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 "go-string.h"
  14 #include "array.h"
  15
  16 /* Many of the types in this file must match the data structures
  17    generated by the compiler, and must also match the Go types which
  18    appear in go/runtime/type.go and go/reflect/type.go.  */
  19
  20 /* Type kinds.  These are used to get the type descriptor to use for
  21    the type itself, when using unsafe.Typeof or unsafe.Reflect.  The
  22    values here must match the values generated by the compiler (the
  23    RUNTIME_TYPE_KIND_xxx values in gcc/go/types.h).  These are macros
  24    rather than an enum to make it easy to change values in the future
  25    and hard to get confused about it.
  26
  27    These correspond to the kind values used by the gc compiler.  */
  28
  29 #define GO_BOOL 1
  30 #define GO_INT 2
  31 #define GO_INT8 3
  32 #define GO_INT16 4
  33 #define GO_INT32 5
  34 #define GO_INT64 6
  35 #define GO_UINT 7
  36 #define GO_UINT8 8
  37 #define GO_UINT16 9
  38 #define GO_UINT32 10
  39 #define GO_UINT64 11
  40 #define GO_UINTPTR 12
  41 #define GO_FLOAT32 13
  42 #define GO_FLOAT64 14
  43 #define GO_COMPLEX64 15
  44 #define GO_COMPLEX128 16
  45 #define GO_ARRAY 17
  46 #define GO_CHAN 18
  47 #define GO_FUNC 19
  48 #define GO_INTERFACE 20
  49 #define GO_MAP 21
  50 #define GO_PTR 22
  51 #define GO_SLICE 23
  52 #define GO_STRING 24
  53 #define GO_STRUCT 25
  54 #define GO_UNSAFE_POINTER 26
  55
  56 #define GO_NO_POINTERS (1 << 7)
  57
  58 #define GO_CODE_MASK 0x7f
  59
  60 /* For each Go type the compiler constructs one of these structures.
  61    This is used for type reflectin, interfaces, maps, and reference
  62    counting.  */
  63
  64 struct __go_type_descriptor
  65 {
  66   /* The type code for this type, one of the type kind values above.
  67      This is used by unsafe.Reflect and unsafe.Typeof to determine the
  68      type descriptor to return for this type itself.  It is also used
  69      by reflect.toType when mapping to a reflect Type structure.  */
  70   unsigned char __code;
  71
  72   /* The alignment in bytes of a variable with this type.  */
  73   unsigned char __align;
  74
  75   /* The alignment in bytes of a struct field with this type.  */
  76   unsigned char __field_align;
  77
  78   /* The size in bytes of a value of this type.  Note that all types
  79      in Go have a fixed size.  */
  80   uintptr_t __size;
  81
  82   /* The type's hash code.  */
  83   uint32_t __hash;
  84
  85   /* This function takes a pointer to a value of this type, and the
  86      size of this type, and returns a hash code.  We pass the size
  87      explicitly becaues it means that we can share a single instance
  88      of this function for various different types.  */
  89   uintptr_t (*__hashfn) (const void *, uintptr_t);
  90
  91   /* This function takes two pointers to values of this type, and the
  92      size of this type, and returns whether the values are equal.  */
  93   _Bool (*__equalfn) (const void *, const void *, uintptr_t);
  94
  95   /* A string describing this type.  This is only used for
  96      debugging.  */
  97   const struct __go_string *__reflection;
  98
  99   /* A pointer to fields which are only used for some types.  */
 100   const struct __go_uncommon_type *__uncommon;
 101
 102   /* The descriptor for the type which is a pointer to this type.
