/* Copyright (C) 2010-2016 Free Software Foundation, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 3 of * the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301 USA */ #if HAVE_CONFIG_H # include #endif #include #include #include #include #include #include #include "libguile/_scm.h" #include "libguile/bytevectors.h" #include "libguile/instructions.h" #include "libguile/threads.h" #include "libguile/foreign.h" SCM_SYMBOL (sym_void, "void"); SCM_SYMBOL (sym_float, "float"); SCM_SYMBOL (sym_double, "double"); SCM_SYMBOL (sym_uint8, "uint8"); SCM_SYMBOL (sym_int8, "int8"); SCM_SYMBOL (sym_uint16, "uint16"); SCM_SYMBOL (sym_int16, "int16"); SCM_SYMBOL (sym_uint32, "uint32"); SCM_SYMBOL (sym_int32, "int32"); SCM_SYMBOL (sym_uint64, "uint64"); SCM_SYMBOL (sym_int64, "int64"); SCM_SYMBOL (sym_short, "short"); SCM_SYMBOL (sym_int, "int"); SCM_SYMBOL (sym_long, "long"); SCM_SYMBOL (sym_unsigned_short, "unsigned-short"); SCM_SYMBOL (sym_unsigned_int, "unsigned-int"); SCM_SYMBOL (sym_unsigned_long, "unsigned-long"); SCM_SYMBOL (sym_size_t, "size_t"); SCM_SYMBOL (sym_ssize_t, "ssize_t"); SCM_SYMBOL (sym_ptrdiff_t, "ptrdiff_t"); /* that's for pointers, you know. */ SCM_SYMBOL (sym_asterisk, "*"); SCM_SYMBOL (sym_null, "%null-pointer"); SCM_SYMBOL (sym_null_pointer_error, "null-pointer-error"); /* The cell representing the null pointer. */ static SCM null_pointer; /* Raise a null pointer dereference error. */ static void null_pointer_error (const char *func_name) { scm_error (sym_null_pointer_error, func_name, "null pointer dereference", SCM_EOL, SCM_EOL); } static SCM cif_to_procedure (SCM cif, SCM func_ptr, int with_errno); static SCM pointer_weak_refs = SCM_BOOL_F; static void register_weak_reference (SCM from, SCM to) { scm_weak_table_putq_x (pointer_weak_refs, from, to); } static void pointer_finalizer_trampoline (void *ptr, void *data) { scm_t_pointer_finalizer finalizer = data; finalizer (SCM_POINTER_VALUE (SCM_PACK_POINTER (ptr))); } SCM_DEFINE (scm_pointer_p, "pointer?", 1, 0, 0, (SCM obj), "Return @code{#t} if @var{obj} is a pointer object, " "@code{#f} otherwise.\n") #define FUNC_NAME s_scm_pointer_p { return scm_from_bool (SCM_POINTER_P (obj)); } #undef FUNC_NAME SCM_DEFINE (scm_make_pointer, "make-pointer", 1, 1, 0, (SCM address, SCM finalizer), "Return a foreign pointer object pointing to @var{address}. " "If @var{finalizer} is passed, it should be a pointer to a " "one-argument C function that will be called when the pointer " "object becomes unreachable.") #define FUNC_NAME s_scm_make_pointer { void *c_finalizer; scm_t_uintptr c_address; c_address = scm_to_uintptr_t (address); if (SCM_UNBNDP (finalizer)) c_finalizer = NULL; else { SCM_VALIDATE_POINTER (2, finalizer); c_finalizer = SCM_POINTER_VALUE (finalizer); } return scm_from_pointer ((void *) c_address, c_finalizer); } #undef FUNC_NAME void * scm_to_pointer (SCM pointer) #define FUNC_NAME "scm_to_pointer" { SCM_VALIDATE_POINTER (1, pointer); return SCM_POINTER_VALUE (pointer); } #undef FUNC_NAME SCM scm_from_pointer (void *ptr, scm_t_pointer_finalizer finalizer) { SCM ret; if (ptr == NULL && finalizer == NULL) ret = null_pointer; else { ret = scm_cell (scm_tc7_pointer, (scm_t_bits) ptr); if (finalizer) scm_i_set_finalizer (SCM2PTR (ret), pointer_finalizer_trampoline, finalizer); } return ret; } SCM_DEFINE (scm_pointer_address, "pointer-address", 1, 0, 0, (SCM pointer), "Return the numerical value of @var{pointer}.") #define FUNC_NAME s_scm_pointer_address { SCM_VALIDATE_POINTER (1, pointer); return scm_from_uintptr_t ((scm_t_uintptr) SCM_POINTER_VALUE (pointer)); } #undef FUNC_NAME SCM_DEFINE (scm_pointer_to_scm, "pointer->scm", 1, 0, 0, (SCM pointer), "Unsafely cast @var{pointer} to a Scheme object.\n" "Cross your fingers!") #define FUNC_NAME s_scm_pointer_to_scm { SCM_VALIDATE_POINTER (1, pointer); return SCM_PACK ((scm_t_bits) SCM_POINTER_VALUE (pointer)); } #undef FUNC_NAME SCM_DEFINE (scm_scm_to_pointer, "scm->pointer", 1, 0, 0, (SCM scm), "Return a foreign pointer object with the @code{object-address}\n" "of @var{scm}.") #define FUNC_NAME s_scm_scm_to_pointer { SCM ret; ret = scm_from_pointer ((void*) SCM_UNPACK (scm), NULL); if (SCM_HEAP_OBJECT_P (ret)) register_weak_reference (ret, scm); return ret; } #undef FUNC_NAME SCM_DEFINE (scm_pointer_to_bytevector, "pointer->bytevector", 2, 2, 0, (SCM pointer, SCM len, SCM offset, SCM uvec_type), "Return a bytevector aliasing the @var{len} bytes pointed\n" "to by @var{pointer}.