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 reflectin, 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   /* A string describing this type.  This is only used for
  97      debugging.  */
  98   const struct String *__reflection;
  99
 100   /* A pointer to fields which are only used for some types.  */
 101   const struct __go_uncommon_type *__uncommon;
 102
 103   /* The descriptor for the type which is a pointer to this type.
 104      This may be NULL.  */
 105   const struct __go_type_descriptor *__pointer_to_this;
 106
 107   /* A pointer to a zero value for this type.  All types will point to
 108      the same zero value, go$zerovalue, which is a common variable so
 109      that it will be large enough.  */
 110   void *__zero;
 111 };
 112
 113 /* The information we store for each method of a type.  */
 114
 115 struct __go_method
 116 {
 117   /* The name of the method.  */
 118   const struct String *__name;
 119
 120   /* This is NULL for an exported method, or the name of the package
 121      where it lives.  */
 122   const struct String *__pkg_path;
 123
 124   /* The type of the method, without the receiver.  This will be a
 125      function type.  */
 126   const struct __go_type_descriptor *__mtype;
 127
 128   /* The type of the method, with the receiver.  This will be a
 129      function type.  */
 130   const struct __go_type_descriptor *__type;
 131
 132   /* A pointer to the code which implements the method.  This is
 133      really a function pointer.  */
 134   const void *__function;
 135 };
 136
 137 /* Additional information that we keep for named types and for types
 138    with methods.  */
 139
 140 struct __go_uncommon_type
 141 {
 142   /* The name of the type.  */
 143   const struct String *__name;
 144
 145   /* The type's package.  This is NULL for builtin types.  */
 146   const struct String *__pkg_path;
 147
 148   /* The type's methods.  This is an array of struct __go_method.  */
 149   struct __go_open_array __methods;
 150 };
 151
 152 /* The type descriptor for a fixed array type.  */
 153
 154 struct __go_array_type
 155 {
 156   /* Starts like all type descriptors.  */
 157   struct __go_type_descriptor __common;
 158
 159   /* The element type.  */
 160   struct __go_type_descriptor *__element_type;
 161
 162   /* The type of a slice of the same element type.  */
 163   struct __go_type_descriptor *__slice_type;
 164
 165   /* The length of the array.  */
 166   uintptr_t __len;
 167 };
 168
 169 /* The type descriptor for a slice.  */
 170
 171 struct __go_slice_type
 172 {
 173   /* Starts like all other type descriptors.  */
 174   struct __go_type_descriptor __common;
 175
 176   /* The element type.  */
 177   struct __go_type_descriptor *__element_type;
 178 };
 179
 180 /* The direction of a channel.  */
 181 #define CHANNEL_RECV_DIR 1
 182 #define CHANNEL_SEND_DIR 2
 183 #define CHANNEL_BOTH_DIR (CHANNEL_RECV_DIR | CHANNEL_SEND_DIR)
 184
 185 /* The type descriptor for a channel.  */
 186
 187 struct __go_channel_type
 188 {
 189   /* Starts like all other type descriptors.  */
 190   struct __go_type_descriptor __common;
 191
 192   /* The element type.  */
 193   const struct __go_type_descriptor *__element_type;
 194
 195   /* The direction.  */
 196   uintptr_t __dir;
 197 };
 198
 199 /* The type descriptor for a function.  */
 200
 201 struct __go_func_type
 202 {
 203   /* Starts like all other type descriptors.  */
 204   struct __go_type_descriptor __common;
 205
 206   /* Whether this is a varargs function.  If this is true, there will
 207      be at least one parameter.  For "..." the last parameter type is
 208      "interface{}".  For "... T" the last parameter type is "[]T".  */
 209   _Bool __dotdotdot;
 210
 211   /* The input parameter types.  This is an array of pointers to
 212      struct __go_type_descriptor.  */
