go.tools/oracle: use TypeString, ObjectString to print relative (unqualified) names when a package is implied by the context.

+ a couple more tests.

R=gri, crawshaw
CC=golang-dev
https://golang.org/cl/26370046

oracle/describe.go

@@ -479,10 +479,10 @@ func (r *describeValueResult) display(printf printfFunc) {
 	if r.obj != nil {
 		if r.obj.Pos() == r.expr.Pos() {
 			// defining ident
-			printf(r.expr, "definition of %s%s%s", prefix, r.obj, suffix)
+			printf(r.expr, "definition of %s%s%s", prefix, r.qpos.ObjectString(r.obj), suffix)
 		} else {
 			// referring ident
-			printf(r.expr, "reference to %s%s%s", prefix, r.obj, suffix)
+			printf(r.expr, "reference to %s%s%s", prefix, r.qpos.ObjectString(r.obj), suffix)
 			if def := r.obj.Pos(); def != token.NoPos {
 				printf(def, "defined here")
 			}
@@ -494,7 +494,7 @@ func (r *describeValueResult) display(printf printfFunc) {
 			printf(r.expr, "%s%s", desc, suffix)
 		} else {
 			// non-constant expression
-			printf(r.expr, "%s of type %s", desc, r.typ)
+			printf(r.expr, "%s of type %s", desc, r.qpos.TypeString(r.typ))
 		}
 	}
 
@@ -514,17 +514,17 @@ func (r *describeValueResult) display(printf printfFunc) {
 		// reflect.Value expression.
 
 		if len(r.ptrs) > 0 {
-			printf(r.qpos, "this %s may contain these dynamic types:", r.typ)
+			printf(r.qpos, "this %s may contain these dynamic types:", r.qpos.TypeString(r.typ))
 			for _, ptr := range r.ptrs {
 				var obj types.Object
 				if nt, ok := deref(ptr.typ).(*types.Named); ok {
 					obj = nt.Obj()
 				}
 				if len(ptr.labels) > 0 {
-					printf(obj, "\t%s, may point to:", ptr.typ)
+					printf(obj, "\t%s, may point to:", r.qpos.TypeString(ptr.typ))
 					printLabels(printf, ptr.labels, "\t\t")
 				} else {
-					printf(obj, "\t%s", ptr.typ)
+					printf(obj, "\t%s", r.qpos.TypeString(ptr.typ))
 				}
 			}
 		} else {
@@ -567,7 +567,7 @@ func (r *describeValueResult) toSerial(res *serial.Result, fset *token.FileSet)
 			})
 		}
 		pts = append(pts, &serial.DescribePointer{
-			Type:    ptr.typ.String(),
+			Type:    r.qpos.TypeString(ptr.typ),
 			NamePos: namePos,
 			Labels:  labels,
 		})
@@ -578,7 +578,7 @@ func (r *describeValueResult) toSerial(res *serial.Result, fset *token.FileSet)
 		Pos:    fset.Position(r.expr.Pos()).String(),
 		Detail: "value",
 		Value: &serial.DescribeValue{
-			Type:   r.typ.String(),
+			Type:   r.qpos.TypeString(r.typ),
 			Value:  value,
 			ObjPos: objpos,
 			PTAErr: ptaerr,
@@ -620,20 +620,19 @@ func describeType(o *Oracle, qpos *QueryPos, path []ast.Node) (*describeTypeResu
 		t = qpos.info.TypeOf(n)
 		switch t := t.(type) {
 		case *types.Basic:
-			description = "reference to built-in type " + t.String()
+			description = "reference to built-in "
 
 		case *types.Named:
 			isDef := t.Obj().Pos() == n.Pos() // see caveats at isDef above
 			if isDef {
-				description = "definition of type " + t.String()
+				description = "definition of "
 			} else {
-				description = "reference to type " + t.String()
+				description = "reference to "
 			}
 		}
 
 	case ast.Expr:
 		t = qpos.info.TypeOf(n)
-		description = "type " + t.String()
 
 	default:
 		// Unreachable?
@@ -641,14 +640,16 @@ func describeType(o *Oracle, qpos *QueryPos, path []ast.Node) (*describeTypeResu
 	}
 
 	return &describeTypeResult{
+		qpos:        qpos,
 		node:        path[0],
-		description: description,
+		description: description + "type " + qpos.TypeString(t),
 		typ:         t,
 		methods:     accessibleMethods(t, qpos.info.Pkg),
 	}, nil
 }
 
 type describeTypeResult struct {
+	qpos        *QueryPos
 	node        ast.Node
 	description string
 	typ         types.Type
@@ -660,7 +661,7 @@ func (r *describeTypeResult) display(printf printfFunc) {
 
