runtime: trivial replacements of _g_ in GC files

Change-Id: Iedf10558d9a1d3b80a151927b99660b688ed9ccb
Reviewed-on: https://go-review.googlesource.com/c/go/+/418585
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

3 files changed, 10 insertions, 11 deletions

diff --git a/src/runtime/heapdump.go b/src/runtime/heapdump.go
index c7f2b7a443..543efeded4 100644
--- a/src/runtime/heapdump.go
+++ b/src/runtime/heapdump.go
@@ -693,9 +693,9 @@ func mdump(m *MemStats) {
 func writeheapdump_m(fd uintptr, m *MemStats) {
 	assertWorldStopped()
 
-	_g_ := getg()
-	casgstatus(_g_.m.curg, _Grunning, _Gwaiting)
-	_g_.waitreason = waitReasonDumpingHeap
+	gp := getg()
+	casgstatus(gp.m.curg, _Grunning, _Gwaiting)
+	gp.waitreason = waitReasonDumpingHeap
 
 	// Set dump file.
 	dumpfd = fd
@@ -710,7 +710,7 @@ func writeheapdump_m(fd uintptr, m *MemStats) {
 		tmpbuf = nil
 	}
 
-	casgstatus(_g_.m.curg, _Gwaiting, _Grunning)
+	casgstatus(gp.m.curg, _Gwaiting, _Grunning)
 }
 
 // dumpint() the kind & offset of each field in an object.
diff --git a/src/runtime/mbitmap.go b/src/runtime/mbitmap.go
index a3a6590d65..fcf59b8b3c 100644
--- a/src/runtime/mbitmap.go
+++ b/src/runtime/mbitmap.go
@@ -2028,11 +2028,10 @@ func getgcmask(ep any) (mask []byte) {
 	}
 
 	// stack
-	if _g_ := getg(); _g_.m.curg.stack.lo <= uintptr(p) && uintptr(p) < _g_.m.curg.stack.hi {
+	if gp := getg(); gp.m.curg.stack.lo <= uintptr(p) && uintptr(p) < gp.m.curg.stack.hi {
 		var frame stkframe
 		frame.sp = uintptr(p)
-		_g_ := getg()
-		gentraceback(_g_.m.curg.sched.pc, _g_.m.curg.sched.sp, 0, _g_.m.curg, 0, nil, 1000, getgcmaskcb, noescape(unsafe.Pointer(&frame)), 0)
+		gentraceback(gp.m.curg.sched.pc, gp.m.curg.sched.sp, 0, gp.m.curg, 0, nil, 1000, getgcmaskcb, noescape(unsafe.Pointer(&frame)), 0)
 		if frame.fn.valid() {
 			locals, _, _ := getStackMap(&frame, nil, false)
 			if locals.n == 0 {
diff --git a/src/runtime/mgcsweep.go b/src/runtime/mgcsweep.go
index de57f18c4f..2ac5d507dd 100644
--- a/src/runtime/mgcsweep.go
+++ b/src/runtime/mgcsweep.go
@@ -431,8 +431,8 @@ func (s *mspan) ensureSwept() {
 	// Caller must disable preemption.
 	// Otherwise when this function returns the span can become unswept again
 	// (if GC is triggered on another goroutine).
-	_g_ := getg()
-	if _g_.m.locks == 0 && _g_.m.mallocing == 0 && _g_ != _g_.m.g0 {
+	gp := getg()
+	if gp.m.locks == 0 && gp.m.mallocing == 0 && gp != gp.m.g0 {
 		throw("mspan.ensureSwept: m is not locked")
 	}
 
@@ -470,8 +470,8 @@ func (s *mspan) ensureSwept() {
 func (sl *sweepLocked) sweep(preserve bool) bool {
 	// It's critical that we enter this function with preemption disabled,
 	// GC must not start while we are in the middle of this function.
-	_g_ := getg()
-	if _g_.m.locks == 0 && _g_.m.mallocing == 0 && _g_ != _g_.m.g0 {
+	gp := getg()
+	if gp.m.locks == 0 && gp.m.mallocing == 0 && gp != gp.m.g0 {
 		throw("mspan.sweep: m is not locked")
 	}