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   if (arg->size == 0)
  80     return FFI_BAD_TYPEDEF;
  81   else
  82     return FFI_OK;
  83 }
  84
  85 #ifndef __CRIS__
  86 /* The CRIS ABI specifies structure elements to have byte
  87    alignment only, so it completely overrides this functions,
  88    which assumes "natural" alignment and padding.  */
  89
  90 /* Perform machine independent ffi_cif preparation, then call
  91    machine dependent routine. */
  92
  93 /* For non variadic functions isvariadic should be 0 and
  94    nfixedargs==ntotalargs.
  95
  96    For variadic calls, isvariadic should be 1 and nfixedargs
  97    and ntotalargs set as appropriate. nfixedargs must always be >=1 */
  98
  99
 100 ffi_status FFI_HIDDEN ffi_prep_cif_core(ffi_cif *cif, ffi_abi abi,
 101                              unsigned int isvariadic,
 102                              unsigned int nfixedargs,
 103                              unsigned int ntotalargs,
 104                              ffi_type *rtype, ffi_type **atypes)
 105 {
 106   unsigned bytes = 0;
 107   unsigned int i;
 108   ffi_type **ptr;
 109
 110   FFI_ASSERT(cif != NULL);
 111   FFI_ASSERT((!isvariadic) || (nfixedargs >= 1));
 112   FFI_ASSERT(nfixedargs <= ntotalargs);
 113
 114 #ifndef X86_WIN32
 115   if (! (abi > FFI_FIRST_ABI && abi < FFI_LAST_ABI))
 116     return FFI_BAD_ABI;
 117 #else
 118   if (! (abi > FFI_FIRST_ABI && abi < FFI_LAST_ABI || abi == FFI_THISCALL))
 119     return FFI_BAD_ABI;
 120 #endif
 121
 122   cif->abi = abi;
 123   cif->arg_types = atypes;
 124   cif->nargs = ntotalargs;
 125   cif->rtype = rtype;
 126
 127   cif->flags = 0;
 128
 129 #if HAVE_LONG_DOUBLE_VARIANT
 130   ffi_prep_types (abi);
 131 #endif
 132
 133   /* Initialize the return type if necessary */
 134   if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))
 135     return FFI_BAD_TYPEDEF;
 136
 137   /* Perform a sanity check on the return type */
 138   FFI_ASSERT_VALID_TYPE(cif->rtype);
 139
 140   /* x86, x86-64 and s390 stack space allocation is handled in prep_machdep. */
 141 #if !defined M68K && !defined X86_ANY && !defined S390 && !defined PA
 142   /* Make space for the return structure pointer */
 143   if (cif->rtype->type == FFI_TYPE_STRUCT
 144 #ifdef SPARC
 145       && (cif->abi != FFI_V9 || cif->rtype->size > 32)
 146 #endif
 147 #ifdef TILE
 148       && (cif->rtype->size > 10 * FFI_SIZEOF_ARG)
 149 #endif
 150      )
 151     bytes = STACK_ARG_SIZE(sizeof(void*));
 152 #endif
 153
 154   for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
 155     {
 156
 157       /* Initialize any uninitialized aggregate type definitions */
 158       if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
 159         return FFI_BAD_TYPEDEF;
 160
 161       /* Perform a sanity check on the argument type, do this
 162          check after the initialization.  */
 163       FFI_ASSERT_VALID_TYPE(*ptr);
 164
 165 #if !defined X86_ANY && !defined S390 && !defined PA
 166 #ifdef SPARC
 167       if (((*ptr)->type == FFI_TYPE_STRUCT
 168            && ((*ptr)->size > 16 || cif->abi != FFI_V9))
 169           || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
 170               && cif->abi != FFI_V9))
 171         bytes += sizeof(void*);
 172       else
 173 #endif
 174         {
 175           /* Add any padding if necessary */
 176           if (((*ptr)->alignment - 1) & bytes)
 177             bytes = ALIGN(bytes, (*ptr)->alignment);
 178
 179 #ifdef TILE
 180           if (bytes < 10 * FFI_SIZEOF_ARG &&
 181               bytes + STACK_ARG_SIZE((*ptr)->size) > 10 * FFI_SIZEOF_ARG)
 182             {
 183               /* An argument is never split between the 10 parameter
 184                  registers and the stack.  */
 185               bytes = 10 * FFI_SIZEOF_ARG;
 186             }
 187 #endif
 188
 189           bytes += STACK_ARG_SIZE((*ptr)->size);
 190         }
 191 #endif
 192     }
 193
 194   cif->bytes = bytes;
 195
 196   /* Perform machine dependent cif processing */
 197 #ifdef FFI_TARGET_SPECIFIC_VARIADIC
 198   if (isvariadic)
 199         return ffi_prep_cif_machdep_var(cif, nfixedargs, ntotalargs);
 200 #endif
 201
 202   return ffi_prep_cif_machdep(cif);
 203 }
 204 #endif /* not __CRIS__ */
 205
 206 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
 207                              ffi_type *rtype, ffi_type **atypes)
 208 {
 209   return ffi_prep_cif_core(cif, abi, 0, nargs, nargs, rtype, atypes);
 210 }
 211
 212 ffi_status ffi_prep_cif_var(ffi_cif *cif,
 213                             ffi_abi abi,
 214                             unsigned int nfixedargs,
 215                             unsigned int ntotalargs,
 216                             ffi_type *rtype,
 217                             ffi_type **atypes)
 218 {
 219   return ffi_prep_cif_core(cif, abi, 1, nfixedargs, ntotalargs, rtype, atypes);
 220 }
 221
 222 #if FFI_CLOSURES
 223
 224 ffi_status
 225 ffi_prep_closure (ffi_closure* closure,
 226                   ffi_cif* cif,
 227                   void (*fun)(ffi_cif*,void*,void**,void*),
 228                   void *user_data)
 229 {
 230   return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
 231 }
 232
 233 #endif