all: merge dev.cc (81884b89bd88) into default

With this change, default now contains Go 1.5 work.
Any future bug fixes for Go 1.4 in the compilers or
the runtime will have to be made directly to the
release branch.

1 files changed, 161 insertions, 0 deletions

diff --git a/src/runtime/panic1.go b/src/runtime/panic1.go
new file mode 100644
index 000000000..17379f963
--- /dev/null
+++ b/src/runtime/panic1.go
@@ -0,0 +1,161 @@
+// Copyright 2012 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"
+
+// Code related to defer, panic and recover.
+// TODO: Merge into panic.go.
+
+//uint32 runtime·panicking;
+var paniclk mutex
+
+const hasLinkRegister = GOARCH == "arm" || GOARCH == "power64" || GOARCH == "power64le"
+
+// Unwind the stack after a deferred function calls recover
+// after a panic.  Then arrange to continue running as though
+// the caller of the deferred function returned normally.
+func recovery(gp *g) {
+	// Info about defer passed in G struct.
+	argp := (unsafe.Pointer)(gp.sigcode0)
+	pc := uintptr(gp.sigcode1)
+
+	// d's arguments need to be in the stack.
+	if argp != nil && (uintptr(argp) < gp.stack.lo || gp.stack.hi < uintptr(argp)) {
+		print("recover: ", argp, " not in [", hex(gp.stack.lo), ", ", hex(gp.stack.hi), "]\n")
+		gothrow("bad recovery")
+	}
+
+	// Make the deferproc for this d return again,
+	// this time returning 1.  The calling function will
+	// jump to the standard return epilogue.
+	// The -2*sizeof(uintptr) makes up for the
+	// two extra words that are on the stack at
+	// each call to deferproc.
+	// (The pc we're returning to does pop pop
+	// before it tests the return value.)
+	// On the arm and power there are 2 saved LRs mixed in too.
+	if hasLinkRegister {
+		gp.sched.sp = uintptr(argp) - 4*ptrSize
+	} else {
+		gp.sched.sp = uintptr(argp) - 2*ptrSize
+	}
+	gp.sched.pc = pc
+	gp.sched.lr = 0
+	gp.sched.ret = 1
+	gogo(&gp.sched)
+}
+
+func startpanic_m() {
+	_g_ := getg()
+	if mheap_.cachealloc.size == 0 { // very early
+		print("runtime: panic before malloc heap initialized\n")
+		_g_.m.mallocing = 1 // tell rest of panic not to try to malloc
+	} else if _g_.m.mcache == nil { // can happen if called from signal handler or throw
+		_g_.m.mcache = allocmcache()
+	}
+
+	switch _g_.m.dying {
+	case 0:
+		_g_.m.dying = 1
+		if _g_ != nil {
+			_g_.writebuf = nil
+		}
+		xadd(&panicking, 1)
+		lock(&paniclk)
+		if debug.schedtrace > 0 || debug.scheddetail > 0 {
+			schedtrace(true)
+		}
+		freezetheworld()
+		return
+	case 1:
+		// Something failed while panicing, probably the print of the
+		// argument to panic().  Just print a stack trace and exit.
+		_g_.m.dying = 2
+		print("panic during panic\n")
+		dopanic(0)
+		exit(3)
+		fallthrough
+	case 2:
+		// This is a genuine bug in the runtime, we couldn't even
+		// print the stack trace successfully.
+		_g_.m.dying = 3
+		print("stack trace unavailable\n")
+		exit(4)
+		fallthrough
+	default:
+		// Can't even print!  Just exit.
+		exit(5)
+	}
+}
+
+var didothers bool
+var deadlock mutex
+
+func dopanic_m(gp *g, pc, sp uintptr) {
+	if gp.sig != 0 {
+		print("[signal ", hex(gp.sig), " code=", hex(gp.sigcode0), " addr=", hex(gp.sigcode1), " pc=", hex(gp.sigpc), "]\n")
+	}
+
+	var docrash bool
+	_g_ := getg()
+	if t := gotraceback(&docrash); t > 0 {
+		if gp != gp.m.g0 {
+			print("\n")
+			goroutineheader(gp)
+			traceback(pc, sp, 0, gp)
+		} else if t >= 2 || _g_.m.throwing > 0 {
+			print("\nruntime stack:\n")
+			traceback(pc, sp, 0, gp)
+		}
+		if !didothers {
+			didothers = true
+			tracebackothers(gp)
+		}
+	}
+	unlock(&paniclk)
+
+	if xadd(&panicking, -1) != 0 {
+		// Some other m is panicking too.
+		// Let it print what it needs to print.
+		// Wait forever without chewing up cpu.
+		// It will exit when it's done.
+		lock(&deadlock)
+		lock(&deadlock)
+	}
+
+	if docrash {
+		crash()
+	}
+
+	exit(2)
+}
+
+//go:nosplit
+func canpanic(gp *g) bool {
+	// Note that g is m->gsignal, different from gp.
+	// Note also that g->m can change at preemption, so m can go stale
+	// if this function ever makes a function call.
+	_g_ := getg()
+	_m_ := _g_.m
+
+	// Is it okay for gp to panic instead of crashing the program?
+	// Yes, as long as it is running Go code, not runtime code,
+	// and not stuck in a system call.
+	if gp == nil || gp != _m_.curg {
+		return false
+	}
+	if _m_.locks-_m_.softfloat != 0 || _m_.mallocing != 0 || _m_.throwing != 0 || _m_.gcing != 0 || _m_.dying != 0 {
+		return false
+	}
+	status := readgstatus(gp)
+	if status&^_Gscan != _Grunning || gp.syscallsp != 0 {
+		return false
+	}
+	if GOOS == "windows" && _m_.libcallsp != 0 {
+		return false
+	}
+	return true
+}