From ad9fabd769d6c705ea5808dc59a3b18390994627 Mon Sep 17 00:00:00 2001
From: Austin Clements <aclements@csail.mit.edu>
Date: Tue, 1 Sep 2009 17:21:44 -0700
Subject: [PATCH] Interpreter unit tests for statements and expressions

R=rsc
APPROVED=rsc
DELTA=1003  (1003 added, 0 deleted, 0 changed)
OCL=34223
CL=34227
---
 usr/austin/eval/eval_test.go | 333 +++++++++++++++++++++++++++++++++
 usr/austin/eval/expr_test.go | 345 +++++++++++++++++++++++++++++++++++
 usr/austin/eval/stmt_test.go | 337 ++++++++++++++++++++++++++++++++++
 3 files changed, 1015 insertions(+)
 create mode 100644 usr/austin/eval/eval_test.go
 create mode 100644 usr/austin/eval/expr_test.go
 create mode 100644 usr/austin/eval/stmt_test.go

diff --git a/usr/austin/eval/eval_test.go b/usr/austin/eval/eval_test.go
new file mode 100644
index 00000000000..848bf6d1939
--- /dev/null
+++ b/usr/austin/eval/eval_test.go
@@ -0,0 +1,333 @@
+// Copyright 2009 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 eval
+
+import (
+	"bignum";
+	"fmt";
+	"go/parser";
+	"go/scanner";
+	"go/token";
+	"log";
+	"os";
+	"reflect";
+	"testing";
+)
+
+// Print each statement or expression before parsing it
+const noisy = true
+
+/*
+ * Generic statement/expression test framework
+ */
+
+type test struct {
+	code string;
+	rterr string;
+	exprs []exprTest;
+	cerr string;
+}
+
+type exprTest struct {
+	code string;
+	val interface{};
+	rterr string;
+}
+
+func runTests(t *testing.T, baseName string, tests []test) {
+	for i, test := range tests {
+		name := fmt.Sprintf("%s[%d]", baseName, i);
+		test.run(t, name);
+	}
+}
+
+func (a *test) run(t *testing.T, name string) {
+	sc := newTestScope();
+
+	var fr *Frame;
+	var cerr os.Error;
+
+	if a.code != "" {
+		if noisy {
+			println(a.code);
+		}
+
+		// Compile statements
+		asts, err := parser.ParseStmtList(name, a.code);
+		if err != nil && cerr == nil {
+			cerr = err;
+		}
+		code, err := CompileStmts(sc, asts);
+		if err != nil && cerr == nil {
+			cerr = err;
+		}
+
+		// Execute statements
+		if cerr == nil {
+			fr = sc.NewFrame(nil);
+			rterr := code.Exec(fr);
+			if a.rterr == "" && rterr != nil {
+				t.Errorf("%s: expected %s to run, got runtime error %v", name, a.code, rterr);
+				return;
+			} else if !checkRTError(t, name, a.code, rterr, a.rterr) {
+				return;
+			}
+		}
+	}
+
+	if fr == nil {
+		fr = sc.NewFrame(nil);
+	}
+	for _, e := range a.exprs {
+		if cerr != nil {
+			break;
+		}
+
+		if noisy {
+			println(e.code);
+		}
+
+		// Compile expression
+		ast, err := parser.ParseExpr(name, e.code);
+		if err != nil && cerr == nil {
+			cerr = err;
+		}
+		code, err := CompileExpr(sc, ast);
+		if err != nil && cerr == nil {
+			cerr = err;
+		}
+
+		// Evaluate expression
+		if cerr == nil {
+			val, rterr := code.Eval(fr);
+			if e.rterr == "" && rterr != nil {
+				t.Errorf("%s: expected %q to have value %T(%v), got runtime error %v", name, e.code, e.val, e.val, rterr);
+			} else if !checkRTError(t, name, e.code, rterr, e.rterr) {
+				continue;
+			}
+			if e.val != nil {
+				wantval := toValue(e.val);
+				if !reflect.DeepEqual(val, wantval) {
+					t.Errorf("%s: expected %q to have value %T(%v), got %T(%v)", name, e.code, wantval, wantval, val, val);
+				}
+			}
+		}
+	}
+
+	// Check compile errors
+	switch {
+	case cerr == nil && a.cerr == "":
+		// Good
+	case cerr == nil && a.cerr != "":
+		t.Errorf("%s: expected compile error matching %q, got no errors", name, a.cerr);
+	case cerr != nil && a.cerr == "":
+		t.Errorf("%s: expected no compile error, got error %v", name, cerr);
+	case cerr != nil && a.cerr != "":
+		cerr := cerr.(scanner.ErrorList);
+		if len(cerr) > 1 {
+			t.Errorf("%s: expected 1 compile error matching %q, got %v", name, a.cerr, cerr);
+			break;
+		}
+		m, err := testing.MatchString(a.cerr, cerr.String());
+		if err != "" {
+			t.Fatalf("%s: failed to compile regexp %q: %s", name, a.cerr, err);
+		}
+		if !m {
+			t.Errorf("%s: expected compile error matching %q, got compile error %v", name, a.cerr, cerr);
+		}
+	}
+}
+
+func checkRTError(t *testing.T, name string, code string, rterr os.Error, pat string) bool {
+	switch {
+	case rterr == nil && pat == "":
+		return true;
+		