\n\n" "The user may specify an alternate default interpretation for\n" "the memory by passing the @var{uvec_type} argument, to indicate\n" "that the memory is an array of elements of that type.\n" "@var{uvec_type} should be something that\n" "@code{uniform-vector-element-type} would return, like @code{f32}\n" "or @code{s16}.\n\n" "When @var{offset} is passed, it specifies the offset in bytes\n" "relative to @var{pointer} of the memory region aliased by the\n" "returned bytevector.") #define FUNC_NAME s_scm_pointer_to_bytevector { SCM ret; scm_t_int8 *ptr; size_t boffset, blen; scm_t_array_element_type btype; SCM_VALIDATE_POINTER (1, pointer); ptr = SCM_POINTER_VALUE (pointer); if (SCM_UNLIKELY (ptr == NULL)) null_pointer_error (FUNC_NAME); if (SCM_UNBNDP (uvec_type)) btype = SCM_ARRAY_ELEMENT_TYPE_VU8; else { int i; for (i = 0; i <= SCM_ARRAY_ELEMENT_TYPE_LAST; i++) if (scm_is_eq (uvec_type, scm_i_array_element_types[i])) break; switch (i) { case SCM_ARRAY_ELEMENT_TYPE_VU8: case SCM_ARRAY_ELEMENT_TYPE_U8: case SCM_ARRAY_ELEMENT_TYPE_S8: case SCM_ARRAY_ELEMENT_TYPE_U16: case SCM_ARRAY_ELEMENT_TYPE_S16: case SCM_ARRAY_ELEMENT_TYPE_U32: case SCM_ARRAY_ELEMENT_TYPE_S32: case SCM_ARRAY_ELEMENT_TYPE_U64: case SCM_ARRAY_ELEMENT_TYPE_S64: case SCM_ARRAY_ELEMENT_TYPE_F32: case SCM_ARRAY_ELEMENT_TYPE_F64: case SCM_ARRAY_ELEMENT_TYPE_C32: case SCM_ARRAY_ELEMENT_TYPE_C64: btype = i; break; default: scm_wrong_type_arg_msg (FUNC_NAME, SCM_ARG1, uvec_type, "uniform vector type"); } } if (SCM_UNBNDP (offset)) boffset = 0; else boffset = scm_to_size_t (offset); blen = scm_to_size_t (len); ret = scm_c_take_typed_bytevector ((signed char *) ptr + boffset, blen, btype, pointer); return ret; } #undef FUNC_NAME SCM_DEFINE (scm_bytevector_to_pointer, "bytevector->pointer", 1, 1, 0, (SCM bv, SCM offset), "Return a pointer pointer aliasing the memory pointed to by\n" "@var{bv} or @var{offset} bytes after @var{bv} when @var{offset}\n" "is passed.") #define FUNC_NAME s_scm_bytevector_to_pointer { SCM ret; signed char *ptr; size_t boffset; SCM_VALIDATE_BYTEVECTOR (1, bv); ptr = SCM_BYTEVECTOR_CONTENTS (bv); if (SCM_UNBNDP (offset)) boffset = 0; else boffset = scm_to_unsigned_integer (offset, 0, SCM_BYTEVECTOR_LENGTH (bv) - 1); ret = scm_from_pointer (ptr + boffset, NULL); register_weak_reference (ret, bv); return ret; } #undef FUNC_NAME SCM_DEFINE (scm_set_pointer_finalizer_x, "set-pointer-finalizer!", 2, 0, 0, (SCM pointer, SCM finalizer), "Arrange for the C procedure wrapped by @var{finalizer} to be\n" "called on the pointer wrapped by @var{pointer} when @var{pointer}\n" "becomes unreachable. Note: the C procedure should not call into\n" "Scheme. If you need a Scheme finalizer, use guardians.") #define FUNC_NAME s_scm_set_pointer_finalizer_x { SCM_VALIDATE_POINTER (1, pointer); SCM_VALIDATE_POINTER (2, finalizer); scm_i_add_finalizer (SCM2PTR (pointer), pointer_finalizer_trampoline, SCM_POINTER_VALUE (finalizer)); return SCM_UNSPECIFIED; } #undef FUNC_NAME void scm_i_pointer_print (SCM pointer, SCM port, scm_print_state *pstate) { scm_puts ("#', port); } /* Non-primitive helpers functions. These procedures could be implemented in terms of the primitives above but would be inefficient (heap allocation overhead, Scheme/C round trips, etc.) */ SCM_DEFINE (scm_dereference_pointer, "dereference-pointer", 1, 0, 0, (SCM pointer), "Assuming @var{pointer} points to a memory region that\n" "holds a pointer, return this pointer.") #define FUNC_NAME s_scm_dereference_pointer { void **ptr; SCM_VALIDATE_POINTER (1, pointer); ptr = SCM_POINTER_VALUE (pointer); if (SCM_UNLIKELY (ptr == NULL)) null_pointer_error (FUNC_NAME); return scm_from_pointer (*ptr, NULL); } #undef FUNC_NAME SCM_DEFINE (scm_string_to_pointer, "string->pointer", 1, 1, 0, (SCM string, SCM encoding), "Return a foreign pointer to a nul-terminated copy of\n" "@var{string} in the given @var{encoding}, defaulting to\n" "the current locale encoding. The C string is freed when\n" "the returned foreign pointer becomes unreachable.