go.tools: fix various minor issues found by go vet

LGTM=adonovan
R=adonovan
CC=golang-codereviews
https://golang.org/cl/96360048

cmd/godoc/godoc_test.go

@@ -182,7 +182,7 @@ func TestTypeAnalysis(t *testing.T) {
 	// Write a fake GOROOT/GOPATH.
 	tmpdir, err := ioutil.TempDir("", "godoc-analysis")
 	if err != nil {
-		t.Fatal("ioutil.TempDir failed: %s", err)
+		t.Fatalf("ioutil.TempDir failed: %s", err)
 	}
 	defer os.RemoveAll(tmpdir)
 	for _, f := range []struct{ file, content string }{

container/intsets/sparse_test.go

@@ -71,17 +71,17 @@ func TestMoreBasics(t *testing.T) {
 		t.Errorf("%s.Len: got %d, want 3", set, set.Len())
 	}
 	if set.IsEmpty() {
-		t.Error("%s.IsEmpty: got true", set)
+		t.Errorf("%s.IsEmpty: got true", set)
 	}
 	if !set.Has(123) {
-		t.Error("%s.Has(123): got false", set)
+		t.Errorf("%s.Has(123): got false", set)
 	}
 	if set.Has(1234) {
-		t.Error("%s.Has(1234): got true", set)
+		t.Errorf("%s.Has(1234): got true", set)
 	}
 	got := set.AppendTo([]int{-1})
 	if want := []int{-1, 123, 456, 789}; fmt.Sprint(got) != fmt.Sprint(want) {
-		t.Error("%s.AppendTo: got %v, want %v", got, want)
+		t.Errorf("%s.AppendTo: got %v, want %v", got, want)
 	}
 
 	set.Clear()
@@ -90,10 +90,10 @@ func TestMoreBasics(t *testing.T) {
 		t.Errorf("Clear: got %d, want 0", set.Len())
 	}
 	if !set.IsEmpty() {
-		t.Error("IsEmpty: got false")
+		t.Errorf("IsEmpty: got false")
 	}
 	if set.Has(123) {
-		t.Error("%s.Has: got false", set)
+		t.Errorf("%s.Has: got false", set)
 	}
 }
 
@@ -440,7 +440,7 @@ func TestFailFastOnShallowCopy(t *testing.T) {
 		got := fmt.Sprint(recover())
 		want := "A Sparse has been copied without (*Sparse).Copy()"
 		if got != want {
-			t.Error("shallow copy: recover() = %q, want %q", got, want)
+			t.Errorf("shallow copy: recover() = %q, want %q", got, want)
 		}
 	}()
 	y.String() // panics

go/loader/importer_test.go

@@ -101,11 +101,16 @@ func TestLoadFromArgsSource(t *testing.T) {
 	args = []string{"testdata/a.go", "testdata/b.go"}
 	prog, _, err = loadFromArgs(args)
 	if err != nil {
-		t.Errorf("loadFromArgs(%q) failed: %s", args, err)
+		t.Fatalf("loadFromArgs(%q) failed: %s", args, err)
-		return
 	}
-	if len(prog.Created) != 1 || prog.Created[0].Pkg.Path() != "P" {
+	if len(prog.Created) != 1 {
-		t.Errorf("loadFromArgs(%q): got %v, want [P]", prog.Created)
+		t.Errorf("loadFromArgs(%q): got %d items, want 1", len(prog.Created))
+	}
+	if len(prog.Created) > 0 {
+		path := prog.Created[0].Pkg.Path()
+		if path != "P" {
+			t.Errorf("loadFromArgs(%q): got %v, want [P]", prog.Created, path)
+		}
 	}
 }
 
@@ -190,7 +195,7 @@ func TestTransitivelyErrorFreeFlag(t *testing.T) {
 
 		if info.TransitivelyErrorFree != wantTEF {
 			t.Errorf("Package %q.TransitivelyErrorFree=%t, want %t",
-				info.TransitivelyErrorFree, wantTEF)
+				pkg.Path(), info.TransitivelyErrorFree, wantTEF)
 		}
 	}
 }

go/ssa/interp/reflect.go

@@ -276,7 +276,6 @@ func ext۰reflect۰Value۰Len(fr *frame, args []value) value {
 	default:
 		panic(fmt.Sprintf("reflect.(Value).Len(%v)", v))
 	}
-	return nil // unreachable
 }
 
 func ext۰reflect۰Value۰MapIndex(fr *frame, args []value) value {
@@ -353,7 +352,6 @@ func ext۰reflect۰Value۰Pointer(fr *frame, args []value) value {
 	default:
 		panic(fmt.Sprintf("reflect.(Value).Pointer(%T)", v))
 	}
-	return nil // unreachable
 }
 
 func ext۰reflect۰Value۰Index(fr *frame, args []value) value {
@@ -368,7 +366,6 @@ func ext۰reflect۰Value۰Index(fr *frame, args []value) value {
 	default:
 		panic(fmt.Sprintf("reflect.(Value).Index(%T)", v))
 	}
-	return nil // unreachable
 }
 
 func ext۰reflect۰Value۰Bool(fr *frame, args []value) value {
@@ -398,7 +395,6 @@ func ext۰reflect۰Value۰Elem(fr *frame, args []value) value {
 	default:
 		panic(fmt.Sprintf("reflect.(Value).Elem(%T)", x))
 	}
-	return nil // unreachable
 }
 
 func ext۰reflect۰Value۰Field(fr *frame, args []value) value {
@@ -440,7 +436,6 @@ func ext۰reflect۰Value۰Int(fr *frame, args []value) value {
 	default:
 		panic(fmt.Sprintf("reflect.(Value).Int(%T)", x))
 	}
-	return nil // unreachable
 }
 
 func ext۰reflect۰Value۰IsNil(fr *frame, args []value) value {
@@ -467,7 +462,6 @@ func ext۰reflect۰Value۰IsNil(fr *frame, args []value) value {
 	default:
 		panic(fmt.Sprintf("reflect.(Value).IsNil(%T)", x))
 	}
-	return nil // unreachable
 }
 
 func ext۰reflect۰Value۰IsValid(fr *frame, args []value) value {

go/vcs/discovery.go

@@ -59,7 +59,6 @@ func parseMetaGoImports(r io.Reader) (imports []metaImport, err error) {
 			})
 		}
 	}
-	return
 }
 
 // attrValue returns the attribute value for the case-insensitive key

godoc/analysis/analysis.go

@@ -500,7 +500,7 @@ func (a *analysis) pointer(mainPkgs []*ssa.Package) {
 	ptares, err := pointer.Analyze(&a.ptaConfig)
 	if err != nil {
 		// If this happens, it indicates a bug.
-		log.Print("Pointer analysis failed: %s", err)
+		log.Printf("Pointer analysis failed: %s", err)
 		return
 	}
 	log.Print("Pointer analysis complete.")

godoc/analysis/callgraph.go

@@ -98,7 +98,7 @@ func (a *analysis) doCallgraph(cg *callgraph.Graph) {
 	for callee, sites := range callingSites {
 		pos := funcToken(callee)
 		if pos == token.NoPos {
-			log.Print("CALLERS: skipping %s: no pos", callee)
+			log.Printf("CALLERS: skipping %s: no pos", callee)
 			continue
 		}