libffi/src/prep_cif.c

   1 /* -----------------------------------------------------------------------
   2    prep_cif.c - Copyright (c) 1996, 1998, 2007  Red Hat, Inc.
   3
   4    Permission is hereby granted, free of charge, to any person obtaining
   5    a copy of this software and associated documentation files (the
   6    ``Software''), to deal in the Software without restriction, including
   7    without limitation the rights to use, copy, modify, merge, publish,
   8    distribute, sublicense, and/or sell copies of the Software, and to
   9    permit persons to whom the Software is furnished to do so, subject to
  10    the following conditions:
  11
  12    The above copyright notice and this permission notice shall be included
  13    in all copies or substantial portions of the Software.
  14
  15    THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
  16    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18    NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  19    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  20    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22    DEALINGS IN THE SOFTWARE.
  23    ----------------------------------------------------------------------- */
  24
  25 #include <ffi.h>
  26 #include <ffi_common.h>
  27 #include <stdlib.h>
  28
  29 /* Round up to FFI_SIZEOF_ARG. */
  30
  31 #define STACK_ARG_SIZE(x) ALIGN(x, FFI_SIZEOF_ARG)
  32
  33 /* Perform machine independent initialization of aggregate type
  34    specifications. */
  35
  36 static ffi_status initialize_aggregate(ffi_type *arg)
  37 {
  38   ffi_type **ptr;
  39
  40   FFI_ASSERT(arg != NULL);
  41
  42   FFI_ASSERT(arg->elements != NULL);
  43   FFI_ASSERT(arg->size == 0);
  44   FFI_ASSERT(arg->alignment == 0);
  45
  46   ptr = &(arg->elements[0]);
  47
  48   while ((*ptr) != NULL)
  49     {
  50       if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
  51         return FFI_BAD_TYPEDEF;
  52
  53       /* Perform a sanity check on the argument type */
  54       FFI_ASSERT_VALID_TYPE(*ptr);
  55
  56       arg->size = ALIGN(arg->size, (*ptr)->alignment);
  57       arg->size += (*ptr)->size;
  58
  59       arg->alignment = (arg->alignment > (*ptr)->alignment) ?
  60         arg->alignment : (*ptr)->alignment;
  61
  62       ptr++;
  63     }
  64
  65   /* Structure size includes tail padding.  This is important for
  66      structures that fit in one register on ABIs like the PowerPC64
  67      Linux ABI that right justify small structs in a register.
  68      It's also needed for nested structure layout, for example
  69      struct A { long a; char b; }; struct B { struct A x; char y; };
  70      should find y at an offset of 2*sizeof(long) and result in a
  71      total size of 3*sizeof(long).  */
  72   arg->size = ALIGN (arg->size, arg->alignment);
  73
  74   if (arg->size == 0)
  75     return FFI_BAD_TYPEDEF;
  76   else
  77     return FFI_OK;
  78 }
  79
  80 #ifndef __CRIS__
  81 /* The CRIS ABI specifies structure elements to have byte
  82    alignment only, so it completely overrides this functions,
  83    which assumes "natural" alignment and padding.  */
  84
  85 /* Perform machine independent ffi_cif preparation, then call
  86    machine dependent routine. */
  87
  88 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
  89                         ffi_type *rtype, ffi_type **atypes)
  90 {
  91   unsigned bytes = 0;
  92   unsigned int i;
  93   ffi_type **ptr;
  94
  95   FFI_ASSERT(cif != NULL);
  96   FFI_ASSERT((abi > FFI_FIRST_ABI) && (abi <= FFI_DEFAULT_ABI));
  97
  98   cif->abi = abi;
  99   cif->arg_types = atypes;
 100   cif->nargs = nargs;
 101   cif->rtype = rtype;
 102
 103   cif->flags = 0;
 104
 105   /* Initialize the return type if necessary */
 106   if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))
 107     return FFI_BAD_TYPEDEF;
 108
 109   /* Perform a sanity check on the return type */
 110   FFI_ASSERT_VALID_TYPE(cif->rtype);
 111
 112   /* x86-64 and s390 stack space allocation is handled in prep_machdep.  */
 113 #if !defined M68K && !defined __x86_64__ && !defined S390 && !defined PA
 114   /* Make space for the return structure pointer */
 115   if (cif->rtype->type == FFI_TYPE_STRUCT
 116 #ifdef SPARC
 117       && (cif->abi != FFI_V9 || cif->rtype->size > 32)
 118 #endif
 119 #ifdef X86_DARWIN
 120       && (cif->rtype->size > 8)
 121 #endif
 122      )
 123     bytes = STACK_ARG_SIZE(sizeof(void*));
 124 #endif
 125
 126   for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
 127     {
 128
 129       /* Initialize any uninitialized aggregate type definitions */
 130       if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
 131         return FFI_BAD_TYPEDEF;
 132
 133       /* Perform a sanity check on the argument type, do this
 134          check after the initialization.  */
 135       FFI_ASSERT_VALID_TYPE(*ptr);
 136
 137 #if !defined __x86_64__ && !defined S390 && !defined PA
 138 #ifdef SPARC
 139       if (((*ptr)->type == FFI_TYPE_STRUCT
 140            && ((*ptr)->size > 16 || cif->abi != FFI_V9))
 141           || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
 142               && cif->abi != FFI_V9))
 143         bytes += sizeof(void*);
 144       else
 145 #endif
 146         {
 147           /* Add any padding if necessary */
 148           if (((*ptr)->alignment - 1) & bytes)
 149             bytes = ALIGN(bytes, (*ptr)->alignment);
 150
 151           bytes += STACK_ARG_SIZE((*ptr)->size);
 152         }
 153 #endif
 154     }
 155
 156   cif->bytes = bytes;
 157
 158   /* Perform machine dependent cif processing */
 159   return ffi_prep_cif_machdep(cif);
 160 }
 161 #endif /* not __CRIS__ */
 162
 163 #if FFI_CLOSURES
 164
 165 ffi_status
 166 ffi_prep_closure (ffi_closure* closure,
 167                   ffi_cif* cif,
 168                   void (*fun)(ffi_cif*,void*,void**,void*),
 169                   void *user_data)
 170 {
 171   return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
 172 }
 173
 174 #endif