 213   struct __go_open_array __in;
 214
 215   /* The output parameter types.  This is an array of pointers to
 216      struct __go_type_descriptor.  */
 217   struct __go_open_array __out;
 218 };
 219
 220 /* A method on an interface type.  */
 221
 222 struct __go_interface_method
 223 {
 224   /* The name of the method.  */
 225   const struct String *__name;
 226
 227   /* This is NULL for an exported method, or the name of the package
 228      where it lives.  */
 229   const struct String *__pkg_path;
 230
 231   /* The real type of the method.  */
 232   struct __go_type_descriptor *__type;
 233 };
 234
 235 /* An interface type.  */
 236
 237 struct __go_interface_type
 238 {
 239   /* Starts like all other type descriptors.  */
 240   struct __go_type_descriptor __common;
 241
 242   /* Array of __go_interface_method .  The methods are sorted in the
 243      same order that they appear in the definition of the
 244      interface.  */
 245   struct __go_open_array __methods;
 246 };
 247
 248 /* A map type.  */
 249
 250 struct __go_map_type
 251 {
 252   /* Starts like all other type descriptors.  */
 253   struct __go_type_descriptor __common;
 254
 255   /* The map key type.  */
 256   const struct __go_type_descriptor *__key_type;
 257
 258   /* The map value type.  */
 259   const struct __go_type_descriptor *__val_type;
 260 };
 261
 262 /* A pointer type.  */
 263
 264 struct __go_ptr_type
 265 {
 266   /* Starts like all other type descriptors.  */
 267   struct __go_type_descriptor __common;
 268
 269   /* The type to which this points.  */
 270   const struct __go_type_descriptor *__element_type;
 271 };
 272
 273 /* A field in a structure.  */
 274
 275 struct __go_struct_field
 276 {
 277   /* The name of the field--NULL for an anonymous field.  */
 278   const struct String *__name;
 279
 280   /* This is NULL for an exported method, or the name of the package
 281      where it lives.  */
 282   const struct String *__pkg_path;
 283
 284   /* The type of the field.  */
 285   const struct __go_type_descriptor *__type;
 286
 287   /* The field tag, or NULL.  */
 288   const struct String *__tag;
 289
 290   /* The offset of the field in the struct.  */
 291   uintptr_t __offset;
 292 };
 293
 294 /* A struct type.  */
 295
 296 struct __go_struct_type
 297 {
 298   /* Starts like all other type descriptors.  */
 299   struct __go_type_descriptor __common;
 300
 301   /* An array of struct __go_struct_field.  */
 302   struct __go_open_array __fields;
 303 };
 304
 305 /* Whether a type descriptor is a pointer.  */
 306
 307 static inline _Bool
 308 __go_is_pointer_type (const struct __go_type_descriptor *td)
 309 {
 310   return td->__code == GO_PTR || td->__code == GO_UNSAFE_POINTER;
 311 }
 312
 313 extern _Bool
 314 __go_type_descriptors_equal(const struct __go_type_descriptor*,
 315                             const struct __go_type_descriptor*);
 316
 317 extern uintptr_t __go_type_hash_identity (const void *, uintptr_t);
 318 extern _Bool __go_type_equal_identity (const void *, const void *, uintptr_t);
 319 extern uintptr_t __go_type_hash_string (const void *, uintptr_t);
 320 extern _Bool __go_type_equal_string (const void *, const void *, uintptr_t);
 321 extern uintptr_t __go_type_hash_float (const void *, uintptr_t);
 322 extern _Bool __go_type_equal_float (const void *, const void *, uintptr_t);
 323 extern uintptr_t __go_type_hash_complex (const void *, uintptr_t);
 324 extern _Bool __go_type_equal_complex (const void *, const void *, uintptr_t);
 325 extern uintptr_t __go_type_hash_interface (const void *, uintptr_t);
 326 extern _Bool __go_type_equal_interface (const void *, const void *, uintptr_t);
 327 extern uintptr_t __go_type_hash_error (const void *, uintptr_t);
 328 extern _Bool __go_type_equal_error (const void *, const void *, uintptr_t);
 329
 330 #endif /* !defined(LIBGO_GO_TYPE_H) */