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|
package main
import (
"fmt"
"strings"
)
const BootstrapMakefile = "*bootstrap*"
type AST interface {
eval(*Evaluator)
show()
}
type ASTBase struct {
filename string
lineno int
}
type AssignAST struct {
ASTBase
lhs string
rhs string
op string
}
func (ast *AssignAST) eval(ev *Evaluator) {
ev.evalAssign(ast)
}
func (ast *AssignAST) evalRHS(ev *Evaluator, lhs string) Var {
origin := "file"
if ast.filename == BootstrapMakefile {
origin = "default"
}
switch ast.op {
case ":=":
return SimpleVar{value: ev.evalExpr(ast.rhs), origin: origin}
case "=":
return RecursiveVar{expr: ast.rhs, origin: origin}
case "+=":
prev := ev.LookupVar(lhs)
if !prev.IsDefined() {
return RecursiveVar{expr: ast.rhs, origin: origin}
}
return prev.Append(ev, ast.rhs)
case "?=":
prev := ev.LookupVar(lhs)
if prev.IsDefined() {
return prev
}
return RecursiveVar{expr: ast.rhs, origin: origin}
default:
panic(fmt.Sprintf("unknown assign op: %q", ast.op))
}
}
func (ast *AssignAST) show() {
Log("%s=%q", ast.lhs, ast.rhs)
}
// Note we cannot be sure what this is, until all variables in |expr|
// are expanded.
type MaybeRuleAST struct {
ASTBase
expr string
cmd string
}
func (ast *MaybeRuleAST) eval(ev *Evaluator) {
ev.evalMaybeRule(ast)
}
func (ast *MaybeRuleAST) show() {
Log("%s", ast.expr)
if ast.cmd != "" {
Log("\t%s", strings.Replace(ast.cmd, "\n", `\n`, -1))
}
}
type CommandAST struct {
ASTBase
cmd string
}
func (ast *CommandAST) eval(ev *Evaluator) {
ev.evalCommand(ast)
}
func (ast *CommandAST) show() {
Log("\t%s", strings.Replace(ast.cmd, "\n", `\n`, -1))
}
type IncludeAST struct {
ASTBase
expr string
op string
}
func (ast *IncludeAST) eval(ev *Evaluator) {
ev.evalInclude(ast)
}
func (ast *IncludeAST) show() {
Log("include %s", ast.expr)
}
type IfAST struct {
ASTBase
op string
lhs string
rhs string // Empty if |op| is ifdef or ifndef.
trueStmts []AST
falseStmts []AST
}
func (ast *IfAST) eval(ev *Evaluator) {
ev.evalIf(ast)
}
func (ast *IfAST) show() {
// TODO
Log("if")
}
|
