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) 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 #ifdef _M_ARM64
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   return ffi_prep_cif_core(cif, abi, 1, nfixedargs, ntotalargs, rtype, atypes);
235 }
236 
237 #if FFI_CLOSURES
238 
239 ffi_status
240 ffi_prep_closure (ffi_closure* closure,
241           ffi_cif* cif,
242           void (*fun)(ffi_cif*,void*,void**,void*),
243           void *user_data)
244 {
245   return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
246 }
247 
248 #endif
249 
250 ffi_status
251 ffi_get_struct_offsets (ffi_abi abi, ffi_type *struct_type, size_t *offsets)
252 {
253   if (! (abi > FFI_FIRST_ABI && abi < FFI_LAST_ABI))
254     return FFI_BAD_ABI;
255   if (struct_type->type != FFI_TYPE_STRUCT)
256     return FFI_BAD_TYPEDEF;
257 
258 #if HAVE_LONG_DOUBLE_VARIANT
259   ffi_prep_types (abi);
260 #endif
261 
262   return initialize_aggregate(struct_type, offsets);
263 }