libgo: update to Go1.16beta1 release

This does not yet include support for the //go:embed directive added
in this release.

	* Makefile.am (check-runtime): Don't create check-runtime-dir.
	(mostlyclean-local): Don't remove check-runtime-dir.
	(check-go-tool, check-vet): Copy in go.mod and modules.txt.
	(check-cgo-test, check-carchive-test): Add go.mod file.
	* Makefile.in: Regenerate.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/280172

1 files changed, 84 insertions, 100 deletions

diff --git a/libgo/go/runtime/malloc.go b/libgo/go/runtime/malloc.go
index feb043a..d3d88a2 100644
--- a/libgo/go/runtime/malloc.go
+++ b/libgo/go/runtime/malloc.go
@@ -208,7 +208,7 @@ const (
 	// mips32 only has access to the low 2GB of virtual memory, so
 	// we further limit it to 31 bits.
 	//
-	// On darwin/arm64, although 64-bit pointers are presumably
+	// On ios/arm64, although 64-bit pointers are presumably
 	// available, pointers are truncated to 33 bits. Furthermore,
 	// only the top 4 GiB of the address space are actually available
 	// to the application, but we allow the whole 33 bits anyway for
@@ -217,7 +217,7 @@ const (
 	// arenaBaseOffset to offset into the top 4 GiB.
 	//
 	// WebAssembly currently has a limit of 4GB linear memory.
-	heapAddrBits = (_64bit*(1-sys.GoarchWasm)*(1-sys.GoosDarwin*sys.GoarchArm64))*48 + (1-_64bit+sys.GoarchWasm)*(32-(sys.GoarchMips+sys.GoarchMipsle)) + 33*sys.GoosDarwin*sys.GoarchArm64
+	heapAddrBits = (_64bit*(1-sys.GoarchWasm)*(1-sys.GoosIos*sys.GoarchArm64))*48 + (1-_64bit+sys.GoarchWasm)*(32-(sys.GoarchMips+sys.GoarchMipsle)) + 33*sys.GoosIos*sys.GoarchArm64
 
 	// maxAlloc is the maximum size of an allocation. On 64-bit,
 	// it's theoretically possible to allocate 1<<heapAddrBits bytes. On
@@ -525,14 +525,22 @@ func mallocinit() {
 		// However, on arm64, we ignore all this advice above and slam the
 		// allocation at 0x40 << 32 because when using 4k pages with 3-level
 		// translation buffers, the user address space is limited to 39 bits
-		// On darwin/arm64, the address space is even smaller.
+		// On ios/arm64, the address space is even smaller.
 		//
 		// On AIX, mmaps starts at 0x0A00000000000000 for 64-bit.
 		// processes.
 		for i := 0x7f; i >= 0; i-- {
 			var p uintptr
 			switch {
-			case GOARCH == "arm64" && GOOS == "darwin":
+			case raceenabled:
+				// The TSAN runtime requires the heap
+				// to be in the range [0x00c000000000,
+				// 0x00e000000000).
+				p = uintptr(i)<<32 | uintptrMask&(0x00c0<<32)
+				if p >= uintptrMask&0x00e000000000 {
+					continue
+				}
+			case GOARCH == "arm64" && GOOS == "ios":
 				p = uintptr(i)<<40 | uintptrMask&(0x0013<<28)
 			case GOARCH == "arm64":
 				p = uintptr(i)<<40 | uintptrMask&(0x0040<<32)
@@ -543,14 +551,6 @@ func mallocinit() {
 					continue
 				}
 				p = uintptr(i)<<40 | uintptrMask&(0xa0<<52)
-			case raceenabled:
-				// The TSAN runtime requires the heap
-				// to be in the range [0x00c000000000,
-				// 0x00e000000000).
-				p = uintptr(i)<<32 | uintptrMask&(0x00c0<<32)
-				if p >= uintptrMask&0x00e000000000 {
-					continue
-				}
 			default:
 				p = uintptr(i)<<40 | uintptrMask&(0x00c0<<32)
 			}
@@ -638,6 +638,8 @@ func mallocinit() {
 //
 // h must be locked.
 func (h *mheap) sysAlloc(n uintptr) (v unsafe.Pointer, size uintptr) {
+	assertLockHeld(&h.lock)
+
 	n = alignUp(n, heapArenaBytes)
 
