tracing/runtime: Add support for Go1.14 (preliminary)

Generate g for ~ Go 1.14beta1 (go1.14beta1-10-g5c6f42773c)
Compared to Go1.13 there are several changed to g, _defer and timer
related to:

- non-cooperative preemption (https://golang.org/issue/10958, https://golang.org/issue/24543);
- inlined defers (https://golang.org/issue/14939, https://golang.org/issue/34481);
- timers rework to be integrated with network poller (https://golang.org/issue/6239, https://golang.org/issue/27707):

Regenerated files stay without changes for Go1.13 and previous releases.

---- 8< ----
diff --git a/zruntime_g_go1.13.go b/zruntime_g_go1.14.go
index 76851fd..19cebae 100644
--- a/zruntime_g_go1.13.go
+++ b/zruntime_g_go1.14.go
@@ -1,6 +1,6 @@
 // Code generated by g_typedef; DO NOT EDIT.

-// +build go1.13,!go1.14
+// +build go1.14,!go1.15

 package xruntime

@@ -32,12 +32,25 @@ type g struct {
 	schedlink    guintptr
 	waitsince    int64      // approx time when the g become blocked
 	waitreason   waitReason // if status==Gwaiting
+
 	preempt       bool // preemption signal, duplicates stackguard0 = stackpreempt
+	preemptStop   bool // transition to _Gpreempted on preemption; otherwise, just deschedule
+	preemptShrink bool // shrink stack at synchronous safe point
+
+	// asyncSafePoint is set if g is stopped at an asynchronous
+	// safe point. This means there are frames on the stack
+	// without precise pointer information.
+	asyncSafePoint bool
+
 	paniconfault bool // panic (instead of crash) on unexpected fault address
-	preemptscan    bool       // preempted g does scan for gc
 	gcscandone   bool // g has scanned stack; protected by _Gscan bit in status
-	gcscanvalid    bool       // false at start of gc cycle, true if G has not run since last scan; TODO: remove?
 	throwsplit   bool // must not split stack
+	// activeStackChans indicates that there are unlocked channels
+	// pointing into this goroutine's stack. If true, stack
+	// copying needs to acquire channel locks to protect these
+	// areas of the stack.
+	activeStackChans bool
+
 	raceignore     int8     // ignore race detection events
 	sysblocktraced bool     // StartTrace has emitted EvGoInSyscall about this goroutine
 	sysexitticks   int64    // cputicks when syscall has returned (for tracing)
@@ -76,18 +89,37 @@ type _panic struct {
 	argp      unsafe.Pointer // pointer to arguments of deferred call run during panic; cannot move - known to liblink
 	arg       interface{}    // argument to panic
 	link      *_panic        // link to earlier panic
+	pc        uintptr        // where to return to in runtime if this panic is bypassed
+	sp        unsafe.Pointer // where to return to in runtime if this panic is bypassed
 	recovered bool           // whether this panic is over
 	aborted   bool           // the panic was aborted
+	goexit    bool
 }
 type _defer struct {
 	siz     int32 // includes both arguments and results
 	started bool
 	heap    bool
+	// openDefer indicates that this _defer is for a frame with open-coded
+	// defers. We have only one defer record for the entire frame (which may
+	// currently have 0, 1, or more defers active).
+	openDefer bool
 	sp        uintptr  // sp at time of defer
-	pc      uintptr
-	fn      *funcval
+	pc        uintptr  // pc at time of defer
+	fn        *funcval // can be nil for open-coded defers
 	_panic    *_panic  // panic that is running defer
 	link      *_defer
+
+	// If openDefer is true, the fields below record values about the stack
+	// frame and associated function that has the open-coded defer(s). sp
+	// above will be the sp for the frame, and pc will be address of the
+	// deferreturn call in the function.
+	fd   unsafe.Pointer // funcdata for the function associated with the frame
+	varp uintptr        // value of varp for the stack frame
+	// framepc is the current pc associated with the stack frame. Together,
+	// with sp above (which is the sp associated with the stack frame),
+	// framepc/sp can be used as pc/sp pair to continue a stack trace via
+	// gentraceback().
+	framepc uintptr
 }
 type gobuf struct {
 	// The offsets of sp, pc, and g are known to (hard-coded in) libmach.
@@ -114,8 +146,10 @@ type funcval struct {
 	fn uintptr
 }
 type timer struct {
-	tb *timersBucket // the bucket the timer lives in
-	i  int           // heap index
+	// If this timer is on a heap, which P's heap it is on.
+	// puintptr rather than *p to match uintptr in the versions
+	// of this struct defined in other packages.
+	pp puintptr

