all: merge master (abc106c) into gopls-release-branch.0.8

Also add a replace directive to gopls/go.mod.

Updates golang/go#51074

Conflicts:

- gopls/go.mod (due to gofumpt update)

Merge List:

+ 2022-02-28 abc106c gopls/integration/govim: build gopls using go1.18rc1
+ 2022-02-28 c2ddf3d internal/lsp: add quick fix for unsupported feature
+ 2022-02-28 0e44f7a gopls/doc/advanced.md: correct commands for unstable version build
+ 2022-02-25 acdddf6 go/ssa: allows right operand of a shift to be signed.
+ 2022-02-25 9ffa3ad internal/lsp: Provide completions for test function definitions
+ 2022-02-24 b7525f4 internal/lsp: hash go version into package key
+ 2022-02-24 5210e0c gopls: wire in LangVersion and ModulePath for gofumpt formatting
+ 2022-02-24 e6ef770 go/types/typeutil: don't recurse into constraints when hashing tparams
+ 2022-02-23 258e473 internal/lsp/source: disable the useany analyzer by default
+ 2022-02-23 b7d2949 internal/lsp: don't store diagnostics for builtin.go
+ 2022-02-23 4f21f7a gopls: update gofumpt to v0.3.0
+ 2022-02-22 3e31058 internal/imports: update to permit multiple main modules
+ 2022-02-22 43f084e internal/typesinternal: update typesinternal for 1.18
+ 2022-02-18 897bd77 internal/gocommand: remove support for -workfile
+ 2022-02-17 e6a7e13 go/analysis/tools/internal/checker: add support for RunDespiteError

Change-Id: I4ca5a581cb276b904f4a9d73d686aaa7cb0c6093

Author: findleyr

cmd/godoc/main.go

@@ -207,21 +207,21 @@ func main() {
 		fmt.Printf("using module mode; GOMOD=%s\n", goModFile)
 
 		// Detect whether to use vendor mode or not.
-		mainMod, vendorEnabled, err := gocommand.VendorEnabled(context.Background(), gocommand.Invocation{}, &gocommand.Runner{})
+		vendorEnabled, mainModVendor, err := gocommand.VendorEnabled(context.Background(), gocommand.Invocation{}, &gocommand.Runner{})
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "failed to determine if vendoring is enabled: %v", err)
 			os.Exit(1)
 		}
 		if vendorEnabled {
 			// Bind the root directory of the main module.
-			fs.Bind(path.Join("/src", mainMod.Path), gatefs.New(vfs.OS(mainMod.Dir), fsGate), "/", vfs.BindAfter)
+			fs.Bind(path.Join("/src", mainModVendor.Path), gatefs.New(vfs.OS(mainModVendor.Dir), fsGate), "/", vfs.BindAfter)
 
 			// Bind the vendor directory.
 			//
 			// Note that in module mode, vendor directories in locations
 			// other than the main module's root directory are ignored.
 			// See https://golang.org/ref/mod#vendoring.
-			vendorDir := filepath.Join(mainMod.Dir, "vendor")
+			vendorDir := filepath.Join(mainModVendor.Dir, "vendor")
 			fs.Bind("/src", gatefs.New(vfs.OS(vendorDir), fsGate), "/", vfs.BindAfter)
 
 		} else {

go/analysis/internal/checker/checker.go

@@ -11,6 +11,7 @@ package checker
 import (
 	"bytes"
 	"encoding/gob"
+	"errors"
 	"flag"
 	"fmt"
 	"go/format"
@@ -129,8 +130,13 @@ func Run(args []string, analyzers []*analysis.Analyzer) (exitcode int) {
 	allSyntax := needFacts(analyzers)
 	initial, err := load(args, allSyntax)
 	if err != nil {
-		log.Print(err)
-		return 1 // load errors
+		if _, ok := err.(typeParseError); !ok {
+			// Fail when some of the errors are not
+			// related to parsing nor typing.
+			log.Print(err)
+			return 1
+		}
+		// TODO: filter analyzers based on RunDespiteError?
 	}
 
 	// Print the results.
@@ -139,11 +145,17 @@ func Run(args []string, analyzers []*analysis.Analyzer) (exitcode int) {
 	if Fix {
 		applyFixes(roots)
 	}
-
 	return printDiagnostics(roots)
 }
 