 	// First, try the arena pre-reservation.
@@ -754,9 +756,9 @@ mapped:
 			throw("arena already initialized")
 		}
 		var r *heapArena
-		r = (*heapArena)(h.heapArenaAlloc.alloc(unsafe.Sizeof(*r), sys.PtrSize, &memstats.gc_sys))
+		r = (*heapArena)(h.heapArenaAlloc.alloc(unsafe.Sizeof(*r), sys.PtrSize, &memstats.gcMiscSys))
 		if r == nil {
-			r = (*heapArena)(persistentalloc(unsafe.Sizeof(*r), sys.PtrSize, &memstats.gc_sys))
+			r = (*heapArena)(persistentalloc(unsafe.Sizeof(*r), sys.PtrSize, &memstats.gcMiscSys))
 			if r == nil {
 				throw("out of memory allocating heap arena metadata")
 			}
@@ -768,7 +770,7 @@ mapped:
 			if size == 0 {
 				size = physPageSize
 			}
-			newArray := (*notInHeap)(persistentalloc(size, sys.PtrSize, &memstats.gc_sys))
+			newArray := (*notInHeap)(persistentalloc(size, sys.PtrSize, &memstats.gcMiscSys))
 			if newArray == nil {
 				throw("out of memory allocating allArenas")
 			}
@@ -920,27 +922,34 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 		return unsafe.Pointer(&zerobase)
 	}
 
-	if debug.sbrk != 0 {
-		align := uintptr(16)
-		if typ != nil {
-			// TODO(austin): This should be just
-			//   align = uintptr(typ.align)
-			// but that's only 4 on 32-bit platforms,
-			// even if there's a uint64 field in typ (see #599).
-			// This causes 64-bit atomic accesses to panic.
-			// Hence, we use stricter alignment that matches
-			// the normal allocator better.
-			if size&7 == 0 {
-				align = 8
-			} else if size&3 == 0 {
-				align = 4
-			} else if size&1 == 0 {
-				align = 2
-			} else {
-				align = 1
+	if debug.malloc {
+		if debug.sbrk != 0 {
+			align := uintptr(16)
+			if typ != nil {
+				// TODO(austin): This should be just
+				//   align = uintptr(typ.align)
+				// but that's only 4 on 32-bit platforms,
+				// even if there's a uint64 field in typ (see #599).
+				// This causes 64-bit atomic accesses to panic.
+				// Hence, we use stricter alignment that matches
+				// the normal allocator better.
+				if size&7 == 0 {
+					align = 8
+				} else if size&3 == 0 {
+					align = 4
+				} else if size&1 == 0 {
+					align = 2
+				} else {
+					align = 1
+				}
 			}
+			return persistentalloc(size, align, &memstats.other_sys)
+		}
+
+		if inittrace.active && inittrace.id == getg().goid {
+			// Init functions are executed sequentially in a single Go routine.
+			inittrace.allocs += 1
 		}
-		return persistentalloc(size, align, &memstats.other_sys)
 	}
 
 	// When using gccgo, when a cgo or SWIG function has an
@@ -987,18 +996,9 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 
 	shouldhelpgc := false
 	dataSize := size
-	var c *mcache
-	if mp.p != 0 {
-		c = mp.p.ptr().mcache
-	} else {
-		// We will be called without a P while bootstrapping,
-		// in which case we use mcache0, which is set in mallocinit.
-		// mcache0 is cleared when bootstrapping is complete,
-		// by procresize.
-		c = mcache0
-		if c == nil {
-			throw("malloc called with no P")
-		}
+	c := getMCache()
+	if c == nil {
+		throw("mallocgc called without a P or outside bootstrapping")
 	}
 	var span *mspan
 	var x unsafe.Pointer
@@ -1038,6 +1038,14 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 			// Align tiny pointer for required (conservative) alignment.
 			if size&7 == 0 {
 				off = alignUp(off, 8)
+			} else if sys.PtrSize == 4 && size == 12 {
+				// Conservatively align 12-byte objects to 8 bytes on 32-bit
+				// systems so that objects whose first field is a 64-bit
+				// value is aligned to 8 bytes and does not cause a fault on
+				// atomic access. See issue 37262.
+				// TODO(mknyszek): Remove this workaround if/when issue 36606
+				// is resolved.
+				off = alignUp(off, 8)
 			} else if size&3 == 0 {
 				off = alignUp(off, 4)
 			} else if size&1 == 0 {
@@ -1047,7 +1055,7 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 				// The object fits into existing tiny block.
 				x = unsafe.Pointer(c.tiny + off)
 				c.tinyoffset = off + size
-				c.local_tinyallocs++
+				c.tinyAllocs++
 				mp.mallocing = 0
 				releasem(mp)
 				if incallback {
@@ -1092,9 +1100,7 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 		}
 	} else {
 		shouldhelpgc = true
-		systemstack(func() {
-			span = largeAlloc(size, needzero, noscan)
-		})
+		span = c.allocLarge(size, needzero, noscan)
 		span.freeindex = 1
 		span.allocCount = 1
 		x = unsafe.Pointer(span.base())
@@ -1114,7 +1120,7 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 		} else {
 			scanSize = typ.ptrdata
 		}
-		c.local_scan += scanSize
+		c.scanAlloc += scanSize
 	}
 
 	// Ensure that the stores above that initialize x to
@@ -1144,13 +1150,20 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 	mp.mallocing = 0
 	releasem(mp)
 