 	// Timer wakes up at when, and then at when+period, ... (period > 0 only)
 	// each time calling f(arg, now) in the timer goroutine, so f must be
@@ -125,6 +159,12 @@ type timer struct {
 	f      func(interface{}, uintptr)
 	arg    interface{}
 	seq    uintptr
+
+	// What to set the when field to in timerModifiedXX status.
+	nextwhen int64
+
+	// The status field holds one of the values below.
+	status uint32
 }
 type guintptr uintptr
 type puintptr uintptr

tracing/internal/xruntime/g_typedef

@@ -87,7 +87,7 @@ gen_zruntime() {
 
 
 # main driver
-gov="go18 go19 go1.10 go1.11 go1.12 go1.13"
+gov="go18 go19 go1.10 go1.11 go1.12 go1.13 go1.14"
 
 for g in $gov; do
 	goset $g

tracing/internal/xruntime/zruntime_g_go1.14.go

+// Code generated by g_typedef; DO NOT EDIT.
+
+// +build go1.14,!go1.15
+
+package xruntime
+
+import "unsafe"
+
+type g struct {
+	// Stack parameters.
+	// stack describes the actual stack memory: [stack.lo, stack.hi).
+	// stackguard0 is the stack pointer compared in the Go stack growth prologue.
+	// It is stack.lo+StackGuard normally, but can be StackPreempt to trigger a preemption.
+	// stackguard1 is the stack pointer compared in the C stack growth prologue.
+	// It is stack.lo+StackGuard on g0 and gsignal stacks.
+	// It is ~0 on other goroutine stacks, to trigger a call to morestackc (and crash).
+	stack       stack   // offset known to runtime/cgo
+	stackguard0 uintptr // offset known to liblink
+	stackguard1 uintptr // offset known to liblink
+
+	_panic       *_panic // innermost panic - offset known to liblink
+	_defer       *_defer // innermost defer
+	m            *m      // current m; offset known to arm liblink
+	sched        gobuf
+	syscallsp    uintptr        // if status==Gsyscall, syscallsp = sched.sp to use during gc
+	syscallpc    uintptr        // if status==Gsyscall, syscallpc = sched.pc to use during gc
+	stktopsp     uintptr        // expected sp at top of stack, to check in traceback
+	param        unsafe.Pointer // passed parameter on wakeup
+	atomicstatus uint32
+	stackLock    uint32 // sigprof/scang lock; TODO: fold in to atomicstatus
+	goid         int64
+	schedlink    guintptr
+	waitsince    int64      // approx time when the g become blocked
+	waitreason   waitReason // if status==Gwaiting
+
+	preempt       bool // preemption signal, duplicates stackguard0 = stackpreempt
+	preemptStop   bool // transition to _Gpreempted on preemption; otherwise, just deschedule
+	preemptShrink bool // shrink stack at synchronous safe point
+
+	// asyncSafePoint is set if g is stopped at an asynchronous
+	// safe point. This means there are frames on the stack
+	// without precise pointer information.
+	asyncSafePoint bool
+
+	paniconfault bool // panic (instead of crash) on unexpected fault address
+	gcscandone   bool // g has scanned stack; protected by _Gscan bit in status
+	throwsplit   bool // must not split stack
+	// activeStackChans indicates that there are unlocked channels
+	// pointing into this goroutine's stack. If true, stack
+	// copying needs to acquire channel locks to protect these
+	// areas of the stack.
+	activeStackChans bool
+
+	raceignore     int8     // ignore race detection events
+	sysblocktraced bool     // StartTrace has emitted EvGoInSyscall about this goroutine
+	sysexitticks   int64    // cputicks when syscall has returned (for tracing)
+	traceseq       uint64   // trace event sequencer
+	tracelastp     puintptr // last P emitted an event for this goroutine
+	lockedm        muintptr
+	sig            uint32
+	writebuf       []byte
+	sigcode0       uintptr
+	sigcode1       uintptr
+	sigpc          uintptr
+	gopc           uintptr         // pc of go statement that created this goroutine
+	ancestors      *[]ancestorInfo // ancestor information goroutine(s) that created this goroutine (only used if debug.tracebackancestors)
+	startpc        uintptr         // pc of goroutine function
+	racectx        uintptr
+	waiting        *sudog         // sudog structures this g is waiting on (that have a valid elem ptr); in lock order
+	cgoCtxt        []uintptr      // cgo traceback context
+	labels         unsafe.Pointer // profiler labels
+	timer          *timer         // cached timer for time.Sleep
+	selectDone     uint32         // are we participating in a select and did someone win the race?