-// load loads the initial packages.
+// typeParseError represents a package load error
+// that is related to typing and parsing.
+type typeParseError struct {
+	error
+}
+
+// load loads the initial packages. If all loading issues are related to
+// typing and parsing, the returned error is of type typeParseError.
 func load(patterns []string, allSyntax bool) ([]*packages.Package, error) {
 	mode := packages.LoadSyntax
 	if allSyntax {
@@ -155,18 +167,43 @@ func load(patterns []string, allSyntax bool) ([]*packages.Package, error) {
 	}
 	initial, err := packages.Load(&conf, patterns...)
 	if err == nil {
-		if n := packages.PrintErrors(initial); n > 1 {
-			err = fmt.Errorf("%d errors during loading", n)
-		} else if n == 1 {
-			err = fmt.Errorf("error during loading")
-		} else if len(initial) == 0 {
+		if len(initial) == 0 {
 			err = fmt.Errorf("%s matched no packages", strings.Join(patterns, " "))
+		} else {
+			err = loadingError(initial)
 		}
 	}
-
 	return initial, err
 }
 
+// loadingError checks for issues during the loading of initial
+// packages. Returns nil if there are no issues. Returns error
+// of type typeParseError if all errors, including those in
+// dependencies, are related to typing or parsing. Otherwise,
+// a plain error is returned with an appropriate message.
+func loadingError(initial []*packages.Package) error {
+	var err error
+	if n := packages.PrintErrors(initial); n > 1 {
+		err = fmt.Errorf("%d errors during loading", n)
+	} else if n == 1 {
+		err = errors.New("error during loading")
+	} else {
+		// no errors
+		return nil
+	}
+	all := true
+	packages.Visit(initial, nil, func(pkg *packages.Package) {
+		for _, err := range pkg.Errors {
+			typeOrParse := err.Kind == packages.TypeError || err.Kind == packages.ParseError
+			all = all && typeOrParse
+		}
+	})
+	if all {
+		return typeParseError{err}
+	}
+	return err
+}
+
 // TestAnalyzer applies an analysis to a set of packages (and their
 // dependencies if necessary) and returns the results.
 //

go/analysis/internal/checker/checker_test.go

@@ -99,3 +99,62 @@ func run(pass *analysis.Pass) (interface{}, error) {
 
 	return nil, nil
 }
+
+func TestRunDespiteErrors(t *testing.T) {
+	testenv.NeedsGoPackages(t)
+
+	files := map[string]string{
+		"rderr/test.go": `package rderr
+
+// Foo deliberately has a type error
+func Foo(s string) int {
+	return s + 1
+}
+`}
+
+	testdata, cleanup, err := analysistest.WriteFiles(files)
+	if err != nil {
+		t.Fatal(err)
+	}
+	path := filepath.Join(testdata, "src/rderr/test.go")
+
+	// A no-op analyzer that should finish regardless of
+	// parse or type errors in the code.
+	noop := &analysis.Analyzer{
+		Name:     "noop",
+		Requires: []*analysis.Analyzer{inspect.Analyzer},
+		Run: func(pass *analysis.Pass) (interface{}, error) {
+			return nil, nil
+		},
+		RunDespiteErrors: true,
+	}
+
+	for _, test := range []struct {
+		name      string
+		pattern   []string
+		analyzers []*analysis.Analyzer
+		code      int
+	}{
+		// parse/type errors
+		{name: "skip-error", pattern: []string{"file=" + path}, analyzers: []*analysis.Analyzer{analyzer}, code: 1},
+		{name: "despite-error", pattern: []string{"file=" + path}, analyzers: []*analysis.Analyzer{noop}, code: 0},
+		// combination of parse/type errors and no errors
+		{name: "despite-error-and-no-error", pattern: []string{"file=" + path, "sort"}, analyzers: []*analysis.Analyzer{analyzer, noop}, code: 1},
+		// non-existing package error
+		{name: "no-package", pattern: []string{"xyz"}, analyzers: []*analysis.Analyzer{analyzer}, code: 1},
+		{name: "no-package-despite-error", pattern: []string{"abc"}, analyzers: []*analysis.Analyzer{noop}, code: 1},
+		{name: "no-multi-package-despite-error", pattern: []string{"xyz", "abc"}, analyzers: []*analysis.Analyzer{noop}, code: 1},
+		// combination of type/parsing and different errors
+		{name: "different-errors", pattern: []string{"file=" + path, "xyz"}, analyzers: []*analysis.Analyzer{analyzer, noop}, code: 1},
+		// non existing dir error
+		{name: "no-match-dir", pattern: []string{"file=non/existing/dir"}, analyzers: []*analysis.Analyzer{analyzer, noop}, code: 1},
+		// no errors
+		{name: "no-errors", pattern: []string{"sort"}, analyzers: []*analysis.Analyzer{analyzer, noop}, code: 0},
+	} {
+		if got := checker.Run(test.pattern, test.analyzers); got != test.code {
+			t.Errorf("got incorrect exit code %d for test %s; want %d", got, test.name, test.code)
+		}
+	}
+
+	defer cleanup()
+}

