* Extract CodeGeneratorImpl, PlatformInfoImpl into common-util module, add copyright to common-util module classes.

* Add KSP Command line processor and logger.
* Implement KSP main execution and initialization logic.

7 files changed, 311 insertions, 0 deletions

diff --git a/common-util/src/main/kotlin/com/google/devtools/ksp/DescriptorUtils.kt b/common-util/src/main/kotlin/com/google/devtools/ksp/DescriptorUtils.kt
index d360d263..9e4ba3c6 100644
--- a/common-util/src/main/kotlin/com/google/devtools/ksp/DescriptorUtils.kt
+++ b/common-util/src/main/kotlin/com/google/devtools/ksp/DescriptorUtils.kt
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2022 Google LLC
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * 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 com.google.devtools.ksp
 
 import com.google.devtools.ksp.symbol.KSAnnotated
diff --git a/common-util/src/main/kotlin/com/google/devtools/ksp/IncrementalUtil.kt b/common-util/src/main/kotlin/com/google/devtools/ksp/IncrementalUtil.kt
new file mode 100644
index 00000000..f0c94dc7
--- /dev/null
+++ b/common-util/src/main/kotlin/com/google/devtools/ksp/IncrementalUtil.kt
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2022 Google LLC
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * 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 com.google.devtools.ksp
+
+import com.google.devtools.ksp.symbol.*
+import java.io.File
+
+abstract class KSVirtualFile(val baseDir: File, val name: String) : KSFile {
+    override val annotations: Sequence<KSAnnotation>
+        get() = throw Exception("$name should not be used.")
+
+    override val declarations: Sequence<KSDeclaration>
+        get() = throw Exception("$name should not be used.")
+
+    override val fileName: String
+        get() = "<$name is a virtual file; DO NOT USE.>"
+
+    override val filePath: String
+        get() = File(baseDir, fileName).path
+
+    override val packageName: KSName
+        get() = throw Exception("$name should not be used.")
+
+    override val origin: Origin
+        get() = throw Exception("$name should not be used.")
+
+    override val location: Location
+        get() = throw Exception("$name should not be used.")
+
+    override val parent: KSNode?
+        get() = throw Exception("$name should not be used.")
+
+    override fun <D, R> accept(visitor: KSVisitor<D, R>, data: D): R {
+        throw Exception("$name should not be used.")
+    }
+}
+
+/**
+ * Used when an output potentially depends on new information.
+ */
+class AnyChanges(baseDir: File) : KSVirtualFile(baseDir, "AnyChanges")
+
+/**
+ * Used for classes from classpath, i.e., classes without source files.
+ */
+class NoSourceFile(baseDir: File, val fqn: String) : KSVirtualFile(baseDir, "NoSourceFile") {
+    override val fileName: String
+        get() = "<NoSourceFile for $fqn is a virtual file; DO NOT USE.>"
+}
diff --git a/common-util/src/main/kotlin/com/google/devtools/ksp/KspOptions.kt b/common-util/src/main/kotlin/com/google/devtools/ksp/KspOptions.kt
index 907e650f..83759d30 100644
--- a/common-util/src/main/kotlin/com/google/devtools/ksp/KspOptions.kt
+++ b/common-util/src/main/kotlin/com/google/devtools/ksp/KspOptions.kt
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2022 Google LLC
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * 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 com.google.devtools.ksp
 
 import org.jetbrains.kotlin.compiler.plugin.AbstractCliOption
diff --git a/common-util/src/main/kotlin/com/google/devtools/ksp/MemoizedSequence.kt b/common-util/src/main/kotlin/com/google/devtools/ksp/MemoizedSequence.kt
index 9fa09323..be7a05d6 100644
--- a/common-util/src/main/kotlin/com/google/devtools/ksp/MemoizedSequence.kt
+++ b/common-util/src/main/kotlin/com/google/devtools/ksp/MemoizedSequence.kt
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2022 Google LLC
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * 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 com.google.devtools.ksp
 
 // TODO: garbage collect underlying sequence after exhaust.
diff --git a/common-util/src/main/kotlin/com/google/devtools/ksp/PsiUtils.kt b/common-util/src/main/kotlin/com/google/devtools/ksp/PsiUtils.kt
index fa31dca2..9003a7fe 100644
--- a/common-util/src/main/kotlin/com/google/devtools/ksp/PsiUtils.kt
+++ b/common-util/src/main/kotlin/com/google/devtools/ksp/PsiUtils.kt
@@ -1,3 +1,20 @@
+/*
+ * Copyright 2022 Google LLC
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * 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 com.google.devtools.ksp
 
