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 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 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 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
