tree args ATTRIBUTE_UNUSED,

                              int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)

{

  if (TREE_CODE (*node) != VAR_DECL)

    {

      warning (OPT_Wattributes, "%qE attribute only applies to variables",

               name);

      *no_add_attrs = true;

    }

  return NULL_TREE;

}

/* Handle a "selectany" attribute;

   arguments as in struct attribute_spec.handler.  */

tree

ix86_handle_selectany_attribute (tree *node, tree name,

                                 tree args ATTRIBUTE_UNUSED,

                                 int flags ATTRIBUTE_UNUSED,

                                 bool *no_add_attrs)

{

  /* The attribute applies only to objects that are initialized and have

     external linkage.  However, we may not know about initialization

     until the language frontend has processed the decl. We'll check for

     initialization later in encode_section_info.  */

  if (TREE_CODE (*node) != VAR_DECL || !TREE_PUBLIC (*node))

    {

      error ("%qE attribute applies only to initialized variables"

             " with external linkage", name);

      *no_add_attrs = true;

    }

  return NULL_TREE;

}

/* Return the type that we should use to determine if DECL is

   imported or exported.  */

static tree

associated_type (tree decl)

{

  return (DECL_CONTEXT (decl) && TYPE_P (DECL_CONTEXT (decl))

          ?  DECL_CONTEXT (decl) : NULL_TREE);

}

/* Return true if DECL should be a dllexport'd object.  */

static bool

i386_pe_determine_dllexport_p (tree decl)

{

  if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)

    return false;

  /* Don't export local clones of dllexports.  */

  if (!TREE_PUBLIC (decl))

    return false;

  if (lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))

    return true;

  return false;

}

/* Return true if DECL should be a dllimport'd object.  */

static bool

i386_pe_determine_dllimport_p (tree decl)

{

  tree assoc;

  if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)

    return false;

  if (DECL_DLLIMPORT_P (decl))

    return true;

  /* The DECL_DLLIMPORT_P flag was set for decls in the class definition

     by  targetm.cxx.adjust_class_at_definition.  Check again to emit

     error message if the class attribute has been overridden by an

     out-of-class definition of static data.  */

  assoc = associated_type (decl);

  if (assoc && lookup_attribute ("dllimport", TYPE_ATTRIBUTES (assoc))

      && TREE_CODE (decl) == VAR_DECL

      && TREE_STATIC (decl) && TREE_PUBLIC (decl)

      && !DECL_EXTERNAL (decl)

      /* vtable's are linkonce constants, so defining a vtable is not

         an error as long as we don't try to import it too.  */

      && !DECL_VIRTUAL_P (decl))

        error ("definition of static data member %q+D of "

               "dllimport'd class", decl);

  return false;

}

/* Handle the -mno-fun-dllimport target switch.  */

bool

i386_pe_valid_dllimport_attribute_p (const_tree decl)

{

   if (TARGET_NOP_FUN_DLLIMPORT && TREE_CODE (decl) == FUNCTION_DECL)

     return false;

   return true;

}

/* Return string which is the function name, identified by ID, modified

   with a suffix consisting of an atsign (@) followed by the number of

   bytes of arguments.  If ID is NULL use the DECL_NAME as base. If

   FASTCALL is true, also add the FASTCALL_PREFIX.

   Return NULL if no change required.  */

static tree

gen_stdcall_or_fastcall_suffix (tree decl, tree id, bool fastcall)

{

  HOST_WIDE_INT total = 0;

  const char *old_str = IDENTIFIER_POINTER (id != NULL_TREE ? id : DECL_NAME (decl));

  char *new_str, *p;

  tree type = TREE_TYPE (decl);

  tree arg;

  function_args_iterator args_iter;

  gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);

  if (prototype_p (type))

    {

      /* This attribute is ignored for variadic functions.  */

      if (stdarg_p (type))

        return NULL_TREE;

      /* Quit if we hit an incomplete type.  Error is reported

         by convert_arguments in c-typeck.c or cp/typeck.c.  */

      FOREACH_FUNCTION_ARGS(type, arg, args_iter)

        {

          HOST_WIDE_INT parm_size;

          HOST_WIDE_INT parm_boundary_bytes = PARM_BOUNDARY / BITS_PER_UNIT;

          if (! COMPLETE_TYPE_P (arg))

            break;

          parm_size = int_size_in_bytes (arg);

          if (parm_size < 0)

            break;