\n\n" "This is the Scheme equivalent of @code{scm_to_stringn}.") #define FUNC_NAME s_scm_string_to_pointer { SCM_VALIDATE_STRING (1, string); /* XXX: Finalizers slow down libgc; they could be avoided if `scm_to_string' & co. were able to use libgc-allocated memory. */ if (SCM_UNBNDP (encoding)) return scm_from_pointer (scm_to_locale_string (string), free); else { char *enc; SCM ret; SCM_VALIDATE_STRING (2, encoding); enc = scm_to_locale_string (encoding); scm_dynwind_begin (0); scm_dynwind_free (enc); ret = scm_from_pointer (scm_to_stringn (string, NULL, enc, scm_i_default_string_failed_conversion_handler ()), free); scm_dynwind_end (); return ret; } } #undef FUNC_NAME SCM_DEFINE (scm_pointer_to_string, "pointer->string", 1, 2, 0, (SCM pointer, SCM length, SCM encoding), "Return the string representing the C string pointed to by\n" "@var{pointer}. If @var{length} is omitted or @code{-1}, the\n" "string is assumed to be nul-terminated. Otherwise\n" "@var{length} is the number of bytes in memory pointed to by\n" "@var{pointer}. The C string is assumed to be in the given\n" "@var{encoding}, defaulting to the current locale encoding.\n\n" "This is the Scheme equivalent of @code{scm_from_stringn}.") #define FUNC_NAME s_scm_pointer_to_string { size_t len; SCM_VALIDATE_POINTER (1, pointer); if (SCM_UNBNDP (length) || scm_is_true (scm_eqv_p (length, scm_from_int (-1)))) len = (size_t)-1; else len = scm_to_size_t (length); if (SCM_UNBNDP (encoding)) return scm_from_locale_stringn (SCM_POINTER_VALUE (pointer), len); else { char *enc; SCM ret; SCM_VALIDATE_STRING (3, encoding); enc = scm_to_locale_string (encoding); scm_dynwind_begin (0); scm_dynwind_free (enc); ret = scm_from_stringn (SCM_POINTER_VALUE (pointer), len, enc, scm_i_default_string_failed_conversion_handler ()); scm_dynwind_end (); return ret; } } #undef FUNC_NAME SCM_DEFINE (scm_alignof, "alignof", 1, 0, 0, (SCM type), "Return the alignment of @var{type}, in bytes.\n\n" "@var{type} should be a valid C type, like @code{int}.\n" "Alternately @var{type} may be the symbol @code{*}, in which\n" "case the alignment of a pointer is returned. @var{type} may\n" "also be a list of types, in which case the alignment of a\n" "@code{struct} with ABI-conventional packing is returned.") #define FUNC_NAME s_scm_alignof { if (SCM_I_INUMP (type)) { switch (SCM_I_INUM (type)) { case SCM_FOREIGN_TYPE_FLOAT: return scm_from_size_t (alignof_type (float)); case SCM_FOREIGN_TYPE_DOUBLE: return scm_from_size_t (alignof_type (double)); case SCM_FOREIGN_TYPE_UINT8: return scm_from_size_t (alignof_type (scm_t_uint8)); case SCM_FOREIGN_TYPE_INT8: return scm_from_size_t (alignof_type (scm_t_int8)); case SCM_FOREIGN_TYPE_UINT16: return scm_from_size_t (alignof_type (scm_t_uint16)); case SCM_FOREIGN_TYPE_INT16: return scm_from_size_t (alignof_type (scm_t_int16)); case SCM_FOREIGN_TYPE_UINT32: return scm_from_size_t (alignof_type (scm_t_uint32)); case SCM_FOREIGN_TYPE_INT32: return scm_from_size_t (alignof_type (scm_t_int32)); case SCM_FOREIGN_TYPE_UINT64: return scm_from_size_t (alignof_type (scm_t_uint64)); case SCM_FOREIGN_TYPE_INT64: return scm_from_size_t (alignof_type (scm_t_int64)); default: scm_wrong_type_arg (FUNC_NAME, 1, type); } } else if (scm_is_eq (type, sym_asterisk)) /* a pointer */ return scm_from_size_t (alignof_type (void*)); else if (scm_is_pair (type)) { /* TYPE is a structure. Section 3-3 of the i386, x86_64, PowerPC, and SPARC P.S. of the System V ABI all say: "Aggregates (structures and arrays) and unions assume the alignment of their most strictly aligned component." */ size_t max; for (max = 0; scm_is_pair (type); type = SCM_CDR (type)) { size_t align; align = scm_to_size_t (scm_alignof (SCM_CAR (type))); if (align > max) max = align; } return scm_from_size_t (max); } else scm_wrong_type_arg (FUNC_NAME, 1, type); } #undef FUNC_NAME SCM_DEFINE (scm_sizeof, "sizeof", 1, 0, 0, (SCM type), "Return the size of @var{type}, in bytes.