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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  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 "ggc.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.

*/

static tree associated_type (tree);

static tree gen_stdcall_or_fastcall_suffix (tree, bool);

static bool i386_pe_dllexport_p (tree);

static bool i386_pe_dllimport_p (tree);

static void i386_pe_mark_dllexport (tree);

static void i386_pe_mark_dllimport (tree);

/* This is we how mark internal identifiers with dllimport or dllexport

   attributes.  */

#ifndef DLL_IMPORT_PREFIX

#define DLL_IMPORT_PREFIX "#i."

#endif

#ifndef DLL_EXPORT_PREFIX

#define DLL_EXPORT_PREFIX "#e."

#endif

/* 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, "%qs attribute only applies to variables",

               IDENTIFIER_POINTER (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 ("%qs attribute applies only to initialized variables"

             " with external linkage",  IDENTIFIER_POINTER (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 is a dllexport'd object.  */

static bool

i386_pe_dllexport_p (tree decl)

{

  if (TREE_CODE (decl) != VAR_DECL

       && TREE_CODE (decl) != FUNCTION_DECL)

    return false;

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

    return true;

  /* Also mark class members of exported classes with dllexport.  */

  if (associated_type (decl)

      && lookup_attribute ("dllexport",

                            TYPE_ATTRIBUTES (associated_type (decl))))

    return i386_pe_type_dllexport_p (decl);

  return false;

}

static bool

i386_pe_dllimport_p (tree decl)

{

  if (TREE_CODE (decl) != VAR_DECL

       && TREE_CODE (decl) != FUNCTION_DECL)

    return false;

  /* Lookup the attribute in addition to checking the DECL_DLLIMPORT_P flag.

     We may need to override an earlier decision.  */

  if (DECL_DLLIMPORT_P (decl)

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

    {

       /* Make a final check to see if this is a definition before we generate

          RTL for an indirect reference.  */

       if (!DECL_EXTERNAL (decl))

        {

          error ("%q+D: definition is marked as dllimport", decl);

          DECL_DLLIMPORT_P (decl) = 0;

          return false;

        }

      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

     warnings if the class attribute has been overridden by an

     out-of-class definition.  */

  else if (associated_type (decl)

           && lookup_attribute ("dllimport",

                                TYPE_ATTRIBUTES (associated_type (decl))))

    return i386_pe_type_dllimport_p (decl);

  return false;

}

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

bool

i386_pe_valid_dllimport_attribute_p (tree decl)

{

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

     return false;

   return true;

}

/* Return nonzero if SYMBOL is marked as being dllexport'd.  */

int

i386_pe_dllexport_name_p (const char *symbol)

{

  return (strncmp (DLL_EXPORT_PREFIX, symbol,

                   strlen (DLL_EXPORT_PREFIX)) == 0);

}

/* Return nonzero if SYMBOL is marked as being dllimport'd.  */

int

i386_pe_dllimport_name_p (const char *symbol)

{

  return (strncmp (DLL_IMPORT_PREFIX, symbol,

                   strlen (DLL_IMPORT_PREFIX)) == 0);

}

/* Mark a DECL as being dllexport'd.

   Note that we override the previous setting (e.g.: dllimport).  */

static void

i386_pe_mark_dllexport (tree decl)

{

  const char *oldname;

  char  *newname;

  rtx rtlname;

  rtx symref;

  tree idp;

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

  if (GET_CODE (rtlname) == MEM)

    rtlname = XEXP (rtlname, 0);

  gcc_assert (GET_CODE (rtlname) == SYMBOL_REF);

  oldname = XSTR (rtlname, 0);

  if (i386_pe_dllimport_name_p (oldname))

    {

      warning (0, "inconsistent dll linkage for %q+D, dllexport assumed",

               decl);

     /* Remove DLL_IMPORT_PREFIX.  */

      oldname += strlen (DLL_IMPORT_PREFIX);

    }

  else if (i386_pe_dllexport_name_p (oldname))

    return;  /*  already done  */

  newname = alloca (strlen (DLL_EXPORT_PREFIX) + strlen (oldname) + 1);

  sprintf (newname, "%s%s", DLL_EXPORT_PREFIX, oldname);

  /* We pass newname through get_identifier to ensure it has a unique

     address.  RTL processing can sometimes peek inside the symbol ref

     and compare the string's addresses to see if two symbols are

     identical.  */

  idp = get_identifier (newname);

  symref = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));

