1 /* go-type.h -- basic information for a Go type.
2
3 Copyright 2009 The Go Authors. All rights reserved.
4 Use of this source code is governed by a BSD-style
5 license that can be found in the LICENSE file. */
6
7 #ifndef LIBGO_GO_TYPE_H
8 #define LIBGO_GO_TYPE_H
9
10 #include <stddef.h>
11 #include <stdint.h>
12
13 #include "array.h"
14
15 struct String;
16
17 /* Many of the types in this file must match the data structures
18 generated by the compiler, and must also match the Go types which
19 appear in go/runtime/type.go and go/reflect/type.go. */
20
21 /* Type kinds. These are used to get the type descriptor to use for
22 the type itself, when using unsafe.Typeof or unsafe.Reflect. The
23 values here must match the values generated by the compiler (the
24 RUNTIME_TYPE_KIND_xxx values in gcc/go/types.h). These are macros
25 rather than an enum to make it easy to change values in the future
26 and hard to get confused about it.
27
28 These correspond to the kind values used by the gc compiler. */
29
30 #define GO_BOOL 1
31 #define GO_INT 2
32 #define GO_INT8 3
33 #define GO_INT16 4
34 #define GO_INT32 5
35 #define GO_INT64 6
36 #define GO_UINT 7
37 #define GO_UINT8 8
38 #define GO_UINT16 9
39 #define GO_UINT32 10
40 #define GO_UINT64 11
41 #define GO_UINTPTR 12
42 #define GO_FLOAT32 13
43 #define GO_FLOAT64 14
44 #define GO_COMPLEX64 15
45 #define GO_COMPLEX128 16
46 #define GO_ARRAY 17
47 #define GO_CHAN 18
48 #define GO_FUNC 19
49 #define GO_INTERFACE 20
50 #define GO_MAP 21
51 #define GO_PTR 22
52 #define GO_SLICE 23
53 #define GO_STRING 24
54 #define GO_STRUCT 25
55 #define GO_UNSAFE_POINTER 26
56
57 #define GO_DIRECT_IFACE (1 << 5)
58 #define GO_GC_PROG (1 << 6)
59 #define GO_NO_POINTERS (1 << 7)
60
61 #define GO_CODE_MASK 0x1f
62
63 /* For each Go type the compiler constructs one of these structures.
64 This is used for type reflection, interfaces, maps, and reference
65 counting. */
66
67 struct __go_type_descriptor
68 {
69 /* The size in bytes of a value of this type. Note that all types
70 in Go have a fixed size. */
71 uintptr_t __size;
72
73 /* The size of the memory prefix of a value of this type that holds
74 all pointers. */
75 uintptr_t __ptrdata;
76
77 /* The type's hash code. */
78 uint32_t __hash;
79
80 /* The type code for this type, one of the type kind values above.
81 This is used by unsafe.Reflect and unsafe.Typeof to determine the
82 type descriptor to return for this type itself. It is also used
83 by reflect.toType when mapping to a reflect Type structure. */
84 unsigned char __code;
85
86 /* The alignment in bytes of a variable with this type. */
87 unsigned char __align;
88
89 /* The alignment in bytes of a struct field with this type. */
90 unsigned char __field_align;
91
92 /* This function takes a pointer to a value of this type, and the
93 size of this type, and returns a hash code. We pass the size
94 explicitly becaues it means that we can share a single instance
95 of this function for various different types. */
96 const FuncVal *__hashfn;
97
98 /* This function takes two pointers to values of this type, and the
99 size of this type, and returns whether the values are equal. */
100 const FuncVal *__equalfn;
101
102 /* The garbage collection data. */
103 const byte *__gcdata;
104
105 /* A string describing this type. This is only used for
106 debugging. */
107 const struct String *__reflection;
108
109 /* A pointer to fields which are only used for some types. */
110 const struct __go_uncommon_type *__uncommon;
111
112 /* The descriptor for the type which is a pointer to this type.