go/ssa/emit.go

@@ -74,9 +74,16 @@ func emitArith(f *Function, op token.Token, x, y Value, t types.Type, pos token.
 	case token.SHL, token.SHR:
 		x = emitConv(f, x, t)
 		// y may be signed or an 'untyped' constant.
-		// TODO(adonovan): whence signed values?
-		if b, ok := y.Type().Underlying().(*types.Basic); ok && b.Info()&types.IsUnsigned == 0 {
-			y = emitConv(f, y, types.Typ[types.Uint64])
+
+		// There is a runtime panic if y is signed and <0. Instead of inserting a check for y<0
+		// and converting to an unsigned value (like the compiler) leave y as is.
+
+		if b, ok := y.Type().Underlying().(*types.Basic); ok && b.Info()&types.IsUntyped != 0 {
+			// Untyped conversion:
+			// Spec https://go.dev/ref/spec#Operators:
+			// The right operand in a shift expression must have integer type or be an untyped constant
+			// representable by a value of type uint.
+			y = emitConv(f, y, types.Typ[types.Uint])
 		}
 
 	case token.ADD, token.SUB, token.MUL, token.QUO, token.REM, token.AND, token.OR, token.XOR, token.AND_NOT:

go/ssa/interp/interp_test.go

@@ -109,6 +109,7 @@ var gorootTestTests = []string{
 var testdataTests = []string{
 	"boundmeth.go",
 	"complit.go",
+	"convert.go",
 	"coverage.go",
 	"defer.go",
 	"fieldprom.go",

go/ssa/interp/ops.go

@@ -137,6 +137,26 @@ func asUint64(x value) uint64 {
 	panic(fmt.Sprintf("cannot convert %T to uint64", x))
 }
 
+// asUnsigned returns the value of x, which must be an integer type, as its equivalent unsigned type,
+// and returns true if x is non-negative.
+func asUnsigned(x value) (value, bool) {
+	switch x := x.(type) {
+	case int:
+		return uint(x), x >= 0
+	case int8:
+		return uint8(x), x >= 0
+	case int16:
+		return uint16(x), x >= 0
+	case int32:
+		return uint32(x), x >= 0
+	case int64:
+		return uint64(x), x >= 0
+	case uint, uint8, uint32, uint64, uintptr:
+		return x, true
+	}
+	panic(fmt.Sprintf("cannot convert %T to unsigned", x))
+}
+
 // zero returns a new "zero" value of the specified type.
 func zero(t types.Type) value {
 	switch t := t.(type) {
@@ -576,7 +596,11 @@ func binop(op token.Token, t types.Type, x, y value) value {
 		}
 
 	case token.SHL:
-		y := asUint64(y)
+		u, ok := asUnsigned(y)
+		if !ok {
+			panic("negative shift amount")
+		}
+		y := asUint64(u)
 		switch x.(type) {
 		case int:
 			return x.(int) << y
@@ -603,7 +627,11 @@ func binop(op token.Token, t types.Type, x, y value) value {
 		}
 
 	case token.SHR:
-		y := asUint64(y)
+		u, ok := asUnsigned(y)
+		if !ok {
+			panic("negative shift amount")
+		}
+		y := asUint64(u)
 		switch x.(type) {
 		case int:
 			return x.(int) >> y

go/ssa/interp/testdata/convert.go

@@ -0,0 +1,38 @@
+// Copyright 2022 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.
+
+// Test conversion operations.
+
+package main
+
+func left(x int)  { _ = 1 << x }
+func right(x int) { _ = 1 >> x }
+
+func main() {
+	wantPanic(
+		func() {
+			left(-1)
+		},
+		"runtime error: negative shift amount",
+	)
+	wantPanic(
+		func() {
+			right(-1)
+		},
+		"runtime error: negative shift amount",
+	)
+}
+
+func wantPanic(fn func(), s string) {
+	defer func() {
+		err := recover()
+		if err == nil {
+			panic("expected panic")
+		}
+		if got := err.(error).Error(); got != s {
+			panic("expected panic " + s + " got " + got)
+		}
+	}()
+	fn()
+}