  SET_SYMBOL_REF_DECL (symref, decl);

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

}

/* Mark a DECL as being dllimport'd.  */

static void

i386_pe_mark_dllimport (tree decl)

{

  const char *oldname;

  char  *newname;

  tree idp;

  rtx rtlname, newrtl;

  rtx symref;

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

  if (GET_CODE (rtlname) == MEM)

    rtlname = XEXP (rtlname, 0);

  gcc_assert (GET_CODE (rtlname) == SYMBOL_REF);

  oldname = XSTR (rtlname, 0);

  if (i386_pe_dllexport_name_p (oldname))

    {

      error ("%qs declared as both exported to and imported from a DLL",

             IDENTIFIER_POINTER (DECL_NAME (decl)));

      return;

    }

  else if (i386_pe_dllimport_name_p (oldname))

    {

      /* Already done, but do a sanity check to prevent assembler

         errors.  */

      gcc_assert (DECL_EXTERNAL (decl) && TREE_PUBLIC (decl)

                  && DECL_DLLIMPORT_P (decl));

      return;

    }

  newname = alloca (strlen (DLL_IMPORT_PREFIX) + strlen (oldname) + 1);

  sprintf (newname, "%s%s", DLL_IMPORT_PREFIX, oldname);

  /* We pass newname through get_identifier to ensure it has a unique

     address.  RTL processing can sometimes peek inside the symbol ref

     and compare the string's addresses to see if two symbols are

     identical.  */

  idp = get_identifier (newname);

  symref = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));

  SET_SYMBOL_REF_DECL (symref, decl);

  newrtl = gen_rtx_MEM (Pmode,symref);

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

  DECL_DLLIMPORT_P (decl) = 1;

}

/* Return string which is the former assembler name modified with a

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

   arguments.  If FASTCALL is true, also add the FASTCALL_PREFIX.  */

static tree

gen_stdcall_or_fastcall_suffix (tree decl, bool fastcall)

{

  int total = 0;

  /* ??? This probably should use XSTR (XEXP (DECL_RTL (decl), 0), 0) instead

     of DECL_ASSEMBLER_NAME.  */

   const char *asmname =  IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));

  char *newsym;

  char *p;

  tree formal_type;

  /* Do not change the identifier if a verbatim asmspec or already done. */

  if (*asmname == '*' || strchr (asmname, '@'))

    return DECL_ASSEMBLER_NAME (decl);

  formal_type = TYPE_ARG_TYPES (TREE_TYPE (decl));

  if (formal_type != NULL_TREE)

    {

      /* These attributes are ignored for variadic functions in

         i386.c:ix86_return_pops_args. For compatibility with MS

         compiler do not add @0 suffix here.  */

      if (TREE_VALUE (tree_last (formal_type)) != void_type_node)

        return DECL_ASSEMBLER_NAME (decl);

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

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

      while (TREE_VALUE (formal_type) != void_type_node

             && COMPLETE_TYPE_P (TREE_VALUE (formal_type)))

        {

          int parm_size

            = TREE_INT_CST_LOW (TYPE_SIZE (TREE_VALUE (formal_type)));

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

               way as in store_one_arg.  */

          parm_size = ((parm_size + PARM_BOUNDARY - 1)

                       / PARM_BOUNDARY * PARM_BOUNDARY);

          total += parm_size;

          formal_type = TREE_CHAIN (formal_type);\

        }

     }

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

  newsym = alloca (1 + strlen (asmname) + 1 + 8 + 1);

  p = newsym;

  if (fastcall)

    *p++ = FASTCALL_PREFIX;

  sprintf (p, "%s@%d", asmname, total/BITS_PER_UNIT);

  return get_identifier (newsym);

}

void

i386_pe_encode_section_info (tree decl, rtx rtl, int first)

{

  default_encode_section_info (decl, rtl, first);

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

    {

      tree type_attributes = TYPE_ATTRIBUTES (TREE_TYPE (decl));

      tree newid = NULL_TREE;

      if (lookup_attribute ("stdcall", type_attributes))

        newid = gen_stdcall_or_fastcall_suffix (decl, false);

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

        newid = gen_stdcall_or_fastcall_suffix (decl, true);

      if (newid != NULL_TREE)