+	case rterr == nil && pat != "":
+		t.Errorf("%s: expected %s to fail with runtime error matching %q, got no error", name, code, pat);
+		return false;
+
+	case rterr != nil && pat != "":
+		m, err := testing.MatchString(pat, rterr.String());
+		if err != "" {
+			t.Fatalf("%s: failed to compile regexp %q: %s", name, pat, err);
+		}
+		if !m {
+			t.Errorf("%s: expected runtime error matching %q, got runtime error %v", name, pat, rterr);
+			return false;
+		}
+		return true;
+	}
+	panic("rterr != nil && pat == \"\" should have been handled by the caller");
+}
+
+/*
+ * Test constructors
+ */
+
+// Expression compile error
+func EErr(expr string, cerr string) test {
+	return test{"", "", []exprTest{exprTest{expr, nil, ""}}, cerr};
+}
+
+// Expression runtime error
+func ERTErr(expr string, rterr string) test {
+	return test{"", "", []exprTest{exprTest{expr, nil, rterr}}, ""};
+}
+
+// Expression value
+func Val(expr string, val interface{}) test {
+	return test{"", "", []exprTest{exprTest{expr, val, ""}}, ""};
+}
+
+// Statement compile error
+func SErr(stmts string, cerr string) test {
+	return test{stmts, "", nil, cerr};
+}
+
+// Statement runtime error
+func SRTErr(stmts string, rterr string) test {
+	return test{stmts, rterr, nil, ""};
+}
+
+// Statement runs without error
+func SRuns(stmts string) test {
+	return test{stmts, "", nil, ""};
+}
+
+// Statement runs and test one expression's value
+func Val1(stmts string, expr1 string, val1 interface{}) test {
+	return test{stmts, "", []exprTest{exprTest{expr1, val1, ""}}, ""};
+}
+
+// Statement runs and test two expressions' values
+func Val2(stmts string, expr1 string, val1 interface{}, expr2 string, val2 interface{}) test {
+	return test{stmts, "", []exprTest{exprTest{expr1, val1, ""}, exprTest{expr2, val2, ""}}, ""};
+}
+
+/*
+ * Value constructors
+ */
+
+type vstruct []interface{}
+
+type varray []interface{}
+
+type vslice struct {
+	arr varray;
+	len, cap int;
+}
+
+func toValue(val interface{}) Value {
+	switch val := val.(type) {
+	case bool:
+		r := boolV(val);
+		return &r;
+	case uint8:
+		r := uint8V(val);
+		return &r;
+	case uint:
+		r := uintV(val);
+		return &r;
+	case int:
+		r := intV(val);
+		return &r;
+	case *bignum.Integer:
+		return &idealIntV{val};
+	case float:
+		r := floatV(val);
+		return &r;
+	case *bignum.Rational:
+		return &idealFloatV{val};
+	case string:
+		r := stringV(val);
+		return &r;
+	case vstruct:
+		elems := make([]Value, len(val));
+		for i, e := range val {
+			elems[i] = toValue(e);
+		}
+		r := structV(elems);
+		return &r;
+	case varray:
+		elems := make([]Value, len(val));
+		for i, e := range val {
+			elems[i] = toValue(e);
+		}
+		r := arrayV(elems);
+		return &r;
+	case vslice:
+		return &sliceV{Slice{toValue(val.arr).(ArrayValue), int64(val.len), int64(val.cap)}};
+	case Func:
+		return &funcV{val};
+	}
+	log.Crashf("toValue(%T) not implemented", val);
+	panic();
+}
+
+/*
+ * Default test scope
+ */
+
+type testFunc struct {};
+
+func (*testFunc) NewFrame() *Frame {
+	return &Frame{nil, &[2]Value {}};
+}
+
+func (*testFunc) Call(fr *Frame) {
+	n := fr.Vars[0].(IntValue).Get();
+
+	res := n + 1;
+
+	fr.Vars[1].(IntValue).Set(res);
+}
+
+type oneTwoFunc struct {};
+
+func (*oneTwoFunc) NewFrame() *Frame {
+	return &Frame{nil, &[2]Value {}};
+}
+
+func (*oneTwoFunc) Call(fr *Frame) {
+	fr.Vars[0].(IntValue).Set(1);
+	fr.Vars[1].(IntValue).Set(2);
+}
+
+type voidFunc struct {};
+
+func (*voidFunc) NewFrame() *Frame {
+	return &Frame{nil, []Value {}};
+}
+
+func (*voidFunc) Call(fr *Frame) {
+}
+
+func newTestScope() *Scope {
+	sc := universe.ChildScope();
+	p := token.Position{"<testScope>", 0, 0, 0};
+
+	def := func(name string, t Type, val interface{}) {
+		v, _ := sc.DefineVar(name, p, t);
+		v.Init = toValue(val);
+	};
+
+	sc.DefineConst("c", p, IdealIntType, toValue(bignum.Int(1)));
+	def("i", IntType, 1);
+	def("i2", IntType, 2);
+	def("u", UintType, uint(1));
+	def("f", FloatType, 1.0);
+	def("s", StringType, "abc");
+	def("t", NewStructType([]StructField {StructField{"a", IntType, false}}), vstruct{1});
+	def("ai", NewArrayType(2, IntType), varray{1, 2});
+	def("aai", NewArrayType(2, NewArrayType(2, IntType)), varray{varray{1,2}, varray{3,4}});
