Product config makefiles to Starlark converter
Test: treehugger; internal tests in mk2rbc_test.go
Bug: 172923994
Change-Id: I43120b9c181ef2b8d9453e743233811b0fec268b
diff --git a/mk2rbc/node.go b/mk2rbc/node.go
new file mode 100644
index 0000000..d4b4222
--- /dev/null
+++ b/mk2rbc/node.go
@@ -0,0 +1,237 @@
+// Copyright 2021 Google LLC
+//
+// 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 mk2rbc
+
+import (
+ "fmt"
+ "strings"
+
+ mkparser "android/soong/androidmk/parser"
+)
+
+// A parsed node for which starlark code will be generated
+// by calling emit().
+type starlarkNode interface {
+ emit(ctx *generationContext)
+}
+
+// Types used to keep processed makefile data:
+type commentNode struct {
+ text string
+}
+
+func (c *commentNode) emit(gctx *generationContext) {
+ chunks := strings.Split(c.text, "\\\n")
+ gctx.newLine()
+ gctx.write(chunks[0]) // It has '#' at the beginning already.
+ for _, chunk := range chunks[1:] {
+ gctx.newLine()
+ gctx.write("#", chunk)
+ }
+}
+
+type inheritedModule struct {
+ path string // Converted Starlark file path
+ originalPath string // Makefile file path
+ moduleName string
+ moduleLocalName string
+ loadAlways bool
+}
+
+func (im inheritedModule) name() string {
+ return MakePath2ModuleName(im.originalPath)
+}
+
+func (im inheritedModule) entryName() string {
+ return im.moduleLocalName + "_init"
+}
+
+type inheritNode struct {
+ *inheritedModule
+}
+
+func (inn *inheritNode) emit(gctx *generationContext) {
+ // Unconditional case:
+ // rblf.inherit(handle, <module>, module_init)
+ // Conditional case:
+ // if <module>_init != None:
+ // same as above
+ gctx.newLine()
+ if inn.loadAlways {
+ gctx.writef("%s(handle, %q, %s)", cfnInherit, inn.name(), inn.entryName())
+ return
+ }
+ gctx.writef("if %s != None:", inn.entryName())
+ gctx.indentLevel++
+ gctx.newLine()
+ gctx.writef("%s(handle, %q, %s)", cfnInherit, inn.name(), inn.entryName())
+ gctx.indentLevel--
+}
+
+type includeNode struct {
+ *inheritedModule
+}
+
+func (inn *includeNode) emit(gctx *generationContext) {
+ gctx.newLine()
+ if inn.loadAlways {
+ gctx.writef("%s(g, handle)", inn.entryName())
+ return
+ }
+ gctx.writef("if %s != None:", inn.entryName())
+ gctx.indentLevel++
+ gctx.newLine()
+ gctx.writef("%s(g, handle)", inn.entryName())
+ gctx.indentLevel--
+}
+
+type assignmentFlavor int
+
+const (
+ // Assignment flavors
+ asgnSet assignmentFlavor = iota // := or =
+ asgnMaybeSet assignmentFlavor = iota // ?= and variable may be unset
+ asgnAppend assignmentFlavor = iota // += and variable has been set before
+ asgnMaybeAppend assignmentFlavor = iota // += and variable may be unset
+)
+
+type assignmentNode struct {
+ lhs variable
+ value starlarkExpr
+ mkValue *mkparser.MakeString
+ flavor assignmentFlavor
+ isTraced bool
+ previous *assignmentNode
+}
+
+func (asgn *assignmentNode) emit(gctx *generationContext) {
+ gctx.newLine()
+ gctx.inAssignment = true
+ asgn.lhs.emitSet(gctx, asgn)
+ gctx.inAssignment = false
+
+ if asgn.isTraced {
+ gctx.newLine()
+ gctx.tracedCount++
+ gctx.writef(`print("%s.%d: %s := ", `, gctx.starScript.mkFile, gctx.tracedCount, asgn.lhs.name())
+ asgn.lhs.emitGet(gctx, true)
+ gctx.writef(")")
+ }
+}
+
+type exprNode struct {
+ expr starlarkExpr
+}
+
+func (exn *exprNode) emit(gctx *generationContext) {
+ gctx.newLine()
+ exn.expr.emit(gctx)
+}
+
+type ifNode struct {
+ isElif bool // true if this is 'elif' statement
+ expr starlarkExpr
+}
+
+func (in *ifNode) emit(gctx *generationContext) {
+ ifElif := "if "
+ if in.isElif {
+ ifElif = "elif "
+ }
+
+ gctx.newLine()
+ if bad, ok := in.expr.(*badExpr); ok {
+ gctx.write("# MK2STAR ERROR converting:")
+ gctx.newLine()
+ gctx.writef("# %s", bad.node.Dump())
+ gctx.newLine()
+ gctx.writef("# %s", bad.message)
+ gctx.newLine()
+ // The init function emits a warning if the conversion was not
+ // fullly successful, so here we (arbitrarily) take the false path.
+ gctx.writef("%sFalse:", ifElif)
+ return
+ }
+ gctx.write(ifElif)
+ in.expr.emit(gctx)
+ gctx.write(":")
+}
+
+type elseNode struct{}
+
+func (br *elseNode) emit(gctx *generationContext) {
+ gctx.newLine()
+ gctx.write("else:")
+}
+
+// switchCase represents as single if/elseif/else branch. All the necessary
+// info about flavor (if/elseif/else) is supposed to be kept in `gate`.
+type switchCase struct {
+ gate starlarkNode
+ nodes []starlarkNode
+}
+
+func (cb *switchCase) newNode(node starlarkNode) {
+ cb.nodes = append(cb.nodes, node)
+}
+
+func (cb *switchCase) emit(gctx *generationContext) {
+ cb.gate.emit(gctx)
+ gctx.indentLevel++
+ hasStatements := false
+ emitNode := func(node starlarkNode) {
+ if _, ok := node.(*commentNode); !ok {
+ hasStatements = true
+ }
+ node.emit(gctx)
+ }
+ if len(cb.nodes) > 0 {
+ emitNode(cb.nodes[0])
+ for _, node := range cb.nodes[1:] {
+ emitNode(node)
+ }
+ if !hasStatements {
+ gctx.emitPass()
+ }
+ } else {
+ gctx.emitPass()
+ }
+ gctx.indentLevel--
+}
+
+// A single complete if ... elseif ... else ... endif sequences
+type switchNode struct {
+ ssCases []*switchCase
+}
+
+func (ssw *switchNode) newNode(node starlarkNode) {
+ switch br := node.(type) {
+ case *switchCase:
+ ssw.ssCases = append(ssw.ssCases, br)
+ default:
+ panic(fmt.Errorf("expected switchCase node, got %t", br))
+ }
+}
+
+func (ssw *switchNode) emit(gctx *generationContext) {
+ if len(ssw.ssCases) == 0 {
+ gctx.emitPass()
+ } else {
+ ssw.ssCases[0].emit(gctx)
+ for _, ssCase := range ssw.ssCases[1:] {
+ ssCase.emit(gctx)
+ }
+ }
+}