 103      This may be NULL.  */
 104   const struct __go_type_descriptor *__pointer_to_this;
 105 };
 106
 107 /* The information we store for each method of a type.  */
 108
 109 struct __go_method
 110 {
 111   /* The name of the method.  */
 112   const struct __go_string *__name;
 113
 114   /* This is NULL for an exported method, or the name of the package
 115      where it lives.  */
 116   const struct __go_string *__pkg_path;
 117
 118   /* The type of the method, without the receiver.  This will be a
 119      function type.  */
 120   const struct __go_type_descriptor *__mtype;
 121
 122   /* The type of the method, with the receiver.  This will be a
 123      function type.  */
 124   const struct __go_type_descriptor *__type;
 125
 126   /* A pointer to the code which implements the method.  This is
 127      really a function pointer.  */
 128   const void *__function;
 129 };
 130
 131 /* Additional information that we keep for named types and for types
 132    with methods.  */
 133
 134 struct __go_uncommon_type
 135 {
 136   /* The name of the type.  */
 137   const struct __go_string *__name;
 138
 139   /* The type's package.  This is NULL for builtin types.  */
 140   const struct __go_string *__pkg_path;
 141
 142   /* The type's methods.  This is an array of struct __go_method.  */
 143   struct __go_open_array __methods;
 144 };
 145
 146 /* The type descriptor for a fixed array type.  */
 147
 148 struct __go_array_type
 149 {
 150   /* Starts like all type descriptors.  */
 151   struct __go_type_descriptor __common;
 152
 153   /* The element type.  */
 154   struct __go_type_descriptor *__element_type;
 155
 156   /* The type of a slice of the same element type.  */
 157   struct __go_type_descriptor *__slice_type;
 158
 159   /* The length of the array.  */
 160   uintptr_t __len;
 161 };
 162
 163 /* The type descriptor for a slice.  */
 164
 165 struct __go_slice_type
 166 {
 167   /* Starts like all other type descriptors.  */
 168   struct __go_type_descriptor __common;
 169
 170   /* The element type.  */
 171   struct __go_type_descriptor *__element_type;
 172 };
 173
 174 /* The direction of a channel.  */
 175 #define CHANNEL_RECV_DIR 1
 176 #define CHANNEL_SEND_DIR 2
 177 #define CHANNEL_BOTH_DIR (CHANNEL_RECV_DIR | CHANNEL_SEND_DIR)
 178
 179 /* The type descriptor for a channel.  */
 180
 181 struct __go_channel_type
 182 {
 183   /* Starts like all other type descriptors.  */
 184   struct __go_type_descriptor __common;
 185
 186   /* The element type.  */
 187   const struct __go_type_descriptor *__element_type;
 188
 189   /* The direction.  */
 190   uintptr_t __dir;
 191 };
 192
 193 /* The type descriptor for a function.  */
 194
 195 struct __go_func_type
 196 {
 197   /* Starts like all other type descriptors.  */
 198   struct __go_type_descriptor __common;
 199
 200   /* Whether this is a varargs function.  If this is true, there will
 201      be at least one parameter.  For "..." the last parameter type is
 202      "interface{}".  For "... T" the last parameter type is "[]T".  */
 203   _Bool __dotdotdot;
 204
 205   /* The input parameter types.  This is an array of pointers to
 206      struct __go_type_descriptor.  */
 207   struct __go_open_array __in;
 208
 209   /* The output parameter types.  This is an array of pointers to
 210      struct __go_type_descriptor.  */
 211   struct __go_open_array __out;
 212 };
 213
 214 /* A method on an interface type.  */
 215
 216 struct __go_interface_method
 217 {
 218   /* The name of the method.  */
 219   const struct __go_string *__name;
 220
 221   /* This is NULL for an exported method, or the name of the package
 222      where it lives.  */
 223   const struct __go_string *__pkg_path;
 224
 225   /* The real type of the method.  */
 226   struct __go_type_descriptor *__type;
 227 };
 228
 229 /* An interface type.  */
 230
 231 struct __go_interface_type
 232 {
 233   /* Starts like all other type descriptors.  */
 234   struct __go_type_descriptor __common;
 235
 236   /* Array of __go_interface_method .  The methods are sorted in the
 237      same order that they appear in the definition of the
 238      interface.  */
 239   struct __go_open_array __methods;
 240 };
 241
 242 /* A map type.  */
 243
 244 struct __go_map_type
 245 {
 246   /* Starts like all other type descriptors.  */
 247   struct __go_type_descriptor __common;
 248
 249   /* The map key type.  */
 250   const struct __go_type_descriptor *__key_type;
 251
 252   /* The map value type.  */
 253   const struct __go_type_descriptor *__val_type;
 254 };
 255
 256 /* A pointer type.  */
 257
 258 struct __go_ptr_type
 259 {
 260   /* Starts like all other type descriptors.  */
 261   struct __go_type_descriptor __common;
 262
 263   /* The type to which this points.  */
 264   const struct __go_type_descriptor *__element_type;
 265 };
 266
 267 /* A field in a structure.  */
 268
 269 struct __go_struct_field
 270 {
 271   /* The name of the field--NULL for an anonymous field.  */
 272   const struct __go_string *__name;
 273
 274   /* This is NULL for an exported method, or the name of the package
 275      where it lives.  */
 276   const struct __go_string *__pkg_path;
 277
 278   /* The type of the field.  */
 279   const struct __go_type_descriptor *__type;
 280
 281   /* The field tag, or NULL.  */
 282   const struct __go_string *__tag;
 283
 284   /* The offset of the field in the struct.  */
 285   uintptr_t __offset;
 286 };
 287
 288 /* A struct type.  */
 289
 290 struct __go_struct_type
 291 {
 292   /* Starts like all other type descriptors.  */
 293   struct __go_type_descriptor __common;
 294
 295   /* An array of struct __go_struct_field.  */
 296   struct __go_open_array __fields;
 297 };
 298
 299 /* If an empty interface has these bits set in its type pointer, it
 300    was copied from a reflect.Value and is not a valid empty
 301    interface.  */
 302
 303 enum
 304 {
 305   reflectFlags = 3,
 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) */