3 files changed, 83 insertions, 49 deletions

diff --git a/src/pkg/go/parser/interface.go b/src/pkg/go/parser/interface.go
index 84d699a67..6f35b495e 100644
--- a/src/pkg/go/parser/interface.go
+++ b/src/pkg/go/parser/interface.go
@@ -14,7 +14,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	pathutil "path"
+	"path/filepath"
 )
 
 
@@ -198,7 +198,7 @@ func ParseDir(fset *token.FileSet, path string, filter func(*os.FileInfo) bool,
 	for i := 0; i < len(list); i++ {
 		d := &list[i]
 		if filter == nil || filter(d) {
-			filenames[n] = pathutil.Join(path, d.Name)
+			filenames[n] = filepath.Join(path, d.Name)
 			n++
 		}
 	}
diff --git a/src/pkg/go/parser/parser.go b/src/pkg/go/parser/parser.go
index 2395b8158..7c5843f36 100644
--- a/src/pkg/go/parser/parser.go
+++ b/src/pkg/go/parser/parser.go
@@ -1327,44 +1327,34 @@ func (p *parser) makeExpr(s ast.Stmt) ast.Expr {
 }
 
 
-func (p *parser) parseControlClause(isForStmt bool) (s1, s2, s3 ast.Stmt) {
-	if p.tok != token.LBRACE {
+func (p *parser) parseIfStmt() *ast.IfStmt {
+	if p.trace {
+		defer un(trace(p, "IfStmt"))
+	}
+
+	pos := p.expect(token.IF)
+
+	var s ast.Stmt
+	var x ast.Expr
+	{
 		prevLev := p.exprLev
 		p.exprLev = -1
-
-		if p.tok != token.SEMICOLON {
-			s1 = p.parseSimpleStmt(false)
-		}
 		if p.tok == token.SEMICOLON {
 			p.next()
-			if p.tok != token.LBRACE && p.tok != token.SEMICOLON {
-				s2 = p.parseSimpleStmt(false)
-			}
-			if isForStmt {
-				// for statements have a 3rd section
-				p.expectSemi()
-				if p.tok != token.LBRACE {
-					s3 = p.parseSimpleStmt(false)
-				}
-			}
+			x = p.parseExpr()
 		} else {
-			s1, s2 = nil, s1
+			s = p.parseSimpleStmt(false)
+			if p.tok == token.SEMICOLON {
+				p.next()
+				x = p.parseExpr()
+			} else {
+				x = p.makeExpr(s)
+				s = nil
+			}
 		}
-
 		p.exprLev = prevLev
 	}
 
-	return s1, s2, s3
-}
-
-
-func (p *parser) parseIfStmt() *ast.IfStmt {
-	if p.trace {
-		defer un(trace(p, "IfStmt"))
-	}
-
-	pos := p.expect(token.IF)
-	s1, s2, _ := p.parseControlClause(false)
 	body := p.parseBlockStmt()
 	var else_ ast.Stmt
 	if p.tok == token.ELSE {
@@ -1374,7 +1364,7 @@ func (p *parser) parseIfStmt() *ast.IfStmt {
 		p.expectSemi()
 	}
 
-	return &ast.IfStmt{pos, s1, p.makeExpr(s2), body, else_}
+	return &ast.IfStmt{pos, s, x, body, else_}
 }
 
 
@@ -1457,7 +1447,24 @@ func (p *parser) parseSwitchStmt() ast.Stmt {
 	}
 
 	pos := p.expect(token.SWITCH)
-	s1, s2, _ := p.parseControlClause(false)
+
+	var s1, s2 ast.Stmt
+	if p.tok != token.LBRACE {
+		prevLev := p.exprLev
+		p.exprLev = -1
+		if p.tok != token.SEMICOLON {
+			s2 = p.parseSimpleStmt(false)
+		}
+		if p.tok == token.SEMICOLON {
+			p.next()
+			s1 = s2
+			s2 = nil
+			if p.tok != token.LBRACE {
+				s2 = p.parseSimpleStmt(false)
+			}
+		}
+		p.exprLev = prevLev
+	}
 
