summaryrefslogtreecommitdiff
path: root/libgo/runtime/runtime.h
blob: 7d22631bddc802fc7943d9e64045fab463675e1a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "config.h"

#include "go-assert.h"
#include <complex.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <pthread.h>
#include <semaphore.h>
#include <ucontext.h>

#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif

#include "go-alloc.h"

#define _STRINGIFY2_(x) #x
#define _STRINGIFY_(x) _STRINGIFY2_(x)
#define GOSYM_PREFIX _STRINGIFY_(__USER_LABEL_PREFIX__)

/* This file supports C files copied from the 6g runtime library.
   This is a version of the 6g runtime.h rewritten for gccgo's version
   of the code.  */

typedef signed int   int8    __attribute__ ((mode (QI)));
typedef unsigned int uint8   __attribute__ ((mode (QI)));
typedef signed int   int16   __attribute__ ((mode (HI)));
typedef unsigned int uint16  __attribute__ ((mode (HI)));
typedef signed int   int32   __attribute__ ((mode (SI)));
typedef unsigned int uint32  __attribute__ ((mode (SI)));
typedef signed int   int64   __attribute__ ((mode (DI)));
typedef unsigned int uint64  __attribute__ ((mode (DI)));
typedef float        float32 __attribute__ ((mode (SF)));
typedef double       float64 __attribute__ ((mode (DF)));
typedef signed int   intptr __attribute__ ((mode (pointer)));
typedef unsigned int uintptr __attribute__ ((mode (pointer)));

typedef intptr		intgo; // Go's int
typedef uintptr		uintgo; // Go's uint

typedef uintptr		uintreg;

/* Defined types.  */

typedef	uint8			bool;
typedef	uint8			byte;
typedef	struct	g		G;
typedef	struct	mutex		Lock;
typedef	struct	m		M;
typedef	struct	p		P;
typedef	struct	note		Note;
typedef	struct	String		String;
typedef	struct	FuncVal		FuncVal;
typedef	struct	SigTab		SigTab;
typedef	struct	mcache		MCache;
typedef struct	FixAlloc	FixAlloc;
typedef	struct	hchan		Hchan;
typedef	struct	timer		Timer;
typedef	struct	gcstats		GCStats;
typedef	struct	lfnode		LFNode;
typedef	struct	ParFor		ParFor;
typedef	struct	ParForThread	ParForThread;
typedef	struct	cgoMal		CgoMal;
typedef	struct	PollDesc	PollDesc;
typedef	struct	sudog		SudoG;

typedef	struct	__go_open_array		Slice;
typedef	struct	iface			Iface;
typedef	struct	eface			Eface;
typedef	struct	__go_type_descriptor	Type;
typedef	struct	_defer			Defer;
typedef	struct	_panic			Panic;

typedef struct	__go_ptr_type		PtrType;
typedef struct	__go_func_type		FuncType;
typedef struct	__go_interface_type	InterfaceType;
typedef struct	__go_map_type		MapType;
typedef struct	__go_channel_type	ChanType;

typedef struct  tracebackg	Traceback;

typedef struct	location	Location;

struct String
{
	const byte*	str;
	intgo		len;
};

struct FuncVal
{
	void	(*fn)(void);
	// variable-size, fn-specific data here
};

#include "array.h"

// Rename Go types generated by mkrsysinfo.sh from C types, to avoid
// the name conflict.
#define timeval go_timeval
#define timespec go_timespec

#include "runtime.inc"

#undef timeval
#undef timespec

/*
 * Per-CPU declaration.
 */
extern M*	runtime_m(void);
extern G*	runtime_g(void)
  __asm__(GOSYM_PREFIX "runtime.getg");

extern M	runtime_m0;
extern G	runtime_g0;

enum
{
	true	= 1,
	false	= 0,
};
enum
{
	PtrSize = sizeof(void*),
};
enum
{
	// Per-M stack segment cache size.
	StackCacheSize = 32,
	// Global <-> per-M stack segment cache transfer batch size.
	StackCacheBatch = 16,
};

struct	SigTab
{
	int32	sig;
	int32	flags;
	void*   fwdsig;
};

#ifdef GOOS_nacl
enum {
   NaCl = 1,
};
#else
enum {
   NaCl = 0,
};
#endif

#ifdef GOOS_windows
enum {
   Windows = 1
};
#else
enum {
   Windows = 0
};
#endif
#ifdef GOOS_solaris
enum {
   Solaris = 1
};
#else
enum {
   Solaris = 0
};
#endif

