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 SPARC
151       && (cif->abi != FFI_V9 || cif->rtype->size > 32)
152 #endif
153 #ifdef TILE
154       && (cif->rtype->size > 10 * FFI_SIZEOF_ARG)
155 #endif
156 #ifdef XTENSA
157       && (cif->rtype->size > 16)
158 #endif
159 #ifdef NIOS2
160       && (cif->rtype->size > 8)
161 #endif
162      )
163     bytes = STACK_ARG_SIZE(sizeof(void*));
164 #endif
165 
166   for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
167     {
168 
169       /* Initialize any uninitialized aggregate type definitions */
170       if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
171     return FFI_BAD_TYPEDEF;
172 
173 #ifndef FFI_TARGET_HAS_COMPLEX_TYPE
174       if ((*ptr)->type == FFI_TYPE_COMPLEX)
175     abort();
176 #endif
177       /* Perform a sanity check on the argument type, do this
178      check after the initialization.  */
179       FFI_ASSERT_VALID_TYPE(*ptr);
180 
181 #if !defined FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION
182 #ifdef SPARC
183       if (((*ptr)->type == FFI_TYPE_STRUCT
184        && ((*ptr)->size > 16 || cif->abi != FFI_V9))
185       || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
186           && cif->abi != FFI_V9))
187     bytes += sizeof(void*);
188       else
189 #endif
190     {
191       /* Add any padding if necessary */
192       if (((*ptr)->alignment - 1) & bytes)
193         bytes = (unsigned)ALIGN(bytes, (*ptr)->alignment);
194 
195 #ifdef TILE
196       if (bytes < 10 * FFI_SIZEOF_ARG &&
197           bytes + STACK_ARG_SIZE((*ptr)->size) > 10 * FFI_SIZEOF_ARG)
198         {
199           /* An argument is never split between the 10 parameter
200          registers and the stack.  */
201           bytes = 10 * FFI_SIZEOF_ARG;
202         }
203 #endif
204 #ifdef XTENSA
205       if (bytes <= 6*4 && bytes + STACK_ARG_SIZE((*ptr)->size) > 6*4)
206         bytes = 6*4;
207 #endif
208 
209       bytes += STACK_ARG_SIZE((*ptr)->size);
210     }
211 #endif
212     }
213 
214   cif->bytes = bytes;
215 
216   /* Perform machine dependent cif processing */
217 #ifdef FFI_TARGET_SPECIFIC_VARIADIC
218   if (isvariadic)
219     return ffi_prep_cif_machdep_var(cif, nfixedargs, ntotalargs);
220 #endif
221 
222   return ffi_prep_cif_machdep(cif);
223 }
224 #endif /* not __CRIS__ */
225 
226 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
227                  ffi_type *rtype, ffi_type **atypes)
228 {
229   return ffi_prep_cif_core(cif, abi, 0, nargs, nargs, rtype, atypes);
230 }
231 
232 ffi_status ffi_prep_cif_var(ffi_cif *cif,
233                             ffi_abi abi,
234                             unsigned int nfixedargs,
235                             unsigned int ntotalargs,
236                             ffi_type *rtype,
237                             ffi_type **atypes)
238 {
239   return ffi_prep_cif_core(cif, abi, 1, nfixedargs, ntotalargs, rtype, atypes);
240 }
241 
242 #if FFI_CLOSURES
243 
244 ffi_status
245 ffi_prep_closure (ffi_closure* closure,
246           ffi_cif* cif,
247           void (*fun)(ffi_cif*,void*,void**,void*),
248           void *user_data)
249 {
250   return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
251 }
252 
253 #endif