libgo/runtime/go-type.h

   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_NO_POINTERS (1 << 7)
  58
  59 #define GO_CODE_MASK 0x7f
  60
  61 /* For each Go type the compiler constructs one of these structures.
  62    This is used for type reflection, interfaces, maps, and reference
  63    counting.  */
  64
  65 struct __go_type_descriptor
  66 {
  67   /* The type code for this type, one of the type kind values above.
  68      This is used by unsafe.Reflect and unsafe.Typeof to determine the
  69      type descriptor to return for this type itself.  It is also used
  70      by reflect.toType when mapping to a reflect Type structure.  */
  71   unsigned char __code;
  72
  73   /* The alignment in bytes of a variable with this type.  */
  74   unsigned char __align;
  75
  76   /* The alignment in bytes of a struct field with this type.  */
  77   unsigned char __field_align;
  78
  79   /* The size in bytes of a value of this type.  Note that all types
  80      in Go have a fixed size.  */
  81   uintptr_t __size;
  82
  83   /* The type's hash code.  */
  84   uint32_t __hash;
  85
  86   /* This function takes a pointer to a value of this type, and the
  87      size of this type, and returns a hash code.  We pass the size
  88      explicitly becaues it means that we can share a single instance
  89      of this function for various different types.  */
  90   uintptr_t (*__hashfn) (const void *, uintptr_t);
  91
  92   /* This function takes two pointers to values of this type, and the
  93      size of this type, and returns whether the values are equal.  */
  94   _Bool (*__equalfn) (const void *, const void *, uintptr_t);
  95
  96   /* The garbage collection data. */
  97   const uintptr *__gc;
  98
  99   /* A string describing this type.  This is only used for
 100      debugging.  */
 101   const struct String *__reflection;
 102
 103   /* A pointer to fields which are only used for some types.  */
 104   const struct __go_uncommon_type *__uncommon;
 105
 106   /* The descriptor for the type which is a pointer to this type.
 107      This may be NULL.  */
 108   const struct __go_type_descriptor *__pointer_to_this;
 109
 110   /* A pointer to a zero value for this type.  All types will point to
 111      the same zero value, go$zerovalue, which is a common variable so
 112      that it will be large enough.  */
 113   void *__zero;
 114 };
 115
 116 /* The information we store for each method of a type.  */
 117
 118 struct __go_method
 119 {
 120   /* The name of the method.  */
 121   const struct String *__name;
 122
 123   /* This is NULL for an exported method, or the name of the package
 124      where it lives.  */
 125   const struct String *__pkg_path;
 126
 127   /* The type of the method, without the receiver.  This will be a
 128      function type.  */
 129   const struct __go_type_descriptor *__mtype;
 130
 131   /* The type of the method, with the receiver.  This will be a
 132      function type.  */
 133   const struct __go_type_descriptor *__type;
 134
 135   /* A pointer to the code which implements the method.  This is
 136      really a function pointer.  */
 137   const void *__function;
 138 };
 139
 140 /* Additional information that we keep for named types and for types
 141    with methods.  */
 142
 143 struct __go_uncommon_type
 144 {
 145   /* The name of the type.  */
 146   const struct String *__name;
 147
 148   /* The type's package.  This is NULL for builtin types.  */
 149   const struct String *__pkg_path;
 150
 151   /* The type's methods.  This is an array of struct __go_method.  */
 152   struct __go_open_array __methods;
 153 };
 154
 155 /* The type descriptor for a fixed array type.  */
 156
 157 struct __go_array_type
 158 {
 159   /* Starts like all type descriptors.  */
 160   struct __go_type_descriptor __common;
 161
 162   /* The element type.  */
 163   struct __go_type_descriptor *__element_type;
 164
 165   /* The type of a slice of the same element type.  */
 166   struct __go_type_descriptor *__slice_type;
 167
 168   /* The length of the array.  */
 169   uintptr_t __len;
 170 };
 171
 172 /* The type descriptor for a slice.  */
 173
 174 struct __go_slice_type
 175 {
 176   /* Starts like all other type descriptors.  */
 177   struct __go_type_descriptor __common;
 178
 179   /* The element type.  */
 180   struct __go_type_descriptor *__element_type;
 181 };
 182
 183 /* The direction of a channel.  */
 184 #define CHANNEL_RECV_DIR 1
 185 #define CHANNEL_SEND_DIR 2
 186 #define CHANNEL_BOTH_DIR (CHANNEL_RECV_DIR | CHANNEL_SEND_DIR)
 187
 188 /* The type descriptor for a channel.  */
 189
 190 struct __go_channel_type
 191 {