// Parallel for descriptor.
struct ParFor
{
	const FuncVal *body;		// executed for each element
	uint32 done;			// number of idle threads
	uint32 nthr;			// total number of threads
	uint32 nthrmax;			// maximum number of threads
	uint32 thrseq;			// thread id sequencer
	uint32 cnt;			// iteration space [0, cnt)
	bool wait;			// if true, wait while all threads finish processing,
					// otherwise parfor may return while other threads are still working
	ParForThread *thr;		// array of thread descriptors
	// stats
	uint64 nsteal;
	uint64 nstealcnt;
	uint64 nprocyield;
	uint64 nosyield;
	uint64 nsleep;
};

extern bool runtime_precisestack;
extern bool runtime_copystack;

/*
 * defined macros
 *    you need super-gopher-guru privilege
 *    to add this list.
 */
#define	nelem(x)	(sizeof(x)/sizeof((x)[0]))
#define	nil		((void*)0)
#define USED(v)		((void) v)
#define	ROUND(x, n)	(((x)+(n)-1)&~(uintptr)((n)-1)) /* all-caps to mark as macro: it evaluates n twice */

byte*	runtime_startup_random_data;
uint32	runtime_startup_random_data_len;
void	runtime_get_random_data(byte**, int32*);

enum {
	// hashinit wants this many random bytes
	HashRandomBytes = 32
};
void	runtime_hashinit(void);

void	runtime_traceback(int32)
  __asm__ (GOSYM_PREFIX "runtime.traceback");
void	runtime_tracebackothers(G*)
  __asm__ (GOSYM_PREFIX "runtime.tracebackothers");
enum
{
	// The maximum number of frames we print for a traceback
	TracebackMaxFrames = 100,
};

/*
 * external data
 */
extern	uintptr* runtime_getZerobase(void)
  __asm__(GOSYM_PREFIX "runtime.getZerobase");
extern	G**	runtime_allg;
extern	uintptr runtime_allglen;
extern	G*	runtime_lastg;
extern	M*	runtime_allm;
extern	P**	runtime_allp;
extern	int32	runtime_gomaxprocs;
extern	uint32	runtime_needextram;
extern	uint32	runtime_panicking;
extern	int8*	runtime_goos;
extern	int32	runtime_ncpu;
extern 	void	(*runtime_sysargs)(int32, uint8**);
extern	struct debugVars runtime_debug;

extern	bool	runtime_isstarted;
extern	bool	runtime_isarchive;

/*
 * common functions and data
 */
#define runtime_strcmp(s1, s2) __builtin_strcmp((s1), (s2))
#define runtime_strncmp(s1, s2, n) __builtin_strncmp((s1), (s2), (n))
#define runtime_strstr(s1, s2) __builtin_strstr((s1), (s2))
intgo	runtime_findnull(const byte*)
  __asm__ (GOSYM_PREFIX "runtime.findnull");

