libffi/src/prep_cif.c

   1 /* -----------------------------------------------------------------------
   2    prep_cif.c - Copyright (c) 1996, 1998  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, EXPRESS
  16    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  18    IN NO EVENT SHALL CYGNUS SOLUTIONS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  19    OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  20    ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  21    OTHER DEALINGS IN THE SOFTWARE.
  22    ----------------------------------------------------------------------- */
  23
  24 #include <ffi.h>
  25 #include <ffi_common.h>
  26 #include <stdlib.h>
  27
  28 /* Round up to FFI_SIZEOF_ARG. */
  29
  30 #define STACK_ARG_SIZE(x) ALIGN(x, FFI_SIZEOF_ARG)
  31
  32 /* Perform machine independent initialization of aggregate type
  33    specifications. */
  34
  35 static ffi_status initialize_aggregate(ffi_type *arg)
  36 {
  37   ffi_type **ptr;
  38
  39   FFI_ASSERT(arg != NULL);
  40
  41   FFI_ASSERT(arg->elements != NULL);
  42   FFI_ASSERT(arg->size == 0);
  43   FFI_ASSERT(arg->alignment == 0);
  44
  45   ptr = &(arg->elements[0]);
  46
  47   while ((*ptr) != NULL)
  48     {
  49       if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
  50         return FFI_BAD_TYPEDEF;
  51
  52       /* Perform a sanity check on the argument type */
  53       FFI_ASSERT_VALID_TYPE(*ptr);
  54
  55       arg->size = ALIGN(arg->size, (*ptr)->alignment);
  56       arg->size += (*ptr)->size;
  57
  58       arg->alignment = (arg->alignment > (*ptr)->alignment) ?
  59         arg->alignment : (*ptr)->alignment;
  60
  61       ptr++;
  62     }
  63
  64   /* Structure size includes tail padding.  This is important for
  65      structures that fit in one register on ABIs like the PowerPC64
  66      Linux ABI that right justify small structs in a register.
  67      It's also needed for nested structure layout, for example
  68      struct A { long a; char b; }; struct B { struct A x; char y; };
  69      should find y at an offset of 2*sizeof(long) and result in a
  70      total size of 3*sizeof(long).  */
  71   arg->size = ALIGN (arg->size, arg->alignment);
  72
  73   if (arg->size == 0)
  74     return FFI_BAD_TYPEDEF;
  75   else
  76     return FFI_OK;
  77 }
  78
  79 #ifndef __CRIS__
  80 /* The CRIS ABI specifies structure elements to have byte
  81    alignment only, so it completely overrides this functions,
  82    which assumes "natural" alignment and padding.  */
  83
  84 /* Perform machine independent ffi_cif preparation, then call
  85    machine dependent routine. */
  86
  87 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
  88                         ffi_type *rtype, ffi_type **atypes)
  89 {
  90   unsigned bytes = 0;
  91   unsigned int i;
  92   ffi_type **ptr;
  93
  94   FFI_ASSERT(cif != NULL);
  95   FFI_ASSERT((abi > FFI_FIRST_ABI) && (abi <= FFI_DEFAULT_ABI));
  96
  97   cif->abi = abi;
  98   cif->arg_types = atypes;
  99   cif->nargs = nargs;
 100   cif->rtype = rtype;
 101
 102   cif->flags = 0;
 103
 104   /* Initialize the return type if necessary */
 105   if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))
 106     return FFI_BAD_TYPEDEF;
 107
 108   /* Perform a sanity check on the return type */
 109   FFI_ASSERT_VALID_TYPE(cif->rtype);
 110
 111   /* x86-64 and s390 stack space allocation is handled in prep_machdep.  */
 112 #if !defined M68K && !defined __x86_64__ && !defined S390 && !defined PA
 113   /* Make space for the return structure pointer */
 114   if (cif->rtype->type == FFI_TYPE_STRUCT
 115 #ifdef SPARC
 116       && (cif->abi != FFI_V9 || cif->rtype->size > 32)
 117 #endif
 118 #ifdef X86_DARWIN
 119       && (cif->rtype->size > 8)
 120 #endif
 121      )
 122     bytes = STACK_ARG_SIZE(sizeof(void*));
 123 #endif
 124
 125   for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
 126     {
 127
 128       /* Initialize any uninitialized aggregate type definitions */
 129       if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
 130         return FFI_BAD_TYPEDEF;
 131
 132       /* Perform a sanity check on the argument type, do this
 133          check after the initialization.  */
 134       FFI_ASSERT_VALID_TYPE(*ptr);
 135
 136 #if !defined __x86_64__ && !defined S390 && !defined PA
 137 #ifdef SPARC
 138       if (((*ptr)->type == FFI_TYPE_STRUCT
 139            && ((*ptr)->size > 16 || cif->abi != FFI_V9))
 140           || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
 141               && cif->abi != FFI_V9))
 142         bytes += sizeof(void*);
 143       else
 144 #endif
 145         {
 146           /* Add any padding if necessary */
 147           if (((*ptr)->alignment - 1) & bytes)
 148             bytes = ALIGN(bytes, (*ptr)->alignment);
 149
 150           bytes += STACK_ARG_SIZE((*ptr)->size);
 151         }
 152 #endif
 153     }
 154
 155   cif->bytes = bytes;
 156
 157   /* Perform machine dependent cif processing */
 158   return ffi_prep_cif_machdep(cif);
 159 }
 160 #endif /* not __CRIS__ */