-	if debug.allocfreetrace != 0 {
-		tracealloc(x, size, typ)
+	if debug.malloc {
+		if debug.allocfreetrace != 0 {
+			tracealloc(x, size, typ)
+		}
+
+		if inittrace.active && inittrace.id == getg().goid {
+			// Init functions are executed sequentially in a single Go routine.
+			inittrace.bytes += uint64(size)
+		}
 	}
 
 	if rate := MemProfileRate; rate > 0 {
-		if rate != 1 && size < c.next_sample {
-			c.next_sample -= size
+		if rate != 1 && size < c.nextSample {
+			c.nextSample -= size
 		} else {
 			mp := acquirem()
 			profilealloc(mp, x, size)
@@ -1182,37 +1195,6 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
 	return x
 }
 
-func largeAlloc(size uintptr, needzero bool, noscan bool) *mspan {
-	// print("largeAlloc size=", size, "\n")
-
-	if size+_PageSize < size {
-		throw("out of memory")
-	}
-	npages := size >> _PageShift
-	if size&_PageMask != 0 {
-		npages++
-	}
-
-	// Deduct credit for this span allocation and sweep if
-	// necessary. mHeap_Alloc will also sweep npages, so this only
-	// pays the debt down to npage pages.
-	deductSweepCredit(npages*_PageSize, npages)
-
-	spc := makeSpanClass(0, noscan)
-	s := mheap_.alloc(npages, spc, needzero)
-	if s == nil {
-		throw("out of memory")
-	}
-	if go115NewMCentralImpl {
-		// Put the large span in the mcentral swept list so that it's
-		// visible to the background sweeper.
-		mheap_.central[spc].mcentral.fullSwept(mheap_.sweepgen).push(s)
-	}
-	s.limit = s.base() + size
-	heapBitsForAddr(s.base()).initSpan(s)
-	return s
-}
-
 // implementation of new builtin
 // compiler (both frontend and SSA backend) knows the signature
 // of this function
@@ -1248,16 +1230,11 @@ func reflect_unsafe_NewArray(typ *_type, n int) unsafe.Pointer {
 }
 
 func profilealloc(mp *m, x unsafe.Pointer, size uintptr) {
-	var c *mcache
-	if mp.p != 0 {
-		c = mp.p.ptr().mcache
-	} else {
-		c = mcache0
-		if c == nil {
-			throw("profilealloc called with no P")
-		}
+	c := getMCache()
+	if c == nil {
+		throw("profilealloc called without a P or outside bootstrapping")
 	}
-	c.next_sample = nextSample()
+	c.nextSample = nextSample()
 	mProf_Malloc(x, size)
 }
 
@@ -1269,6 +1246,13 @@ func profilealloc(mp *m, x unsafe.Pointer, size uintptr) {
 // distribution (exp(MemProfileRate)), so the best return value is a random
 // number taken from an exponential distribution whose mean is MemProfileRate.
 func nextSample() uintptr {
+	if MemProfileRate == 1 {
+		// Callers assign our return value to
+		// mcache.next_sample, but next_sample is not used
+		// when the rate is 1. So avoid the math below and
+		// just return something.
+		return 0
+	}
 	if GOOS == "plan9" {
 		// Plan 9 doesn't support floating point in note handler.
 		if g := getg(); g == g.m.gsignal {
@@ -1349,7 +1333,7 @@ var persistentChunks *notInHeap
 // The returned memory will be zeroed.
 //
 // Consider marking persistentalloc'd types go:notinheap.
-func persistentalloc(size, align uintptr, sysStat *uint64) unsafe.Pointer {
+func persistentalloc(size, align uintptr, sysStat *sysMemStat) unsafe.Pointer {
 	var p *notInHeap
 	systemstack(func() {
 		p = persistentalloc1(size, align, sysStat)
@@ -1360,7 +1344,7 @@ func persistentalloc(size, align uintptr, sysStat *uint64) unsafe.Pointer {
 // Must run on system stack because stack growth can (re)invoke it.
 // See issue 9174.
 //go:systemstack
-func persistentalloc1(size, align uintptr, sysStat *uint64) *notInHeap {
+func persistentalloc1(size, align uintptr, sysStat *sysMemStat) *notInHeap {
 	const (
 		maxBlock = 64 << 10 // VM reservation granularity is 64K on windows
 	)
@@ -1419,8 +1403,8 @@ func persistentalloc1(size, align uintptr, sysStat *uint64) *notInHeap {
 	}
 
 	if sysStat != &memstats.other_sys {
-		mSysStatInc(sysStat, size)
-		mSysStatDec(&memstats.other_sys, size)
+		sysStat.add(int64(size))
+		memstats.other_sys.add(-int64(size))
 	}
 	return p
 }
@@ -1461,7 +1445,7 @@ func (l *linearAlloc) init(base, size uintptr) {
 	l.end = base + size
 }
 
-func (l *linearAlloc) alloc(size, align uintptr, sysStat *uint64) unsafe.Pointer {
+func (l *linearAlloc) alloc(size, align uintptr, sysStat *sysMemStat) unsafe.Pointer {
 	p := alignUp(l.next, align)
 	if p+size > l.end {
 		return nil