void	runtime_gogo(G*);
struct __go_func_type;
void	runtime_args(int32, byte**)
  __asm__ (GOSYM_PREFIX "runtime.args");
void	runtime_osinit();
void	runtime_goargs(void)
  __asm__ (GOSYM_PREFIX "runtime.goargs");
void	runtime_goenvs(void);
void	runtime_goenvs_unix(void)
  __asm__ (GOSYM_PREFIX "runtime.goenvs_unix");
void	runtime_throw(const char*) __attribute__ ((noreturn));
void	runtime_panicstring(const char*) __attribute__ ((noreturn));
bool	runtime_canpanic(G*);
void	runtime_printf(const char*, ...);
int32	runtime_snprintf(byte*, int32, const char*, ...);
#define runtime_mcmp(a, b, s) __builtin_memcmp((a), (b), (s))
#define runtime_memmove(a, b, s) __builtin_memmove((a), (b), (s))
void*	runtime_mal(uintptr);
String	runtime_gostringnocopy(const byte*)
  __asm__ (GOSYM_PREFIX "runtime.gostringnocopy");
void	runtime_schedinit(void);
void	runtime_initsig(bool)
  __asm__ (GOSYM_PREFIX "runtime.initsig");
int32	runtime_gotraceback(bool *crash);
void	runtime_goroutineheader(G*)
  __asm__ (GOSYM_PREFIX "runtime.goroutineheader");
void	runtime_printtrace(Slice, G*)
  __asm__ (GOSYM_PREFIX "runtime.printtrace");
#define runtime_open(p, f, m) open((p), (f), (m))
#define runtime_read(d, v, n) read((d), (v), (n))
#define runtime_write(d, v, n) write((d), (v), (n))
#define runtime_close(d) close(d)
void	runtime_ready(G*);
String	runtime_getenv(const char*);
int32	runtime_atoi(const byte*, intgo);
void*	runtime_mstart(void*);
G*	runtime_malg(int32, byte**, uintptr*);
void	runtime_mpreinit(M*);
void	runtime_minit(void);
void	runtime_unminit(void);
void	runtime_needm(void)
  __asm__ (GOSYM_PREFIX "runtime.needm");
void	runtime_dropm(void)
  __asm__ (GOSYM_PREFIX "runtime.dropm");
void	runtime_signalstack(byte*, int32);
MCache*	runtime_allocmcache(void);
void	runtime_freemcache(MCache*);
void	runtime_mallocinit(void);
void	runtime_mprofinit(void);
#define runtime_malloc(s) __go_alloc(s)
#define runtime_free(p) __go_free(p)
#define runtime_getcallersp(p) __builtin_frame_address(0)
int32	runtime_mcount(void)
  __asm__ (GOSYM_PREFIX "runtime.mcount");
int32	runtime_gcount(void);
void	runtime_mcall(void(*)(G*));
uint32	runtime_fastrand1(void) __asm__ (GOSYM_PREFIX "runtime.fastrand1");
int32	runtime_timediv(int64, int32, int32*)
  __asm__ (GOSYM_PREFIX "runtime.timediv");
int32	runtime_round2(int32 x); // round x up to a power of 2.

// atomic operations
#define runtime_cas(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
#define runtime_cas64(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
#define runtime_casp(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
// Don't confuse with XADD x86 instruction,
// this one is actually 'addx', that is, add-and-fetch.
#define runtime_xadd(p, v) __sync_add_and_fetch (p, v)
#define runtime_xadd64(p, v) __sync_add_and_fetch (p, v)
#define runtime_xchg(p, v) __atomic_exchange_n (p, v, __ATOMIC_SEQ_CST)
#define runtime_xchg64(p, v) __atomic_exchange_n (p, v, __ATOMIC_SEQ_CST)
#define runtime_xchgp(p, v) __atomic_exchange_n (p, v, __ATOMIC_SEQ_CST)
#define runtime_atomicload(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
#define runtime_atomicstore(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
#define runtime_atomicstore64(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
#define runtime_atomicload64(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
#define runtime_atomicloadp(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
#define runtime_atomicstorep(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)

void runtime_setg(G*)
  __asm__ (GOSYM_PREFIX "runtime.setg");
void runtime_newextram(void);
#define runtime_exit(s) exit(s)
#define runtime_breakpoint() __builtin_trap()
void	runtime_gosched(void);
void	runtime_gosched0(G*);
void	runtime_schedtrace(bool);
void	runtime_park(bool(*)(G*, void*), void*, const char*);
void	runtime_parkunlock(Lock*, const char*);
void	runtime_tsleep(int64, const char*);
M*	runtime_newm(void);
void	runtime_goexit(void);
void	runtime_entersyscall(int32)
  __asm__ (GOSYM_PREFIX "runtime.entersyscall");
void	runtime_entersyscallblock(int32)
  __asm__ (GOSYM_PREFIX "runtime.entersyscallblock");
void	runtime_exitsyscall(int32)
  __asm__ (GOSYM_PREFIX "runtime.exitsyscall");
G*	__go_go(void (*pfn)(void*), void*);
int32	runtime_callers(int32, Location*, int32, bool keep_callers);
int64	runtime_nanotime(void)	// monotonic time
  __asm__(GOSYM_PREFIX "runtime.nanotime");
int64	runtime_unixnanotime(void) // real time, can skip
  __asm__ (GOSYM_PREFIX "runtime.unixnanotime");
void	runtime_dopanic(int32) __attribute__ ((noreturn));
void	runtime_startpanic(void)
  __asm__ (GOSYM_PREFIX "runtime.startpanic");
void	runtime_freezetheworld(void);
void	runtime_unwindstack(G*, byte*);
void	runtime_sigprof()
  __asm__ (GOSYM_PREFIX "runtime.sigprof");
void	runtime_resetcpuprofiler(int32)
  __asm__ (GOSYM_PREFIX "runtime.resetcpuprofiler");
void	runtime_setcpuprofilerate_m(int32)
     __asm__ (GOSYM_PREFIX "runtime.setcpuprofilerate_m");
void	runtime_cpuprofAdd(Slice)
     __asm__ (GOSYM_PREFIX "runtime.cpuprofAdd");
void	runtime_usleep(uint32)
     __asm__ (GOSYM_PREFIX "runtime.usleep");
int64	runtime_cputicks(void)
     __asm__ (GOSYM_PREFIX "runtime.cputicks");
int64	runtime_tickspersecond(void)
     __asm__ (GOSYM_PREFIX "runtime.tickspersecond");
void	runtime_blockevent(int64, int32);
extern int64 runtime_blockprofilerate;
G*	runtime_netpoll(bool)
  __asm__ (GOSYM_PREFIX "runtime.netpoll");
void	runtime_crash(void)
  __asm__ (GOSYM_PREFIX "runtime.crash");
void	runtime_parsedebugvars(void)
  __asm__(GOSYM_PREFIX "runtime.parsedebugvars");
void	_rt0_go(void);
intgo	runtime_setmaxthreads(intgo)
  __asm__ (GOSYM_PREFIX "runtime.setmaxthreads");
G*	runtime_timejump(void);
void	runtime_iterate_finq(void (*callback)(FuncVal*, void*, const FuncType*, const PtrType*));

