[dev.typeparams] cmd/compile/internal/importer, types2: initial check-in of types2 and importer

This is a copy of the importer and types2 (unreviewed) prototype version
excluding the testdata directory containing tests (see below). Each file
is marked with the comment

// UNREVIEWED

on the first line. The plan is to check in this code wholesale (it runs and
passes all tests) and then review the code file-by-file via subsequent CLs
and remove the "// UNREVIEWED" comments as we review the files.

Since most tests are unchanged from the original go/types, the next CL will
commit those tests as they don't need to be reviewed again. (Eventually we
may want to factor them out and share them from a single place, e.g. the
test directory.)

The existing file fmtmap_test.go was updated.

Change-Id: I9bd0ad1a7e7188b501423483a44d18e623c0fe71
Reviewed-on: https://go-review.googlesource.com/c/go/+/263624
Trust: Robert Griesemer <gri@golang.org>
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

1 files changed, 223 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/types2/resolver_test.go b/src/cmd/compile/internal/types2/resolver_test.go
new file mode 100644
index 0000000000..cdfdba6b43
--- /dev/null
+++ b/src/cmd/compile/internal/types2/resolver_test.go
@@ -0,0 +1,223 @@
+// UNREVIEWED
+// Copyright 2011 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.
+
+package types2_test
+
+import (
+	"cmd/compile/internal/syntax"
+	"fmt"
+	"internal/testenv"
+	"sort"
+	"testing"
+
+	. "cmd/compile/internal/types2"
+)
+
+type resolveTestImporter struct {
+	importer ImporterFrom
+	imported map[string]bool
+}
+
+func (imp *resolveTestImporter) Import(string) (*Package, error) {
+	panic("should not be called")
+}
+
+func (imp *resolveTestImporter) ImportFrom(path, srcDir string, mode ImportMode) (*Package, error) {
+	if mode != 0 {
+		panic("mode must be 0")
+	}
+	if imp.importer == nil {
+		imp.importer = defaultImporter().(ImporterFrom)
+		imp.imported = make(map[string]bool)
+	}
+	pkg, err := imp.importer.ImportFrom(path, srcDir, mode)
+	if err != nil {
+		return nil, err
+	}
+	imp.imported[path] = true
+	return pkg, nil
+}
+
+func TestResolveIdents(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+
+	sources := []string{
+		`
+		package p
+		import "fmt"
+		import "math"
+		const pi = math.Pi
+		func sin(x float64) float64 {
+			return math.Sin(x)
+		}
+		var Println = fmt.Println
+		`,
+		`
+		package p
+		import "fmt"
+		type errorStringer struct { fmt.Stringer; error }
+		func f() string {
+			_ = "foo"
+			return fmt.Sprintf("%d", g())
+		}
+		func g() (x int) { return }
+		`,
+		`
+		package p
+		import . "go/parser"
+		import "sync"
+		func h() Mode { return ImportsOnly }
+		var _, x int = 1, 2
+		func init() {}
+		type T struct{ *sync.Mutex; a, b, c int}
+		type I interface{ m() }
+		var _ = T{a: 1, b: 2, c: 3}
+		func (_ T) m() {}
+		func (T) _() {}
+		var i I
+		var _ = i.m
+		func _(s []int) { for i, x := range s { _, _ = i, x } }
+		func _(x interface{}) {
+			switch x := x.(type) {
+			case int:
+				_ = x
+			}
+			switch {} // implicit 'true' tag
+		}
+		`,
+		`
+		package p
+		type S struct{}
+		func (T) _() {}
+		func (T) _() {}
+		`,
+		`
+		package p
+		func _() {
+		L0:
+		L1:
+			goto L0
+			for {
+				goto L1
+			}
+			if true {
+				goto L2
+			}
+		L2:
+		}
+		`,
+	}
+
+	pkgnames := []string{
+		"fmt",
+		"math",
+	}
+
+	// parse package files
+	var files []*syntax.File
+	for i, src := range sources {
+		f, err := parseSrc(fmt.Sprintf("sources[%d]", i), src)
+		if err != nil {
+			t.Fatal(err)
+		}
+		files = append(files, f)
+	}
+
+	// resolve and type-check package AST
+	importer := new(resolveTestImporter)
+	conf := Config{Importer: importer}
+	uses := make(map[*syntax.Name]Object)
+	defs := make(map[*syntax.Name]Object)
+	_, err := conf.Check("testResolveIdents", files, &Info{Defs: defs, Uses: uses})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// check that all packages were imported
+	for _, name := range pkgnames {
+		if !importer.imported[name] {
+			t.Errorf("package %s not imported", name)
+		}
+	}
+
+	// check that qualified identifiers are resolved
+	for _, f := range files {
+		Walk(f, func(n syntax.Node) bool {
+			if s, ok := n.(*syntax.SelectorExpr); ok {
+				if x, ok := s.X.(*syntax.Name); ok {
+					obj := uses[x]
+					if obj == nil {
+						t.Errorf("%s: unresolved qualified identifier %s", x.Pos(), x.Value)
+						return true
+					}
+					if _, ok := obj.(*PkgName); ok && uses[s.Sel] == nil {
+						t.Errorf("%s: unresolved selector %s", s.Sel.Pos(), s.Sel.Value)
+						return true
+					}
+					return true
+				}
+				return true
+			}
+			return false
+		})
+	}
+
+	for id, obj := range uses {
+		if obj == nil {
+			t.Errorf("%s: Uses[%s] == nil", id.Pos(), id.Value)
+		}
+	}
+
+	// Check that each identifier in the source is found in uses or defs or both.
+	// We need the foundUses/Defs maps (rather then just deleting the found objects
+	// from the uses and defs maps) because Walk traverses shared nodes multiple
+	// times (e.g. types in field lists such as "a, b, c int").
+	foundUses := make(map[*syntax.Name]bool)
+	foundDefs := make(map[*syntax.Name]bool)
+	var both []string
+	for _, f := range files {
+		Walk(f, func(n syntax.Node) bool {
+			if x, ok := n.(*syntax.Name); ok {
+				var objects int
+				if _, found := uses[x]; found {
+					objects |= 1
+					foundUses[x] = true
+				}
+				if _, found := defs[x]; found {
+					objects |= 2
+					foundDefs[x] = true
+				}
+				switch objects {
+				case 0:
+					t.Errorf("%s: unresolved identifier %s", x.Pos(), x.Value)
+				case 3:
+					both = append(both, x.Value)
+				}
+				return true
+			}
+			return false
+		})
+	}
+
+	// check the expected set of idents that are simultaneously uses and defs
+	sort.Strings(both)
+	if got, want := fmt.Sprint(both), "[Mutex Stringer error]"; got != want {
+		t.Errorf("simultaneous uses/defs = %s, want %s", got, want)
+	}
+
+	// any left-over identifiers didn't exist in the source
+	for x := range uses {
+		if !foundUses[x] {
+			t.Errorf("%s: identifier %s not present in source", x.Pos(), x.Value)
+		}
+	}
+	for x := range defs {
+		if !foundDefs[x] {
+			t.Errorf("%s: identifier %s not present in source", x.Pos(), x.Value)
+		}
+	}
+
+	// TODO(gri) add tests to check ImplicitObj callbacks
+}