+	def("aai2", NewArrayType(2, NewArrayType(2, IntType)), varray{varray{5,6}, varray{7,8}});
+	def("fn", NewFuncType([]Type{IntType}, false, []Type {IntType}), &testFunc{});
+	def("oneTwo", NewFuncType([]Type{}, false, []Type {IntType, IntType}), &oneTwoFunc{});
+	def("void", NewFuncType([]Type{}, false, []Type {}), &voidFunc{});
+	def("sli", NewSliceType(IntType), vslice{varray{1, 2, 3}, 2, 3});
+
+	return sc;
+}
diff --git a/usr/austin/eval/expr_test.go b/usr/austin/eval/expr_test.go
new file mode 100644
index 00000000000..2b2dd9d4f19
--- /dev/null
+++ b/usr/austin/eval/expr_test.go
@@ -0,0 +1,345 @@
+// Copyright 2009 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 eval
+
+import (
+	"bignum";
+	"testing";
+)
+
+var undefined = "undefined"
+var typeAsExpr = "type .* used as expression"
+var badCharLit = "character literal"
+var illegalEscape = "illegal char escape"
+var opTypes = "illegal (operand|argument) type|cannot index into"
+var badAddrOf = "cannot take the address"
+var constantTruncated = "constant [^ ]* truncated"
+var constantUnderflows = "constant [^ ]* underflows"
+var constantOverflows = "constant [^ ]* overflows"
+var implLimit = "implementation limit"
+var mustBeUnsigned = "must be unsigned"
+var divByZero = "divide by zero"
+
+var hugeInteger = bignum.Int(1).Shl(64);
+
+var exprTests = []test {
+	Val("i", 1),
+	EErr("zzz", undefined),
+	// TODO(austin) Test variable in constant context
+	//EErr("t", typeAsExpr),
+
+	Val("'a'", bignum.Int('a')),
+	Val("'\\uffff'", bignum.Int('\uffff')),
+	Val("'\\n'", bignum.Int('\n')),
+	EErr("''+x", badCharLit),
+	// Produces two parse errors
+	//EErr("'''", ""),
+	EErr("'\n'", badCharLit),
+	EErr("'\\z'", illegalEscape),
+	EErr("'ab'", badCharLit),
+
+	Val("1.0", bignum.Rat(1, 1)),
+	Val("1.", bignum.Rat(1, 1)),
+	Val(".1", bignum.Rat(1, 10)),
+	Val("1e2", bignum.Rat(100, 1)),
+
+	Val("\"abc\"", "abc"),
+	Val("\"\"", ""),
+	Val("\"\\n\\\"\"", "\n\""),
+	EErr("\"\\z\"", illegalEscape),
+	EErr("\"abc", "string not terminated"),
+
+	Val("\"abc\" \"def\"", "abcdef"),
+	EErr("\"abc\" \"\\z\"", illegalEscape),
+
+	Val("(i)", 1),
+
+	Val("ai[0]", 1),
+	Val("(&ai)[0]", 1),
+	Val("ai[1]", 2),
+	Val("ai[i]", 2),
+	Val("ai[u]", 2),
+	EErr("ai[f]", opTypes),
+	EErr("ai[0][0]", opTypes),
+	EErr("ai[2]", "index 2 exceeds"),
+	EErr("ai[1+1]", "index 2 exceeds"),
+	EErr("ai[-1]", "negative index"),
+	ERTErr("ai[i+i]", "index 2 exceeds"),
+	ERTErr("ai[-i]", "negative index"),
+	EErr("i[0]", opTypes),
+	EErr("f[0]", opTypes),
+
+	Val("aai[0][0]", 1),
+	Val("aai[1][1]", 4),
+	EErr("aai[2][0]", "index 2 exceeds"),
+	EErr("aai[0][2]", "index 2 exceeds"),
+
+	Val("sli[0]", 1),
+	Val("sli[1]", 2),
+	EErr("sli[-1]", "negative index"),
+	ERTErr("sli[-i]", "negative index"),
+	ERTErr("sli[2]", "index 2 exceeds"),
+
+	Val("s[0]", uint8('a')),
+	Val("s[1]", uint8('b')),
+	EErr("s[-1]", "negative index"),
+	ERTErr("s[-i]", "negative index"),
+	ERTErr("s[3]", "index 3 exceeds"),
+
+	EErr("1(2)", "cannot call"),
+	EErr("fn(1,2)", "too many"),
+	EErr("fn()", "not enough"),
+	EErr("fn(true)", opTypes),
+	EErr("fn(true)", "function call"),
+	// Single argument functions don't say which argument.
+	//EErr("fn(true)", "argument 1"),
+	Val("fn(1)", 2),
+	Val("fn(1.0)", 2),
+	EErr("fn(1.5)", constantTruncated),
+	Val("fn(i)", 2),
+	EErr("fn(u)", opTypes),
+
+	EErr("void()+2", opTypes),
+	EErr("oneTwo()+2", opTypes),
+
+	Val("cap(ai)", 2),
+	Val("cap(&ai)", 2),
+	Val("cap(aai)", 2),
+	Val("cap(sli)", 3),
+	EErr("cap(0)", opTypes),
+	EErr("cap(i)", opTypes),
+	EErr("cap(s)", opTypes),
+
+	Val("len(s)", 3),
+	Val("len(ai)", 2),
+	Val("len(&ai)", 2),
+	Val("len(aai)", 2),
+	Val("len(sli)", 2),
+	// TODO(austin) Test len of map
+	EErr("len(0)", opTypes),
+	EErr("len(i)", opTypes),
+
+	EErr("*i", opTypes),
+	Val("*&i", 1),
+	Val("*&(i)", 1),
+	EErr("&1", badAddrOf),
+	EErr("&c", badAddrOf),
+	Val("*(&ai[0])", 1),
+
+	Val("+1", bignum.Int(+1)),
+	Val("+1.0", bignum.Rat(1, 1)),
+	EErr("+\"x\"", opTypes),
+
+	Val("-42", bignum.Int(-42)),
+	Val("-i", -1),
+	Val("-f", -1.0),
+	// 6g bug?
+	//Val("-(f-1)", -0.0),
+	EErr("-\"x\"", opTypes),
+
+	// TODO(austin) Test unary !
