libffi/src/prep_cif.c

   1 /* -----------------------------------------------------------------------
   2    prep_cif.c - Copyright (c) 2011, 2012  Anthony Green
   3                 Copyright (c) 1996, 1998, 2007  Red Hat, Inc.
   4
   5    Permission is hereby granted, free of charge, to any person obtaining
   6    a copy of this software and associated documentation files (the
   7    ``Software''), to deal in the Software without restriction, including
   8    without limitation the rights to use, copy, modify, merge, publish,
   9    distribute, sublicense, and/or sell copies of the Software, and to
  10    permit persons to whom the Software is furnished to do so, subject to
  11    the following conditions:
  12
  13    The above copyright notice and this permission notice shall be included
  14    in all copies or substantial portions of the Software.
  15
  16    THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
  17    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  19    NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  20    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  21    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23    DEALINGS IN THE SOFTWARE.
  24    ----------------------------------------------------------------------- */
  25
  26 #include <ffi.h>
  27 #include <ffi_common.h>
  28 #include <stdlib.h>
  29
  30 /* Round up to FFI_SIZEOF_ARG. */
  31
  32 #define STACK_ARG_SIZE(x) ALIGN(x, FFI_SIZEOF_ARG)
  33
  34 /* Perform machine independent initialization of aggregate type
  35    specifications. */
  36
  37 static ffi_status initialize_aggregate(ffi_type *arg)
  38 {
  39   ffi_type **ptr;
  40
  41   if (UNLIKELY(arg == NULL || arg->elements == NULL))
  42     return FFI_BAD_TYPEDEF;
  43
  44   arg->size = 0;
  45   arg->alignment = 0;
  46
  47   ptr = &(arg->elements[0]);
  48
  49   if (UNLIKELY(ptr == 0))
  50     return FFI_BAD_TYPEDEF;
  51
  52   while ((*ptr) != NULL)
  53     {
  54       if (UNLIKELY(((*ptr)->size == 0)
  55                     && (initialize_aggregate((*ptr)) != FFI_OK)))
  56         return FFI_BAD_TYPEDEF;
  57
  58       /* Perform a sanity check on the argument type */
  59       FFI_ASSERT_VALID_TYPE(*ptr);
  60
  61       arg->size = ALIGN(arg->size, (*ptr)->alignment);
  62       arg->size += (*ptr)->size;
  63
  64       arg->alignment = (arg->alignment > (*ptr)->alignment) ?
  65         arg->alignment : (*ptr)->alignment;
  66
  67       ptr++;
  68     }
  69
  70   /* Structure size includes tail padding.  This is important for
  71      structures that fit in one register on ABIs like the PowerPC64
  72      Linux ABI that right justify small structs in a register.
  73      It's also needed for nested structure layout, for example
  74      struct A { long a; char b; }; struct B { struct A x; char y; };
  75      should find y at an offset of 2*sizeof(long) and result in a
  76      total size of 3*sizeof(long).  */
  77   arg->size = ALIGN (arg->size, arg->alignment);
  78
  79   /* On some targets, the ABI defines that structures have an additional
  80      alignment beyond the "natural" one based on their elements.  */
  81 #ifdef FFI_AGGREGATE_ALIGNMENT
  82   if (FFI_AGGREGATE_ALIGNMENT > arg->alignment)
  83     arg->alignment = FFI_AGGREGATE_ALIGNMENT;
  84 #endif
  85
  86   if (arg->size == 0)
  87     return FFI_BAD_TYPEDEF;
  88   else
  89     return FFI_OK;
  90 }
  91
  92 #ifndef __CRIS__
  93 /* The CRIS ABI specifies structure elements to have byte
  94    alignment only, so it completely overrides this functions,
  95    which assumes "natural" alignment and padding.  */
  96
  97 /* Perform machine independent ffi_cif preparation, then call
  98    machine dependent routine. */
  99
 100 /* For non variadic functions isvariadic should be 0 and
 101    nfixedargs==ntotalargs.