\n\n" "@var{type} should be a valid C type, like @code{int}.\n" "Alternately @var{type} may be the symbol @code{*}, in which\n" "case the size of a pointer is returned. @var{type} may also\n" "be a list of types, in which case the size of a @code{struct}\n" "with ABI-conventional packing is returned.") #define FUNC_NAME s_scm_sizeof { if (SCM_I_INUMP (type)) { switch (SCM_I_INUM (type)) { case SCM_FOREIGN_TYPE_FLOAT: return scm_from_size_t (sizeof (float)); case SCM_FOREIGN_TYPE_DOUBLE: return scm_from_size_t (sizeof (double)); case SCM_FOREIGN_TYPE_UINT8: return scm_from_size_t (sizeof (scm_t_uint8)); case SCM_FOREIGN_TYPE_INT8: return scm_from_size_t (sizeof (scm_t_int8)); case SCM_FOREIGN_TYPE_UINT16: return scm_from_size_t (sizeof (scm_t_uint16)); case SCM_FOREIGN_TYPE_INT16: return scm_from_size_t (sizeof (scm_t_int16)); case SCM_FOREIGN_TYPE_UINT32: return scm_from_size_t (sizeof (scm_t_uint32)); case SCM_FOREIGN_TYPE_INT32: return scm_from_size_t (sizeof (scm_t_int32)); case SCM_FOREIGN_TYPE_UINT64: return scm_from_size_t (sizeof (scm_t_uint64)); case SCM_FOREIGN_TYPE_INT64: return scm_from_size_t (sizeof (scm_t_int64)); default: scm_wrong_type_arg (FUNC_NAME, 1, type); } } else if (scm_is_eq (type, sym_asterisk)) /* a pointer */ return scm_from_size_t (sizeof (void*)); else if (scm_is_pair (type)) { /* a struct */ size_t off = 0; size_t align = scm_to_size_t (scm_alignof(type)); while (scm_is_pair (type)) { off = ROUND_UP (off, scm_to_size_t (scm_alignof (scm_car (type)))); off += scm_to_size_t (scm_sizeof (scm_car (type))); type = scm_cdr (type); } return scm_from_size_t (ROUND_UP(off, align)); } else scm_wrong_type_arg (FUNC_NAME, 1, type); } #undef FUNC_NAME /* return 1 on success, 0 on failure */ static int parse_ffi_type (SCM type, int return_p, long *n_structs, long *n_struct_elts) { if (SCM_I_INUMP (type)) { if ((SCM_I_INUM (type) < 0 ) || (SCM_I_INUM (type) > SCM_FOREIGN_TYPE_LAST)) return 0; else if (SCM_I_INUM (type) == SCM_FOREIGN_TYPE_VOID && !return_p) return 0; else return 1; } else if (scm_is_eq (type, sym_asterisk)) /* a pointer */ return 1; else { long len; len = scm_ilength (type); if (len < 1) return 0; while (len--) { if (!parse_ffi_type (scm_car (type), 0, n_structs, n_struct_elts)) return 0; (*n_struct_elts)++; type = scm_cdr (type); } (*n_structs)++; return 1; } } static void fill_ffi_type (SCM type, ffi_type *ftype, ffi_type ***type_ptrs, ffi_type **types) { if (SCM_I_INUMP (type)) { switch (SCM_I_INUM (type)) { case SCM_FOREIGN_TYPE_FLOAT: *ftype = ffi_type_float; return; case SCM_FOREIGN_TYPE_DOUBLE: *ftype = ffi_type_double; return; case SCM_FOREIGN_TYPE_UINT8: *ftype = ffi_type_uint8; return; case SCM_FOREIGN_TYPE_INT8: *ftype = ffi_type_sint8; return; case SCM_FOREIGN_TYPE_UINT16: *ftype = ffi_type_uint16; return; case SCM_FOREIGN_TYPE_INT16: *ftype = ffi_type_sint16; return; case SCM_FOREIGN_TYPE_UINT32: *ftype = ffi_type_uint32; return; case SCM_FOREIGN_TYPE_INT32: *ftype = ffi_type_sint32; return; case SCM_FOREIGN_TYPE_UINT64: *ftype = ffi_type_uint64; return; case SCM_FOREIGN_TYPE_INT64: *ftype = ffi_type_sint64; return; case SCM_FOREIGN_TYPE_VOID: *ftype = ffi_type_void; return; default: scm_wrong_type_arg_msg ("pointer->procedure", 0, type, "foreign type"); } } else if (scm_is_eq (type, sym_asterisk)) /* a pointer */ { *ftype = ffi_type_pointer; return; } else { long i, len; len = scm_ilength (type); ftype->size = 0; ftype->alignment = 0; ftype->type = FFI_TYPE_STRUCT; ftype->elements = *type_ptrs; *type_ptrs += len + 1; for (i = 0; i < len; i++) { ftype->elements[i] = *types; *types += 1; fill_ffi_type (scm_car (type), ftype->elements[i], type_ptrs, types); type = scm_cdr (type); } ftype->elements[i] = NULL; } } /* Return a "cif" (call interface) for the given RETURN_TYPE and ARG_TYPES. */ static ffi_cif * make_cif (SCM return_type, SCM arg_types, const char *caller) #define FUNC_NAME caller { SCM walk; long i, nargs, n_structs, n_struct_elts; size_t cif_len; char *mem; ffi_cif *cif; ffi_type **type_ptrs; ffi_type *types; nargs = scm_ilength (arg_types); SCM_ASSERT (nargs >= 0, arg_types, 3, FUNC_NAME); /* fixme: assert nargs < 1<<32 */ n_structs = n_struct_elts = 0; /* For want of talloc, we're going to have to do this in two passes: first we figure out how much memory is needed for all types, then we allocate the cif and the types all in one block. */ if (!parse_ffi_type (return_type, 1, &n_structs, &n_struct_elts)) scm_wrong_type_arg (FUNC_NAME, 1, return_type); for (walk = arg_types; scm_is_pair (walk); walk = scm_cdr (walk)) if (!parse_ffi_type (scm_car (walk), 0, &n_structs, &n_struct_elts)) scm_wrong_type_arg (FUNC_NAME, 3, scm_car (walk)); /* the memory: with space for the cif itself */ cif_len = sizeof (ffi_cif); /* then ffi_type pointers: one for each arg, one for each struct element, and one for each struct (for null-termination) */ cif_len = (ROUND_UP (cif_len, alignof_type (void *)) + (nargs + n_structs + n_struct_elts)*sizeof(void*)); /* then the ffi_type structs themselves, one per arg and struct element, and one for the return val */ cif_len = (ROUND_UP (cif_len, alignof_type (ffi_type)) + (nargs + n_struct_elts + 1)*sizeof(ffi_type)); mem = scm_gc_malloc_pointerless (cif_len, "foreign"); /* ensure all the memory is initialized, even the holes */ memset (mem, 0, cif_len); cif = (ffi_cif *) mem; /* reuse cif_len to walk through the mem */ cif_len = ROUND_UP (sizeof (ffi_cif), alignof_type (void *)); type_ptrs = (ffi_type**)(mem + cif_len); cif_len = ROUND_UP (cif_len + (nargs + n_structs + n_struct_elts)*sizeof(void*), alignof_type (ffi_type)); types = (ffi_type*)(mem + cif_len); /* whew. now knit the pointers together. */ cif->rtype = types++; fill_ffi_type (return_type, cif->rtype, &type_ptrs, &types); cif->arg_types = type_ptrs; type_ptrs += nargs; for (walk = arg_types, i = 0; scm_is_pair (walk); walk = scm_cdr (walk), i++) { cif->arg_types[i] = types++; fill_ffi_type (scm_car (walk), cif->arg_types[i], &type_ptrs, &types); } /* round out the cif, and we're done. */ cif->abi = FFI_DEFAULT_ABI; cif->nargs = nargs; cif->bytes = 0; cif->flags = 0; if (FFI_OK != ffi_prep_cif (cif, FFI_DEFAULT_ABI, cif->nargs, cif->rtype, cif->arg_types)) SCM_MISC_ERROR ("ffi_prep_cif failed", SCM_EOL); return cif; } #undef FUNC_NAME static SCM pointer_to_procedure (SCM return_type, SCM func_ptr, SCM arg_types, int with_errno) #define FUNC_NAME "pointer->procedure" { ffi_cif *cif; SCM_VALIDATE_POINTER (2, func_ptr); cif = make_cif (return_type, arg_types, FUNC_NAME); return cif_to_procedure (scm_from_pointer (cif, NULL), func_ptr, with_errno); } #undef FUNC_NAME SCM scm_pointer_to_procedure (SCM return_type, SCM func_ptr, SCM arg_types) { return pointer_to_procedure (return_type, func_ptr, arg_types, 0); } SCM scm_pointer_to_procedure_with_errno (SCM return_type, SCM func_ptr, SCM arg_types) { return pointer_to_procedure (return_type, func_ptr, arg_types, 1); } SCM_KEYWORD (k_return_errno, "return-errno?"); SCM_INTERNAL SCM scm_i_pointer_to_procedure (SCM, SCM, SCM, SCM); SCM_DEFINE (scm_i_pointer_to_procedure, "pointer->procedure", 3, 0, 1, (SCM return_type, SCM func_ptr, SCM arg_types, SCM keyword_args), "Make a foreign function.\n\n" "Given the foreign void pointer @var{func_ptr}, its argument and\n" "return types @var{arg_types} and @var{return_type}, return a\n" "procedure that will pass arguments to the foreign function\n" "and return appropriate values.\n\n" "@var{arg_types} should be a list of foreign types.\n" "@code{return_type} should be a foreign type.\n" "If the @code{#:return-errno?} keyword argument is provided and\n" "its value is true, then the returned procedure will return two\n" "values, with @code{errno} as the second value.") #define FUNC_NAME s_scm_i_pointer_to_procedure { SCM return_errno = SCM_BOOL_F; scm_c_bind_keyword_arguments (FUNC_NAME, keyword_args, 0, k_return_errno, &return_errno, SCM_UNDEFINED); return pointer_to_procedure (return_type, func_ptr, arg_types, scm_to_bool (return_errno)); } #undef FUNC_NAME static const scm_t_uint32 * get_foreign_stub_code (unsigned int nargs, int with_errno) { size_t i; size_t code_len = with_errno ? 