+
+	Val("^2", bignum.Int(^2)),
+	Val("^(-2)", bignum.Int(^(-2))),
+	EErr("^2.0", opTypes),
+	EErr("^2.5", opTypes),
+	Val("^i", ^1),
+	Val("^u", ^uint(1)),
+	EErr("^f", opTypes),
+
+	Val("1+i", 2),
+	Val("1+u", uint(2)),
+	Val("3.0+i", 4),
+	Val("1+1", bignum.Int(2)),
+	Val("f+f", 2.0),
+	Val("1+f", 2.0),
+	Val("1.0+1", bignum.Rat(2, 1)),
+	Val("\"abc\" + \"def\"", "abcdef"),
+	EErr("i+u", opTypes),
+	EErr("-1+u", constantUnderflows),
+	// TODO(austin) Test named types
+
+	Val("2-1", bignum.Int(1)),
+	Val("2.0-1", bignum.Rat(1, 1)),
+	Val("f-2", -1.0),
+	// TOOD(austin) bignum can't do negative 0?
+	//Val("-0.0", XXX),
+	Val("2*2", bignum.Int(4)),
+	Val("2*i", 2),
+	Val("3/2", bignum.Int(1)),
+	Val("3/i", 3),
+	EErr("1/0", divByZero),
+	EErr("1.0/0", divByZero),
+	ERTErr("i/0", divByZero),
+	Val("3%2", bignum.Int(1)),
+	Val("i%2", 1),
+	EErr("3%0", divByZero),
+	EErr("3.0%0", opTypes),
+	ERTErr("i%0", divByZero),
+
+	// Examples from "Arithmetic operators"
+	Val("5/3", bignum.Int(1)),
+	Val("(i+4)/(i+2)", 1),
+	Val("5%3", bignum.Int(2)),
+	Val("(i+4)%(i+2)", 2),
+	Val("-5/3", bignum.Int(-1)),
+	Val("(i-6)/(i+2)", -1),
+	Val("-5%3", bignum.Int(-2)),
+	Val("(i-6)%(i+2)", -2),
+	Val("5/-3", bignum.Int(-1)),
+	Val("(i+4)/(i-4)", -1),
+	Val("5%-3", bignum.Int(2)),
+	Val("(i+4)%(i-4)", 2),
+	Val("-5/-3", bignum.Int(1)),
+	Val("(i-6)/(i-4)", 1),
+	Val("-5%-3", bignum.Int(-2)),
+	Val("(i-6)%(i-4)", -2),
+
+	// Examples from "Arithmetic operators"
+	Val("11/4", bignum.Int(2)),
+	Val("(i+10)/4", 2),
+	Val("11%4", bignum.Int(3)),
+	Val("(i+10)%4", 3),
+	Val("11>>2", bignum.Int(2)),
+	Val("(i+10)>>2", 2),
+	Val("11&3", bignum.Int(3)),
+	Val("(i+10)&3", 3),
+	Val("-11/4", bignum.Int(-2)),
+	Val("(i-12)/4", -2),
+	Val("-11%4", bignum.Int(-3)),
+	Val("(i-12)%4", -3),
+	Val("-11>>2", bignum.Int(-3)),
+	Val("(i-12)>>2", -3),
+	Val("-11&3", bignum.Int(1)),
+	Val("(i-12)&3", 1),
+
+	// TODO(austin) Test bit ops
+
+	// For shift, we try nearly every combination of positive
+	// ideal int, negative ideal int, big ideal int, ideal
+	// fractional float, ideal non-fractional float, int, uint,
+	// and float.
+	Val("2<<2", bignum.Int(2<<2)),
+	EErr("2<<(-1)", constantUnderflows),
+	EErr("2<<0x10000000000000000", constantOverflows),
+	EErr("2<<2.5", constantTruncated),
+	Val("2<<2.0", bignum.Int(2<<2.0)),
+	EErr("2<<i", mustBeUnsigned),
+	Val("2<<u", 2<<1),
+	EErr("2<<f", opTypes),
+
+	Val("-2<<2", bignum.Int(-2<<2)),
+	EErr("-2<<(-1)", constantUnderflows),
+	EErr("-2<<0x10000000000000000", constantOverflows),
+	EErr("-2<<2.5", constantTruncated),
+	Val("-2<<2.0", bignum.Int(-2<<2.0)),
+	EErr("-2<<i", mustBeUnsigned),
+	Val("-2<<u", -2<<1),
+	EErr("-2<<f", opTypes),
+
+	Val("0x10000000000000000<<2", hugeInteger.Shl(2)),
+	EErr("0x10000000000000000<<(-1)", constantUnderflows),
+	EErr("0x10000000000000000<<0x10000000000000000", constantOverflows),
+	EErr("0x10000000000000000<<2.5", constantTruncated),
+	Val("0x10000000000000000<<2.0", hugeInteger.Shl(2)),
+	EErr("0x10000000000000000<<i", mustBeUnsigned),
+	EErr("0x10000000000000000<<u", constantOverflows),
+	EErr("0x10000000000000000<<f", opTypes),
+
+	EErr("2.5<<2", opTypes),
+	EErr("2.0<<2", opTypes),
+
+	Val("i<<2", 1<<2),
+	EErr("i<<(-1)", constantUnderflows),
+	EErr("i<<0x10000000000000000", constantOverflows),
+	EErr("i<<2.5", constantTruncated),
+	Val("i<<2.0", 1<<2),
+	EErr("i<<i", mustBeUnsigned),
+	Val("i<<u", 1<<1),
+	EErr("i<<f", opTypes),
+	Val("i<<u", 1<<1),
+
+	Val("u<<2", uint(1<<2)),
+	EErr("u<<(-1)", constantUnderflows),
+	EErr("u<<0x10000000000000000", constantOverflows),
+	EErr("u<<2.5", constantTruncated),
+	Val("u<<2.0", uint(1<<2)),
+	EErr("u<<i", mustBeUnsigned),
+	Val("u<<u", uint(1<<1)),
+	EErr("u<<f", opTypes),
+	Val("u<<u", uint(1<<1)),
+
+	EErr("f<<2", opTypes),
+
+	// <, <=, >, >=
+	Val("1<2", 1<2),
+	Val("1<=2", 1<=2),
+	Val("2<=2", 2<=2),
+	Val("1>2", 1>2),
+	Val("1>=2", 1>=2),
+	Val("2>=2", 2>=2),
+
+	Val("i<2", 1<2),
+	Val("i<=2", 1<=2),
+	Val("i+1<=2", 2<=2),
+	Val("i>2", 1>2),
+	Val("i>=2", 1>=2),
+	Val("i+1>=2", 2>=2),
+
+	Val("u<2", 1<2),