 102
 103    For variadic calls, isvariadic should be 1 and nfixedargs
 104    and ntotalargs set as appropriate. nfixedargs must always be >=1 */
 105
 106
 107 ffi_status FFI_HIDDEN ffi_prep_cif_core(ffi_cif *cif, ffi_abi abi,
 108                              unsigned int isvariadic,
 109                              unsigned int nfixedargs,
 110                              unsigned int ntotalargs,
 111                              ffi_type *rtype, ffi_type **atypes)
 112 {
 113   unsigned bytes = 0;
 114   unsigned int i;
 115   ffi_type **ptr;
 116
 117   FFI_ASSERT(cif != NULL);
 118   FFI_ASSERT((!isvariadic) || (nfixedargs >= 1));
 119   FFI_ASSERT(nfixedargs <= ntotalargs);
 120
 121   if (! (abi > FFI_FIRST_ABI && abi < FFI_LAST_ABI))
 122     return FFI_BAD_ABI;
 123
 124   cif->abi = abi;
 125   cif->arg_types = atypes;
 126   cif->nargs = ntotalargs;
 127   cif->rtype = rtype;
 128
 129   cif->flags = 0;
 130
 131 #if HAVE_LONG_DOUBLE_VARIANT
 132   ffi_prep_types (abi);
 133 #endif
 134
 135   /* Initialize the return type if necessary */
 136   if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))
 137     return FFI_BAD_TYPEDEF;
 138
 139 #ifndef FFI_TARGET_HAS_COMPLEX_TYPE
 140   if (rtype->type == FFI_TYPE_COMPLEX)
 141     abort();
 142 #endif
 143   /* Perform a sanity check on the return type */
 144   FFI_ASSERT_VALID_TYPE(cif->rtype);
 145
 146   /* x86, x86-64 and s390 stack space allocation is handled in prep_machdep. */
 147 #if !defined FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION
 148   /* Make space for the return structure pointer */
 149   if (cif->rtype->type == FFI_TYPE_STRUCT
 150 #ifdef TILE
 151       && (cif->rtype->size > 10 * FFI_SIZEOF_ARG)
 152 #endif
 153 #ifdef XTENSA
 154       && (cif->rtype->size > 16)
 155 #endif
 156 #ifdef NIOS2
 157       && (cif->rtype->size > 8)
 158 #endif
 159      )
 160     bytes = STACK_ARG_SIZE(sizeof(void*));
 161 #endif
 162
 163   for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
 164     {
 165
 166       /* Initialize any uninitialized aggregate type definitions */
 167       if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
 168         return FFI_BAD_TYPEDEF;
 169
 170 #ifndef FFI_TARGET_HAS_COMPLEX_TYPE
 171       if ((*ptr)->type == FFI_TYPE_COMPLEX)
 172         abort();
 173 #endif
 174       /* Perform a sanity check on the argument type, do this
 175          check after the initialization.  */
 176       FFI_ASSERT_VALID_TYPE(*ptr);
 177
 178 #if !defined FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION
 179         {
 180           /* Add any padding if necessary */
 181           if (((*ptr)->alignment - 1) & bytes)
 182             bytes = (unsigned)ALIGN(bytes, (*ptr)->alignment);
 183
 184 #ifdef TILE
 185           if (bytes < 10 * FFI_SIZEOF_ARG &&
 186               bytes + STACK_ARG_SIZE((*ptr)->size) > 10 * FFI_SIZEOF_ARG)
 187             {
 188               /* An argument is never split between the 10 parameter
 189                  registers and the stack.  */
 190               bytes = 10 * FFI_SIZEOF_ARG;
 191             }
 192 #endif
 193 #ifdef XTENSA
 194           if (bytes <= 6*4 && bytes + STACK_ARG_SIZE((*ptr)->size) > 6*4)
 195             bytes = 6*4;
 196 #endif
 197
 198           bytes += STACK_ARG_SIZE((*ptr)->size);
 199         }
 200 #endif
 201     }
 202
 203   cif->bytes = bytes;
 204
 205   /* Perform machine dependent cif processing */
 206 #ifdef FFI_TARGET_SPECIFIC_VARIADIC
 207   if (isvariadic)
 208         return ffi_prep_cif_machdep_var(cif, nfixedargs, ntotalargs);
 209 #endif
 210
 211   return ffi_prep_cif_machdep(cif);
 212 }
 213 #endif /* not __CRIS__ */
 214
 215 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
 216                              ffi_type *rtype, ffi_type **atypes)
 217 {
 218   return ffi_prep_cif_core(cif, abi, 0, nargs, nargs, rtype, atypes);
 219 }
 220
 221 ffi_status ffi_prep_cif_var(ffi_cif *cif,
 222                             ffi_abi abi,
 223                             unsigned int nfixedargs,
 224                             unsigned int ntotalargs,
 225                             ffi_type *rtype,
 226                             ffi_type **atypes)
 227 {
 228   return ffi_prep_cif_core(cif, abi, 1, nfixedargs, ntotalargs, rtype, atypes);
 229 }
 230
 231 #if FFI_CLOSURES
 232
 233 ffi_status
 234 ffi_prep_closure (ffi_closure* closure,
 235                   ffi_cif* cif,
 236                   void (*fun)(ffi_cif*,void*,void**,void*),
 237                   void *user_data)
 238 {
 239   return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
 240 }
 241
 242 #endif