          /* Must round up to include padding.  This is done the same

             way as in store_one_arg.  */

          parm_size = ((parm_size + parm_boundary_bytes - 1)

                       / parm_boundary_bytes * parm_boundary_bytes);

          total += parm_size;

        }

      }

  /* Assume max of 8 base 10 digits in the suffix.  */

  p = new_str = XALLOCAVEC (char, 1 + strlen (old_str) + 1 + 8 + 1);

  if (fastcall)

    *p++ = FASTCALL_PREFIX;

  sprintf (p, "%s@" HOST_WIDE_INT_PRINT_DEC, old_str, total);

  return get_identifier (new_str);

}

/* Maybe decorate and get a new identifier for the DECL of a stdcall or

   fastcall function. The original identifier is supplied in ID. */

static tree

i386_pe_maybe_mangle_decl_assembler_name (tree decl, tree id)

{

  tree new_id = NULL_TREE;

  if (TREE_CODE (decl) == FUNCTION_DECL)

    {

      tree type_attributes = TYPE_ATTRIBUTES (TREE_TYPE (decl));

      if (lookup_attribute ("stdcall", type_attributes))

        new_id = gen_stdcall_or_fastcall_suffix (decl, id, false);

      else if (lookup_attribute ("fastcall", type_attributes))

        new_id = gen_stdcall_or_fastcall_suffix (decl, id, true);

    }

  return new_id;

}

/* This is used as a target hook to modify the DECL_ASSEMBLER_NAME

   in the language-independent default hook

   langhooks,c:lhd_set_decl_assembler_name ()

   and in cp/mangle,c:mangle_decl ().  */

tree

i386_pe_mangle_decl_assembler_name (tree decl, tree id)

{

  tree new_id = i386_pe_maybe_mangle_decl_assembler_name (decl, id);

  return (new_id ? new_id : id);

}

void

i386_pe_encode_section_info (tree decl, rtx rtl, int first)

{

  rtx symbol;

  int flags;

  /* Do this last, due to our frobbing of DECL_DLLIMPORT_P above.  */

  default_encode_section_info (decl, rtl, first);

  /* Careful not to prod global register variables.  */

  if (!MEM_P (rtl))

    return;

  symbol = XEXP (rtl, 0);

  gcc_assert (GET_CODE (symbol) == SYMBOL_REF);

  switch (TREE_CODE (decl))

    {

    case FUNCTION_DECL:

      /* FIXME:  Imported stdcall names are not modified by the Ada frontend.

         Check and decorate the RTL name now.  */

      if  (strcmp (lang_hooks.name, "GNU Ada") == 0)

        {

          tree new_id;

          tree old_id = DECL_ASSEMBLER_NAME (decl);

          const char* asm_str = IDENTIFIER_POINTER (old_id);

          /* Do not change the identifier if a verbatim asmspec

             or if stdcall suffix already added. */

          if (!(*asm_str == '*' || strchr (asm_str, '@'))

              && (new_id = i386_pe_maybe_mangle_decl_assembler_name (decl,

                                                                     old_id)))

            XSTR (symbol, 0) = IDENTIFIER_POINTER (new_id);

        }

      break;

    case VAR_DECL:

      if (lookup_attribute ("selectany", DECL_ATTRIBUTES (decl)))

        {

          if (DECL_INITIAL (decl)

              /* If an object is initialized with a ctor, the static

                 initialization and destruction code for it is present in

                 each unit defining the object.  The code that calls the

                 ctor is protected by a link-once guard variable, so that

                 the object still has link-once semantics,  */

              || TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (decl)))

            make_decl_one_only (decl, DECL_ASSEMBLER_NAME (decl));

          else

            error ("%q+D:'selectany' attribute applies only to "

                   "initialized objects", decl);

        }

      break;

    default:

      return;

    }

  /* Mark the decl so we can tell from the rtl whether the object is

     dllexport'd or dllimport'd.  tree.c: merge_dllimport_decl_attributes

     handles dllexport/dllimport override semantics.  */

  flags = (SYMBOL_REF_FLAGS (symbol) &

           ~(SYMBOL_FLAG_DLLIMPORT | SYMBOL_FLAG_DLLEXPORT));

  if (i386_pe_determine_dllexport_p (decl))

    flags |= SYMBOL_FLAG_DLLEXPORT;

  else if (i386_pe_determine_dllimport_p (decl))

    flags |= SYMBOL_FLAG_DLLIMPORT;

