Rebased from gcc
[libffi.git] / 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_DEFAULT_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 )
144 bytes = STACK_ARG_SIZE(sizeof(void*));
145 #endif
146
147 for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
148 {
149
150 /* Initialize any uninitialized aggregate type definitions */
151 if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
152 return FFI_BAD_TYPEDEF;
153
154 /* Perform a sanity check on the argument type, do this
155 check after the initialization. */
156 FFI_ASSERT_VALID_TYPE(*ptr);
157
158 #if !defined X86_ANY && !defined S390 && !defined PA
159 #ifdef SPARC
160 if (((*ptr)->type == FFI_TYPE_STRUCT
161 && ((*ptr)->size > 16 || cif->abi != FFI_V9))
162 || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
163 && cif->abi != FFI_V9))
164 bytes += sizeof(void*);
165 else
166 #endif
167 {
168 /* Add any padding if necessary */
169 if (((*ptr)->alignment - 1) & bytes)
170 bytes = ALIGN(bytes, (*ptr)->alignment);
171
172 bytes += STACK_ARG_SIZE((*ptr)->size);
173 }
174 #endif
175 }
176
177 cif->bytes = bytes;
178
179 /* Perform machine dependent cif processing */
180 #ifdef FFI_TARGET_SPECIFIC_VARIADIC
181 if (isvariadic)
182 return ffi_prep_cif_machdep_var(cif, nfixedargs, ntotalargs);
183 #endif
184
185 return ffi_prep_cif_machdep(cif);
186 }
187 #endif /* not __CRIS__ */
188
189 ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi, unsigned int nargs,
190 ffi_type *rtype, ffi_type **atypes)
191 {
192 return ffi_prep_cif_core(cif, abi, 0, nargs, nargs, rtype, atypes);
193 }
194
195 ffi_status ffi_prep_cif_var(ffi_cif *cif,
196 ffi_abi abi,
197 unsigned int nfixedargs,
198 unsigned int ntotalargs,
199 ffi_type *rtype,
200 ffi_type **atypes)
201 {
202 return ffi_prep_cif_core(cif, abi, 1, nfixedargs, ntotalargs, rtype, atypes);
203 }
204
205 #if FFI_CLOSURES
206
207 ffi_status
208 ffi_prep_closure (ffi_closure* closure,
209 ffi_cif* cif,
210 void (*fun)(ffi_cif*,void*,void**,void*),
211 void *user_data)
212 {
213 return ffi_prep_closure_loc (closure, cif, fun, user_data, closure);
214 }
215
216 #endif