 	// Show the underlying type for a reference to a named type.
 	if nt, ok := r.typ.(*types.Named); ok && r.node.Pos() != nt.Obj().Pos() {
-		printf(nt.Obj(), "defined as %s", nt.Underlying())
+		printf(nt.Obj(), "defined as %s", r.qpos.TypeString(nt.Underlying()))
 	}
 
 	// Print the method set, if the type kind is capable of bearing methods.
@@ -688,7 +689,7 @@ func (r *describeTypeResult) toSerial(res *serial.Result, fset *token.FileSet) {
 		Pos:    fset.Position(r.node.Pos()).String(),
 		Detail: "type",
 		Type: &serial.DescribeType{
-			Type:    r.typ.String(),
+			Type:    r.qpos.TypeString(r.typ),
 			NamePos: namePos,
 			NameDef: nameDef,
 			Methods: methodsToSerial(r.methods, fset),

oracle/oracle.go

@@ -110,6 +110,16 @@ type QueryPos struct {
 	path       []ast.Node            // AST path from query node to root of ast.File
 }
 
+// TypeString prints type T relative to the query position.
+func (qpos *QueryPos) TypeString(T types.Type) string {
+	return types.TypeString(qpos.info.Pkg, T)
+}
+
+// ObjectString prints object obj relative to the query position.
+func (qpos *QueryPos) ObjectString(obj types.Object) string {
+	return types.ObjectString(qpos.info.Pkg, obj)
+}
+
 // A Result encapsulates the result of an oracle.Query.
 type Result struct {
 	fset *token.FileSet
@@ -244,7 +254,7 @@ func newOracle(imp *importer.Importer, args []string, ptalog io.Writer, needs in
 		o.typeInfo = m
 	}
 
-	// Create SSA package for the initial package and its dependencies.
+	// Create SSA package for the initial packages and their dependencies.
 	if needs&needSSA != 0 {
 		start = time.Now()
 

oracle/testdata/src/main/describe-json.golden

@@ -101,11 +101,11 @@
 		"pos": "testdata/src/main/describe-json.go:18:6",
 		"detail": "value",
 		"value": {
-			"type": "describe.I",
+			"type": "I",
 			"objpos": "testdata/src/main/describe-json.go:14:6",
 			"pts": [
 				{
-					"type": "*describe.D",
+					"type": "*D",
 					"namepos": "testdata/src/main/describe-json.go:28:6",
 					"labels": [
 						{
@@ -115,7 +115,7 @@
 					]
 				},
 				{
-					"type": "describe.C",
+					"type": "C",
 					"namepos": "testdata/src/main/describe-json.go:27:6"
 				}
 			]
@@ -133,11 +133,11 @@
 {
 	"mode": "describe",
 	"describe": {
-		"desc": "definition of type describe.C",
+		"desc": "definition of type C",
 		"pos": "testdata/src/main/describe-json.go:27:6",
 		"detail": "type",
 		"type": {
-			"type": "describe.C",
+			"type": "C",
 			"namepos": "testdata/src/main/describe-json.go:27:6",
 			"namedef": "int",
 			"methods": [

oracle/testdata/src/main/describe.go

@@ -8,6 +8,8 @@ package describe // @describe pkgdecl "describe"
 
 type cake float64 // @describe type-ref-builtin "float64"
 
+const c = iota // @describe const-ref-iota "iota"
+
 const pi = 3.141     // @describe const-def-pi "pi"
 const pie = cake(pi) // @describe const-def-pie "pie"
 const _ = pi         // @describe const-ref-pi "pi"
@@ -65,6 +67,8 @@ func main() { // @describe func-def-main "main"
 
 	defer main() // @describe defer-stmt "defer"
 	go main()    // @describe go-stmt "go"
+
+	panic(3) // @describe builtin-ref-panic "panic"
 }
 
 func deadcode() {

oracle/testdata/src/main/describe.golden

@@ -6,6 +6,7 @@ definition of package "describe"
 		method (describe.D) f()
 	type  I        interface{f()}
 		method (describe.I) f()
+	const c        untyped integer = 0
 	type  cake     float64
 	func  deadcode func()
 	var   global   *string
@@ -16,64 +17,67 @@ definition of package "describe"
 -------- @describe type-ref-builtin --------
 reference to built-in type float64
 
