libffi/src/prep_cif.c

   1 /* -----------------------------------------------------------------------
   2    prep_cif.c - Copyright (c) 2011, 2012, 2021  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) FFI_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, size_t *offsets)
  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), NULL) != 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 = FFI_ALIGN(arg->size, (*ptr)->alignment);
  62       if (offsets)
  63         *offsets++ = arg->size;
  64       arg->size += (*ptr)->size;
  65
  66       arg->alignment = (arg->alignment > (*ptr)->alignment) ?
  67         arg->alignment : (*ptr)->alignment;
  68
  69       ptr++;
  70     }
  71
  72   /* Structure size includes tail padding.  This is important for
  73      structures that fit in one register on ABIs like the PowerPC64
  74      Linux ABI that right justify small structs in a register.
  75      It's also needed for nested structure layout, for example
  76      struct A { long a; char b; }; struct B { struct A x; char y; };
  77      should find y at an offset of 2*sizeof(long) and result in a
  78      total size of 3*sizeof(long).  */
  79   arg->size = FFI_ALIGN (arg->size, arg->alignment);
  80
  81   /* On some targets, the ABI defines that structures have an additional
  82      alignment beyond the "natural" one based on their elements.  */
  83 #ifdef FFI_AGGREGATE_ALIGNMENT
  84   if (FFI_AGGREGATE_ALIGNMENT > arg->alignment)
  85     arg->alignment = FFI_AGGREGATE_ALIGNMENT;
  86 #endif
  87
  88   if (arg->size == 0)
  89     return FFI_BAD_TYPEDEF;
  90   else
  91     return FFI_OK;
  92 }
  93
  94 #ifndef __CRIS__
  95 /* The CRIS ABI specifies structure elements to have byte
  96    alignment only, so it completely overrides this functions,
  97    which assumes "natural" alignment and padding.  */
  98
  99 /* Perform machine independent ffi_cif preparation, then call
 100    machine dependent routine. */
 101
 102 /* For non variadic functions isvariadic should be 0 and
 103    nfixedargs==ntotalargs.
 104
 105    For variadic calls, isvariadic should be 1 and nfixedargs
 106    and ntotalargs set as appropriate. nfixedargs must always be >=1 */
 107
 108
 109 ffi_status FFI_HIDDEN ffi_prep_cif_core(ffi_cif *cif, ffi_abi abi,
 110                              unsigned int isvariadic,
 111                              unsigned int nfixedargs,
 112                              unsigned int ntotalargs,
 113                              ffi_type *rtype, ffi_type **atypes)
 114 {
 115   unsigned bytes = 0;
 116   unsigned int i;
 117   ffi_type **ptr;
 118
 119   FFI_ASSERT(cif != NULL);
 120   FFI_ASSERT((!isvariadic) || (nfixedargs >= 1));
 121   FFI_ASSERT(nfixedargs <= ntotalargs);
 122
 123   if (! (abi > FFI_FIRST_ABI && abi < FFI_LAST_ABI))
 124     return FFI_BAD_ABI;
 125
 126   cif->abi = abi;
 127   cif->arg_types = atypes;
 128   cif->nargs = ntotalargs;
 129   cif->rtype = rtype;
 130
 131   cif->flags = 0;
 132 #if (defined(_M_ARM64) || defined(__aarch64__)) && defined(_WIN32)
 133   cif->is_variadic = isvariadic;
 134 #endif
 135 #if HAVE_LONG_DOUBLE_VARIANT
 136   ffi_prep_types (abi);
 137 #endif
 138
 139   /* Initialize the return type if necessary */
 140   if ((cif->rtype->size == 0)
 141       && (initialize_aggregate(cif->rtype, NULL) != FFI_OK))
 142     return FFI_BAD_TYPEDEF;
 143
 144 #ifndef FFI_TARGET_HAS_COMPLEX_TYPE
 145   if (rtype->type == FFI_TYPE_COMPLEX)
 146     abort();
 147 #endif
 148   /* Perform a sanity check on the return type */
 149   FFI_ASSERT_VALID_TYPE(cif->rtype);
 150
 151   /* x86, x86-64 and s390 stack space allocation is handled in prep_machdep. */
 152 #if !defined FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION
 153   /* Make space for the return structure pointer */
 154   if (cif->rtype->type == FFI_TYPE_STRUCT
 155 #ifdef TILE
 156       && (cif->rtype->size > 10 * FFI_SIZEOF_ARG)
