[dev.typeparams] all: merge master (912f075) into dev.typeparams

Conflicts:

- src/cmd/compile/internal/escape/escape.go

  On master, CL 332230 changed the ">=" in HeapAllocReason to ">"; but
  on dev.typeparams, CL 329989 moved HeapAllocReason into utils.go.

Merge List:

+ 2021-07-02 912f075047 net/http: mention socks5 support in proxy
+ 2021-07-02 287c5e8066 cmd/compile: fix stack growing algorithm
+ 2021-07-02 743f03eeb0 spec, unsafe: clarify unsafe.Slice docs
+ 2021-07-02 6125d0c426 cmd/dist: correct comment: SysProcAttri -> SysProcAttr
+ 2021-07-01 03761ede02 net: don't reject null mx records
+ 2021-07-01 877688c838 testing: add TB.Setenv
+ 2021-07-01 ef8ae82b37 cmd/compile: fix bug in dwarf-gen var location generation
+ 2021-07-01 770899f7e1 cmd/go: add a regression test for 'go mod vendor' path traversal
+ 2021-07-01 835d86a17e cmd/go: use path.Dir instead of filepath.Dir for package paths in 'go mod vendor'
+ 2021-07-01 eb437ba92c cmd/compile: make stack value size threshold comparisons consistent
+ 2021-07-01 9d65578b83 cmd/compile: fix typos in document

Change-Id: I08aa852441af0f070aa32dd2f99b6fa4e9d79cfa

api/go1.17.txt

@@ -181,6 +181,7 @@ pkg syscall (windows-amd64), type SysProcAttr struct, AdditionalInheritedHandles
 pkg syscall (windows-amd64), type SysProcAttr struct, ParentProcess Handle
 pkg testing, method (*B) Setenv(string, string)
 pkg testing, method (*T) Setenv(string, string)
+pkg testing, type TB interface, Setenv(string, string)
 pkg text/template/parse, const SkipFuncCheck = 2
 pkg text/template/parse, const SkipFuncCheck Mode
 pkg time, const Layout = "01/02 03:04:05PM '06 -0700"

doc/go_spec.html

@@ -1,6 +1,6 @@
 <!--{
 	"Title": "The Go Programming Language Specification",
-	"Subtitle": "Version of Jun 28, 2021",
+	"Subtitle": "Version of Jul 1, 2021",
 	"Path": "/ref/spec"
 }-->
 
@@ -6782,7 +6782,8 @@ The rules for <a href="/pkg/unsafe#Pointer">valid uses</a> of <code>Pointer</cod
 
 <p>
 The function <code>Slice</code> returns a slice whose underlying array starts at <code>ptr</code>
-and whose length and capacity are <code>len</code>:
+and whose length and capacity are <code>len</code>.
+<code>Slice(ptr, len)</code> is equivalent to
 </p>
 
 <pre>
@@ -6790,7 +6791,8 @@ and whose length and capacity are <code>len</code>:
 </pre>
 
 <p>
-As a special case, if <code>ptr</code> is <code>nil</code> and <code>len</code> is zero,
+except that, as a special case, if <code>ptr</code>
+is <code>nil</code> and <code>len</code> is zero,
 <code>Slice</code> returns <code>nil</code>.
 </p>
 

src/cmd/compile/abi-internal.md

@@ -233,7 +233,7 @@ stack frame is laid out in the following sequence:
     r1.x    uintptr
     r1.y    [2]uintptr
     a1Spill uint8
-    a2Spill uint8
+    a3Spill uint8
     _       [6]uint8  // alignment padding
 
 In the stack frame, only the `a2` field is initialized on entry; the

src/cmd/compile/internal/escape/utils.go

@@ -186,14 +186,14 @@ func HeapAllocReason(n ir.Node) string {
 		return "too large for stack"
 	}
 
-	if (n.Op() == ir.ONEW || n.Op() == ir.OPTRLIT) && n.Type().Elem().Width >= ir.MaxImplicitStackVarSize {
+	if (n.Op() == ir.ONEW || n.Op() == ir.OPTRLIT) && n.Type().Elem().Width > ir.MaxImplicitStackVarSize {
 		return "too large for stack"
 	}
 
-	if n.Op() == ir.OCLOSURE && typecheck.ClosureType(n.(*ir.ClosureExpr)).Size() >= ir.MaxImplicitStackVarSize {
+	if n.Op() == ir.OCLOSURE && typecheck.ClosureType(n.(*ir.ClosureExpr)).Size() > ir.MaxImplicitStackVarSize {
 		return "too large for stack"
 	}
-	if n.Op() == ir.OMETHVALUE && typecheck.PartialCallType(n.(*ir.SelectorExpr)).Size() >= ir.MaxImplicitStackVarSize {
+	if n.Op() == ir.OMETHVALUE && typecheck.PartialCallType(n.(*ir.SelectorExpr)).Size() > ir.MaxImplicitStackVarSize {
 		return "too large for stack"
 	}
 
