mirror of
https://github.com/golang/go
synced 2024-11-20 10:04:45 -07:00
9204821731
The conversion was done with an automated tool and then modified only as necessary to make it compile and run. vlrt.c was only called from C. Pure delete. [This CL is part of the removal of C code from package runtime. See golang.org/s/dev.cc for an overview.] LGTM=r R=r, austin CC=dvyukov, golang-codereviews, iant, khr https://golang.org/cl/174860043
55 lines
1.8 KiB
Go
55 lines
1.8 KiB
Go
// Copyright 2013 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.
|
|
|
|
// +build amd64 amd64p32 386
|
|
|
|
package runtime
|
|
|
|
import "unsafe"
|
|
|
|
// adjust Gobuf as it if executed a call to fn with context ctxt
|
|
// and then did an immediate gosave.
|
|
func gostartcall(buf *gobuf, fn, ctxt unsafe.Pointer) {
|
|
sp := buf.sp
|
|
if regSize > ptrSize {
|
|
sp -= ptrSize
|
|
*(*uintptr)(unsafe.Pointer(sp)) = 0
|
|
}
|
|
sp -= ptrSize
|
|
*(*uintptr)(unsafe.Pointer(sp)) = buf.pc
|
|
buf.sp = sp
|
|
buf.pc = uintptr(fn)
|
|
buf.ctxt = ctxt
|
|
}
|
|
|
|
// Called to rewind context saved during morestack back to beginning of function.
|
|
// To help us, the linker emits a jmp back to the beginning right after the
|
|
// call to morestack. We just have to decode and apply that jump.
|
|
func rewindmorestack(buf *gobuf) {
|
|
pc := (*[8]byte)(unsafe.Pointer(buf.pc))
|
|
if pc[0] == 0xe9 { // jmp 4-byte offset
|
|
buf.pc = buf.pc + 5 + uintptr(int64(*(*int32)(unsafe.Pointer(&pc[1]))))
|
|
return
|
|
}
|
|
if pc[0] == 0xeb { // jmp 1-byte offset
|
|
buf.pc = buf.pc + 2 + uintptr(int64(*(*int8)(unsafe.Pointer(&pc[1]))))
|
|
return
|
|
}
|
|
if pc[0] == 0xcc {
|
|
// This is a breakpoint inserted by gdb. We could use
|
|
// runtime·findfunc to find the function. But if we
|
|
// do that, then we will continue execution at the
|
|
// function entry point, and we will not hit the gdb
|
|
// breakpoint. So for this case we don't change
|
|
// buf.pc, so that when we return we will execute
|
|
// the jump instruction and carry on. This means that
|
|
// stack unwinding may not work entirely correctly
|
|
// (http://golang.org/issue/5723) but the user is
|
|
// running under gdb anyhow.
|
|
return
|
|
}
|
|
print("runtime: pc=", pc, " ", hex(pc[0]), " ", hex(pc[1]), " ", hex(pc[2]), " ", hex(pc[3]), " ", hex(pc[4]), "\n")
|
|
gothrow("runtime: misuse of rewindmorestack")
|
|
}
|