  SYMBOL_REF_FLAGS (symbol) = flags;

}

bool

i386_pe_binds_local_p (const_tree exp)

{

  /* PE does not do dynamic binding.  Indeed, the only kind of

     non-local reference comes from a dllimport'd symbol.  */

  if ((TREE_CODE (exp) == VAR_DECL || TREE_CODE (exp) == FUNCTION_DECL)

      && DECL_DLLIMPORT_P (exp))

    return false;

  /* Or a weak one, now that they are supported.  */

  if ((TREE_CODE (exp) == VAR_DECL || TREE_CODE (exp) == FUNCTION_DECL)

      && DECL_WEAK (exp))

    /* But x64 gets confused and attempts to use unsupported GOTPCREL

       relocations if we tell it the truth, so we still return true in

       that case until the deeper problem can be fixed.  */

    return (TARGET_64BIT && DEFAULT_ABI == MS_ABI);

  return true;

}

/* Also strip the fastcall prefix and stdcall suffix.  */

const char *

i386_pe_strip_name_encoding_full (const char *str)

{

  const char *p;

  const char *name = default_strip_name_encoding (str);

  /* Strip leading '@' on fastcall symbols.  */

  if (*name == '@')

    name++;

  /* Strip trailing "@n".  */

  p = strchr (name, '@');

  if (p)

    return ggc_alloc_string (name, p - name);

  return name;

}

void

i386_pe_unique_section (tree decl, int reloc)

{

  int len;

  const char *name, *prefix;

  char *string;

  name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));

  name = i386_pe_strip_name_encoding_full (name);

  /* The object is put in, for example, section .text$foo.

     The linker will then ultimately place them in .text

     (everything from the $ on is stripped). Don't put

     read-only data in .rdata section to avoid a PE linker

     bug when .rdata$* grouped sections are used in code

     without a .rdata section.  */

  if (TREE_CODE (decl) == FUNCTION_DECL)

    prefix = ".text$";

  else if (decl_readonly_section (decl, reloc))

    prefix = ".rdata$";

  else

    prefix = ".data$";

  len = strlen (name) + strlen (prefix);

  string = XALLOCAVEC (char, len + 1);

  sprintf (string, "%s%s", prefix, name);

  DECL_SECTION_NAME (decl) = build_string (len, string);

}

/* Select a set of attributes for section NAME based on the properties

   of DECL and whether or not RELOC indicates that DECL's initializer

   might contain runtime relocations.

   We make the section read-only and executable for a function decl,

   read-only for a const data decl, and writable for a non-const data decl.

   If the section has already been defined, to not allow it to have

   different attributes, as (1) this is ambiguous since we're not seeing

   all the declarations up front and (2) some assemblers (e.g. SVR4)

   do not recognize section redefinitions.  */

/* ??? This differs from the "standard" PE implementation in that we

   handle the SHARED variable attribute.  Should this be done for all

   PE targets?  */

#define SECTION_PE_SHARED       SECTION_MACH_DEP

unsigned int

i386_pe_section_type_flags (tree decl, const char *name, int reloc)

{

  static htab_t htab;

  unsigned int flags;

  unsigned int **slot;

  /* The names we put in the hashtable will always be the unique

     versions given to us by the stringtable, so we can just use

     their addresses as the keys.  */

  if (!htab)

    htab = htab_create (31, htab_hash_pointer, htab_eq_pointer, NULL);

  if (decl && TREE_CODE (decl) == FUNCTION_DECL)

    flags = SECTION_CODE;

  else if (decl && decl_readonly_section (decl, reloc))

    flags = 0;

  else if (current_function_decl

           && cfun

           && crtl->subsections.unlikely_text_section_name

           && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)

    flags = SECTION_CODE;

  else if (!decl

           && (!current_function_decl || !cfun)

           && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)

    flags = SECTION_CODE;

  else

    {

      flags = SECTION_WRITE;

      if (decl && TREE_CODE (decl) == VAR_DECL

          && lookup_attribute ("shared", DECL_ATTRIBUTES (decl)))

        flags |= SECTION_PE_SHARED;

