pkg/compiler: more static error checking

Update #217

7 files changed, 211 insertions, 103 deletions

diff --git a/pkg/ast/ast.go b/pkg/ast/ast.go
index b283ca5f8..4c9101f79 100644
--- a/pkg/ast/ast.go
+++ b/pkg/ast/ast.go
@@ -18,7 +18,9 @@ type Description struct {
 }
 
 // Node is AST node interface.
-type Node interface{}
+type Node interface {
+	Info() (pos Pos, typ string, name string)
+}
 
 // Top-level AST nodes:
 
@@ -26,34 +28,58 @@ type NewLine struct {
 	Pos Pos
 }
 
+func (n *NewLine) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokNewLine], ""
+}
+
 type Comment struct {
 	Pos  Pos
 	Text string
 }
 
+func (n *Comment) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokComment], ""
+}
+
 type Include struct {
 	Pos  Pos
 	File *String
 }
 
+func (n *Include) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokInclude], ""
+}
+
 type Incdir struct {
 	Pos Pos
 	Dir *String
 }
 
+func (n *Incdir) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokInclude], ""
+}
+
 type Define struct {
 	Pos   Pos
 	Name  *Ident
 	Value *Int
 }
 
+func (n *Define) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokDefine], n.Name.Name
+}
+
 type Resource struct {
 	Pos    Pos
 	Name   *Ident
-	Base   *Ident
+	Base   *Type
 	Values []*Int
 }
 
+func (n *Resource) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokResource], n.Name.Name
+}
+
 type Call struct {
 	Pos      Pos
 	Name     *Ident
@@ -63,6 +89,10 @@ type Call struct {
 	Ret      *Type
 }
 
+func (n *Call) Info() (Pos, string, string) {
+	return n.Pos, "syscall", n.Name.Name
+}
+
 type Struct struct {
 	Pos      Pos
 	Name     *Ident
@@ -72,18 +102,34 @@ type Struct struct {
 	IsUnion  bool
 }
 
+func (n *Struct) Info() (Pos, string, string) {
+	typ := "struct"
+	if n.IsUnion {
+		typ = "union"
+	}
+	return n.Pos, typ, n.Name.Name
+}
+
 type IntFlags struct {
 	Pos    Pos
 	Name   *Ident
 	Values []*Int
 }
 
+func (n *IntFlags) Info() (Pos, string, string) {
+	return n.Pos, "flags", n.Name.Name
+}
+
 type StrFlags struct {
 	Pos    Pos
 	Name   *Ident
 	Values []*String
 }
 
+func (n *StrFlags) Info() (Pos, string, string) {
+	return n.Pos, "string flags", n.Name.Name
+}
+
 // Not top-level AST nodes:
 
 type Ident struct {
@@ -91,11 +137,19 @@ type Ident struct {
 	Name string
 }
 
+func (n *Ident) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokIdent], n.Name
+}
+
 type String struct {
 	Pos   Pos
 	Value string
 }
 
+func (n *String) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokString], ""
+}
+
 type Int struct {
 	Pos Pos
 	// Only one of Value, Ident, CExpr is filled.
@@ -105,6 +159,10 @@ type Int struct {
 	CExpr    string
 }
 
+func (n *Int) Info() (Pos, string, string) {
+	return n.Pos, tok2str[tokInt], ""
+}
+
 type Type struct {
 	Pos Pos
 	// Only one of Value, Ident, String is filled.
@@ -121,6 +179,10 @@ type Type struct {
 	Args      []*Type
 }
 
+func (n *Type) Info() (Pos, string, string) {
+	return n.Pos, "type", n.Ident
+}
+
 type Field struct {
 	Pos      Pos
 	Name     *Ident
@@ -128,3 +190,7 @@ type Field struct {
 	NewBlock bool // separated from previous fields by a new line
 	Comments []*Comment
 }
+
+func (n *Field) Info() (Pos, string, string) {
+	return n.Pos, "arg/field", n.Name.Name
+}
diff --git a/pkg/ast/format.go b/pkg/ast/format.go
index e7e21dcdd..0f95d7ebf 100644
--- a/pkg/ast/format.go
+++ b/pkg/ast/format.go
@@ -50,7 +50,7 @@ func (def *Define) serialize(w io.Writer) {
 }
 