void	runtime_stopTheWorldWithSema(void)
  __asm__(GOSYM_PREFIX "runtime.stopTheWorldWithSema");
void	runtime_startTheWorldWithSema(void)
  __asm__(GOSYM_PREFIX "runtime.startTheWorldWithSema");
void	runtime_acquireWorldsema(void)
  __asm__(GOSYM_PREFIX "runtime.acquireWorldsema");
void	runtime_releaseWorldsema(void)
  __asm__(GOSYM_PREFIX "runtime.releaseWorldsema");

/*
 * mutual exclusion locks.  in the uncontended case,
 * as fast as spin locks (just a few user-level instructions),
 * but on the contention path they sleep in the kernel.
 * a zeroed Lock is unlocked (no need to initialize each lock).
 */
void	runtime_lock(Lock*)
  __asm__(GOSYM_PREFIX "runtime.lock");
void	runtime_unlock(Lock*)
  __asm__(GOSYM_PREFIX "runtime.unlock");

/*
 * sleep and wakeup on one-time events.
 * before any calls to notesleep or notewakeup,
 * must call noteclear to initialize the Note.
 * then, exactly one thread can call notesleep
 * and exactly one thread can call notewakeup (once).
 * once notewakeup has been called, the notesleep
 * will return.  future notesleep will return immediately.
 * subsequent noteclear must be called only after
 * previous notesleep has returned, e.g. it's disallowed
 * to call noteclear straight after notewakeup.
 *
 * notetsleep is like notesleep but wakes up after
 * a given number of nanoseconds even if the event
 * has not yet happened.  if a goroutine uses notetsleep to
 * wake up early, it must wait to call noteclear until it
 * can be sure that no other goroutine is calling
 * notewakeup.
 *
 * notesleep/notetsleep are generally called on g0,
 * notetsleepg is similar to notetsleep but is called on user g.
 */
void	runtime_noteclear(Note*)
  __asm__ (GOSYM_PREFIX "runtime.noteclear");
void	runtime_notesleep(Note*)
  __asm__ (GOSYM_PREFIX "runtime.notesleep");
void	runtime_notewakeup(Note*)
  __asm__ (GOSYM_PREFIX "runtime.notewakeup");
bool	runtime_notetsleep(Note*, int64)  // false - timeout
  __asm__ (GOSYM_PREFIX "runtime.notetsleep");
bool	runtime_notetsleepg(Note*, int64)  // false - timeout
  __asm__ (GOSYM_PREFIX "runtime.notetsleepg");

/*
 * Lock-free stack.
 * Initialize uint64 head to 0, compare with 0 to test for emptiness.
 * The stack does not keep pointers to nodes,
 * so they can be garbage collected if there are no other pointers to nodes.
 */
void	runtime_lfstackpush(uint64 *head, LFNode *node)
  __asm__ (GOSYM_PREFIX "runtime.lfstackpush");
void*	runtime_lfstackpop(uint64 *head)
  __asm__ (GOSYM_PREFIX "runtime.lfstackpop");

