mirror of git://gcc.gnu.org/git/gcc.git
387 lines
12 KiB
Go
387 lines
12 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package runtime
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import (
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"runtime/internal/atomic"
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"runtime/internal/sys"
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"unsafe"
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)
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// Should be a built-in for unsafe.Pointer?
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//go:nosplit
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func add(p unsafe.Pointer, x uintptr) unsafe.Pointer {
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return unsafe.Pointer(uintptr(p) + x)
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}
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// getg returns the pointer to the current g.
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// The compiler rewrites calls to this function into instructions
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// that fetch the g directly (from TLS or from the dedicated register).
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func getg() *g
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// mcall switches from the g to the g0 stack and invokes fn(g),
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// where g is the goroutine that made the call.
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// mcall saves g's current PC/SP in g->sched so that it can be restored later.
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// It is up to fn to arrange for that later execution, typically by recording
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// g in a data structure, causing something to call ready(g) later.
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// mcall returns to the original goroutine g later, when g has been rescheduled.
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// fn must not return at all; typically it ends by calling schedule, to let the m
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// run other goroutines.
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//
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// mcall can only be called from g stacks (not g0, not gsignal).
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//
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// This must NOT be go:noescape: if fn is a stack-allocated closure,
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// fn puts g on a run queue, and g executes before fn returns, the
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// closure will be invalidated while it is still executing.
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func mcall(fn func(*g))
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// systemstack runs fn on a system stack.
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//
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// It is common to use a func literal as the argument, in order
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// to share inputs and outputs with the code around the call
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// to system stack:
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//
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// ... set up y ...
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// systemstack(func() {
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// x = bigcall(y)
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// })
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// ... use x ...
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//
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// For the gc toolchain this permits running a function that requires
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// additional stack space in a context where the stack can not be
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// split. For gccgo, however, stack splitting is not managed by the
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// Go runtime. In effect, all stacks are system stacks. So this gccgo
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// version just runs the function.
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func systemstack(fn func()) {
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fn()
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}
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func badsystemstack() {
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throw("systemstack called from unexpected goroutine")
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}
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// memclr clears n bytes starting at ptr.
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// in memclr_*.s
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//go:noescape
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func memclr(ptr unsafe.Pointer, n uintptr)
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//go:linkname reflect_memclr reflect.memclr
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func reflect_memclr(ptr unsafe.Pointer, n uintptr) {
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memclr(ptr, n)
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}
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// memmove copies n bytes from "from" to "to".
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// in memmove_*.s
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//go:noescape
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func memmove(to, from unsafe.Pointer, n uintptr)
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//go:linkname reflect_memmove reflect.memmove
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func reflect_memmove(to, from unsafe.Pointer, n uintptr) {
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memmove(to, from, n)
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}
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// exported value for testing
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var hashLoad = loadFactor
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// in asm_*.s
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func fastrand1() uint32
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// in asm_*.s
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//go:noescape
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func memequal(a, b unsafe.Pointer, size uintptr) bool
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// noescape hides a pointer from escape analysis. noescape is
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// the identity function but escape analysis doesn't think the
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// output depends on the input. noescape is inlined and currently
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// compiles down to a single xor instruction.
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// USE CAREFULLY!
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//go:nosplit
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func noescape(p unsafe.Pointer) unsafe.Pointer {
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x := uintptr(p)
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return unsafe.Pointer(x ^ 0)
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}
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func mincore(addr unsafe.Pointer, n uintptr, dst *byte) int32
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//go:noescape
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func jmpdefer(fv *funcval, argp uintptr)
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func exit1(code int32)
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func asminit()
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func setg(gg *g)
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func breakpoint()
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// reflectcall calls fn with a copy of the n argument bytes pointed at by arg.
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// After fn returns, reflectcall copies n-retoffset result bytes
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// back into arg+retoffset before returning. If copying result bytes back,
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// the caller should pass the argument frame type as argtype, so that
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// call can execute appropriate write barriers during the copy.
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// Package reflect passes a frame type. In package runtime, there is only
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// one call that copies results back, in cgocallbackg1, and it does NOT pass a
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// frame type, meaning there are no write barriers invoked. See that call
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// site for justification.
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func reflectcall(argtype *_type, fn, arg unsafe.Pointer, argsize uint32, retoffset uint32)
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func procyield(cycles uint32)
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type neverCallThisFunction struct{}
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// goexit is the return stub at the top of every goroutine call stack.
