1 files changed, 240 insertions, 0 deletions
diff --git a/src/runtime/stubs.go b/src/runtime/stubs.go
new file mode 100644
index 000000000..03f618e15
--- /dev/null
+++ b/src/runtime/stubs.go
@@ -0,0 +1,240 @@
+// Copyright 2014 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.
+
+package runtime
+
+import "unsafe"
+
+// Declarations for runtime services implemented in C or assembly.
+// C implementations of these functions are in stubs.goc.
+// Assembly implementations are in various files, see comments with
+// each function.
+
+const ptrSize = 4 << (^uintptr(0) >> 63) // unsafe.Sizeof(uintptr(0)) but an ideal const
+const regSize = 4 << (^uintreg(0) >> 63) // unsafe.Sizeof(uintreg(0)) but an ideal const
+
+// Should be a built-in for unsafe.Pointer?
+//go:nosplit
+func add(p unsafe.Pointer, x uintptr) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(p) + x)
+}
+
+// n must be a power of 2
+func roundup(p unsafe.Pointer, n uintptr) unsafe.Pointer {
+	delta := -uintptr(p) & (n - 1)
+	return unsafe.Pointer(uintptr(p) + delta)
+}
+
+// in stubs.goc
+func getg() *g
+func acquirem() *m
+func releasem(mp *m)
+func gomcache() *mcache
+
+// mcall switches from the g to the g0 stack and invokes fn(g),
+// where g is the goroutine that made the call.
+// mcall saves g's current PC/SP in g->sched so that it can be restored later.
+// It is up to fn to arrange for that later execution, typically by recording
+// g in a data structure, causing something to call ready(g) later.
+// mcall returns to the original goroutine g later, when g has been rescheduled.
+// fn must not return at all; typically it ends by calling schedule, to let the m
+// run other goroutines.
+//
+// mcall can only be called from g stacks (not g0, not gsignal).
+//go:noescape
+func mcall(fn func(*g))
+
+// onM switches from the g to the g0 stack and invokes fn().
+// When fn returns, onM switches back to the g and returns,
+// continuing execution on the g stack.
+// If arguments must be passed to fn, they can be written to
+// g->m->ptrarg (pointers) and g->m->scalararg (non-pointers)
+// before the call and then consulted during fn.
+// Similarly, fn can pass return values back in those locations.
+// If fn is written in Go, it can be a closure, which avoids the need for
+// ptrarg and scalararg entirely.
+// After reading values out of ptrarg and scalararg it is conventional
+// to zero them to avoid (memory or information) leaks.
+//
+// If onM is called from a g0 stack, it invokes fn and returns,
+// without any stack switches.
+//
+// If onM is called from a gsignal stack, it crashes the program.
+// The implication is that functions used in signal handlers must
+// not use onM.
+//
+// NOTE(rsc): We could introduce a separate onMsignal that is
+// like onM but if called from a gsignal stack would just run fn on
+// that stack. The caller of onMsignal would be required to save the
+// old values of ptrarg/scalararg and restore them when the call
+// was finished, in case the signal interrupted an onM sequence
+// in progress on the g or g0 stacks. Until there is a clear need for this,
+// we just reject onM in signal handling contexts entirely.
+//
+//go:noescape
+func onM(fn func())
+
+func badonm() {
+	gothrow("onM called from signal goroutine")
+}
+
+// C functions that run on the M stack.
+// Call using mcall.
+func gosched_m(*g)
+func park_m(*g)
+func recovery_m(*g)
+
+// More C functions that run on the M stack.
+// Call using onM.
+func mcacheRefill_m()
+func largeAlloc_m()
+func gc_m()
+func scavenge_m()
+func setFinalizer_m()
+func removeFinalizer_m()
+func markallocated_m()
+func unrollgcprog_m()
+func unrollgcproginplace_m()
+func setgcpercent_m()
+func setmaxthreads_m()
+func ready_m()
+func deferproc_m()
+func goexit_m()
+func startpanic_m()
+func dopanic_m()
+
+// memclr clears n bytes starting at ptr.
