/* -----------------------------------------------------------------------

   prep_cif.c - Copyright (c) 1996, 1998  Red Hat, Inc.

   Permission is hereby granted, free of charge, to any person obtaining

   a copy of this software and associated documentation files (the

   ``Software''), to deal in the Software without restriction, including

   without limitation the rights to use, copy, modify, merge, publish,

   distribute, sublicense, and/or sell copies of the Software, and to

   permit persons to whom the Software is furnished to do so, subject to

   the following conditions:

   The above copyright notice and this permission notice shall be included

   in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS

   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

   IN NO EVENT SHALL CYGNUS SOLUTIONS BE LIABLE FOR ANY CLAIM, DAMAGES OR

   OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,

   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

   OTHER DEALINGS IN THE SOFTWARE.

   ----------------------------------------------------------------------- */

#include <ffi.h>

#include <ffi_common.h>

#include <stdlib.h>

/* Round up to FFI_SIZEOF_ARG. */

#define STACK_ARG_SIZE(x) ALIGN(x, FFI_SIZEOF_ARG)

/* Perform machine independent initialization of aggregate type

   specifications. */

static ffi_status initialize_aggregate(/*@out@*/ ffi_type *arg)

{

  ffi_type **ptr; 

  FFI_ASSERT(arg != NULL);

  /*@-usedef@*/

  FFI_ASSERT(arg->elements != NULL);

  FFI_ASSERT(arg->size == 0);

  FFI_ASSERT(arg->alignment == 0);

  ptr = &(arg->elements[0]);

  while ((*ptr) != NULL)

    {

      if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))

	return FFI_BAD_TYPEDEF;

      /* Perform a sanity check on the argument type */

      FFI_ASSERT_VALID_TYPE(*ptr);

      arg->size = ALIGN(arg->size, (*ptr)->alignment);

      arg->size += (*ptr)->size;

      arg->alignment = (arg->alignment > (*ptr)->alignment) ? 

	arg->alignment : (*ptr)->alignment;

      ptr++;

    }

  /* Structure size includes tail padding.  This is important for

     structures that fit in one register on ABIs like the PowerPC64

     Linux ABI that right justify small structs in a register.

     It's also needed for nested structure layout, for example

     struct A { long a; char b; }; struct B { struct A x; char y; };

     should find y at an offset of 2*sizeof(long) and result in a

     total size of 3*sizeof(long).  */

  arg->size = ALIGN (arg->size, arg->alignment);

  if (arg->size == 0)

    return FFI_BAD_TYPEDEF;

  else

    return FFI_OK;

  /*@=usedef@*/

}

/* Perform machine independent ffi_cif preparation, then call

   machine dependent routine. */

ffi_status ffi_prep_cif(/*@out@*/ /*@partial@*/ ffi_cif *cif, 

			ffi_abi abi, unsigned int nargs, 

			/*@dependent@*/ /*@out@*/ /*@partial@*/ ffi_type *rtype, 

			/*@dependent@*/ ffi_type **atypes)

{

  unsigned bytes = 0;

  unsigned int i;

  ffi_type **ptr;

  FFI_ASSERT(cif != NULL);

  FFI_ASSERT((abi > FFI_FIRST_ABI) && (abi <= FFI_DEFAULT_ABI));

  cif->abi = abi;

  cif->arg_types = atypes;

  cif->nargs = nargs;

  cif->rtype = rtype;

  cif->flags = 0;

  /* Initialize the return type if necessary */

  /*@-usedef@*/

  if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))

    return FFI_BAD_TYPEDEF;

  /*@=usedef@*/

  /* Perform a sanity check on the return type */

  FFI_ASSERT_VALID_TYPE(cif->rtype);

  /* x86-64 and s390 stack space allocation is handled in prep_machdep.  */

#if !defined M68K && !defined __x86_64__ && !defined S390

  /* Make space for the return structure pointer */

  if (cif->rtype->type == FFI_TYPE_STRUCT

      /* MSVC returns small structures in registers.  But we have a different

      workaround: pretend int32 or int64 return type, and converting to

      structure afterwards. */

#ifdef SPARC

      && (cif->abi != FFI_V9 || cif->rtype->size > 32)

#endif

      )

    bytes = STACK_ARG_SIZE(sizeof(void*));

#endif

  for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)

    {

      /* Initialize any uninitialized aggregate type definitions */

      if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))

	return FFI_BAD_TYPEDEF;

      /* Perform a sanity check on the argument type, do this 

	 check after the initialization.  */

      FFI_ASSERT_VALID_TYPE(*ptr);

#if !defined __x86_64__ && !defined S390

#ifdef SPARC

      if (((*ptr)->type == FFI_TYPE_STRUCT

	   && ((*ptr)->size > 16 || cif->abi != FFI_V9))

	  || ((*ptr)->type == FFI_TYPE_LONGDOUBLE

	      && cif->abi != FFI_V9))

	bytes += sizeof(void*);

      else

#endif

	{

#ifndef _MSC_VER

		/* Don't know if this is a libffi bug or not.  At least on

		   Windows with MSVC, function call parameters are *not*

		   aligned in the same way as structure fields are, they are

		   only aligned in integer boundaries.

		   This doesn't do any harm for cdecl functions and closures,

		   since the caller cleans up the stack, but it is wrong for

		   stdcall functions where the callee cleans.

		*/

	  /* Add any padding if necessary */

	  if (((*ptr)->alignment - 1) & bytes)

	    bytes = ALIGN(bytes, (*ptr)->alignment);

#endif

	  bytes += STACK_ARG_SIZE((*ptr)->size);

	}

#endif

    }

  cif->bytes = bytes;

  /* Perform machine dependent cif processing */

  return ffi_prep_cif_machdep(cif);

}