go/types/typeutil/map.go

@@ -379,7 +379,7 @@ func (h Hasher) hashFor(t types.Type) uint32 {
 func (h Hasher) hashTuple(tuple *types.Tuple) uint32 {
 	// See go/types.identicalTypes for rationale.
 	n := tuple.Len()
-	var hash uint32 = 9137 + 2*uint32(n)
+	hash := 9137 + 2*uint32(n)
 	for i := 0; i < n; i++ {
 		hash += 3 * h.Hash(tuple.At(i).Type())
 	}
@@ -398,7 +398,7 @@ func (h Hasher) hashUnion(t *typeparams.Union) uint32 {
 }
 
 func (h Hasher) hashTermSet(terms []*typeparams.Term) uint32 {
-	var hash uint32 = 9157 + 2*uint32(len(terms))
+	hash := 9157 + 2*uint32(len(terms))
 	for _, term := range terms {
 		// term order is not significant.
 		termHash := h.Hash(term.Type())
@@ -416,14 +416,16 @@ func (h Hasher) hashTermSet(terms []*typeparams.Term) uint32 {
 // If h.sigTParams is set and contains t, then we are in the process of hashing
 // a signature, and the hash value of t must depend only on t's index and
 // constraint: signatures are considered identical modulo type parameter
-// renaming.
+// renaming. To avoid infinite recursion, we only hash the type parameter
+// index, and rely on types.Identical to handle signatures where constraints
+// are not identical.
 //
 // Otherwise the hash of t depends only on t's pointer identity.
 func (h Hasher) hashTypeParam(t *typeparams.TypeParam) uint32 {
 	if h.sigTParams != nil {
 		i := t.Index()
 		if i >= 0 && i < h.sigTParams.Len() && t == h.sigTParams.At(i) {
-			return 9173 + 2*h.Hash(t.Constraint()) + 3*uint32(i)
+			return 9173 + 3*uint32(i)
 		}
 	}
 	return h.hashPtr(t.Obj())

go/types/typeutil/map_test.go

@@ -233,6 +233,17 @@ var ME2 = G2[int].M
 
 // ME1Type should have identical type as ME1.
 var ME1Type func(G1[int], G1[int], G2[int])
+
+// Examples from issue #51314
+type Constraint[T any] interface{}
+func Foo[T Constraint[T]]() {}
+func Fn[T1 ~*T2, T2 ~*T1](t1 T1, t2 T2) {}
+
+// Bar and Baz are identical to Foo.
+func Bar[P Constraint[P]]() {}
+func Baz[Q any]() {} // The underlying type of Constraint[P] is any.
+// But Quux is not.
+func Quux[Q interface{ quux() }]() {}
 `
 
 	fset := token.NewFileSet()
@@ -284,6 +295,13 @@ var ME1Type func(G1[int], G1[int], G2[int])
 		ME1     = scope.Lookup("ME1").Type()
 		ME1Type = scope.Lookup("ME1Type").Type()
 		ME2     = scope.Lookup("ME2").Type()
+
+		Constraint = scope.Lookup("Constraint").Type()
+		Foo        = scope.Lookup("Foo").Type()
+		Fn         = scope.Lookup("Fn").Type()
+		Bar        = scope.Lookup("Foo").Type()
+		Baz        = scope.Lookup("Foo").Type()
+		Quux       = scope.Lookup("Quux").Type()
 	)
 
 	tmap := new(typeutil.Map)
@@ -345,6 +363,14 @@ var ME1Type func(G1[int], G1[int], G2[int])
 		{ME1, "ME1", true},
 		{ME1Type, "ME1Type", false},
 		{ME2, "ME2", true},
+
+		// See golang/go#51314: avoid infinite recursion on cyclic type constraints.
+		{Constraint, "Constraint", true},
+		{Foo, "Foo", true},
+		{Fn, "Fn", true},
+		{Bar, "Bar", false},
+		{Baz, "Baz", false},
+		{Quux, "Quux", true},
 	}
 
 	for _, step := range steps {