 func (res *Resource) serialize(w io.Writer) {
-	fmt.Fprintf(w, "resource %v[%v]", res.Name.Name, res.Base.Name)
+	fmt.Fprintf(w, "resource %v[%v]", res.Name.Name, fmtType(res.Base))
 	for i, v := range res.Values {
 		if i == 0 {
 			fmt.Fprintf(w, ": ")
diff --git a/pkg/ast/parser.go b/pkg/ast/parser.go
index ca2505e19..fd7b9ad4f 100644
--- a/pkg/ast/parser.go
+++ b/pkg/ast/parser.go
@@ -228,7 +228,7 @@ func (p *parser) parseResource() *Resource {
 	p.consume(tokResource)
 	name := p.parseIdent()
 	p.consume(tokLBrack)
-	base := p.parseIdent()
+	base := p.parseType()
 	p.consume(tokRBrack)
 	var values []*Int
 	if p.tryConsume(tokColon) {
diff --git a/pkg/ast/parser_test.go b/pkg/ast/parser_test.go
index 84a5fedf0..46ad1e5d3 100644
--- a/pkg/ast/parser_test.go
+++ b/pkg/ast/parser_test.go
@@ -4,7 +4,6 @@
 package ast
 
 import (
-	"bufio"
 	"bytes"
 	"io/ioutil"
 	"path/filepath"
@@ -29,7 +28,7 @@ func TestParseAll(t *testing.T) {
 		}
 		t.Run(file.Name(), func(t *testing.T) {
 			eh := func(pos Pos, msg string) {
-				t.Fatalf("%v:%v:%v: %v", pos.File, pos.Line, pos.Col, msg)
+				t.Fatalf("%v: %v", pos, msg)
 			}
 			desc := Parse(data, file.Name(), eh)
 			if desc == nil {
@@ -65,7 +64,7 @@ func TestParse(t *testing.T) {
 	for _, test := range parseTests {
 		t.Run(test.name, func(t *testing.T) {
 			errorHandler := func(pos Pos, msg string) {
-				t.Logf("%v:%v:%v: %v", pos.File, pos.Line, pos.Col, msg)
+				t.Logf("%v: %v", pos, msg)
 			}
 			Parse([]byte(test.input), "foo", errorHandler)
 		})
@@ -96,13 +95,6 @@ var parseTests = []struct {
 	},
 }
 
-type Error struct {
-	Line    int
-	Col     int
-	Text    string
-	Matched bool
-}
-
 func TestErrors(t *testing.T) {
 	files, err := ioutil.ReadDir("testdata")
 	if err != nil {
@@ -115,71 +107,18 @@ func TestErrors(t *testing.T) {
 		if !strings.HasSuffix(f.Name(), ".txt") {
 			continue
 		}
-		t.Run(f.Name(), func(t *testing.T) {
-			data, err := ioutil.ReadFile(filepath.Join("testdata", f.Name()))
-			if err != nil {
-				t.Fatalf("failed to open input file: %v", err)
-			}
-			var stripped []byte
-			var errors []*Error
-			s := bufio.NewScanner(bytes.NewReader(data))
-			for i := 1; s.Scan(); i++ {
-				ln := s.Bytes()
-				for {
-					pos := bytes.LastIndex(ln, []byte("###"))
-					if pos == -1 {
-						break
-					}
-					errors = append(errors, &Error{
-						Line: i,
-						Text: strings.TrimSpace(string(ln[pos+3:])),
-					})
-					ln = ln[:pos]
-				}
-				stripped = append(stripped, ln...)
-				stripped = append(stripped, '\n')
-			}
-			if err := s.Err(); err != nil {
-				t.Fatalf("failed to scan input file: %v", err)
+		name := f.Name()
+		t.Run(name, func(t *testing.T) {
+			em := NewErrorMatcher(t, filepath.Join("testdata", name))
+			desc := Parse(em.Data, name, em.ErrorHandler)
+			if desc != nil && em.Count() != 0 {
+				em.DumpErrors(t)
+				t.Fatalf("parsing succeed, but got errors")
 			}
-			var got []*Error
-			desc := Parse(stripped, "test", func(pos Pos, msg string) {
-				got = append(got, &Error{
-					Line: pos.Line,
-					Col:  pos.Col,
-					Text: msg,
-				})
-			})
-			if desc != nil && len(got) != 0 {
-				t.Fatalf("parsing succeed, but got errors: %v", got)
-			}
-			if desc == nil && len(got) == 0 {
+			if desc == nil && em.Count() == 0 {
 				t.Fatalf("parsing failed, but got no errors")
 			}
-		nextErr:
-			for _, gotErr := range got {
-				for _, wantErr := range errors {
-					if wantErr.Matched {
-						continue
-					}
-					if wantErr.Line != gotErr.Line {
-						continue
-					}
-					if wantErr.Text != gotErr.Text {
-						continue
-					}
-					wantErr.Matched = true
-					continue nextErr
-				}
-				t.Errorf("unexpected error: %v:%v: %v",
-					gotErr.Line, gotErr.Col, gotErr.Text)
-			}
-			for _, wantErr := range errors {
-				if wantErr.Matched {
-					continue
-				}
-				t.Errorf("not matched error: %v: %v", wantErr.Line, wantErr.Text)
-			}
+			em.Check(t)
 		})
 	}
 }
diff --git a/pkg/ast/scanner.go b/pkg/ast/scanner.go
index 387a58529..f1573350b 100644
--- a/pkg/ast/scanner.go
+++ b/pkg/ast/scanner.go
@@ -118,7 +118,11 @@ func newScanner(data []byte, filename string, errorHandler ErrorHandler) *scanne
 type ErrorHandler func(pos Pos, msg string)
 