 import com.google.devtools.ksp.symbol.*
diff --git a/common-util/src/main/kotlin/com/google/devtools/ksp/processing/impl/CodeGeneratorImpl.kt b/common-util/src/main/kotlin/com/google/devtools/ksp/processing/impl/CodeGeneratorImpl.kt
new file mode 100644
index 00000000..6bf1941d
--- /dev/null
+++ b/common-util/src/main/kotlin/com/google/devtools/ksp/processing/impl/CodeGeneratorImpl.kt
@@ -0,0 +1,130 @@
+/*
+ * Copyright 2020 Google LLC
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * 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 com.google.devtools.ksp.processing.impl
+
+import com.google.devtools.ksp.NoSourceFile
+import com.google.devtools.ksp.processing.CodeGenerator
+import com.google.devtools.ksp.processing.Dependencies
+import com.google.devtools.ksp.symbol.KSClassDeclaration
+import com.google.devtools.ksp.symbol.KSFile
+import java.io.File
+import java.io.FileOutputStream
+import java.io.OutputStream
+
+class CodeGeneratorImpl(
+    private val classDir: File,
+    private val javaDir: File,
+    private val kotlinDir: File,
+    private val resourcesDir: File,
+    private val projectBase: File,
+    private val anyChangesWildcard: KSFile,
+    private val allSources: List<KSFile>,
+    private val isIncremental: Boolean
+) : CodeGenerator {
+    private val fileMap = mutableMapOf<String, File>()
+    private val fileOutputStreamMap = mutableMapOf<String, FileOutputStream>()
+
+    private val separator = File.separator
+
+    val sourceToOutputs: MutableMap<File, MutableSet<File>> = mutableMapOf()
+
+    // This function will also clear `fileOutputStreamMap` which will change the result of `generatedFile`
+    fun closeFiles() {
+        fileOutputStreamMap.keys.forEach {
+            fileOutputStreamMap[it]!!.close()
+        }
+        fileOutputStreamMap.clear()
+    }
+
+    fun pathOf(packageName: String, fileName: String, extensionName: String): String {
+        val packageDirs = if (packageName != "") "${packageName.split(".").joinToString(separator)}$separator" else ""
+        val extension = if (extensionName != "") ".$extensionName" else ""
+        val typeRoot = when (extensionName) {
+            "class" -> classDir
+            "java" -> javaDir
+            "kt" -> kotlinDir
+            else -> resourcesDir
+        }.path
+        return "$typeRoot$separator$packageDirs$fileName$extension"
+    }
+
+    override fun createNewFile(
+        dependencies: Dependencies,
+        packageName: String,
+        fileName: String,
+        extensionName: String
+    ): OutputStream {
+        val path = pathOf(packageName, fileName, extensionName)
+        val file = File(path)
+        if (path in fileMap) {
+            throw FileAlreadyExistsException(file)
+        }
+        val parentFile = file.parentFile
+        if (!parentFile.exists() && !parentFile.mkdirs()) {
+            throw IllegalStateException("failed to make parent directories.")
+        }
+        file.writeText("")
+        fileMap[path] = file
+        val sources = if (dependencies.isAllSources) {
+            allSources + anyChangesWildcard
+        } else {
+            if (dependencies.aggregating) {
+                dependencies.originatingFiles + anyChangesWildcard
+            } else {
+                dependencies.originatingFiles
+            }
+        }
+        associate(sources, path)
+        fileOutputStreamMap[path] = fileMap[path]!!.outputStream()
+        return fileOutputStreamMap[path]!!
+    }
+
+    override fun associate(sources: List<KSFile>, packageName: String, fileName: String, extensionName: String) {
+        val path = pathOf(packageName, fileName, extensionName)
+        associate(sources, path)
+    }
+
+    override fun associateWithClasses(
+        classes: List<KSClassDeclaration>,
+        packageName: String,
+        fileName: String,
+        extensionName: String
+    ) {
+        val path = pathOf(packageName, fileName, extensionName)
+        val files = classes.map {
+            it.containingFile ?: NoSourceFile(projectBase, it.qualifiedName?.asString().toString())
+        }
+        associate(files, path)
+    }
+
+    private fun associate(sources: List<KSFile>, outputPath: String) {
+        if (!isIncremental)
+            return
+
+        val output = File(outputPath).relativeTo(projectBase)
+        sources.forEach { source ->
+            sourceToOutputs.getOrPut(File(source.filePath).relativeTo(projectBase)) { mutableSetOf() }.add(output)
+        }
+    }
+
+    val outputs: Set<File>
+        get() = fileMap.keys.mapTo(mutableSetOf()) { File(it).relativeTo(projectBase) }
+
+    override val generatedFile: Collection<File>
+        get() = fileOutputStreamMap.keys.map { fileMap[it]!! }
+}
diff --git a/common-util/src/main/kotlin/com/google/devtools/ksp/processing/impl/PlatformInfoImpl.kt b/common-util/src/main/kotlin/com/google/devtools/ksp/processing/impl/PlatformInfoImpl.kt
new file mode 100644
index 00000000..cccae381
--- /dev/null
+++ b/common-util/src/main/kotlin/com/google/devtools/ksp/processing/impl/PlatformInfoImpl.kt
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2022 Google LLC
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * 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 com.google.devtools.ksp.processing.impl
+
+import com.google.devtools.ksp.processing.JsPlatformInfo
+import com.google.devtools.ksp.processing.JvmPlatformInfo
+import com.google.devtools.ksp.processing.NativePlatformInfo
+import com.google.devtools.ksp.processing.UnknownPlatformInfo
+
+class JvmPlatformInfoImpl(
+    override val platformName: String,
+    override val jvmTarget: String
+) : JvmPlatformInfo {
+    override fun toString() = "$platformName ($jvmTarget)"
+}
+
+class JsPlatformInfoImpl(
+    override val platformName: String
+) : JsPlatformInfo {
+    override fun toString() = platformName
+}
+
+class NativePlatformInfoImpl(
+    override val platformName: String,
+    override val targetName: String
+) : NativePlatformInfo {
+    override fun toString() = "$platformName ($targetName)"
+}
+
+class UnknownPlatformInfoImpl(
+    override val platformName: String
+) : UnknownPlatformInfo {
+    override fun toString() = platformName
+}