0e2e1166ad992c0931102e1e88d0ccb3c89080f0
[libffi.git] / src / prep_cif.c
1 /* -----------------------------------------------------------------------
2 prep_cif.c - Copyright (c) 2011 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 if (! (abi > FFI_FIRST_ABI && abi < FFI_LAST_ABI))
115 return FFI_BAD_ABI;
116
117 cif->abi = abi;
118 cif->arg_types = atypes;
119 cif->nargs = ntotalargs;
120 cif->rtype = rtype;
121
122 cif->flags = 0;
123
124 /* Initialize the return type if necessary */
125 if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))
126 return FFI_BAD_TYPEDEF;
127
128 /* Perform a sanity check on the return type */
129 FFI_ASSERT_VALID_TYPE(cif->rtype);
130
131 /* x86, x86-64 and s390 stack space allocation is handled in prep_machdep. */
132 #if !defined M68K && !defined X86_ANY && !defined S390 && !defined PA
133 /* Make space for the return structure pointer */
134 if (cif->rtype->type == FFI_TYPE_STRUCT
135 #ifdef SPARC
136 && (cif->abi != FFI_V9 || cif->rtype->size > 32)
137 #endif
138 )
139 bytes = STACK_ARG_SIZE(sizeof(void*));
140 #endif
141
142 for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
143 {
144
145 /* Initialize any uninitialized aggregate type definitions */
146 if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
147 return FFI_BAD_TYPEDEF;
148
149 /* Perform a sanity check on the argument type, do this
150 check after the initialization. */
151 FFI_ASSERT_VALID_TYPE(*ptr);
152
153 #if !defined X86_ANY && !defined S390 && !defined PA
154 #ifdef SPARC
155 if (((*ptr)->type == FFI_TYPE_STRUCT
156 && ((*ptr)->size > 16 || cif->abi != FFI_V9))
157 || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
158 && cif->abi != FFI_V9))
159 bytes += sizeof(void*);
160 else
161 #endif
162 {
163 /* Add any padding if necessary */
164 if (((*ptr)->alignment - 1) & bytes)
165 bytes = ALIGN(bytes, (*ptr)->alignment);
166
167 bytes += STACK_ARG_SIZE((*ptr)->size);
168 }
169 #endif
170 }
171
172 cif->bytes = bytes;
173
174 /* Perform machine dependent cif processing */
175 #ifdef FFI_TARGET_SPECIFIC_VARIADIC
176 if (isvariadic)
177 return ffi_prep_cif_machdep_var(cif, nfixedargs, ntotalargs);
178 #endif
179
180 return ffi_prep_cif_machdep(cif);
181 }
182 #endif /* not __CRIS__ */
183
184 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
185 ffi_type *rtype, ffi_type **atypes)
186 {
187 return ffi_prep_cif_core(cif, abi, 0, nargs, nargs, rtype, atypes);
188 }
189
190 ffi_status ffi_prep_cif_var(ffi_cif *cif,
191 ffi_abi abi,
192 unsigned int nfixedargs,
193 unsigned int ntotalargs,
194 ffi_type *rtype,
195 ffi_type **atypes)
196 {
197 return ffi_prep_cif_core(cif, abi, 1, nfixedargs, ntotalargs, rtype, atypes);
198 }
199
200 #if FFI_CLOSURES
201
202 ffi_status
203 ffi_prep_closure (ffi_closure* closure,
204 ffi_cif* cif,
205 void (*fun)(ffi_cif*,void*,void**,void*),
206 void *user_data)
207 {
208 return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
209 }
210
211 #endif