4 : 5; scm_t_uint32 *code; code = scm_gc_malloc_pointerless (code_len * sizeof (scm_t_uint32), "foreign code"); if (nargs >= (1 << 24) + 1) scm_misc_error ("make-foreign-function", "too many arguments: ~a", scm_list_1 (scm_from_uint (nargs))); i = 0; code[i++] = SCM_PACK_OP_24 (assert_nargs_ee, nargs + 1); code[i++] = SCM_PACK_OP_12_12 (foreign_call, 0, 1); code[i++] = SCM_PACK_OP_24 (handle_interrupts, 0); if (!with_errno) code[i++] = SCM_PACK_OP_24 (reset_frame, 2); code[i++] = SCM_PACK_OP_24 (return_values, 0); return code; } static SCM cif_to_procedure (SCM cif, SCM func_ptr, int with_errno) { ffi_cif *c_cif; SCM ret; scm_t_bits nfree = 2; scm_t_bits flags = SCM_F_PROGRAM_IS_FOREIGN; c_cif = (ffi_cif *) SCM_POINTER_VALUE (cif); ret = scm_words (scm_tc7_program | (nfree << 16) | flags, nfree + 2); SCM_SET_CELL_WORD_1 (ret, get_foreign_stub_code (c_cif->nargs, with_errno)); SCM_PROGRAM_FREE_VARIABLE_SET (ret, 0, cif); SCM_PROGRAM_FREE_VARIABLE_SET (ret, 1, func_ptr); return ret; } /* Set *LOC to the foreign representation of X with TYPE. */ static void unpack (const ffi_type *type, void *loc, SCM x, int return_value_p) #define FUNC_NAME "scm_i_foreign_call" { switch (type->type) { case FFI_TYPE_FLOAT: *(float *) loc = scm_to_double (x); break; case FFI_TYPE_DOUBLE: *(double *) loc = scm_to_double (x); break; /* For integer return values smaller than `int', libffi expects the result in an `ffi_arg'-long buffer. */ case FFI_TYPE_UINT8: if (return_value_p) *(ffi_arg *) loc = scm_to_uint8 (x); else *(scm_t_uint8 *) loc = scm_to_uint8 (x); break; case FFI_TYPE_SINT8: if (return_value_p) *(ffi_arg *) loc = scm_to_int8 (x); else *(scm_t_int8 *) loc = scm_to_int8 (x); break; case FFI_TYPE_UINT16: if (return_value_p) *(ffi_arg *) loc = scm_to_uint16 (x); else *(scm_t_uint16 *) loc = scm_to_uint16 (x); break; case FFI_TYPE_SINT16: if (return_value_p) *(ffi_arg *) loc = scm_to_int16 (x); else *(scm_t_int16 *) loc = scm_to_int16 (x); break; case FFI_TYPE_UINT32: if (return_value_p) *(ffi_arg *) loc = scm_to_uint32 (x); else *(scm_t_uint32 *) loc = scm_to_uint32 (x); break; case FFI_TYPE_SINT32: if (return_value_p) *(ffi_arg *) loc = scm_to_int32 (x); else *(scm_t_int32 *) loc = scm_to_int32 (x); break; case FFI_TYPE_UINT64: *(scm_t_uint64 *) loc = scm_to_uint64 (x); break; case FFI_TYPE_SINT64: *(scm_t_int64 *) loc = scm_to_int64 (x); break; case FFI_TYPE_STRUCT: SCM_VALIDATE_POINTER (1, x); memcpy (loc, SCM_POINTER_VALUE (x), type->size); break; case FFI_TYPE_POINTER: SCM_VALIDATE_POINTER (1, x); *(void **) loc = SCM_POINTER_VALUE (x); break; case FFI_TYPE_VOID: /* Do nothing. */ break; default: abort (); } } #undef FUNC_NAME /* Return a Scheme representation of the foreign value at LOC of type TYPE. When RETURN_VALUE_P is true, LOC is assumed to point to a return value buffer; otherwise LOC is assumed to point to an argument buffer. */ static SCM pack (const ffi_type * type, const void *loc, int return_value_p) { switch (type->type) { case FFI_TYPE_VOID: return SCM_UNSPECIFIED; case FFI_TYPE_FLOAT: return scm_from_double (*(float *) loc); case FFI_TYPE_DOUBLE: return scm_from_double (*(double *) loc); /* For integer return values smaller than `int', libffi stores the result in an `ffi_arg'-long buffer, of which only the significant bits must be kept---hence the pair of casts below. See for details. */ case FFI_TYPE_UINT8: if (return_value_p) return scm_from_uint8 ((scm_t_uint8) *(ffi_arg *) loc); else return scm_from_uint8 (* (scm_t_uint8 *) loc); case FFI_TYPE_SINT8: if (return_value_p) return scm_from_int8 ((scm_t_int8) *(ffi_arg *) loc); else return scm_from_int8 (* (scm_t_int8 *) loc); case FFI_TYPE_UINT16: if (return_value_p) return scm_from_uint16 ((scm_t_uint16) *(ffi_arg *) loc); else return scm_from_uint16 (* (scm_t_uint16 *) loc); case FFI_TYPE_SINT16: if (return_value_p) return scm_from_int16 ((scm_t_int16) *(ffi_arg *) loc); else return scm_from_int16 (* (scm_t_int16 *) loc); case FFI_TYPE_UINT32: if (return_value_p) return scm_from_uint32 ((scm_t_uint32) *(ffi_arg *) loc); else return scm_from_uint32 (* (scm_t_uint32 *) loc); case