1 files changed, 178 insertions, 0 deletions
diff --git a/golang/kati/ast.go b/golang/kati/ast.go
new file mode 100644
index 0000000..2b43176
--- /dev/null
+++ b/golang/kati/ast.go
@@ -0,0 +1,178 @@
+// Copyright 2015 Google Inc. All rights reserved
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package kati
+
+import (
+	"strings"
+
+	"github.com/golang/glog"
+)
+
+type ast interface {
+	eval(*Evaluator) error
+	show()
+}
+
+type assignAST struct {
+	srcpos
+	lhs Value
+	rhs Value
+	op  string
+	opt string // "override", "export"
+}
+
+func (ast *assignAST) eval(ev *Evaluator) error {
+	return ev.evalAssign(ast)
+}
+
+func (ast *assignAST) evalRHS(ev *Evaluator, lhs string) (Var, error) {
+	origin := "file"
+	if ast.filename == bootstrapMakefileName {
+		origin = "default"
+	}
+	if ast.opt == "override" {
+		origin = "override"
+	}
+	// TODO(ukai): handle ast.opt == "export"
+	switch ast.op {
+	case ":=":
+		switch v := ast.rhs.(type) {
+		case literal:
+			return &simpleVar{value: []string{v.String()}, origin: origin}, nil
+		case tmpval:
+			return &simpleVar{value: []string{v.String()}, origin: origin}, nil
+		default:
+			var buf evalBuffer
+			buf.resetSep()
+			err := v.Eval(&buf, ev)
+			if err != nil {
+				return nil, err
+			}
+			return &simpleVar{value: []string{buf.String()}, origin: origin}, nil
+		}
+	case "=":
+		return &recursiveVar{expr: ast.rhs, origin: origin}, nil
+	case "+=":
+		prev := ev.lookupVarInCurrentScope(lhs)
+		if !prev.IsDefined() {
+			return &recursiveVar{expr: ast.rhs, origin: origin}, nil
+		}
+		return prev.AppendVar(ev, ast.rhs)
+	case "?=":
+		prev := ev.lookupVarInCurrentScope(lhs)
+		if prev.IsDefined() {
+			return prev, nil
+		}
+		return &recursiveVar{expr: ast.rhs, origin: origin}, nil
+	}
+	return nil, ast.errorf("unknown assign op: %q", ast.op)
+}
+
+func (ast *assignAST) show() {
+	glog.Infof("%s %s %s %q", ast.opt, ast.lhs, ast.op, ast.rhs)
+}
+
+// maybeRuleAST is an ast for rule line.
+// Note we cannot be sure what this is, until all variables in |expr|
+// are expanded.
+type maybeRuleAST struct {
+	srcpos
+	isRule bool // found literal ':'
+	expr   Value
+	assign *assignAST // target specific var
+	semi   []byte     // after ';' if ';' exists
+}
+
+func (ast *maybeRuleAST) eval(ev *Evaluator) error {
+	return ev.evalMaybeRule(ast)
+}
+
+func (ast *maybeRuleAST) show() {
+	glog.Info(ast.expr)
+}
+
+type commandAST struct {
+	srcpos
+	cmd string
+}
+
+func (ast *commandAST) eval(ev *Evaluator) error {
+	return ev.evalCommand(ast)
+}
+
+func (ast *commandAST) show() {
+	glog.Infof("\t%s", strings.Replace(ast.cmd, "\n", `\n`, -1))
+}
+
+type includeAST struct {
+	srcpos
+	expr string
+	op   string
+}
+
+func (ast *includeAST) eval(ev *Evaluator) error {
+	return ev.evalInclude(ast)
+}
+
+func (ast *includeAST) show() {
+	glog.Infof("include %s", ast.expr)
+}
+
+type ifAST struct {
+	srcpos
+	op         string
+	lhs        Value
+	rhs        Value // Empty if |op| is ifdef or ifndef.
+	trueStmts  []ast
+	falseStmts []ast
+}
+
+func (ast *ifAST) eval(ev *Evaluator) error {
+	return ev.evalIf(ast)
+}
+
+func (ast *ifAST) show() {
+	// TODO
+	glog.Info("if")
+}
+
+type exportAST struct {
+	srcpos
+	expr     []byte
+	hasEqual bool
+	export   bool
+}
+
+func (ast *exportAST) eval(ev *Evaluator) error {
+	return ev.evalExport(ast)
+}
+
+func (ast *exportAST) show() {
+	// TODO
+	glog.Info("export")
+}
+
+type vpathAST struct {
+	srcpos
+	expr Value
+}
+
+func (ast *vpathAST) eval(ev *Evaluator) error {
+	return ev.evalVpath(ast)
+}
+
+func (ast *vpathAST) show() {
+	glog.Infof("vpath %s", ast.expr.String())
+}