+	Val("f<2", 1<2),
+
+	Val("s<\"b\"", true),
+	Val("s<\"a\"", false),
+	Val("s<=\"abc\"", true),
+	Val("s>\"aa\"", true),
+	Val("s>\"ac\"", false),
+	Val("s>=\"abc\"", true),
+
+	EErr("i<u", opTypes),
+	EErr("i<f", opTypes),
+	EErr("i<s", opTypes),
+	EErr("&i<&i", opTypes),
+	EErr("ai<ai", opTypes),
+
+	// ==, !=
+	Val("1==1", true),
+	Val("1!=1", false),
+	Val("1==2", false),
+	Val("1!=2", true),
+
+	Val("1.0==1", true),
+	Val("1.5==1", false),
+
+	Val("i==1", true),
+	Val("i!=1", false),
+	Val("i==2", false),
+	Val("i!=2", true),
+
+	Val("u==1", true),
+	Val("f==1", true),
+
+	Val("s==\"abc\"", true),
+	Val("s!=\"abc\"", false),
+	Val("s==\"abcd\"", false),
+	Val("s!=\"abcd\"", true),
+
+	Val("&i==&i", true),
+	Val("&i==&i2", false),
+
+	Val("fn==fn", true),
+	Val("fn==func(int)int{return 0}", false),
+
+	EErr("i==u", opTypes),
+	EErr("i==f", opTypes),
+	EErr("&i==&f", opTypes),
+	EErr("ai==ai", opTypes),
+	EErr("t==t", opTypes),
+	EErr("fn==oneTwo", opTypes),
+}
+
+func TestExpr(t *testing.T) {
+	runTests(t, "exprTests", exprTests);
+}
diff --git a/usr/austin/eval/stmt_test.go b/usr/austin/eval/stmt_test.go
new file mode 100644
index 00000000000..9de269a2d78
--- /dev/null
+++ b/usr/austin/eval/stmt_test.go
@@ -0,0 +1,337 @@
+// Copyright 2009 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 eval
+
+import "testing"
+
+var atLeastOneDecl = "at least one new variable must be declared";
+
+var stmtTests = []test {
+	// Short declarations
+	Val1("x := i", "x", 1),
+	Val1("x := f", "x", 1.0),
+	// Type defaulting
+	Val1("a := 42", "a", 42),
+	Val1("a := 1.0", "a", 1.0),
+	// Parallel assignment
+	Val2("a, b := 1, 2", "a", 1, "b", 2),
+	Val2("a, i := 1, 2", "a", 1, "i", 2),
+	SErr("a, i := 1, f", opTypes),
+	// TODO(austin) The parser produces an error message for this
+	// one that's inconsistent with the errors I give for other
+	// things
+	//SErr("a, b := 1, 2, 3", "too many"),
+	SErr("a, b := 1, 2, 3", "arity"),
+	SErr("a := 1, 2", "too many"),
+	SErr("a, b := 1", "not enough"),
+	// Mixed declarations
+	SErr("i := 1", atLeastOneDecl),
+	SErr("i, u := 1, 2", atLeastOneDecl),
+	Val2("i, x := 2, f", "i", 2, "x", 1.0),
+	// Various errors
+	SErr("1 := 2", "left side of := must be a name"),
+	SErr("c, a := 1, 1", "cannot assign"),
+	// Unpacking
+	Val2("x, y := oneTwo()", "x", 1, "y", 2),
+	SErr("x := oneTwo()", "too many"),
+	SErr("x, y, z := oneTwo()", "not enough"),
+	SErr("x, y := oneTwo(), 2", "multi-valued"),
+	SErr("x := oneTwo()+2", opTypes),
+	// TOOD(austin) This error message is weird
+	SErr("x := void()", "not enough"),
+	// Placeholders
+	SErr("x := 1+\"x\"; i=x+1", opTypes),
+
+	// Assignment
+	Val1("i = 2", "i", 2),
+	Val1("(i) = 2", "i", 2),
+	SErr("1 = 2", "cannot assign"),
+	SErr("1-1 = 2", "- expression"),
+	Val1("i = 2.0", "i", 2),
+	SErr("i = 2.2", constantTruncated),
+	SErr("u = -2", constantUnderflows),
+	SErr("i = f", opTypes),
+	SErr("i, u = 0, f", opTypes),
+	SErr("i, u = 0, f", "value 2"),
+	Val2("i, i2 = i2, i", "i", 2, "i2", 1),
+	SErr("c = 1", "cannot assign"),
+
+	Val1("x := &i; *x = 2", "i", 2),
+
+	Val1("ai[0] = 42", "ai", varray{ 42, 2 }),
+	Val1("aai[1] = ai; ai[0] = 42", "aai", varray{ varray{1, 2}, varray{1, 2} }),
+	Val1("aai = aai2", "aai", varray{ varray{5, 6}, varray{7, 8} }),
+
+	// Assignment conversions
+	SRuns("var sl []int; sl = &ai"),
+	SErr("type ST []int; type AT *[2]int; var x AT = &ai; var y ST = x", opTypes),
+	SRuns("type ST []int; var y ST = &ai"),
+	SRuns("type AT *[2]int; var x AT = &ai; var y []int = x"),
+
+	// Op-assignment
+	Val1("i += 2", "i", 3),
+	Val1("f += 2", "f", 3.0),
+	SErr("2 += 2", "cannot assign"),
+	SErr("i, j += 2", "cannot be combined"),
+	SErr("i += 2, 3", "cannot be combined"),
+	Val2("s2 := s; s += \"def\"", "s2", "abc", "s", "abcdef"),
+	SErr("s += 1", opTypes),
+	// Single evaluation
+	Val2("ai[func()int{i+=1;return 0}()] *= 3; i2 = ai[0]", "i", 2, "i2", 3),
+
+	// Type declarations
+	// Identifiers
+	SRuns("type T int"),
+	SErr("type T x", "undefined"),
+	SErr("type T c", "constant"),
+	SErr("type T i", "variable"),