+-------- @describe const-ref-iota --------
+reference to const iota untyped integer of constant value 0
+
 -------- @describe const-def-pi --------
 definition of const pi untyped float
 
 -------- @describe const-def-pie --------
-definition of const pie describe.cake
+definition of const pie cake
 
 -------- @describe const-ref-pi --------
 reference to const pi untyped float of constant value 3141/1000
 defined here
 
 -------- @describe func-def-main --------
-definition of func describe.main()
+definition of func main()
 
 -------- @describe func-ref-main --------
-reference to func describe.main()
+reference to func main()
 defined here
 
 -------- @describe func-ref-*C.f --------
-reference to method func (*describe.C).f()
+reference to method func (*C).f()
 defined here
 
 -------- @describe func-ref-D.f --------
-reference to method func (describe.D).f()
+reference to method func (D).f()
 defined here
 
 -------- @describe func-ref-I.f --------
-reference to interface method func (describe.I).f()
+reference to interface method func (I).f()
 defined here
 
 -------- @describe type-D --------
-reference to type describe.D
+reference to type D
 defined as struct{}
 Method set:
 	method (describe.D) f()
 
 -------- @describe type-I --------
-reference to type describe.I
+reference to type I
 defined as interface{f()}
 Method set:
 	method (describe.I) f()
 
 -------- @describe func-ref-d.f --------
-reference to method func (describe.D).f()
+reference to method func (D).f()
 defined here
 
 -------- @describe func-ref-i.f --------
-reference to interface method func (describe.I).f()
+reference to interface method func (I).f()
 defined here
 
 -------- @describe ref-lexical-d --------
-reference to var d describe.D
+reference to var d D
 defined here
 
 -------- @describe ref-anon --------
 reference to var anon func()
 defined here
 value may point to these labels:
-	func@29.10
+	func@31.10
 
 -------- @describe ref-global --------
 reference to var global *string
@@ -105,42 +109,42 @@ value may point to these labels:
 	b
 
 -------- @describe var-ref-i-C --------
-reference to var i describe.I
+reference to var i I
 defined here
-this describe.I may contain these dynamic types:
+this I may contain these dynamic types:
-	*describe.C, may point to:
+	*C, may point to:
 		new
 
 -------- @describe var-ref-i-D --------
-reference to var i describe.I
+reference to var i I
 defined here
-this describe.I may contain these dynamic types:
+this I may contain these dynamic types:
-	describe.D
+	D
 
 -------- @describe var-ref-i --------
-reference to var i describe.I
+reference to var i I
 defined here
-this describe.I may contain these dynamic types:
+this I may contain these dynamic types:
-	*describe.C, may point to:
+	*C, may point to:
 		new
-	describe.D
+	D
 
 -------- @describe const-local-pi --------
 definition of const localpi untyped float
 
 -------- @describe const-local-pie --------
-definition of const localpie describe.cake
+definition of const localpie cake
 
 -------- @describe const-ref-localpi --------
 reference to const localpi untyped float of constant value 3141/1000
 defined here
 
 -------- @describe type-def-T --------
-definition of type describe.T
+definition of type T
 No methods.
 
 -------- @describe type-ref-T --------
-reference to type describe.T
+reference to type T
 defined as int
 No methods.
 
@@ -171,6 +175,9 @@ defer statement
 -------- @describe go-stmt --------
 go statement
 
+-------- @describe builtin-ref-panic --------
+function call (or conversion) of type ()
+
 -------- @describe var-decl-stmt --------
 definition of var a int
 
@@ -179,7 +186,7 @@ definition of var b *int
 no points-to information: PTA did not encounter this expression (dead code?)
 
 -------- @describe def-iface-I --------
-definition of type describe.I
+definition of type I
 Method set:
 	method (describe.I) f()
 

oracle/testdata/src/main/imports.golden

@@ -7,7 +7,7 @@ import of package "lib"
 	var   Var   int
 
 -------- @describe ref-const --------
-reference to const Const untyped integer
+reference to const lib.Const untyped integer
 defined here
 
 -------- @describe ref-func --------
@@ -15,7 +15,7 @@ reference to func lib.Func()
 defined here
 
 -------- @describe ref-var --------
-reference to var Var int
+reference to var lib.Var int
 defined here
 
 -------- @describe ref-type --------