113 This may be NULL. */
114 const struct __go_type_descriptor *__pointer_to_this;
115 };
116
117 /* The information we store for each method of a type. */
118
119 struct __go_method
120 {
121 /* The name of the method. */
122 const struct String *__name;
123
124 /* This is NULL for an exported method, or the name of the package
125 where it lives. */
126 const struct String *__pkg_path;
127
128 /* The type of the method, without the receiver. This will be a
129 function type. */
130 const struct __go_type_descriptor *__mtype;
131
132 /* The type of the method, with the receiver. This will be a
133 function type. */
134 const struct __go_type_descriptor *__type;
135
136 /* A pointer to the code which implements the method. This is
137 really a function pointer. */
138 const void *__function;
139 };
140
141 /* Additional information that we keep for named types and for types
142 with methods. */
143
144 struct __go_uncommon_type
145 {
146 /* The name of the type. */
147 const struct String *__name;
148
149 /* The type's package. This is NULL for builtin types. */
150 const struct String *__pkg_path;
151
152 /* The type's methods. This is an array of struct __go_method. */
153 struct __go_open_array __methods;
154 };
155
156 /* The type descriptor for a fixed array type. */
157
158 struct __go_array_type
159 {
160 /* Starts like all type descriptors. */
161 struct __go_type_descriptor __common;
162
163 /* The element type. */
164 struct __go_type_descriptor *__element_type;
165
166 /* The type of a slice of the same element type. */
167 struct __go_type_descriptor *__slice_type;
168
169 /* The length of the array. */
170 uintptr_t __len;
171 };
172
173 /* The type descriptor for a slice. */
174
175 struct __go_slice_type
176 {
177 /* Starts like all other type descriptors. */
178 struct __go_type_descriptor __common;
179
180 /* The element type. */
181 struct __go_type_descriptor *__element_type;
182 };
183
184 /* The direction of a channel. */
185 #define CHANNEL_RECV_DIR 1
186 #define CHANNEL_SEND_DIR 2
187 #define CHANNEL_BOTH_DIR (CHANNEL_RECV_DIR | CHANNEL_SEND_DIR)
188
189 /* The type descriptor for a channel. */
190
191 struct __go_channel_type
192 {
193 /* Starts like all other type descriptors. */
194 struct __go_type_descriptor __common;
195
196 /* The element type. */
197 const struct __go_type_descriptor *__element_type;
198
199 /* The direction. */
200 uintptr_t __dir;
201 };
202
203 /* The type descriptor for a function. */
204
205 struct __go_func_type
206 {
207 /* Starts like all other type descriptors. */
208 struct __go_type_descriptor __common;
209
210 /* Whether this is a varargs function. If this is true, there will
211 be at least one parameter. For "..." the last parameter type is
212 "interface{}". For "... T" the last parameter type is "[]T". */
213 _Bool __dotdotdot;
214
215 /* The input parameter types. This is an array of pointers to
216 struct __go_type_descriptor. */
217 struct __go_open_array __in;
218
219 /* The output parameter types. This is an array of pointers to
220 struct __go_type_descriptor. */
221 struct __go_open_array __out;
222 };
223
224 /* A method on an interface type. */
225
226 struct __go_interface_method
227 {
228 /* The name of the method. */
229 const struct String *__name;
230
231 /* This is NULL for an exported method, or the name of the package
232 where it lives. */
233 const struct String *__pkg_path;
234
235 /* The real type of the method. */
236 struct __go_type_descriptor *__type;
237 };
238
239 /* An interface type. */
240
241 struct __go_interface_type
242 {
243 /* Starts like all other type descriptors. */
244 struct __go_type_descriptor __common;
245
246 /* Array of __go_interface_method . The methods are sorted in the