+	SErr("type T T", "recursive"),
+	SErr("type T x; type U T; var v U; v = 1", "undefined"),
+	// Pointer types
+	SRuns("type T *int"),
+	SRuns("type T *T"),
+	// Array types
+	SRuns("type T [5]int"),
+	SRuns("type T [c+42/2]int"),
+	SRuns("type T [2.0]int"),
+	SErr("type T [i]int", "constant expression"),
+	SErr("type T [2.5]int", constantTruncated),
+	SErr("type T [-1]int", "negative"),
+	SErr("type T [2]T", "recursive"),
+	// Struct types
+	SRuns("type T struct { a int; b int }"),
+	SRuns("type T struct { a int; int }"),
+	SRuns("type T struct { x *T }"),
+	SRuns("type T int; type U struct { T }"),
+	SErr("type T *int; type U struct { T }", "embedded.*pointer"),
+	SErr("type T *struct { T }", "embedded.*pointer"),
+	SErr("type T struct { a int; a int }", " a .*redeclared.*:1:17"),
+	SErr("type T struct { int; int }", "int .*redeclared.*:1:17"),
+	SErr("type T struct { int int; int }", "int .*redeclared.*:1:17"),
+	SRuns("type T struct { x *struct { T } }"),
+	SErr("type T struct { x struct { T } }", "recursive"),
+	SErr("type T struct { x }; type U struct { T }", "undefined"),
+	// Function types
+	SRuns("type T func()"),
+	SRuns("type T func(a, b int) int"),
+	SRuns("type T func(a, b int) (x int, y int)"),
+	SRuns("type T func(a, a int) (a int, a int)"),
+	SRuns("type T func(a, b int) (x, y int)"),
+	SRuns("type T func(int, int) (int, int)"),
+	SErr("type T func(x); type U T", "undefined"),
+	SErr("type T func(a T)", "recursive"),
+	// Parens
+	SRuns("type T (int)"),
+
+	// Variable declarations
+	Val2("var x int", "i", 1, "x", 0),
+	Val1("var x = 1", "x", 1),
+	Val1("var x = 1.0", "x", 1.0),
+	Val1("var x int = 1.0", "x", 1),
+	// Placeholders
+	SErr("var x foo; x = 1", "undefined"),
+	SErr("var x foo = 1; x = 1", "undefined"),
+	// Redeclaration
+	SErr("var i, x int", " i .*redeclared"),
+	SErr("var x int; var x int", " x .*redeclared.*:1:5"),
+
+	// Expression statements
+	SErr("1-1", "expression statement"),
+	SErr("1-1", "- expression"),
+	Val1("fn(2)", "i", 1),
+
+	// IncDec statements
+	Val1("i++", "i", 2),
+	Val1("i--", "i", 0),
+	Val1("u++", "u", uint(2)),
+	Val1("u--", "u", uint(0)),
+	Val1("f++", "f", 2.0),
+	Val1("f--", "f", 0.0),
+	// Single evaluation
+	Val2("ai[func()int{i+=1;return 0}()]++; i2 = ai[0]", "i", 2, "i2", 2),
+	// Operand types
+	SErr("s++", opTypes),
+	SErr("s++", "'\\+\\+'"),
+	SErr("2++", "cannot assign"),
+	SErr("c++", "cannot assign"),
+
+	// Function scoping
+	Val1("fn1 := func() { i=2 }; fn1()", "i", 2),
+	Val1("fn1 := func() { i:=2 }; fn1()", "i", 1),
+	Val2("fn1 := func() int { i=2; i:=3; i=4; return i }; x := fn1()", "i", 2, "x", 4),
+
+	// Basic returns
+	SErr("fn1 := func() int {}", "return"),
+	SRuns("fn1 := func() {}"),
+	SErr("fn1 := func() (r int) {}", "return"),
+	Val1("fn1 := func() (r int) {return}; i = fn1()", "i", 0),
+	Val1("fn1 := func() (r int) {r = 2; return}; i = fn1()", "i", 2),
+	Val1("fn1 := func() (r int) {return 2}; i = fn1()", "i", 2),
+	Val1("fn1 := func(int) int {return 2}; i = fn1(1)", "i", 2),
+
+	// Multi-valued returns
+	Val2("fn1 := func() (bool, int) {return true, 2}; x, y := fn1()", "x", true, "y", 2),
+	SErr("fn1 := func() int {return}", "not enough values"),
+	SErr("fn1 := func() int {return 1,2}", "too many values"),
+	SErr("fn1 := func() {return 1}", "too many values"),
+	SErr("fn1 := func() (int,int,int) {return 1,2}", "not enough values"),
+	Val2("fn1 := func() (int, int) {return oneTwo()}; x, y := fn1()", "x", 1, "y", 2),
+	SErr("fn1 := func() int {return oneTwo()}", "too many values"),
+	SErr("fn1 := func() (int,int,int) {return oneTwo()}", "not enough values"),
+	Val1("fn1 := func(x,y int) int {return x+y}; x := fn1(oneTwo())", "x", 3),
+
+	// Return control flow
+	Val2("fn1 := func(x *int) bool { *x = 2; return true; *x = 3; }; x := fn1(&i)", "i", 2, "x", true),
+
+	// Break/continue/goto/fallthrough
+	SErr("break", "outside"),
+	SErr("break foo", "break.*foo.*not defined"),
+	SErr("continue", "outside"),
+	SErr("continue foo", "continue.*foo.*not defined"),
+	SErr("fallthrough", "outside"),
+	SErr("goto foo", "foo.*not defined"),
