diff options
Diffstat (limited to 'Objective-C/PyObjC/libffi_support.m')
| -rw-r--r-- | Objective-C/PyObjC/libffi_support.m | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/Objective-C/PyObjC/libffi_support.m b/Objective-C/PyObjC/libffi_support.m new file mode 100644 index 0000000..4bc1137 --- /dev/null +++ b/Objective-C/PyObjC/libffi_support.m @@ -0,0 +1,401 @@ +/* + * Support for libffi (http://sources.redhat.com/libffi) + * + * libffi is a library that makes it possible to dynamicly create calls + * to C functions (without knowing the signature at compile-time). It also + * provides a way to create closures, that is dynamicly create functions with + * a runtime specified interface. + * + * This file contains functions to dynamicly call objc_msgSendSuper and to + * dynamicly create IMPs for use in Objective-C method dispatch tables. The + * file 'register.m' contains compile-time generated equivalents of these. + */ +#include "pyobjc.h" + +#import <Foundation/NSDictionary.h> +#import <Foundation/NSString.h> +#import <Foundation/NSHost.h> + +#ifdef MACOSX +/* + * Define SMALL_STRUCT_LIMIT as the largest struct that will be returned + * in registers instead of with a hidden pointer argument. + */ + +#if defined(__ppc__) + +# define SMALL_STRUCT_LIMIT 4 + +#elif defined(__i386__) + +# define SMALL_STRUCT_LIMIT 8 + +#else + +# error "Unsupported MACOSX platform" + +#endif + +#endif /* MACOSX */ + + + +#if 0 /* Usefull during debugging, only used in the debugger */ +static void describe_ffitype(ffi_type* type) +{ + switch (type->type) { + case FFI_TYPE_VOID: printf("%s", "void"); break; + case FFI_TYPE_INT: printf("%s", "int"); break; + case FFI_TYPE_FLOAT: printf("%s", "float"); break; + case FFI_TYPE_DOUBLE: printf("%s", "double"); break; + case FFI_TYPE_UINT8: printf("%s", "uint8"); break; + case FFI_TYPE_SINT8: printf("%s", "sint8"); break; + case FFI_TYPE_UINT16: printf("%s", "uint16"); break; + case FFI_TYPE_SINT16: printf("%s", "sint16"); break; + case FFI_TYPE_UINT32: printf("%s", "uint32"); break; + case FFI_TYPE_SINT32: printf("%s", "sint32"); break; + case FFI_TYPE_UINT64: printf("%s", "uint64"); break; + case FFI_TYPE_SINT64: printf("%s", "sint64"); break; + case FFI_TYPE_POINTER: printf("%s", "*"); break; + case FFI_TYPE_STRUCT: { + ffi_type** elems = type->elements; + + printf("%s", "struct { "); + if (elems) { + while (*elems) { + describe_ffitype(*(elems++)); + printf("%s", "; "); + } + } + printf("%s", "}"); + } + break; + + default: + // Don't abort, this is called from the debugger + printf("?(%d)", type->type); + } +} + +static void describe_cif(ffi_cif* cif) +{ + size_t i; + printf("<ffi_cif abi=%d nargs=%d bytes=%d flags=%#x args=[", + cif->abi, cif->nargs, cif->bytes, cif->flags); + for (i = 0; i < cif->nargs; i++) { + describe_ffitype(cif->arg_types[i]); + printf("%s", ", "); + } + printf("%s", "] rettype="); + describe_ffitype(cif->rtype); + printf("%s", ">\n"); +} + +#endif + + +static Py_ssize_t +num_struct_fields(const char* argtype) +{ + Py_ssize_t res = 0; + + if (*argtype != _C_STRUCT_B) return -1; + while (*argtype != _C_STRUCT_E && *argtype != '=') argtype++; + if (*argtype == _C_STRUCT_E) return 0; + + argtype++; + while (*argtype != _C_STRUCT_E) { + argtype = PyObjCRT_SkipTypeSpec(argtype); + if (argtype == NULL) return -1; + res ++; + } + return res; +} + + +static void +free_type(void *obj) +{ + PyMem_Free(((ffi_type*)obj)->elements); + PyMem_Free(obj); +} + +static ffi_type* signature_to_ffi_type(const char* argtype); + +static ffi_type* +array_to_ffi_type(const char* argtype) +{ + static NSMutableDictionary* array_types = nil; + NSValue *v; + ffi_type* type; + Py_ssize_t field_count; + Py_ssize_t i; + const NSString* key = [NSString stringWithUTF8String: argtype]; + + if (array_types == NULL || array_types == nil) { + array_types = [NSMutableDictionary dictionaryWithCapacity: 100]; + if (array_types == NULL || array_types == nil) return NULL; + } + + v = [array_types objectForKey: key]; + if (v != nil) { + return (ffi_type*)[v pointerValue]; + } + + /* We don't have a type description yet, dynamicly + * create it. + */ + field_count = atoi(argtype+1); + + type = PyMem_Malloc(sizeof(*type)); + if (type == NULL) { + PyErr_NoMemory(); + return NULL; + } + type->size = PyObjCRT_SizeOfType(argtype); + type->alignment = PyObjCRT_AlignOfType(argtype); + + /* Libffi doesn't really know about arrays as part of larger + * data-structres (e.g. struct foo { int field[3]; };). We fake it + * by treating the nested array as a struct. This seems to work + * fine on MacOS X. + */ + type->type = FFI_TYPE_STRUCT; + type->elements = PyMem_Malloc((1+field_count) * sizeof(ffi_type*)); + if (type->elements == NULL) { + PyMem_Free(type); + PyErr_NoMemory(); + return NULL; + } + + while (isdigit(*++argtype)); + type->elements[0] = signature_to_ffi_type(argtype); + for (i = 1; i < field_count; i++) { + type->elements[i] = type->elements[0]; + } + type->elements[field_count] = 0; + + v = [NSValue valueWithPointer: type]; + if (v == NULL || v == nil) { + free_type(type); + return NULL; + } + + NS_DURING + { + [array_types setObject: v forKey: key]; + } + NS_HANDLER + { + NS_VALUERETURN (NULL, ffi_type*); + } + NS_ENDHANDLER + + return type; +} + +static ffi_type* +struct_to_ffi_type(const char* argtype) +{ + static NSMutableDictionary* struct_types = nil; + NSValue* v; + ffi_type* type; + Py_ssize_t field_count; + const char* curtype; + const NSString* key = [NSString stringWithUTF8String: argtype]; + + if (struct_types == NULL || struct_types == nil) { + struct_types = [NSMutableDictionary dictionaryWithCapacity: 100]; + if (struct_types == NULL || struct_types == nil) return NULL; + } + + v = [struct_types objectForKey: key]; + if (v != nil) { + return (ffi_type*)[v pointerValue]; + } + + /* We don't have a type description yet, dynamicly + * create it. + */ + field_count = num_struct_fields(argtype); + if (field_count == -1) { +#ifdef STRICT_TYPE_PARSING + [[NSException exceptionWithName: @"PyObjCExc_InternalError" + reason: [NSString stringWithFormat: @"Cannot determine layout of %s", argtype] + userInfo: NULL] raise]; +#else + NSLog (@"PyObjCExc_InternalError: Cannot determine layout of %s", argtype); +#endif + return NULL; + } + + type = PyMem_Malloc(sizeof(*type)); + if (type == NULL) { + PyErr_NoMemory(); + return NULL; + } + type->size = PyObjCRT_SizeOfType(argtype); + type->alignment = PyObjCRT_AlignOfType(argtype); + type->type = FFI_TYPE_STRUCT; + type->elements = PyMem_Malloc((1+field_count) * sizeof(ffi_type*)); + if (type->elements == NULL) { + PyMem_Free(type); + PyErr_NoMemory(); + return NULL; + } + + field_count = 0; + curtype = argtype+1; + while (*curtype != _C_STRUCT_E && *curtype != '=') curtype++; + if (*curtype == '=') { + curtype ++; + while (*curtype != _C_STRUCT_E) { + type->elements[field_count] = + signature_to_ffi_type(curtype); + if (type->elements[field_count] == NULL) { + PyMem_Free(type->elements); + return NULL; + } + field_count++; + curtype = PyObjCRT_SkipTypeSpec(curtype); + if (curtype == NULL) { + PyMem_Free(type->elements); + return NULL; + } + } + } + type->elements[field_count] = NULL; + + v = [NSValue valueWithPointer: type]; + if (v == NULL || v == nil) { + free_type(type); + return NULL; + } + + NS_DURING + { + [struct_types setObject: v forKey: key]; + } + NS_HANDLER + { + NS_VALUERETURN (NULL, ffi_type*); + } + NS_ENDHANDLER + + return type; +} + +ffi_type* +objcl_pyobjc_signature_to_ffi_return_type(const char* argtype) +{ + switch (*argtype) { + case _C_CHR: case _C_SHT: + return &ffi_type_sint; + case _C_UCHR: case _C_USHT: + return &ffi_type_uint; +#ifdef _C_BOOL + case _C_BOOL: return &ffi_type_sint; +#endif + default: + return signature_to_ffi_type(argtype); + } +} + + +static ffi_type* +signature_to_ffi_type(const char* argtype) +{ + switch (*argtype) { + case _C_VOID: return &ffi_type_void; + case _C_ID: return &ffi_type_pointer; + case _C_CLASS: return &ffi_type_pointer; + case _C_SEL: return &ffi_type_pointer; + case _C_CHR: return &ffi_type_schar; +#ifdef _C_BOOL + case _C_BOOL: return &ffi_type_sint; +#endif + case _C_UCHR: return &ffi_type_uchar; + case _C_SHT: return &ffi_type_sshort; + case _C_USHT: return &ffi_type_ushort; + case _C_INT: return &ffi_type_sint; + case _C_UINT: return &ffi_type_uint; + + /* The next to defintions are incorrect, but the correct definitions + * don't work (e.g. give testsuite failures). We should be fine + * as long as sizeof(long) == sizeof(int) + */ + case _C_LNG: return &ffi_type_sint; /* ffi_type_slong */ + case _C_ULNG: return &ffi_type_uint; /* ffi_type_ulong */ + case _C_LNGLNG: return &ffi_type_sint64; + case _C_ULNGLNG: return &ffi_type_uint64; + case _C_FLT: return &ffi_type_float; + case _C_DBL: return &ffi_type_double; + case _C_CHARPTR: return &ffi_type_pointer; + case _C_PTR: return &ffi_type_pointer; + case _C_ARY_B: + return array_to_ffi_type(argtype); + case _C_IN: case _C_OUT: case _C_INOUT: case _C_CONST: + return signature_to_ffi_type(argtype+1); + case _C_STRUCT_B: + return struct_to_ffi_type(argtype); + default: +#ifdef STRICT_TYPE_PARSING + [[NSException exceptionWithName: @"PyExc_NotImplementedError" + reason: [NSString stringWithFormat: @"Type '%c' not supported", *argtype] + userInfo: NULL] raise]; +#else + NSLog (@"PyExc_NotImplementedError: Type '%#x' not supported", *argtype); +#endif + return NULL; + } +} + +/* + * arg_signature_to_ffi_type: Make the ffi_type for the call to the method IMP, + * on MacOS X this is the same as the normal signature_to_ffi_type, but on + * Linux/GNUstep we need a slightly different function. + */ +#ifdef MACOSX + +#ifdef __ppc__ +ffi_type* +objcl_pyobjc_arg_signature_to_ffi_type(const char* argtype) +{ + return signature_to_ffi_type (argtype); +} + +#else +ffi_type* +objcl_pyobjc_arg_signature_to_ffi_type(const char* argtype) +{ + /* NOTE: This is the minimal change to pass the unittests, it is not + * based on analysis of the calling conventions. + */ + switch (*argtype) { + case _C_CHR: return &ffi_type_sint; + case _C_UCHR: return &ffi_type_uint; + case _C_SHT: return &ffi_type_sint; + case _C_USHT: return &ffi_type_uint; + default: return signature_to_ffi_type(argtype); + } +} +#endif + +#else /* GNUstep */ + +ffi_type* +objcl_pyobjc_arg_signature_to_ffi_type(const char* argtype) +{ + /* NOTE: This is the minimal change to pass the unittests, it is not + * based on analysis of the calling conventions. + */ + switch (*argtype) { + case _C_CHR: return &ffi_type_sint; + case _C_UCHR: return &ffi_type_uint; + case _C_SHT: return &ffi_type_sint; + case _C_USHT: return &ffi_type_uint; + default: return signature_to_ffi_type(argtype); + } +} + +#endif /* GNUstep */ |