 192   /* Starts like all other type descriptors.  */
 193   struct __go_type_descriptor __common;
 194
 195   /* The element type.  */
 196   const struct __go_type_descriptor *__element_type;
 197
 198   /* The direction.  */
 199   uintptr_t __dir;
 200 };
 201
 202 /* The type descriptor for a function.  */
 203
 204 struct __go_func_type
 205 {
 206   /* Starts like all other type descriptors.  */
 207   struct __go_type_descriptor __common;
 208
 209   /* Whether this is a varargs function.  If this is true, there will
 210      be at least one parameter.  For "..." the last parameter type is
 211      "interface{}".  For "... T" the last parameter type is "[]T".  */
 212   _Bool __dotdotdot;
 213
 214   /* The input parameter types.  This is an array of pointers to
 215      struct __go_type_descriptor.  */
 216   struct __go_open_array __in;
 217
 218   /* The output parameter types.  This is an array of pointers to
 219      struct __go_type_descriptor.  */
 220   struct __go_open_array __out;
 221 };
 222
 223 /* A method on an interface type.  */
 224
 225 struct __go_interface_method
 226 {
 227   /* The name of the method.  */
 228   const struct String *__name;
 229
 230   /* This is NULL for an exported method, or the name of the package
 231      where it lives.  */
 232   const struct String *__pkg_path;
 233
 234   /* The real type of the method.  */
 235   struct __go_type_descriptor *__type;
 236 };
 237
 238 /* An interface type.  */
 239
 240 struct __go_interface_type
 241 {
 242   /* Starts like all other type descriptors.  */
 243   struct __go_type_descriptor __common;
 244
 245   /* Array of __go_interface_method .  The methods are sorted in the
 246      same order that they appear in the definition of the
 247      interface.  */
 248   struct __go_open_array __methods;
 249 };
 250
 251 /* A map type.  */
 252
 253 struct __go_map_type
 254 {
 255   /* Starts like all other type descriptors.  */
 256   struct __go_type_descriptor __common;
 257
 258   /* The map key type.  */
 259   const struct __go_type_descriptor *__key_type;
 260
 261   /* The map value type.  */
 262   const struct __go_type_descriptor *__val_type;
 263 };
 264
 265 /* A pointer type.  */
 266
 267 struct __go_ptr_type
 268 {
 269   /* Starts like all other type descriptors.  */
 270   struct __go_type_descriptor __common;
 271
 272   /* The type to which this points.  */
 273   const struct __go_type_descriptor *__element_type;
 274 };
 275
 276 /* A field in a structure.  */
 277
 278 struct __go_struct_field
 279 {
 280   /* The name of the field--NULL for an anonymous field.  */
 281   const struct String *__name;
 282
 283   /* This is NULL for an exported method, or the name of the package
 284      where it lives.  */
 285   const struct String *__pkg_path;
 286
 287   /* The type of the field.  */
 288   const struct __go_type_descriptor *__type;
 289
 290   /* The field tag, or NULL.  */
 291   const struct String *__tag;
 292
 293   /* The offset of the field in the struct.  */
 294   uintptr_t __offset;
 295 };
 296
 297 /* A struct type.  */
 298
 299 struct __go_struct_type
 300 {
 301   /* Starts like all other type descriptors.  */
 302   struct __go_type_descriptor __common;
 303
 304   /* An array of struct __go_struct_field.  */
 305   struct __go_open_array __fields;
 306 };
 307
 308 /* Whether a type descriptor is a pointer.  */
 309
 310 static inline _Bool
 311 __go_is_pointer_type (const struct __go_type_descriptor *td)
 312 {
 313   return td->__code == GO_PTR || td->__code == GO_UNSAFE_POINTER;
 314 }
 315
 316 extern _Bool
 317 __go_type_descriptors_equal(const struct __go_type_descriptor*,
 318                             const struct __go_type_descriptor*);
 319
 320 extern uintptr_t __go_type_hash_identity (const void *, uintptr_t);
 321 extern _Bool __go_type_equal_identity (const void *, const void *, uintptr_t);
 322 extern uintptr_t __go_type_hash_string (const void *, uintptr_t);
 323 extern _Bool __go_type_equal_string (const void *, const void *, uintptr_t);
 324 extern uintptr_t __go_type_hash_float (const void *, uintptr_t);
 325 extern _Bool __go_type_equal_float (const void *, const void *, uintptr_t);
 326 extern uintptr_t __go_type_hash_complex (const void *, uintptr_t);
 327 extern _Bool __go_type_equal_complex (const void *, const void *, uintptr_t);
 328 extern uintptr_t __go_type_hash_interface (const void *, uintptr_t);
 329 extern _Bool __go_type_equal_interface (const void *, const void *, uintptr_t);
 330 extern uintptr_t __go_type_hash_error (const void *, uintptr_t);
 331 extern _Bool __go_type_equal_error (const void *, const void *, uintptr_t);
 332
 333 #endif /* !defined(LIBGO_GO_TYPE_H) */