 	if isExprSwitch(s2) {
 		lbrace := p.expect(token.LBRACE)
@@ -1575,7 +1582,29 @@ func (p *parser) parseForStmt() ast.Stmt {
 	}
 
 	pos := p.expect(token.FOR)
-	s1, s2, s3 := p.parseControlClause(true)
+
+	var s1, s2, s3 ast.Stmt
+	if p.tok != token.LBRACE {
+		prevLev := p.exprLev
+		p.exprLev = -1
+		if p.tok != token.SEMICOLON {
+			s2 = p.parseSimpleStmt(false)
+		}
+		if p.tok == token.SEMICOLON {
+			p.next()
+			s1 = s2
+			s2 = nil
+			if p.tok != token.SEMICOLON {
+				s2 = p.parseSimpleStmt(false)
+			}
+			p.expectSemi()
+			if p.tok != token.LBRACE {
+				s3 = p.parseSimpleStmt(false)
+			}
+		}
+		p.exprLev = prevLev
+	}
+
 	body := p.parseBlockStmt()
 	p.expectSemi()
 
diff --git a/src/pkg/go/parser/parser_test.go b/src/pkg/go/parser/parser_test.go
index 5a7f05ca8..38535627a 100644
--- a/src/pkg/go/parser/parser_test.go
+++ b/src/pkg/go/parser/parser_test.go
@@ -18,6 +18,9 @@ var illegalInputs = []interface{}{
 	3.14,
 	[]byte(nil),
 	"foo!",
+	`package p; func f() { if /* should have condition */ {} };`,
+	`package p; func f() { if ; /* should have condition */ {} };`,
+	`package p; func f() { if f(); /* should have condition */ {} };`,
 }
 
 
@@ -32,21 +35,23 @@ func TestParseIllegalInputs(t *testing.T) {
 
 
 var validPrograms = []interface{}{
-	"package main\n",
-	`package main;`,
-	`package main; import "fmt"; func main() { fmt.Println("Hello, World!") };`,
-	`package main; func main() { if f(T{}) {} };`,
-	`package main; func main() { _ = (<-chan int)(x) };`,
-	`package main; func main() { _ = (<-chan <-chan int)(x) };`,
-	`package main; func f(func() func() func());`,
-	`package main; func f(...T);`,
-	`package main; func f(float, ...int);`,
-	`package main; func f(x int, a ...int) { f(0, a...); f(1, a...,) };`,
-	`package main; type T []int; var a []bool; func f() { if a[T{42}[0]] {} };`,
-	`package main; type T []int; func g(int) bool { return true }; func f() { if g(T{42}[0]) {} };`,
-	`package main; type T []int; func f() { for _ = range []int{T{42}[0]} {} };`,
-	`package main; var a = T{{1, 2}, {3, 4}}`,
-	`package main; func f() { select { case <- c: case c <- d: case c <- <- d: case <-c <- d: } };`,
+	"package p\n",
+	`package p;`,
+	`package p; import "fmt"; func f() { fmt.Println("Hello, World!") };`,
+	`package p; func f() { if f(T{}) {} };`,
+	`package p; func f() { _ = (<-chan int)(x) };`,
+	`package p; func f() { _ = (<-chan <-chan int)(x) };`,
+	`package p; func f(func() func() func());`,
+	`package p; func f(...T);`,
+	`package p; func f(float, ...int);`,
+	`package p; func f(x int, a ...int) { f(0, a...); f(1, a...,) };`,
+	`package p; type T []int; var a []bool; func f() { if a[T{42}[0]] {} };`,
+	`package p; type T []int; func g(int) bool { return true }; func f() { if g(T{42}[0]) {} };`,
+	`package p; type T []int; func f() { for _ = range []int{T{42}[0]} {} };`,
+	`package p; var a = T{{1, 2}, {3, 4}}`,
+	`package p; func f() { select { case <- c: case c <- d: case c <- <- d: case <-c <- d: } };`,
+	`package p; func f() { if ; true {} };`,
+	`package p; func f() { switch ; {} };`,
 }