247 same order that they appear in the definition of the
248 interface. */
249 struct __go_open_array __methods;
250 };
251
252 /* A map type. */
253
254 struct __go_map_type
255 {
256 /* Starts like all other type descriptors. */
257 struct __go_type_descriptor __common;
258
259 /* The map key type. */
260 const struct __go_type_descriptor *__key_type;
261
262 /* The map value type. */
263 const struct __go_type_descriptor *__val_type;
264
265 /* The map bucket type. */
266 const struct __go_type_descriptor *__bucket_type;
267
268 /* The map header type. */
269 const struct __go_type_descriptor *__hmap_type;
270
271 /* The size of the key slot. */
272 uint8_t __key_size;
273
274 /* Whether to store a pointer to key rather than the key itself. */
275 uint8_t __indirect_key;
276
277 /* The size of the value slot. */
278 uint8_t __value_size;
279
280 /* Whether to store a pointer to value rather than the value itself. */
281 uint8_t __indirect_value;
282
283 /* The size of a bucket. */
284 uint16_t __bucket_size;
285
286 /* Whether the key type is reflexive--whether k==k for all keys. */
287 _Bool __reflexive_key;
288
289 /* Whether we should update the key when overwriting an entry. */
290 _Bool __need_key_update;
291 };
292
293 /* A pointer type. */
294
295 struct __go_ptr_type
296 {
297 /* Starts like all other type descriptors. */
298 struct __go_type_descriptor __common;
299
300 /* The type to which this points. */
301 const struct __go_type_descriptor *__element_type;
302 };
303
304 /* A field in a structure. */
305
306 struct __go_struct_field
307 {
308 /* The name of the field--NULL for an anonymous field. */
309 const struct String *__name;
310
311 /* This is NULL for an exported method, or the name of the package
312 where it lives. */
313 const struct String *__pkg_path;
314
315 /* The type of the field. */
316 const struct __go_type_descriptor *__type;
317
318 /* The field tag, or NULL. */
319 const struct String *__tag;
320
321 /* The offset of the field in the struct. */
322 uintptr_t __offset;
323 };
324
325 /* A struct type. */
326
327 struct __go_struct_type
328 {
329 /* Starts like all other type descriptors. */
330 struct __go_type_descriptor __common;
331
332 /* An array of struct __go_struct_field. */
333 struct __go_open_array __fields;
334 };
335
336 /* Whether a type descriptor is a pointer. */
337
338 static inline _Bool
__go_is_pointer_type(const struct __go_type_descriptor * td)339 __go_is_pointer_type (const struct __go_type_descriptor *td)
340 {
341 return ((td->__code & GO_CODE_MASK) == GO_PTR
342 || (td->__code & GO_CODE_MASK) == GO_UNSAFE_POINTER);
343 }
344
345 /* Call a type hash function, given the __hashfn value. */
346
347 static inline uintptr_t
__go_call_hashfn(const FuncVal * hashfn,const void * p,uintptr_t seed,uintptr_t size)348 __go_call_hashfn (const FuncVal *hashfn, const void *p, uintptr_t seed,
349 uintptr_t size)
350 {
351 uintptr_t (*h) (const void *, uintptr_t, uintptr_t) = (void *) hashfn->fn;
352 return __builtin_call_with_static_chain (h (p, seed, size), hashfn);
353 }
354
355 /* Call a type equality function, given the __equalfn value. */
356
357 static inline _Bool
__go_call_equalfn(const FuncVal * equalfn,const void * p1,const void * p2,uintptr_t size)358 __go_call_equalfn (const FuncVal *equalfn, const void *p1, const void *p2,
359 uintptr_t size)
360 {
361 _Bool (*e) (const void *, const void *, uintptr_t) = (void *) equalfn->fn;
362 return __builtin_call_with_static_chain (e (p1, p2, size), equalfn);
363 }
364
365 extern _Bool
366 __go_type_descriptors_equal(const struct __go_type_descriptor*,
367 const struct __go_type_descriptor*);
368
369 #endif /* !defined(LIBGO_GO_TYPE_H) */
370