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// Each goroutine stack is constructed as if goexit called the
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// goroutine's entry point function, so that when the entry point
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// function returns, it will return to goexit, which will call goexit1
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// to perform the actual exit.
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//
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// This function must never be called directly. Call goexit1 instead.
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// gentraceback assumes that goexit terminates the stack. A direct
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// call on the stack will cause gentraceback to stop walking the stack
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// prematurely and if there are leftover stack barriers it may panic.
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func goexit(neverCallThisFunction)
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// publicationBarrier performs a store/store barrier (a "publication"
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// or "export" barrier). Some form of synchronization is required
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// between initializing an object and making that object accessible to
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// another processor. Without synchronization, the initialization
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// writes and the "publication" write may be reordered, allowing the
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// other processor to follow the pointer and observe an uninitialized
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// object. In general, higher-level synchronization should be used,
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// such as locking or an atomic pointer write. publicationBarrier is
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// for when those aren't an option, such as in the implementation of
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// the memory manager.
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//
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// There's no corresponding barrier for the read side because the read
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// side naturally has a data dependency order. All architectures that
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// Go supports or seems likely to ever support automatically enforce
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// data dependency ordering.
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func publicationBarrier()
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//go:noescape
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func setcallerpc(argp unsafe.Pointer, pc uintptr)
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// getcallerpc returns the program counter (PC) of its caller's caller.
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// getcallersp returns the stack pointer (SP) of its caller's caller.
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// For both, the argp must be a pointer to the caller's first function argument.
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// The implementation may or may not use argp, depending on
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// the architecture.
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//
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// For example:
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//
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// func f(arg1, arg2, arg3 int) {
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// pc := getcallerpc(unsafe.Pointer(&arg1))
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// sp := getcallersp(unsafe.Pointer(&arg1))
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// }
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//
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// These two lines find the PC and SP immediately following
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// the call to f (where f will return).
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//
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// The call to getcallerpc and getcallersp must be done in the
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// frame being asked about. It would not be correct for f to pass &arg1
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// to another function g and let g call getcallerpc/getcallersp.
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// The call inside g might return information about g's caller or
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// information about f's caller or complete garbage.
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//
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// The result of getcallersp is correct at the time of the return,
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// but it may be invalidated by any subsequent call to a function
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// that might relocate the stack in order to grow or shrink it.
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// A general rule is that the result of getcallersp should be used
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// immediately and can only be passed to nosplit functions.
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//go:noescape
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func getcallerpc(argp unsafe.Pointer) uintptr
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//go:noescape
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func getcallersp(argp unsafe.Pointer) uintptr
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// argp used in Defer structs when there is no argp.
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const _NoArgs = ^uintptr(0)
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// //go:linkname time_now time.now
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// func time_now() (sec int64, nsec int32)
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/*
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func unixnanotime() int64 {
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sec, nsec := time_now()
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return sec*1e9 + int64(nsec)
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}
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*/
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// round n up to a multiple of a. a must be a power of 2.
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func round(n, a uintptr) uintptr {
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return (n + a - 1) &^ (a - 1)
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}
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// checkASM returns whether assembly runtime checks have passed.
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func checkASM() bool {
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return true
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}
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// For gccgo this is in the C code.
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func osyield()
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// For gccgo this can be called directly.
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//extern syscall
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func syscall(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) uintptr
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// throw crashes the program.
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// For gccgo unless and until we port panic.go.
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func throw(string)
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// newobject allocates a new object.
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// For gccgo unless and until we port malloc.go.
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func newobject(*_type) unsafe.Pointer
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// newarray allocates a new array of objects.
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// For gccgo unless and until we port malloc.go.
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func newarray(*_type, int) unsafe.Pointer
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// funcPC returns the entry PC of the function f.
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// It assumes that f is a func value. Otherwise the behavior is undefined.
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// For gccgo here unless and until we port proc.go.
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//go:nosplit
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func funcPC(f interface{}) uintptr {
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return **(**uintptr)(add(unsafe.Pointer(&f), sys.PtrSize))
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}
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// typedmemmove copies a typed value.
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// For gccgo for now.
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//go:nosplit
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func typedmemmove(typ *_type, dst, src unsafe.Pointer) {
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memmove(dst, src, typ.size)
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}
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// Here for gccgo unless and until we port string.go.