+
+	// gcAssistBytes is this G's GC assist credit in terms of
+	// bytes allocated. If this is positive, then the G has credit
+	// to allocate gcAssistBytes bytes without assisting. If this
+	// is negative, then the G must correct this by performing
+	// scan work. We track this in bytes to make it fast to update
+	// and check for debt in the malloc hot path. The assist ratio
+	// determines how this corresponds to scan work debt.
+	gcAssistBytes int64
+}
+type stack struct {
+	lo uintptr
+	hi uintptr
+}
+type _panic struct {
+	argp      unsafe.Pointer // pointer to arguments of deferred call run during panic; cannot move - known to liblink
+	arg       interface{}    // argument to panic
+	link      *_panic        // link to earlier panic
+	pc        uintptr        // where to return to in runtime if this panic is bypassed
+	sp        unsafe.Pointer // where to return to in runtime if this panic is bypassed
+	recovered bool           // whether this panic is over
+	aborted   bool           // the panic was aborted
+	goexit    bool
+}
+type _defer struct {
+	siz     int32 // includes both arguments and results
+	started bool
+	heap    bool
+	// openDefer indicates that this _defer is for a frame with open-coded
+	// defers. We have only one defer record for the entire frame (which may
+	// currently have 0, 1, or more defers active).
+	openDefer bool
+	sp        uintptr  // sp at time of defer
+	pc        uintptr  // pc at time of defer
+	fn        *funcval // can be nil for open-coded defers
+	_panic    *_panic  // panic that is running defer
+	link      *_defer
+
+	// If openDefer is true, the fields below record values about the stack
+	// frame and associated function that has the open-coded defer(s). sp
+	// above will be the sp for the frame, and pc will be address of the
+	// deferreturn call in the function.
+	fd   unsafe.Pointer // funcdata for the function associated with the frame
+	varp uintptr        // value of varp for the stack frame
+	// framepc is the current pc associated with the stack frame. Together,
+	// with sp above (which is the sp associated with the stack frame),
+	// framepc/sp can be used as pc/sp pair to continue a stack trace via
+	// gentraceback().
+	framepc uintptr
+}
+type gobuf struct {
+	// The offsets of sp, pc, and g are known to (hard-coded in) libmach.
+	//
+	// ctxt is unusual with respect to GC: it may be a
+	// heap-allocated funcval, so GC needs to track it, but it
+	// needs to be set and cleared from assembly, where it's
+	// difficult to have write barriers. However, ctxt is really a
+	// saved, live register, and we only ever exchange it between
+	// the real register and the gobuf. Hence, we treat it as a
+	// root during stack scanning, which means assembly that saves
+	// and restores it doesn't need write barriers. It's still
+	// typed as a pointer so that any other writes from Go get
+	// write barriers.
+	sp   uintptr
+	pc   uintptr
+	g    guintptr
+	ctxt unsafe.Pointer
+	ret  uintreg
+	lr   uintptr
+	bp   uintptr // for GOEXPERIMENT=framepointer
+}
+type funcval struct {
+	fn uintptr
+}
+type timer struct {
+	// If this timer is on a heap, which P's heap it is on.
+	// puintptr rather than *p to match uintptr in the versions
+	// of this struct defined in other packages.
+	pp puintptr
+
+	// Timer wakes up at when, and then at when+period, ... (period > 0 only)
+	// each time calling f(arg, now) in the timer goroutine, so f must be
+	// a well-behaved function and not block.
+	when   int64
+	period int64
+	f      func(interface{}, uintptr)
+	arg    interface{}
+	seq    uintptr
+
+	// What to set the when field to in timerModifiedXX status.
+	nextwhen int64
+
+	// The status field holds one of the values below.
+	status uint32
+}
+type guintptr uintptr
+type puintptr uintptr
+type muintptr uintptr
+type waitReason uint8
+type ancestorInfo struct {
+	pcs  []uintptr // pcs from the stack of this goroutine
+	goid int64     // goroutine id of this goroutine; original goroutine possibly dead
+	gopc uintptr   // pc of go statement that created this goroutine
+}
+type uintreg  uint	// FIXME wrong on amd64p32
+type m struct {}		// FIXME stub
+type sudog struct {}	// FIXME stub
+type timersBucket struct {}	// FIXME stub