        {

          rtx rtlname = XEXP (rtl, 0);

          if (GET_CODE (rtlname) == MEM)

            rtlname = XEXP (rtlname, 0);

          XSTR (rtlname, 0) = IDENTIFIER_POINTER (newid);

          /* These attributes must be present on first declaration,

             change_decl_assembler_name will warn if they are added

             later and the decl has been referenced, but duplicate_decls

             should catch the mismatch before this is called.  */

          change_decl_assembler_name (decl, newid);

        }

    }

  else if (TREE_CODE (decl) == VAR_DECL

           && 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);

      else

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

               decl);

    }

  /* 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.  */

  if (i386_pe_dllexport_p (decl))

    i386_pe_mark_dllexport (decl);

  else if (i386_pe_dllimport_p (decl))

    i386_pe_mark_dllimport (decl);

  /* It might be that DECL has been declared as dllimport, but a

     subsequent definition nullified that.  Assert that

     tree.c: merge_dllimport_decl_attributes has removed the attribute

     before the RTL name was marked with the DLL_IMPORT_PREFIX.  */

  else

    gcc_assert (!((TREE_CODE (decl) == FUNCTION_DECL

                   || TREE_CODE (decl) == VAR_DECL)

                  && rtl != NULL_RTX

                  && GET_CODE (rtl) == MEM

                  && GET_CODE (XEXP (rtl, 0)) == MEM

                  && GET_CODE (XEXP (XEXP (rtl, 0), 0)) == SYMBOL_REF

                  && i386_pe_dllimport_name_p (XSTR (XEXP (XEXP (rtl, 0), 0), 0))));

}

/* Strip only the leading encoding, leaving the stdcall suffix and fastcall

   prefix if it exists.  */

const char *

i386_pe_strip_name_encoding (const char *str)

{

  if (strncmp (str, DLL_IMPORT_PREFIX, strlen (DLL_IMPORT_PREFIX))

      == 0)

    str += strlen (DLL_IMPORT_PREFIX);

  else if (strncmp (str, DLL_EXPORT_PREFIX, strlen (DLL_EXPORT_PREFIX))

           == 0)

    str += strlen (DLL_EXPORT_PREFIX);

  if (*str == '*')

    str += 1;

  return str;

}

/* 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 = i386_pe_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;

}

/* Output a reference to a label. Fastcall symbols are prefixed with @,

   whereas symbols for functions using other calling conventions don't

   have a prefix (unless they are marked dllimport or dllexport).  */

void i386_pe_output_labelref (FILE *stream, const char *name)

{

  if (strncmp (name, DLL_IMPORT_PREFIX, strlen (DLL_IMPORT_PREFIX))

      == 0)

    /* A dll import */

    {

      if (name[strlen (DLL_IMPORT_PREFIX)] == FASTCALL_PREFIX)

      /* A dllimport fastcall symbol.  */

        {

          fprintf (stream, "__imp_%s",

                   i386_pe_strip_name_encoding (name));

        }

      else

      /* A dllimport non-fastcall symbol.  */

        {

          fprintf (stream, "__imp__%s",

                   i386_pe_strip_name_encoding (name));

        }

    }

  else if ((name[0] == FASTCALL_PREFIX)

           || (strncmp (name, DLL_EXPORT_PREFIX, strlen (DLL_EXPORT_PREFIX))

               == 0

               && name[strlen (DLL_EXPORT_PREFIX)] == FASTCALL_PREFIX))

    /* A fastcall symbol.  */

    {

      fprintf (stream, "%s",

               i386_pe_strip_name_encoding (name));

    }

  else

    /* Everything else.  */

    {

      fprintf (stream, "%s%s", USER_LABEL_PREFIX,

               i386_pe_strip_name_encoding (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 = alloca (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

    {

      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';

    }

  *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"));

    }

}

/* 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 PUBLIC is nonzero if the function is globally

   visible.  */

void

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

{

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

  assemble_name (file, name);

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

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

           (int) DT_FCN << N_BTSHFT);

}

/* Keep a list of external functions.  */

struct extern_list GTY(())

{

  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 export_list GTY(())

{

  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.  */

void

i386_pe_record_exported_symbol (const char *name, int is_data)

{

  struct export_list *p;

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

  p->next = export_head;

  p->name = name;

  p->is_data = is_data;

  export_head = p;

}

/* 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.  */