 func LoggingHandler(pos Pos, msg string) {
-	fmt.Fprintf(os.Stderr, "%v:%v:%v: %v\n", pos.File, pos.Line, pos.Col, msg)
+	fmt.Fprintf(os.Stderr, "%v: %v\n", pos, msg)
+}
+
+func (pos Pos) String() string {
+	return fmt.Sprintf("%v:%v:%v", pos.File, pos.Line, pos.Col)
 }
 
 func (s *scanner) Scan() (tok token, lit string, pos Pos) {
diff --git a/pkg/ast/test_util.go b/pkg/ast/test_util.go
new file mode 100644
index 000000000..0aed0a2dc
--- /dev/null
+++ b/pkg/ast/test_util.go
@@ -0,0 +1,99 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package ast
+
+import (
+	"bufio"
+	"bytes"
+	"io/ioutil"
+	"strings"
+	"testing"
+)
+
+type ErrorMatcher struct {
+	Data   []byte
+	expect []*errorDesc
+	got    []*errorDesc
+}
+
+type errorDesc struct {
+	file    string
+	line    int
+	col     int
+	text    string
+	matched bool
+}
+
+func NewErrorMatcher(t *testing.T, file string) *ErrorMatcher {
+	data, err := ioutil.ReadFile(file)
+	if err != nil {
+		t.Fatalf("failed to open input file: %v", err)
+	}
+	var stripped []byte
+	var errors []*errorDesc
+	s := bufio.NewScanner(bytes.NewReader(data))
+	for i := 1; s.Scan(); i++ {
+		ln := s.Bytes()
+		for {
+			pos := bytes.LastIndex(ln, []byte("###"))
+			if pos == -1 {
+				break
+			}
+			errors = append(errors, &errorDesc{
+				file: file,
+				line: i,
+				text: strings.TrimSpace(string(ln[pos+3:])),
+			})
+			ln = ln[:pos]
+		}
+		stripped = append(stripped, ln...)
+		stripped = append(stripped, '\n')
+	}
+	if err := s.Err(); err != nil {
+		t.Fatalf("failed to scan input file: %v", err)
+	}
+	return &ErrorMatcher{
+		Data:   stripped,
+		expect: errors,
+	}
+}
+
+func (em *ErrorMatcher) ErrorHandler(pos Pos, msg string) {
+	em.got = append(em.got, &errorDesc{
+		file: pos.File,
+		line: pos.Line,
+		col:  pos.Col,
+		text: msg,
+	})
+}
+
+func (em *ErrorMatcher) Count() int {
+	return len(em.got)
+}
+
+func (em *ErrorMatcher) Check(t *testing.T) {
+nextErr:
+	for _, e := range em.got {
+		for _, want := range em.expect {
+			if want.matched || want.line != e.line || want.text != e.text {
+				continue
+			}
+			want.matched = true
+			continue nextErr
+		}
+		t.Errorf("unexpected error: %v:%v:%v: %v", e.file, e.line, e.col, e.text)
+	}
+	for _, want := range em.expect {
+		if want.matched {
+			continue
+		}
+		t.Errorf("unmatched error: %v:%v: %v", want.file, want.line, want.text)
+	}
+}
+
+func (em *ErrorMatcher) DumpErrors(t *testing.T) {
+	for _, e := range em.got {
+		t.Logf("%v:%v:%v: %v", e.file, e.line, e.col, e.text)
+	}
+}
diff --git a/pkg/ast/walk.go b/pkg/ast/walk.go
index af62884fe..79e0b4bec 100644
--- a/pkg/ast/walk.go
+++ b/pkg/ast/walk.go
@@ -8,71 +8,71 @@ import (
 )
 