@@ -206,7 +206,7 @@ func HeapAllocReason(n ir.Node) string {
 		if !ir.IsSmallIntConst(r) {
 			return "non-constant size"
 		}
-		if t := n.Type(); t.Elem().Width != 0 && ir.Int64Val(r) >= ir.MaxImplicitStackVarSize/t.Elem().Width {
+		if t := n.Type(); t.Elem().Width != 0 && ir.Int64Val(r) > ir.MaxImplicitStackVarSize/t.Elem().Width {
 			return "too large for stack"
 		}
 	}

src/cmd/compile/internal/ssa/debug.go

@@ -1115,8 +1115,14 @@ func (state *debugState) buildLocationLists(blockLocs []*BlockDebug) {
 			continue
 		}
 
+		mustBeFirst := func(v *Value) bool {
+			return v.Op == OpPhi || v.Op.isLoweredGetClosurePtr() ||
+				v.Op == OpArgIntReg || v.Op == OpArgFloatReg
+		}
+
 		zeroWidthPending := false
-		apcChangedSize := 0 // size of changedVars for leading Args, Phi, ClosurePtr
+		blockPrologComplete := false // set to true at first non-zero-width op
+		apcChangedSize := 0          // size of changedVars for leading Args, Phi, ClosurePtr
 		// expect to see values in pattern (apc)* (zerowidth|real)*
 		for _, v := range b.Values {
 			slots := state.valueNames[v.ID]
@@ -1125,16 +1131,16 @@ func (state *debugState) buildLocationLists(blockLocs []*BlockDebug) {
 
 			if opcodeTable[v.Op].zeroWidth {
 				if changed {
-					if hasAnyArgOp(v) || v.Op == OpPhi || v.Op.isLoweredGetClosurePtr() {
+					if mustBeFirst(v) || v.Op == OpArg {
 						// These ranges begin at true beginning of block, not after first instruction
-						if zeroWidthPending {
-							panic(fmt.Errorf("Unexpected op '%s' mixed with OpArg/OpPhi/OpLoweredGetClosurePtr at beginning of block %s in %s\n%s", v.LongString(), b, b.Func.Name, b.Func))
+						if blockPrologComplete && mustBeFirst(v) {
+							panic(fmt.Errorf("Unexpected placement of op '%s' appearing after non-pseudo-op at beginning of block %s in %s\n%s", v.LongString(), b, b.Func.Name, b.Func))
 						}
 						apcChangedSize = len(state.changedVars.contents())
+						// Other zero-width ops must wait on a "real" op.
+						zeroWidthPending = true
 						continue
 					}
-					// Other zero-width ops must wait on a "real" op.
-					zeroWidthPending = true
 				}
 				continue
 			}
@@ -1145,6 +1151,7 @@ func (state *debugState) buildLocationLists(blockLocs []*BlockDebug) {
 			// Not zero-width; i.e., a "real" instruction.
 
 			zeroWidthPending = false
+			blockPrologComplete = true
 			for i, varID := range state.changedVars.contents() {
 				if i < apcChangedSize { // buffered true start-of-block changes
 					state.updateVar(VarID(varID), v.Block, BlockStart)

src/cmd/compile/internal/walk/builtin.go

@@ -489,7 +489,7 @@ func walkNew(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
 		base.Errorf("%v can't be allocated in Go; it is incomplete (or unallocatable)", n.Type().Elem())
 	}
 	if n.Esc() == ir.EscNone {
-		if t.Size() >= ir.MaxImplicitStackVarSize {
+		if t.Size() > ir.MaxImplicitStackVarSize {
 			base.Fatalf("large ONEW with EscNone: %v", n)
 		}
 		return stackTempAddr(init, t)

src/cmd/dist/test.go

@@ -781,7 +781,7 @@ func (t *tester) registerTests() {
 			t.registerTest("testasan", "../misc/cgo/testasan", "go", "run", ".")
 		}
 		if goos == "linux" && goarch != "ppc64le" {
-			// because syscall.SysProcAttri struct used in misc/cgo/testsanitizers is only built on linux.
+			// because syscall.SysProcAttr struct used in misc/cgo/testsanitizers is only built on linux.
 			// Some inconsistent failures happen on ppc64le so disable for now.
 			t.registerHostTest("testsanitizers", "../misc/cgo/testsanitizers", "misc/cgo/testsanitizers", ".")
 		}

src/cmd/go/internal/modcmd/vendor.go

@@ -13,6 +13,7 @@ import (
 	"io"
 	"io/fs"
 	"os"
+	"path"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -299,7 +300,7 @@ func copyMetadata(modPath, pkg, dst, src string, copiedFiles map[string]bool) {
 		if modPath == pkg {
 			break
 		}
-		pkg = filepath.Dir(pkg)
+		pkg = path.Dir(pkg)
 		dst = filepath.Dir(dst)
 		src = filepath.Dir(src)
 	}

