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   /* Initialize the return type if necessary */
 130   if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))
 131     return FFI_BAD_TYPEDEF;
 132
 133   /* Perform a sanity check on the return type */
 134   FFI_ASSERT_VALID_TYPE(cif->rtype);
 135
 136   /* x86, x86-64 and s390 stack space allocation is handled in prep_machdep. */
 137 #if !defined M68K && !defined X86_ANY && !defined S390 && !defined PA
 138   /* Make space for the return structure pointer */
 139   if (cif->rtype->type == FFI_TYPE_STRUCT
 140 #ifdef SPARC
 141       && (cif->abi != FFI_V9 || cif->rtype->size > 32)
 142 #endif
 143 #ifdef TILE
 144       && (cif->rtype->size > 10 * FFI_SIZEOF_ARG)
 145 #endif
 146      )
 147     bytes = STACK_ARG_SIZE(sizeof(void*));
 148 #endif
 149
 150   for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
 151     {
 152
 153       /* Initialize any uninitialized aggregate type definitions */
 154       if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
 155         return FFI_BAD_TYPEDEF;
 156
 157       /* Perform a sanity check on the argument type, do this
 158          check after the initialization.  */
 159       FFI_ASSERT_VALID_TYPE(*ptr);
 160
 161 #if !defined X86_ANY && !defined S390 && !defined PA
 162 #ifdef SPARC
 163       if (((*ptr)->type == FFI_TYPE_STRUCT
 164            && ((*ptr)->size > 16 || cif->abi != FFI_V9))
 165           || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
 166               && cif->abi != FFI_V9))
 167         bytes += sizeof(void*);
 168       else
 169 #endif
 170         {
 171           /* Add any padding if necessary */
 172           if (((*ptr)->alignment - 1) & bytes)
 173             bytes = ALIGN(bytes, (*ptr)->alignment);
 174
 175 #ifdef TILE
 176           if (bytes < 10 * FFI_SIZEOF_ARG &&
 177               bytes + STACK_ARG_SIZE((*ptr)->size) > 10 * FFI_SIZEOF_ARG)
 178             {
 179               /* An argument is never split between the 10 parameter
 180                  registers and the stack.  */
 181               bytes = 10 * FFI_SIZEOF_ARG;
 182             }
 183 #endif
 184
 185           bytes += STACK_ARG_SIZE((*ptr)->size);
 186         }
 187 #endif
 188     }
 189
 190   cif->bytes = bytes;
 191
 192   /* Perform machine dependent cif processing */
 193 #ifdef FFI_TARGET_SPECIFIC_VARIADIC
 194   if (isvariadic)
 195         return ffi_prep_cif_machdep_var(cif, nfixedargs, ntotalargs);
 196 #endif
 197
 198   return ffi_prep_cif_machdep(cif);
 199 }
 200 #endif /* not __CRIS__ */
 201
 202 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
 203                              ffi_type *rtype, ffi_type **atypes)
 204 {
 205   return ffi_prep_cif_core(cif, abi, 0, nargs, nargs, rtype, atypes);
 206 }
 207
 208 ffi_status ffi_prep_cif_var(ffi_cif *cif,
 209                             ffi_abi abi,
 210                             unsigned int nfixedargs,
 211                             unsigned int ntotalargs,
 212                             ffi_type *rtype,
 213                             ffi_type **atypes)
 214 {
 215   return ffi_prep_cif_core(cif, abi, 1, nfixedargs, ntotalargs, rtype, atypes);
 216 }
 217
 218 #if FFI_CLOSURES
 219
 220 ffi_status
 221 ffi_prep_closure (ffi_closure* closure,
 222                   ffi_cif* cif,
 223                   void (*fun)(ffi_cif*,void*,void**,void*),
 224                   void *user_data)
 225 {
 226   return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
 227 }
 228
 229 #endif