+// in memclr_*.s
+//go:noescape
+func memclr(ptr unsafe.Pointer, n uintptr)
+
+// memmove copies n bytes from "from" to "to".
+// in memmove_*.s
+//go:noescape
+func memmove(to unsafe.Pointer, from unsafe.Pointer, n uintptr)
+
+const (
+	concurrentSweep = true
+)
+
+func gosched()
+func starttheworld()
+func stoptheworld()
+func newextram()
+func lockOSThread()
+func unlockOSThread()
+
+// exported value for testing
+var hashLoad = loadFactor
+
+// in asm_*.s
+//go:noescape
+func memeq(a, b unsafe.Pointer, size uintptr) bool
+
+// Code pointers for the nohash/noequal algorithms. Used for producing better error messages.
+var nohashcode uintptr
+var noequalcode uintptr
+
+// noescape hides a pointer from escape analysis.  noescape is
+// the identity function but escape analysis doesn't think the
+// output depends on the input.  noescape is inlined and currently
+// compiles down to a single xor instruction.
+// USE CAREFULLY!
+//go:nosplit
+func noescape(p unsafe.Pointer) unsafe.Pointer {
+	x := uintptr(p)
+	return unsafe.Pointer(x ^ 0)
+}
+
+func entersyscall()
+func entersyscallblock()
+func exitsyscall()
+
+func cgocallback(fn, frame unsafe.Pointer, framesize uintptr)
+func gogo(buf *gobuf)
+func gosave(buf *gobuf)
+func read(fd int32, p unsafe.Pointer, n int32) int32
+func close(fd int32) int32
+func mincore(addr unsafe.Pointer, n uintptr, dst *byte) int32
+
+//go:noescape
+func jmpdefer(fv *funcval, argp uintptr)
+func exit1(code int32)
+func asminit()
+func setg(gg *g)
+func exit(code int32)
+func breakpoint()
+func nanotime() int64
+func usleep(usec uint32)
+func cputicks() int64
+func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) unsafe.Pointer
+func munmap(addr unsafe.Pointer, n uintptr)
+func madvise(addr unsafe.Pointer, n uintptr, flags int32)
+func reflectcall(fn, arg unsafe.Pointer, n uint32, retoffset uint32)
+func osyield()
+func procyield(cycles uint32)
+func cgocallback_gofunc(fv *funcval, frame unsafe.Pointer, framesize uintptr)
+func readgogc() int32
+func purgecachedstats(c *mcache)
+func gostringnocopy(b *byte) string
+func goexit()
+
+//go:noescape
+func write(fd uintptr, p unsafe.Pointer, n int32) int32
+
+//go:noescape
+func cas(ptr *uint32, old, new uint32) bool
+
+//go:noescape
+func casp(ptr *unsafe.Pointer, old, new unsafe.Pointer) bool
+
+//go:noescape
+func casuintptr(ptr *uintptr, old, new uintptr) bool
+
+//go:noescape
+func atomicstoreuintptr(ptr *uintptr, new uintptr)
+
+//go:noescape
+func atomicloaduintptr(ptr *uintptr) uintptr
+
+//go:noescape
+func atomicloaduint(ptr *uint) uint
+
+//go:noescape
+func setcallerpc(argp unsafe.Pointer, pc uintptr)
+
+//go:noescape
+func getcallerpc(argp unsafe.Pointer) uintptr
+
+//go:noescape
+func getcallersp(argp unsafe.Pointer) uintptr
+
+//go:noescape
+func asmcgocall(fn, arg unsafe.Pointer)
+
+//go:noescape
+func asmcgocall_errno(fn, arg unsafe.Pointer) int32
+
+//go:noescape
+func open(name *byte, mode, perm int32) int32
+
+//go:noescape
+func gotraceback(*bool) int32
+
+const _NoArgs = ^uintptr(0)
+
+func newstack()
+func newproc()
+func lessstack()
+func morestack()
+func mstart()
+func rt0_go()
+func sigpanic()
+
+// return0 is a stub used to return 0 from deferproc.
+// It is called at the very end of deferproc to signal
+// the calling Go function that it should not jump
+// to deferreturn.
+// in asm_*.s
+func return0()