    }

  if (decl && DECL_ONE_ONLY (decl))

    flags |= SECTION_LINKONCE;

  /* See if we already have an entry for this section.  */

  slot = (unsigned int **) htab_find_slot (htab, name, INSERT);

  if (!*slot)

    {

      *slot = (unsigned int *) xmalloc (sizeof (unsigned int));

      **slot = flags;

    }

  else

    {

      if (decl && **slot != flags)

        error ("%q+D causes a section type conflict", decl);

    }

  return flags;

}

void

i386_pe_asm_named_section (const char *name, unsigned int flags,

                           tree decl)

{

  char flagchars[8], *f = flagchars;

  if ((flags & (SECTION_CODE | SECTION_WRITE)) == 0)

    /* readonly data */

    {

      *f++ ='d';  /* This is necessary for older versions of gas.  */

      *f++ ='r';

    }

  else

    {

      if (flags & SECTION_CODE)

        *f++ = 'x';

      if (flags & SECTION_WRITE)

        *f++ = 'w';

      if (flags & SECTION_PE_SHARED)

        *f++ = 's';

    }

  /* LTO sections need 1-byte alignment to avoid confusing the

     zlib decompression algorithm with trailing zero pad bytes.  */

  if (strncmp (name, LTO_SECTION_NAME_PREFIX,

                        strlen (LTO_SECTION_NAME_PREFIX)) == 0)

    *f++ = '0';

  *f = '\0';

  fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);

  if (flags & SECTION_LINKONCE)

    {

      /* Functions may have been compiled at various levels of

         optimization so we can't use `same_size' here.

         Instead, have the linker pick one, without warning.

         If 'selectany' attribute has been specified,  MS compiler

         sets 'discard' characteristic, rather than telling linker

         to warn of size or content mismatch, so do the same.  */

      bool discard = (flags & SECTION_CODE)

                      || lookup_attribute ("selectany",

                                           DECL_ATTRIBUTES (decl));

      fprintf (asm_out_file, "\t.linkonce %s\n",

               (discard  ? "discard" : "same_size"));

    }

}

/* Beware, DECL may be NULL if compile_file() is emitting the LTO marker.  */

void

i386_pe_asm_output_aligned_decl_common (FILE *stream, tree decl,

                                        const char *name, HOST_WIDE_INT size,

                                        HOST_WIDE_INT align ATTRIBUTE_UNUSED)

{

  HOST_WIDE_INT rounded;

  /* Compute as in assemble_noswitch_variable, since we don't have

     support for aligned common on older binutils.  We must also

     avoid emitting a common symbol of size zero, as this is the

     overloaded representation that indicates an undefined external

     symbol in the PE object file format.  */

  rounded = size ? size : 1;

  rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;

  rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)

             * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));

  i386_pe_maybe_record_exported_symbol (decl, name, 1);

  fprintf (stream, "\t.comm\t");

  assemble_name (stream, name);

  if (use_pe_aligned_common)

    fprintf (stream, ", " HOST_WIDE_INT_PRINT_DEC ", %d\n",

           size ? size : (HOST_WIDE_INT) 1,

           exact_log2 (align) - exact_log2 (CHAR_BIT));

  else

    fprintf (stream, ", " HOST_WIDE_INT_PRINT_DEC "\t" ASM_COMMENT_START

           " " HOST_WIDE_INT_PRINT_DEC "\n", rounded, size);

}

/* The Microsoft linker requires that every function be marked as

   DT_FCN.  When using gas on cygwin, we must emit appropriate .type

   directives.  */

#include "gsyms.h"

/* Mark a function appropriately.  This should only be called for

   functions for which we are not emitting COFF debugging information.