 157 #endif
 158 #ifdef XTENSA
 159       && (cif->rtype->size > 16)
 160 #endif
 161 #ifdef NIOS2
 162       && (cif->rtype->size > 8)
 163 #endif
 164      )
 165     bytes = STACK_ARG_SIZE(sizeof(void*));
 166 #endif
 167
 168   for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
 169     {
 170
 171       /* Initialize any uninitialized aggregate type definitions */
 172       if (((*ptr)->size == 0)
 173           && (initialize_aggregate((*ptr), NULL) != FFI_OK))
 174         return FFI_BAD_TYPEDEF;
 175
 176 #ifndef FFI_TARGET_HAS_COMPLEX_TYPE
 177       if ((*ptr)->type == FFI_TYPE_COMPLEX)
 178         abort();
 179 #endif
 180       /* Perform a sanity check on the argument type, do this
 181          check after the initialization.  */
 182       FFI_ASSERT_VALID_TYPE(*ptr);
 183
 184 #if !defined FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION
 185         {
 186           /* Add any padding if necessary */
 187           if (((*ptr)->alignment - 1) & bytes)
 188             bytes = (unsigned)FFI_ALIGN(bytes, (*ptr)->alignment);
 189
 190 #ifdef TILE
 191           if (bytes < 10 * FFI_SIZEOF_ARG &&
 192               bytes + STACK_ARG_SIZE((*ptr)->size) > 10 * FFI_SIZEOF_ARG)
 193             {
 194               /* An argument is never split between the 10 parameter
 195                  registers and the stack.  */
 196               bytes = 10 * FFI_SIZEOF_ARG;
 197             }
 198 #endif
 199 #ifdef XTENSA
 200           if (bytes <= 6*4 && bytes + STACK_ARG_SIZE((*ptr)->size) > 6*4)
 201             bytes = 6*4;
 202 #endif
 203
 204           bytes += (unsigned int)STACK_ARG_SIZE((*ptr)->size);
 205         }
 206 #endif
 207     }
 208
 209   cif->bytes = bytes;
 210
 211   /* Perform machine dependent cif processing */
 212 #ifdef FFI_TARGET_SPECIFIC_VARIADIC
 213   if (isvariadic)
 214         return ffi_prep_cif_machdep_var(cif, nfixedargs, ntotalargs);
 215 #endif
 216
 217   return ffi_prep_cif_machdep(cif);
 218 }
 219 #endif /* not __CRIS__ */
 220
 221 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
 222                              ffi_type *rtype, ffi_type **atypes)
 223 {
 224   return ffi_prep_cif_core(cif, abi, 0, nargs, nargs, rtype, atypes);
 225 }
 226
 227 ffi_status ffi_prep_cif_var(ffi_cif *cif,
 228                             ffi_abi abi,
 229                             unsigned int nfixedargs,
 230                             unsigned int ntotalargs,
 231                             ffi_type *rtype,
 232                             ffi_type **atypes)
 233 {
 234   ffi_status rc;
 235   size_t int_size = ffi_type_sint.size;
 236   int i;
 237
 238   rc = ffi_prep_cif_core(cif, abi, 1, nfixedargs, ntotalargs, rtype, atypes);
 239
 240   if (rc != FFI_OK)
 241     return rc;
 242
 243   for (i = 1; i < ntotalargs; i++)
 244     {
 245       ffi_type *arg_type = atypes[i];
 246       if (arg_type == &ffi_type_float
 247           || ((arg_type->type != FFI_TYPE_STRUCT
 248                && arg_type->type != FFI_TYPE_COMPLEX)
 249               && arg_type->size < int_size))
 250         return FFI_BAD_ARGTYPE;
 251     }
 252
 253   return FFI_OK;
 254 }
 255
 256 #if FFI_CLOSURES
 257
 258 ffi_status
 259 ffi_prep_closure (ffi_closure* closure,
 260                   ffi_cif* cif,
 261                   void (*fun)(ffi_cif*,void*,void**,void*),
 262                   void *user_data)
 263 {
 264   return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
 265 }
 266
 267 #endif
 268
 269 ffi_status
 270 ffi_get_struct_offsets (ffi_abi abi, ffi_type *struct_type, size_t *offsets)
 271 {
 272   if (! (abi > FFI_FIRST_ABI && abi < FFI_LAST_ABI))
 273     return FFI_BAD_ABI;
 274   if (struct_type->type != FFI_TYPE_STRUCT)
 275     return FFI_BAD_TYPEDEF;
 276
 277 #if HAVE_LONG_DOUBLE_VARIANT
 278   ffi_prep_types (abi);
 279 #endif
 280
 281   return initialize_aggregate(struct_type, offsets);
 282 }