1 /* -----------------------------------------------------------------------
2 prep_cif.c - Copyright (c) 1996, 1998 Red Hat, Inc.
3
4 Permission is hereby granted, free of charge, to any person obtaining
5 a copy of this software and associated documentation files (the
6 ``Software''), to deal in the Software without restriction, including
7 without limitation the rights to use, copy, modify, merge, publish,
8 distribute, sublicense, and/or sell copies of the Software, and to
9 permit persons to whom the Software is furnished to do so, subject to
10 the following conditions:
11
12 The above copyright notice and this permission notice shall be included
13 in all copies or substantial portions of the Software.
14
15 THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS
16 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 IN NO EVENT SHALL CYGNUS SOLUTIONS BE LIABLE FOR ANY CLAIM, DAMAGES OR
19 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21 OTHER DEALINGS IN THE SOFTWARE.
22 ----------------------------------------------------------------------- */
23
24 #include <ffi.h>
25 #include <ffi_common.h>
26
27 #include <stdbool.h>
28 #include <stdlib.h>
29
30 /* Round up to FFI_SIZEOF_ARG. */
31 #define STACK_ARG_SIZE(x) ALIGN(x, FFI_SIZEOF_ARG)
32
33 /* Perform machine independent initialization of aggregate type
34 specifications. */
35
36 static ffi_status
initialize_aggregate(ffi_type * arg)37 initialize_aggregate(
38 /*@out@*/ ffi_type* arg)
39 {
40 /*@-usedef@*/
41
42 if (arg == NULL || arg->elements == NULL ||
43 arg->size != 0 || arg->alignment != 0)
44 return FFI_BAD_TYPEDEF;
45
46 ffi_type** ptr = &(arg->elements[0]);
47
48 while ((*ptr) != NULL)
49 {
50 if (((*ptr)->size == 0) && (initialize_aggregate(*ptr) != FFI_OK))
51 return FFI_BAD_TYPEDEF;
52
53 /* Perform a sanity check on the argument type */
54 FFI_ASSERT_VALID_TYPE(*ptr);
55
56 #ifdef POWERPC_DARWIN
57 int curalign = (*ptr)->alignment;
58
59 if (ptr != &(arg->elements[0]))
60 {
61 if (curalign > 4 && curalign != 16)
62 curalign = 4;
63 }
64
65 arg->size = ALIGN(arg->size, curalign);
66 arg->size += (*ptr)->size;
67 arg->alignment = (arg->alignment > curalign) ?
68 arg->alignment : curalign;
69 #else
70 arg->size = ALIGN(arg->size, (*ptr)->alignment);
71 arg->size += (*ptr)->size;
72 arg->alignment = (arg->alignment > (*ptr)->alignment) ?
73 arg->alignment : (*ptr)->alignment;
74 #endif
75
76 ptr++;
77 }
78
79 /* Structure size includes tail padding. This is important for
80 structures that fit in one register on ABIs like the PowerPC64
81 Linux ABI that right justify small structs in a register.
82 It's also needed for nested structure layout, for example
83 struct A { long a; char b; }; struct B { struct A x; char y; };
84 should find y at an offset of 2*sizeof(long) and result in a
85 total size of 3*sizeof(long). */
86 arg->size = ALIGN(arg->size, arg->alignment);
87
88 if (arg->size == 0)
89 return FFI_BAD_TYPEDEF;
90
91 return FFI_OK;
92
93 /*@=usedef@*/
94 }
95
96 #ifndef __CRIS__
97 /* The CRIS ABI specifies structure elements to have byte
98 alignment only, so it completely overrides this functions,
99 which assumes "natural" alignment and padding. */
100
101 /* Perform machine independent ffi_cif preparation, then call
102 machine dependent routine. */
103
104 #if defined(X86_DARWIN) && !defined __x86_64__
105
106 static inline bool
struct_on_stack(int size)107 struct_on_stack(
108 int size)
109 {
110 if (size > 8)
111 return true;
112
113 /* This is not what the ABI says, but is what is really implemented */
114 switch (size)
115 {
116 case 1:
117 case 2:
118 case 4:
119 case 8:
120 return false;
121
122 default:
123 return true;
124 }
125 }
126
127 #endif // defined(X86_DARWIN) && !defined __x86_64__
128
129 // Arguments' ffi_type->alignment must be nonzero.