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type stringStruct struct {
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str unsafe.Pointer
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len int
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}
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// Here for gccgo unless and until we port string.go.
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func stringStructOf(sp *string) *stringStruct {
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return (*stringStruct)(unsafe.Pointer(sp))
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}
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// Here for gccgo unless and until we port slice.go.
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type slice struct {
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array unsafe.Pointer
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len int
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cap int
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}
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// Here for gccgo until we port malloc.go.
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const (
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_64bit = 1 << (^uintptr(0) >> 63) / 2
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_MHeapMap_TotalBits = (_64bit*sys.GoosWindows)*35 + (_64bit*(1-sys.GoosWindows)*(1-sys.GoosDarwin*sys.GoarchArm64))*39 + sys.GoosDarwin*sys.GoarchArm64*31 + (1-_64bit)*32
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_MaxMem = uintptr(1<<_MHeapMap_TotalBits - 1)
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)
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// Here for gccgo until we port malloc.go.
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//extern runtime_mallocgc
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func c_mallocgc(size uintptr, typ uintptr, flag uint32) unsafe.Pointer
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func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
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flag := uint32(0)
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if !needzero {
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flag = 1 << 3
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}
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return c_mallocgc(size, uintptr(unsafe.Pointer(typ)), flag)
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}
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// Here for gccgo unless and until we port string.go.
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func rawstring(size int) (p unsafe.Pointer, s string) {
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p = mallocgc(uintptr(size), nil, false)
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(*(*stringStruct)(unsafe.Pointer(&s))).str = p
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(*(*stringStruct)(unsafe.Pointer(&s))).len = size
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return
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}
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// Here for gccgo unless and until we port string.go.
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func gostring(p *byte) string {
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l := findnull(p)
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if l == 0 {
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return ""
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}
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m, s := rawstring(l)
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memmove(m, unsafe.Pointer(p), uintptr(l))
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return s
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}
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// Here for gccgo unless and until we port string.go.
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func index(s, t string) int {
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if len(t) == 0 {
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return 0
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}
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for i := 0; i < len(s); i++ {
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if s[i] == t[0] && hasprefix(s[i:], t) {
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return i
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}
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}
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return -1
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}
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// Here for gccgo unless and until we port string.go.
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func hasprefix(s, t string) bool {
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return len(s) >= len(t) && s[:len(t)] == t
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}
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// Here for gccgo unless and until we port string.go.
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//go:nosplit
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func findnull(s *byte) int {
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if s == nil {
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return 0
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}
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p := (*[_MaxMem/2 - 1]byte)(unsafe.Pointer(s))
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l := 0
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for p[l] != 0 {
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l++
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}
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return l
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}
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// Here for gccgo unless and until we port string.go.
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//go:nosplit
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func gostringnocopy(str *byte) string {
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ss := stringStruct{str: unsafe.Pointer(str), len: findnull(str)}
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return *(*string)(unsafe.Pointer(&ss))
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}
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// Here for gccgo unless and until we port string.go.
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func atoi(s string) int {
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n := 0
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for len(s) > 0 && '0' <= s[0] && s[0] <= '9' {
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n = n*10 + int(s[0]) - '0'
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s = s[1:]
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}
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return n
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}
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// Here for gccgo until we port mgc.go.
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var writeBarrier struct {
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enabled bool // compiler emits a check of this before calling write barrier
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needed bool // whether we need a write barrier for current GC phase
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cgo bool // whether we need a write barrier for a cgo check
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alignme uint64 // guarantee alignment so that compiler can use a 32 or 64-bit load
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}
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// Here for gccgo until we port atomic_pointer.go and mgc.go.
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//go:nosplit
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func casp(ptr *unsafe.Pointer, old, new unsafe.Pointer) bool {
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if !atomic.Casp1((*unsafe.Pointer)(noescape(unsafe.Pointer(ptr))), noescape(old), new) {
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return false
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}
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return true
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}
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// Here for gccgo until we port lock_*.go.
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func lock(l *mutex)
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func unlock(l *mutex)
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// Here for gccgo for Solaris.
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func errno() int
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// Temporary for gccgo until we port proc.go.
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func entersyscall(int32)
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func entersyscallblock(int32)
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func exitsyscall(int32)
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