+	SErr(" foo: foo:;", "foo.*redeclared.*:1:2"),
+	Val1("i+=2; goto L; i+=4; L: i+=8", "i", 1+2+8),
+	// Return checking
+	SErr("fn1 := func() int { goto L; return 1; L: }", "return"),
+	SRuns("fn1 := func() int { L: goto L; i = 2 }"),
+	SRuns("fn1 := func() int { return 1; L: goto L }"),
+	// Scope checking
+	SRuns("fn1 := func() { { L: x:=1 } goto L }"),
+	SErr("fn1 := func() { { x:=1; L: } goto L }", "into scope"),
+	SErr("fn1 := func() { goto L; x:=1; L: }", "into scope"),
+	SRuns("fn1 := func() { goto L; { L: x:=1 } }"),
+	SErr("fn1 := func() { goto L; { x:=1; L: } }", "into scope"),
+
+	// Blocks
+	SErr("fn1 := func() int {{}}", "return"),
+	Val1("fn1 := func() bool { { return true } }; b := fn1()", "b", true),
+
+	// If
+	Val2("if true { i = 2 } else { i = 3 }; i2 = 4", "i", 2, "i2", 4),
+	Val2("if false { i = 2 } else { i = 3 }; i2 = 4", "i", 3, "i2", 4),
+	Val2("if i == i2 { i = 2 } else { i = 3 }; i2 = 4", "i", 3, "i2", 4),
+	// Omit optional parts
+	Val2("if { i = 2 } else { i = 3 }; i2 = 4", "i", 2, "i2", 4),
+	Val2("if true { i = 2 }; i2 = 4", "i", 2, "i2", 4),
+	Val2("if false { i = 2 }; i2 = 4", "i", 1, "i2", 4),
+	// Init
+	Val2("if x := true; x { i = 2 } else { i = 3 }; i2 = 4", "i", 2, "i2", 4),
+	Val2("if x := false; x { i = 2 } else { i = 3 }; i2 = 4", "i", 3, "i2", 4),
+	// Statement else
+	Val2("if true { i = 2 } else i = 3; i2 = 4", "i", 2, "i2", 4),
+	Val2("if false { i = 2 } else i = 3; i2 = 4", "i", 3, "i2", 4),
+	// Scoping
+	Val2("if true { i := 2 } else { i := 3 }; i2 = i", "i", 1, "i2", 1),
+	Val2("if false { i := 2 } else { i := 3 }; i2 = i", "i", 1, "i2", 1),
+	Val2("if false { i := 2 } else i := 3; i2 = i", "i", 1, "i2", 1),
+	SErr("if true { x := 2 }; x = 4", undefined),
+	Val2("if i := 2; true { i2 = i; i := 3 }", "i", 1, "i2", 2),
+	Val2("if i := 2; false {} else { i2 = i; i := 3 }", "i", 1, "i2", 2),
+	// Return checking
+	SRuns("fn1 := func() int { if true { return 1 } else { return 2 } }"),
+	SRuns("fn1 := func() int { if true { return 1 } else return 2 }"),
+	SErr("fn1 := func() int { if true { return 1 } else { } }", "return"),
+	SErr("fn1 := func() int { if true { } else { return 1 } }", "return"),
+	SErr("fn1 := func() int { if true { } else return 1 }", "return"),
+	SErr("fn1 := func() int { if true { } else { } }", "return"),
+	SErr("fn1 := func() int { if true { return 1 } }", "return"),
+	SErr("fn1 := func() int { if true { } }", "return"),
+	SRuns("fn1 := func() int { if true { }; return 1 }"),
+	SErr("fn1 := func() int { if { } }", "return"),
+	SErr("fn1 := func() int { if { } else { return 2 } }", "return"),
+	SRuns("fn1 := func() int { if { return 1 } }"),
+	SRuns("fn1 := func() int { if { return 1 } else { } }"),
+	SRuns("fn1 := func() int { if { return 1 } else { } }"),
+
+	// Switch
+	Val1("switch { case false: i += 2; case true: i += 4; default: i += 8 }", "i", 1+4),
+	Val1("switch { default: i += 2; case false: i += 4; case true: i += 8 }", "i", 1+8),
+	SErr("switch { default: i += 2; default: i += 4 }", "more than one"),
+	Val1("switch false { case false: i += 2; case true: i += 4; default: i += 8 }", "i", 1+2),
+	SErr("switch s { case 1: }", opTypes),
+	SErr("switch ai { case ai: i += 2 }", opTypes),
+	Val1("switch 1.0 { case 1: i += 2; case 2: i += 4 }", "i", 1+2),
+	Val1("switch 1.5 { case 1: i += 2; case 2: i += 4 }", "i", 1),
+	SErr("switch oneTwo() {}", "multi-valued expression"),
+	Val1("switch 2 { case 1: i += 2; fallthrough; case 2: i += 4; fallthrough; case 3: i += 8; fallthrough }", "i", 1+4+8),
+	Val1("switch 5 { case 1: i += 2; fallthrough; default: i += 4; fallthrough; case 2: i += 8; fallthrough; case 3: i += 16; fallthrough }", "i", 1+4+8+16),
+	SErr("switch { case true: fallthrough; i += 2 }", "final statement"),
+	Val1("switch { case true: i += 2; fallthrough; ; ; case false: i += 4 }", "i", 1+2+4),
+	Val1("switch 2 { case 0, 1: i += 2; case 2, 3: i += 4 }", "i", 1+4),
+	Val2("switch func()int{i2++;return 5}() { case 1, 2: i += 2; case 4, 5: i += 4 }", "i", 1+4, "i2", 3),
+	SRuns("switch i { case i: }"),
+	// TODO(austin) Why doesn't this fail?