/*
 * Parallel for over [0, n).
 * body() is executed for each iteration.
 * nthr - total number of worker threads.
 * if wait=true, threads return from parfor() when all work is done;
 * otherwise, threads can return while other threads are still finishing processing.
 */
ParFor*	runtime_parforalloc(uint32 nthrmax);
void	runtime_parforsetup(ParFor *desc, uint32 nthr, uint32 n, bool wait, const FuncVal *body);
void	runtime_parfordo(ParFor *desc);
void	runtime_parforiters(ParFor*, uintptr, uintptr*, uintptr*);

/*
 * low level C-called
 */
#define runtime_mmap mmap
#define runtime_munmap munmap
#define runtime_madvise madvise
#define runtime_memclr(buf, size) __builtin_memset((buf), 0, (size))
#define runtime_getcallerpc(p) __builtin_return_address(0)

#ifdef __rtems__
void __wrap_rtems_task_variable_add(void **);
#endif

/*
 * runtime go-called
 */
void reflect_call(const struct __go_func_type *, FuncVal *, _Bool, _Bool,
		  void **, void **)
  __asm__ (GOSYM_PREFIX "reflect.call");
#define runtime_panic __go_panic

/*
 * runtime c-called (but written in Go)
 */
void	runtime_printany(Eface)
     __asm__ (GOSYM_PREFIX "runtime.Printany");
void	runtime_newTypeAssertionError(const String*, const String*, const String*, const String*, Eface*)
     __asm__ (GOSYM_PREFIX "runtime.NewTypeAssertionError");
void	runtime_newErrorCString(const char*, Eface*)
     __asm__ (GOSYM_PREFIX "runtime.NewErrorCString");

/*
 * wrapped for go users
 */
void	runtime_semacquire(uint32 volatile *, bool)
     __asm__ (GOSYM_PREFIX "runtime.semacquire");
void	runtime_semrelease(uint32 volatile *)
     __asm__ (GOSYM_PREFIX "runtime.semrelease");
int32	runtime_gomaxprocsfunc(int32 n);
void	runtime_procyield(uint32)
  __asm__(GOSYM_PREFIX "runtime.procyield");
void	runtime_osyield(void)
  __asm__(GOSYM_PREFIX "runtime.osyield");
void	runtime_lockOSThread(void);
void	runtime_unlockOSThread(void);
bool	runtime_lockedOSThread(void);

void	runtime_printcreatedby(G*)
  __asm__(GOSYM_PREFIX "runtime.printcreatedby");

uintptr	runtime_memlimit(void);

#define ISNAN(f) __builtin_isnan(f)

enum
{
	UseSpanType = 1,
};

#define runtime_setitimer setitimer

void	runtime_check(void)
  __asm__ (GOSYM_PREFIX "runtime.check");

// A list of global variables that the garbage collector must scan.
struct root_list {
	struct root_list *next;
	struct root {
		void *decl;
		size_t size;
	} roots[];
};

void	__go_register_gc_roots(struct root_list*);

// Size of stack space allocated using Go's allocator.
// This will be 0 when using split stacks, as in that case
// the stacks are allocated by the splitstack library.
extern uintptr runtime_stacks_sys;

struct backtrace_state;
extern struct backtrace_state *__go_get_backtrace_state(void);
extern _Bool __go_file_line(uintptr, int, String*, String*, intgo *);
extern void runtime_main(void*);
extern uint32 runtime_in_callers;

int32 getproccount(void);

#define PREFETCH(p) __builtin_prefetch(p)

bool	runtime_gcwaiting(void);
void	runtime_badsignal(int);
Defer*	runtime_newdefer(void);
void	runtime_freedefer(Defer*);

struct time_now_ret
{
  int64_t sec;
  int32_t nsec;
};

struct time_now_ret now() __asm__ (GOSYM_PREFIX "time.now")
  __attribute__ ((no_split_stack));

extern void _cgo_wait_runtime_init_done (void);
extern void _cgo_notify_runtime_init_done (void);
extern _Bool runtime_iscgo;
extern _Bool runtime_cgoHasExtraM;
extern Hchan *runtime_main_init_done;
extern uintptr __go_end __attribute__ ((weak));
extern void *getitab(const struct __go_type_descriptor *,
		     const struct __go_type_descriptor *,
		     _Bool)
  __asm__ (GOSYM_PREFIX "runtime.getitab");