   FILE is the assembler output file, NAME is the name of the

   function, and PUB is nonzero if the function is globally

   visible.  */

void

i386_pe_declare_function_type (FILE *file, const char *name, int pub)

{

  fprintf (file, "\t.def\t");

  assemble_name (file, name);

  fprintf (file, ";\t.scl\t%d;\t.type\t%d;\t.endef\n",

           pub ? (int) C_EXT : (int) C_STAT,

           (int) DT_FCN << N_BTSHFT);

}

/* Keep a list of external functions.  */

struct GTY(()) extern_list

{

  struct extern_list *next;

  tree decl;

  const char *name;

};

static GTY(()) struct extern_list *extern_head;

/* Assemble an external function reference.  We need to keep a list of

   these, so that we can output the function types at the end of the

   assembly.  We can't output the types now, because we might see a

   definition of the function later on and emit debugging information

   for it then.  */

void

i386_pe_record_external_function (tree decl, const char *name)

{

  struct extern_list *p;

  p = (struct extern_list *) ggc_alloc (sizeof *p);

  p->next = extern_head;

  p->decl = decl;

  p->name = name;

  extern_head = p;

}

/* Keep a list of exported symbols.  */

struct GTY(()) export_list

{

  struct export_list *next;

  const char *name;

  int is_data;          /* used to type tag exported symbols.  */

};

static GTY(()) struct export_list *export_head;

/* Assemble an export symbol entry.  We need to keep a list of

   these, so that we can output the export list at the end of the

   assembly.  We used to output these export symbols in each function,

   but that causes problems with GNU ld when the sections are

   linkonce.  Beware, DECL may be NULL if compile_file() is emitting

   the LTO marker.  */

void

i386_pe_maybe_record_exported_symbol (tree decl, const char *name, int is_data)

{

  rtx symbol;

  struct export_list *p;

  if (!decl)

    return;

  symbol = XEXP (DECL_RTL (decl), 0);

  gcc_assert (GET_CODE (symbol) == SYMBOL_REF);

  if (!SYMBOL_REF_DLLEXPORT_P (symbol))

    return;

  gcc_assert (TREE_PUBLIC (decl));

  p = (struct export_list *) ggc_alloc (sizeof *p);

  p->next = export_head;

  p->name = name;

  p->is_data = is_data;

  export_head = p;

}

#ifdef CXX_WRAP_SPEC_LIST

/*  Hash table equality helper function.  */

static int

wrapper_strcmp (const void *x, const void *y)

{

  return !strcmp ((const char *) x, (const char *) y);

}

/* Search for a function named TARGET in the list of library wrappers

   we are using, returning a pointer to it if found or NULL if not.

   This function might be called on quite a few symbols, and we only

   have the list of names of wrapped functions available to us as a

   spec string, so first time round we lazily initialise a hash table

   to make things quicker.  */

static const char *

i386_find_on_wrapper_list (const char *target)

{

  static char first_time = 1;

  static htab_t wrappers;

  if (first_time)

    {

      /* Beware that this is not a complicated parser, it assumes

         that any sequence of non-whitespace beginning with an

         underscore is one of the wrapped symbols.  For now that's

         adequate to distinguish symbols from spec substitutions

         and command-line options.  */

      static char wrapper_list_buffer[] = CXX_WRAP_SPEC_LIST;

      char *bufptr;

      /* Breaks up the char array into separated strings

         strings and enter them into the hash table.  */

      wrappers = htab_create_alloc (8, htab_hash_string, wrapper_strcmp,

        0, xcalloc, free);

      for (bufptr = wrapper_list_buffer; *bufptr; ++bufptr)

        {

          char *found = NULL;

          if (ISSPACE (*bufptr))

            continue;

          if (*bufptr == '_')

            found = bufptr;

          while (*bufptr && !ISSPACE (*bufptr))

            ++bufptr;

          if (*bufptr)

            *bufptr = 0;

          if (found)

            *htab_find_slot (wrappers, found, INSERT) = found;

        }

      first_time = 0;

    }

  return (const char *) htab_find (wrappers, target);

}

#endif /* CXX_WRAP_SPEC_LIST */

/* This is called at the end of assembly.  For each external function

   which has not been defined, we output a declaration now.  We also

   output the .drectve section.  */

void

i386_pe_file_end (void)

{

  struct extern_list *p;

  for (p = extern_head; p != NULL; p = p->next)

    {

      tree decl;

      decl = p->decl;

      /* Positively ensure only one declaration for any given symbol.  */

      if (! TREE_ASM_WRITTEN (decl)

          && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))

        {

#ifdef CXX_WRAP_SPEC_LIST

          /* To ensure the DLL that provides the corresponding real

             functions is still loaded at runtime, we must reference

             the real function so that an (unused) import is created.  */

          const char *realsym = i386_find_on_wrapper_list (p->name);