 // Walk calls callback cb for every node in AST.
-func Walk(desc *Description, cb func(n, parent Node)) {
+func Walk(desc *Description, cb func(n Node)) {
 	for _, n := range desc.Nodes {
-		WalkNode(n, nil, cb)
+		WalkNode(n, cb)
 	}
 }
 
-func WalkNode(n0, parent Node, cb func(n, parent Node)) {
-	cb(n0, parent)
+func WalkNode(n0 Node, cb func(n Node)) {
+	cb(n0)
 	switch n := n0.(type) {
 	case *NewLine:
 	case *Comment:
 	case *Include:
-		WalkNode(n.File, n, cb)
+		WalkNode(n.File, cb)
 	case *Incdir:
-		WalkNode(n.Dir, n, cb)
+		WalkNode(n.Dir, cb)
 	case *Define:
-		WalkNode(n.Name, n, cb)
-		WalkNode(n.Value, n, cb)
+		WalkNode(n.Name, cb)
+		WalkNode(n.Value, cb)
 	case *Resource:
-		WalkNode(n.Name, n, cb)
-		WalkNode(n.Base, n, cb)
+		WalkNode(n.Name, cb)
+		WalkNode(n.Base, cb)
 		for _, v := range n.Values {
-			WalkNode(v, n, cb)
+			WalkNode(v, cb)
 		}
 	case *Call:
-		WalkNode(n.Name, n, cb)
+		WalkNode(n.Name, cb)
 		for _, f := range n.Args {
-			WalkNode(f, n, cb)
+			WalkNode(f, cb)
 		}
 		if n.Ret != nil {
-			WalkNode(n.Ret, n, cb)
+			WalkNode(n.Ret, cb)
 		}
 	case *Struct:
-		WalkNode(n.Name, n, cb)
+		WalkNode(n.Name, cb)
 		for _, f := range n.Fields {
-			WalkNode(f, n, cb)
+			WalkNode(f, cb)
 		}
 		for _, a := range n.Attrs {
-			WalkNode(a, n, cb)
+			WalkNode(a, cb)
 		}
 		for _, c := range n.Comments {
-			WalkNode(c, n, cb)
+			WalkNode(c, cb)
 		}
 	case *IntFlags:
-		WalkNode(n.Name, n, cb)
+		WalkNode(n.Name, cb)
 		for _, v := range n.Values {
-			WalkNode(v, n, cb)
+			WalkNode(v, cb)
 		}
 	case *StrFlags:
-		WalkNode(n.Name, n, cb)
+		WalkNode(n.Name, cb)
 		for _, v := range n.Values {
-			WalkNode(v, n, cb)
+			WalkNode(v, cb)
 		}
 	case *Ident:
 	case *String:
 	case *Int:
 	case *Type:
 		for _, t := range n.Args {
-			WalkNode(t, n, cb)
+			WalkNode(t, cb)
 		}
 	case *Field:
-		WalkNode(n.Name, n, cb)
-		WalkNode(n.Type, n, cb)
+		WalkNode(n.Name, cb)
+		WalkNode(n.Type, cb)
 		for _, c := range n.Comments {
-			WalkNode(c, n, cb)
+			WalkNode(c, cb)
 		}
 	default:
 		panic(fmt.Sprintf("unknown AST node: %#v", n))