+	SErr("case 1:", "XXX"),
+
+	// For
+	Val2("for x := 1; x < 5; x++ { i+=x }; i2 = 4", "i", 11, "i2", 4),
+	Val2("for x := 1; x < 5; x++ { i+=x; break; i++ }; i2 = 4", "i", 2, "i2", 4),
+	Val2("for x := 1; x < 5; x++ { i+=x; continue; i++ }; i2 = 4", "i", 11, "i2", 4),
+	Val2("for i = 2; false; i = 3 { i = 4 }; i2 = 4", "i", 2, "i2", 4),
+	Val2("for i < 5 { i++ }; i2 = 4", "i", 5, "i2", 4),
+	Val2("for i < 0 { i++ }; i2 = 4", "i", 1, "i2", 4),
+	// Scoping
+	Val2("for i := 2; true; { i2 = i; i := 3; break }", "i", 1, "i2", 2),
+	// Labeled break/continue
+	Val1("L1: for { L2: for { i+=2; break L1; i+=4 } i+=8 }", "i", 1+2),
+	Val1("L1: for { L2: for { i+=2; break L2; i+=4 } i+=8; break; i+=16 }", "i", 1+2+8),
+	SErr("L1: { for { break L1 } }", "break.*not defined"),
+	SErr("L1: for {} for { break L1 }", "break.*not defined"),
+	SErr("L1:; for { break L1 }", "break.*not defined"),
+	Val2("L1: for i = 0; i < 2; i++ { L2: for { i2++; continue L1; i2++ } }", "i", 2, "i2", 4),
+	SErr("L1: { for { continue L1 } }", "continue.*not defined"),
+	SErr("L1:; for { continue L1 }", "continue.*not defined"),
+	// Return checking
+	SRuns("fn1 := func() int{ for {} }"),
+	SErr("fn1 := func() int{ for true {} }", "return"),
+	SErr("fn1 := func() int{ for true {return 1} }", "return"),
+	SErr("fn1 := func() int{ for {break} }", "return"),
+	SRuns("fn1 := func() int{ for { for {break} } }"),
+	SErr("fn1 := func() int{ L1: for { for {break L1} } }", "return"),
+	SRuns("fn1 := func() int{ for true {} return 1 }"),
+
+	// Selectors
+	Val1("var x struct { a int; b int }; x.a = 42; i = x.a", "i", 42),
+	Val1("type T struct { x int }; var y struct { T }; y.x = 42; i = y.x", "i", 42),
+	Val2("type T struct { x int }; var y struct { T; x int }; y.x = 42; i = y.x; i2 = y.T.x", "i", 42, "i2", 0),
+	SRuns("type T struct { x int }; var y struct { *T }; a := func(){i=y.x}"),
+	SErr("type T struct { x int }; var x T; x.y = 42", "no field"),
+	SErr("type T struct { x int }; type U struct { x int }; var y struct { T; U }; y.x = 42", "ambiguous.*\tT\\.x\n\tU\\.x"),
+	SErr("type T struct { *T }; var x T; x.foo", "no field"),
+
+	//Val1("fib := func(int) int{return 0;}; fib = func(v int) int { if v < 2 { return 1 } return fib(v-1)+fib(v-2) }; i = fib(20)", "i", 0),
+
+	// Make slice
+	Val2("x := make([]int, 2); x[0] = 42; i, i2 = x[0], x[1]", "i", 42, "i2", 0),
+	Val2("x := make([]int, 2); x[1] = 42; i, i2 = x[0], x[1]", "i", 0, "i2", 42),
+	SRTErr("x := make([]int, 2); x[-i] = 42", "negative index"),
+	SRTErr("x := make([]int, 2); x[2] = 42", "index 2 exceeds"),
+	Val2("x := make([]int, 2, 3); i, i2 = len(x), cap(x)", "i", 2, "i2", 3),
+	Val2("x := make([]int, 3, 2); i, i2 = len(x), cap(x)", "i", 3, "i2", 3),
+	SRTErr("x := make([]int, -i)", "negative length"),
+	SRTErr("x := make([]int, 2, -i)", "negative capacity"),
+	SRTErr("x := make([]int, 2, 3); x[2] = 42", "index 2 exceeds"),
+	SErr("x := make([]int, 2, 3, 4)", "too many"),
+	SErr("x := make([]int)", "not enough"),
+
+	// TODO(austin) Test make map
+
+	// Maps
+	Val1("x := make(map[int] int); x[1] = 42; i = x[1]", "i", 42),
+	Val2("x := make(map[int] int); x[1] = 42; i, y := x[1]", "i", 42, "y", true),
+	Val2("x := make(map[int] int); x[1] = 42; i, y := x[2]", "i", 0, "y", false),
+	// Not implemented
+	//Val1("x := make(map[int] int); x[1] = 42, true; i = x[1]", "i", 42),
+	//Val2("x := make(map[int] int); x[1] = 42; x[1] = 42, false; i, y := x[1]", "i", 0, "y", false),
+	SRuns("var x int; a := make(map[int] int); a[0], x = 1, 2"),
+	SErr("x := make(map[int] int); (func(a,b int){})(x[0])", "not enough"),
+	SErr("x := make(map[int] int); x[1] = oneTwo()", "too many"),
+	SRTErr("x := make(map[int] int); i = x[1]", "key '1' not found"),
+}
+
+func TestStmt(t *testing.T) {
+	runTests(t, "stmtTests", stmtTests);
+}