winnt.c

Mac OS X 10.4.9 for x86 Source Code gcc 实现源代码

  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);
	}
    }

  /* Mark the decl so we can tell from the rtl whether the object is
     dllexport'd or dllimport'd.  This also 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 already been marked as dllimport, but a
     subsequent definition nullified that.  The attribute is gone but
     DECL_RTL still has (DLL_IMPORT_PREFIX) prefixed. We need to remove
     that. Ditto for the DECL_NON_ADDR_CONST_P flag.  */
  else if ((TREE_CODE (decl) == FUNCTION_DECL
	    || TREE_CODE (decl) == VAR_DECL)
	   && DECL_RTL (decl) != NULL_RTX
	   && GET_CODE (DECL_RTL (decl)) == MEM
	   && GET_CODE (XEXP (DECL_RTL (decl), 0)) == MEM
	   && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == SYMBOL_REF
	   && i386_pe_dllimport_name_p (XSTR (XEXP (XEXP (DECL_RTL (decl), 0), 0), 0)))
    {
      const char *oldname = XSTR (XEXP (XEXP (DECL_RTL (decl), 0), 0), 0);

      /* Remove DLL_IMPORT_PREFIX.  */
      tree idp = get_identifier (oldname + strlen (DLL_IMPORT_PREFIX));
      rtx symref = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));
      SYMBOL_REF_DECL (symref) = decl;
      XEXP (DECL_RTL (decl), 0) = symref;
      DECL_NON_ADDR_CONST_P (decl) = 0;

      /* We previously set TREE_PUBLIC and DECL_EXTERNAL.
	 We leave these alone for now.  */

      if (DECL_INITIAL (decl) || !DECL_EXTERNAL (decl))
	warning ("%J'%D' defined locally after being "
		 "referenced with dllimport linkage", decl, decl);
      else
	warning ("%J'%D' redeclared without dllimport attribute "
		 "after being referenced with dllimport linkage", decl, decl);
    }
}

/* 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 ("%J'%D' causes a section type conflict", decl, decl);
    }

  return flags;
}

void
i386_pe_asm_named_section (const char *name, unsigned int flags, 
			   tree decl ATTRIBUTE_UNUSED)
{
  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.  */
      fprintf (asm_out_file, "\t.linkonce %s\n",
	       (flags & SECTION_CODE ? "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;
  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 (const char *name)
{
  struct extern_list *p;

  p = (struct extern_list *) ggc_alloc (sizeof *p);
  p->next = extern_head;
  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.  */

void
i386_pe_file_end (void)
{
  struct extern_list *p;

  ix86_file_end ();

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

      decl = get_identifier (p->name);

      /* Positively ensure only one declaration for any given symbol.  */
      if (! TREE_ASM_WRITTEN (decl) && TREE_SYMBOL_REFERENCED (decl))
	{
	  TREE_ASM_WRITTEN (decl) = 1;
	  i386_pe_declare_function_type (asm_out_file, p->name,
					 TREE_PUBLIC (decl));
	}
    }

  if (export_head)
    {
      struct export_list *q;
      drectve_section ();
      for (q = export_head; q != NULL; q = q->next)
	{
	  fprintf (asm_out_file, "\t.ascii \" -export:%s%s\"\n",
		   i386_pe_strip_name_encoding (q->name),
		   (q->is_data) ? ",data" : "");
	}
    }
}

#include "gt-winnt.h"