130 ffi_status
ffi_prep_cif(ffi_cif * cif,ffi_abi abi,unsigned int nargs,ffi_type * rtype,ffi_type ** atypes)131 ffi_prep_cif(
132 /*@out@*/ /*@partial@*/ ffi_cif* cif,
133 ffi_abi abi,
134 unsigned int nargs,
135 /*@dependent@*/ /*@out@*/ /*@partial@*/ ffi_type* rtype,
136 /*@dependent@*/ ffi_type** atypes)
137 {
138 if (cif == NULL)
139 return FFI_BAD_TYPEDEF;
140
141 if (abi <= FFI_FIRST_ABI || abi > FFI_DEFAULT_ABI)
142 return FFI_BAD_ABI;
143
144 unsigned int bytes = 0;
145 unsigned int i;
146 ffi_type** ptr;
147
148 cif->abi = abi;
149 cif->arg_types = atypes;
150 cif->nargs = nargs;
151 cif->rtype = rtype;
152 cif->flags = 0;
153
154 /* Initialize the return type if necessary */
155 /*@-usedef@*/
156 if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))
157 return FFI_BAD_TYPEDEF;
158 /*@=usedef@*/
159
160 /* Perform a sanity check on the return type */
161 FFI_ASSERT_VALID_TYPE(cif->rtype);
162
163 /* x86-64 and s390 stack space allocation is handled in prep_machdep. */
164 #if !defined M68K && !defined __x86_64__ && !defined S390 && !defined PA
165 /* Make space for the return structure pointer */
166 if (cif->rtype->type == FFI_TYPE_STRUCT
167 #ifdef SPARC
168 && (cif->abi != FFI_V9 || cif->rtype->size > 32)
169 #endif
170 #ifdef X86_DARWIN
171 && (struct_on_stack(cif->rtype->size))
172 #endif
173 )
174 bytes = STACK_ARG_SIZE(sizeof(void*));
175 #endif
176
177 for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
178 {
179 /* Initialize any uninitialized aggregate type definitions */
180 if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
181 return FFI_BAD_TYPEDEF;
182
183 if ((*ptr)->alignment == 0)
184 return FFI_BAD_TYPEDEF;
185
186 /* Perform a sanity check on the argument type, do this
187 check after the initialization. */
188 FFI_ASSERT_VALID_TYPE(*ptr);
189
190 #if defined(X86_DARWIN)
191 {
192 int align = (*ptr)->alignment;
193
194 if (align > 4)
195 align = 4;
196
197 if ((align - 1) & bytes)
198 bytes = ALIGN(bytes, align);
199
200 bytes += STACK_ARG_SIZE((*ptr)->size);
201 }
202 #elif !defined __x86_64__ && !defined S390 && !defined PA
203 #ifdef SPARC
204 if (((*ptr)->type == FFI_TYPE_STRUCT
205 && ((*ptr)->size > 16 || cif->abi != FFI_V9))
206 || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
207 && cif->abi != FFI_V9))
208 bytes += sizeof(void*);
209 else
210 #endif
211 {
212 /* Add any padding if necessary */
213 if (((*ptr)->alignment - 1) & bytes)
214 bytes = ALIGN(bytes, (*ptr)->alignment);
215
216 bytes += STACK_ARG_SIZE((*ptr)->size);
217 }
218 #endif
219 }
220
221 cif->bytes = bytes;
222
223 /* Perform machine dependent cif processing */
224 return ffi_prep_cif_machdep(cif);
225 }
226 #endif /* not __CRIS__ */
227