FFI_TYPE_SINT32: if (return_value_p) return scm_from_int32 ((scm_t_int32) *(ffi_arg *) loc); else return scm_from_int32 (* (scm_t_int32 *) loc); case FFI_TYPE_UINT64: return scm_from_uint64 (*(scm_t_uint64 *) loc); case FFI_TYPE_SINT64: return scm_from_int64 (*(scm_t_int64 *) loc); case FFI_TYPE_STRUCT: { void *mem = scm_gc_malloc_pointerless (type->size, "foreign"); memcpy (mem, loc, type->size); return scm_from_pointer (mem, NULL); } case FFI_TYPE_POINTER: return scm_from_pointer (*(void **) loc, NULL); default: abort (); } } SCM scm_i_foreign_call (SCM cif_scm, SCM pointer_scm, int *errno_ret, const union scm_vm_stack_element *argv) { /* FOREIGN is the pair that cif_to_procedure set as the 0th element of the objtable. */ ffi_cif *cif; void (*func) (void); scm_t_uint8 *data; void *rvalue; void **args; unsigned i; size_t arg_size; scm_t_ptrdiff off; cif = SCM_POINTER_VALUE (cif_scm); func = SCM_POINTER_VALUE (pointer_scm); /* Argument pointers. */ args = alloca (sizeof (void *) * cif->nargs); /* Compute the worst-case amount of memory needed to store all the argument values. Note: as of libffi 3.0.9 `cif->bytes' is undocumented and is zero, so it can't be used for that purpose. */ for (i = 0, arg_size = 0; i < cif->nargs; i++) arg_size += cif->arg_types[i]->size + cif->arg_types[i]->alignment - 1; /* Space for argument values, followed by return value. */ data = alloca (arg_size + cif->rtype->size + max (sizeof (void *), cif->rtype->alignment)); /* Unpack ARGV to native values, setting ARGV pointers. */ for (i = 0, off = 0; i < cif->nargs; off = (scm_t_uint8 *) args[i] - data + cif->arg_types[i]->size, i++) { /* Suitably align the storage area for argument I. */ args[i] = (void *) ROUND_UP ((scm_t_uintptr) data + off, cif->arg_types[i]->alignment); assert ((scm_t_uintptr) args[i] % cif->arg_types[i]->alignment == 0); unpack (cif->arg_types[i], args[i], argv[cif->nargs - i - 1].as_scm, 0); } /* Prepare space for the return value. On some platforms, such as `armv5tel-*-linux-gnueabi', the return value has to be at least word-aligned, even if its type doesn't have any alignment requirement as is the case with `char'. */ rvalue = (void *) ROUND_UP ((scm_t_uintptr) data + off, max (sizeof (void *), cif->rtype->alignment)); /* off we go! */ errno = 0; ffi_call (cif, func, rvalue, args); *errno_ret = errno; return pack (cif->rtype, rvalue, 1); } /* Function pointers aka. "callbacks" or "closures". */ #ifdef FFI_CLOSURES /* Trampoline to invoke a libffi closure that wraps a Scheme procedure. */ static void invoke_closure (ffi_cif *cif, void *ret, void **args, void *data) { size_t i; SCM proc, *argv, result; proc = SCM_PACK_POINTER (data); argv = alloca (cif->nargs * sizeof (*argv)); /* Pack ARGS to SCM values, setting ARGV pointers. */ for (i = 0; i < cif->nargs; i++) argv[i] = pack (cif->arg_types[i], args[i], 0); result = scm_call_n (proc, argv, cif->nargs); unpack (cif->rtype, ret, result, 1); } SCM_DEFINE (scm_procedure_to_pointer, "procedure->pointer", 3, 0, 0, (SCM return_type, SCM proc, SCM arg_types), "Return a pointer to a C function of type @var{return_type}\n" "taking arguments of types @var{arg_types} (a list) and\n" "behaving as a proxy to procedure @var{proc}. Thus\n" "@var{proc}'s arity, supported argument types, and return\n" "type should match @var{return_type} and @var{arg_types}.\n") #define FUNC_NAME s_scm_procedure_to_pointer { SCM cif_pointer, pointer; ffi_cif *cif; ffi_status err; void *closure, *executable; cif = make_cif (return_type, arg_types, FUNC_NAME); closure = ffi_closure_alloc (sizeof (ffi_closure), &executable); err = ffi_prep_closure_loc ((ffi_closure *) closure, cif, invoke_closure, SCM_UNPACK_POINTER (proc), executable); if (err != FFI_OK) { ffi_closure_free (closure); SCM_MISC_ERROR ("`ffi_prep_closure_loc' failed", SCM_EOL); } /* CIF points to GC-managed memory and it should remain as long as POINTER (see below) is live. Wrap it in a Scheme pointer to then hold a weak reference on it. */ cif_pointer = scm_from_pointer (cif, NULL); if (closure == executable) { pointer = scm_from_pointer (executable, ffi_closure_free); register_weak_reference (pointer, scm_list_2 (proc, cif_pointer)); } else { /* CLOSURE needs to be freed eventually. However, since `GC_all_interior_pointers' is disabled, we can't just register a finalizer for CLOSURE. Instead, we create a pointer object for CLOSURE, with a finalizer, and register it as a weak reference of POINTER. */ SCM friend; pointer = scm_from_pointer (executable, NULL); friend = scm_from_pointer (closure, ffi_closure_free); register_weak_reference (pointer, scm_list_3 (proc, cif_pointer, friend)); } return pointer; } #undef FUNC_NAME #endif /* FFI_CLOSURES */ static void scm_init_foreign (void) { #ifndef SCM_MAGIC_SNARFER #include "libguile/foreign.x" #endif scm_define (sym_void, scm_from_uint8 (SCM_FOREIGN_TYPE_VOID)); scm_define (sym_float, scm_from_uint8 (SCM_FOREIGN_TYPE_FLOAT)); scm_define (sym_double, scm_from_uint8 (SCM_FOREIGN_TYPE_DOUBLE)); scm_define (sym_uint8, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT8)); scm_define (sym_int8, scm_from_uint8 (SCM_FOREIGN_TYPE_INT8)); scm_define (sym_uint16, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT16)); scm_define (sym_int16, scm_from_uint8 (SCM_FOREIGN_TYPE_INT16)); scm_define (sym_uint32, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32)); scm_define (sym_int32, scm_from_uint8 (SCM_FOREIGN_TYPE_INT32)); scm_define (sym_uint64, scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64)); scm_define (sym_int64, scm_from_uint8 (SCM_FOREIGN_TYPE_INT64)); scm_define (sym_short, #if SIZEOF_SHORT == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) #elif SIZEOF_SHORT == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) #elif SIZEOF_SHORT == 2 scm_from_uint8 (SCM_FOREIGN_TYPE_INT16) #else # error unsupported sizeof (short) #endif ); scm_define (sym_unsigned_short, #if SIZEOF_SHORT == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64) #elif SIZEOF_SHORT == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32) #elif SIZEOF_SHORT == 2 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT16) #else # error unsupported sizeof (short) #endif ); scm_define (sym_int, #if SIZEOF_INT == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) #elif SIZEOF_INT == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) #else # error unsupported sizeof (int) #endif ); scm_define (sym_unsigned_int, #if SIZEOF_UNSIGNED_INT == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64) #elif SIZEOF_UNSIGNED_INT == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32) #else # error unsupported sizeof (unsigned int) #endif ); scm_define (sym_long, #if SIZEOF_LONG == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) #elif SIZEOF_LONG == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) #else # error unsupported sizeof (long) #endif ); scm_define (sym_unsigned_long, #if SIZEOF_UNSIGNED_LONG == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64) #elif SIZEOF_UNSIGNED_LONG == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32) #else # error unsupported sizeof (unsigned long) #endif ); scm_define (sym_size_t, #if SIZEOF_SIZE_T == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT64) #elif SIZEOF_SIZE_T == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_UINT32) #else # error unsupported sizeof (size_t) #endif ); scm_define (sym_ssize_t, #if SIZEOF_SIZE_T == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) #elif SIZEOF_SIZE_T == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) #else # error unsupported sizeof (ssize_t) #endif ); scm_define (sym_ptrdiff_t, #if SCM_SIZEOF_SCM_T_PTRDIFF == 8 scm_from_uint8 (SCM_FOREIGN_TYPE_INT64) #elif SCM_SIZEOF_SCM_T_PTRDIFF == 4 scm_from_uint8 (SCM_FOREIGN_TYPE_INT32) #else # error unsupported sizeof (scm_t_ptrdiff) #endif ); null_pointer = scm_cell (scm_tc7_pointer, 0); scm_define (sym_null, null_pointer); } void scm_register_foreign (void) { scm_c_register_extension ("libguile-" SCM_EFFECTIVE_VERSION, "scm_init_foreign", (scm_t_extension_init_func)scm_init_foreign, NULL); pointer_weak_refs = scm_c_make_weak_table (0, SCM_WEAK_TABLE_KIND_KEY); } /* Local Variables: c-file-style: "gnu" End: */