src/cmd/go/testdata/script/mod_vendor_issue46867.txt

@@ -0,0 +1,31 @@
+# Regression test for golang.org/issue/46867:
+# 'go mod vendor' on Windows attempted to open and copy
+# files from directories outside of the module.
+
+cd subdir
+go mod vendor
+! exists vendor/example.net/NOTICE
+exists vendor/example.net/m/NOTICE
+
+-- subdir/go.mod --
+module golang.org/issue46867
+
+go 1.17
+
+replace example.net/m v0.1.0 => ./m
+
+require example.net/m v0.1.0
+-- subdir/issue.go --
+package issue
+
+import _ "example.net/m/n"
+-- subdir/m/go.mod --
+module example.net/m
+
+go 1.17
+-- subdir/m/n/n.go --
+package n
+-- subdir/m/NOTICE --
+This notice is in module m and SHOULD be vendored.
+-- subdir/NOTICE --
+This notice is outside of module m and SHOULD NOT be vendored.

src/net/dnsclient_unix_test.go

@@ -1957,3 +1957,43 @@ func TestCVE202133195(t *testing.T) {
 		t.Errorf("LookupAddr returned unexpected error, got %q, want %q", err, expected)
 	}
 }
+
+func TestNullMX(t *testing.T) {
+	fake := fakeDNSServer{
+		rh: func(n, _ string, q dnsmessage.Message, _ time.Time) (dnsmessage.Message, error) {
+			r := dnsmessage.Message{
+				Header: dnsmessage.Header{
+					ID:       q.Header.ID,
+					Response: true,
+					RCode:    dnsmessage.RCodeSuccess,
+				},
+				Questions: q.Questions,
+				Answers: []dnsmessage.Resource{
+					{
+						Header: dnsmessage.ResourceHeader{
+							Name:  q.Questions[0].Name,
+							Type:  dnsmessage.TypeMX,
+							Class: dnsmessage.ClassINET,
+						},
+						Body: &dnsmessage.MXResource{
+							MX: dnsmessage.MustNewName("."),
+						},
+					},
+				},
+			}
+			return r, nil
+		},
+	}
+	r := Resolver{PreferGo: true, Dial: fake.DialContext}
+	rrset, err := r.LookupMX(context.Background(), "golang.org")
+	if err != nil {
+		t.Fatalf("LookupMX: %v", err)
+	}
+	if want := []*MX{&MX{Host: "."}}; !reflect.DeepEqual(rrset, want) {
+		records := []string{}
+		for _, rr := range rrset {
+			records = append(records, fmt.Sprintf("%v", rr))
+		}
+		t.Errorf("records = [%v]; want [%v]", strings.Join(records, " "), want[0])
+	}
+}

src/net/http/transport.go

@@ -427,6 +427,7 @@ func (t *Transport) onceSetNextProtoDefaults() {
 //
 // The environment values may be either a complete URL or a
 // "host[:port]", in which case the "http" scheme is assumed.
+// The schemes "http", "https", and "socks5" are supported.
 // An error is returned if the value is a different form.
 //
 // A nil URL and nil error are returned if no proxy is defined in the

src/net/lookup.go

@@ -500,7 +500,9 @@ func (r *Resolver) LookupMX(ctx context.Context, name string) ([]*MX, error) {
 		if mx == nil {
 			continue
 		}
-		if !isDomainName(mx.Host) {
+		// Bypass the hostname validity check for targets which contain only a dot,
+		// as this is used to represent a 'Null' MX record.
+		if mx.Host != "." && !isDomainName(mx.Host) {
 			return nil, &DNSError{Err: "MX target is invalid", Name: name}
 		}
 	}

src/runtime/stack.go

@@ -1061,7 +1061,9 @@ func newstack() {
 	// recheck the bounds on return.)
 	if f := findfunc(gp.sched.pc); f.valid() {
 		max := uintptr(funcMaxSPDelta(f))
-		for newsize-gp.sched.sp < max+_StackGuard {
+		needed := max + _StackGuard
+		used := gp.stack.hi - gp.sched.sp
+		for newsize-used < needed {
 			newsize *= 2
 		}
 	}

src/testing/testing.go

@@ -644,6 +644,7 @@ type TB interface {
 	Log(args ...interface{})
 	Logf(format string, args ...interface{})
 	Name() string
+	Setenv(key, value string)
 	Skip(args ...interface{})
 	SkipNow()
 	Skipf(format string, args ...interface{})

src/unsafe/unsafe.go

@@ -217,11 +217,13 @@ func Alignof(x ArbitraryType) uintptr
 func Add(ptr Pointer, len IntegerType) Pointer
 
 // The function Slice returns a slice whose underlying array starts at ptr
-// and whose length and capacity are len:
+// and whose length and capacity are len.
+// Slice(ptr, len) is equivalent to
 //
 //	(*[len]ArbitraryType)(unsafe.Pointer(ptr))[:]
 //
-// As a special case, if ptr is nil and len is zero, Slice returns nil.
+// except that, as a special case, if ptr is nil and len is zero,
+// Slice returns nil.
 //
 // The len argument must be of integer type or an untyped constant.
 // A constant len argument must be non-negative and representable by a value of type int;