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 #include <stdlib.h>
27
28
29 /* Round up to FFI_SIZEOF_ARG. */
30
31 #define STACK_ARG_SIZE(x) ALIGN(x, FFI_SIZEOF_ARG)
32
33 /* Perform machine independent initialization of aggregate type
34 specifications. */
35
initialize_aggregate(ffi_type * arg)36 static ffi_status initialize_aggregate(/*@out@*/ ffi_type *arg)
37 {
38 ffi_type **ptr;
39
40 FFI_ASSERT(arg != NULL);
41
42 /*@-usedef@*/
43
44 FFI_ASSERT(arg->elements != NULL);
45 FFI_ASSERT(arg->size == 0);
46 FFI_ASSERT(arg->alignment == 0);
47
48 ptr = &(arg->elements[0]);
49
50 while ((*ptr) != NULL)
51 {
52 if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
53 return FFI_BAD_TYPEDEF;
54
55 /* Perform a sanity check on the argument type */
56 FFI_ASSERT_VALID_TYPE(*ptr);
57
58 arg->size = ALIGN(arg->size, (*ptr)->alignment);
59 arg->size += (*ptr)->size;
60
61 arg->alignment = (arg->alignment > (*ptr)->alignment) ?
62 arg->alignment : (*ptr)->alignment;
63
64 ptr++;
65 }
66
67 /* Structure size includes tail padding. This is important for
68 structures that fit in one register on ABIs like the PowerPC64
69 Linux ABI that right justify small structs in a register.
70 It's also needed for nested structure layout, for example
71 struct A { long a; char b; }; struct B { struct A x; char y; };
72 should find y at an offset of 2*sizeof(long) and result in a
73 total size of 3*sizeof(long). */
74 arg->size = ALIGN (arg->size, arg->alignment);
75
76 if (arg->size == 0)
77 return FFI_BAD_TYPEDEF;
78 else
79 return FFI_OK;
80
81 /*@=usedef@*/
82 }
83
84 /* Perform machine independent ffi_cif preparation, then call
85 machine dependent routine. */
86
ffi_prep_cif(ffi_cif * cif,ffi_abi abi,unsigned int nargs,ffi_type * rtype,ffi_type ** atypes)87 ffi_status ffi_prep_cif(/*@out@*/ /*@partial@*/ ffi_cif *cif,
88 ffi_abi abi, unsigned int nargs,
89 /*@dependent@*/ /*@out@*/ /*@partial@*/ ffi_type *rtype,
90 /*@dependent@*/ ffi_type **atypes)
91 {
92 unsigned bytes = 0;
93 unsigned int i;
94 ffi_type **ptr;
95
96 FFI_ASSERT(cif != NULL);
97 FFI_ASSERT((abi > FFI_FIRST_ABI) && (abi <= FFI_DEFAULT_ABI));
98
99 cif->abi = abi;
100 cif->arg_types = atypes;
101 cif->nargs = nargs;
102 cif->rtype = rtype;
103
104 cif->flags = 0;
105
106 /* Initialize the return type if necessary */
107 /*@-usedef@*/
108 if ((cif->rtype->size == 0) && (initialize_aggregate(cif->rtype) != FFI_OK))
109 return FFI_BAD_TYPEDEF;
110 /*@=usedef@*/
111
112 /* Perform a sanity check on the return type */
113 FFI_ASSERT_VALID_TYPE(cif->rtype);
114
115 /* x86-64 and s390 stack space allocation is handled in prep_machdep. */
116 #if !defined M68K && !defined __x86_64__ && !defined S390
117 /* Make space for the return structure pointer */
118 if (cif->rtype->type == FFI_TYPE_STRUCT
119 #ifdef _WIN32
120 && (cif->rtype->size > 8) /* MSVC returns small structs in registers */
121 #endif
122 #ifdef SPARC
123 && (cif->abi != FFI_V9 || cif->rtype->size > 32)
124 #endif
125 )
126 bytes = STACK_ARG_SIZE(sizeof(void*));
127 #endif
128
129 for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++)
130 {
131
132 /* Initialize any uninitialized aggregate type definitions */
133 if (((*ptr)->size == 0) && (initialize_aggregate((*ptr)) != FFI_OK))
134 return FFI_BAD_TYPEDEF;
135
136 /* Perform a sanity check on the argument type, do this
137 check after the initialization. */
138 FFI_ASSERT_VALID_TYPE(*ptr);
139
140 #if !defined __x86_64__ && !defined S390
141 #ifdef SPARC
142 if (((*ptr)->type == FFI_TYPE_STRUCT
143 && ((*ptr)->size > 16 || cif->abi != FFI_V9))
144 || ((*ptr)->type == FFI_TYPE_LONGDOUBLE
145 && cif->abi != FFI_V9))
146 bytes += sizeof(void*);
147 else
148 #endif
149 {
150 #if !defined(_MSC_VER) && !defined(__MINGW32__)
151 /* Don't know if this is a libffi bug or not. At least on
152 Windows with MSVC, function call parameters are *not*
153 aligned in the same way as structure fields are, they are
154 only aligned in integer boundaries.
155
156 This doesn't do any harm for cdecl functions and closures,
157 since the caller cleans up the stack, but it is wrong for
158 stdcall functions where the callee cleans.
159 */
160
161 /* Add any padding if necessary */
162 if (((*ptr)->alignment - 1) & bytes)
163 bytes = ALIGN(bytes, (*ptr)->alignment);
164
165 #endif
166 bytes += STACK_ARG_SIZE((*ptr)->size);
167 }
168 #endif
169 }
170
171 #ifdef _WIN64
172 /* Function call needs at least 40 bytes stack size, on win64 AMD64 */
173 if (bytes < 40)
174 bytes = 40;
175 #endif
176
177 cif->bytes = bytes;
178
179 /* Perform machine dependent cif processing */
180 return ffi_prep_cif_machdep(cif);
181 }
182