backend: implement compile-time eval of varargs and listOf;

also perform some refactoring around.
2016-12-05 11:24:11 +07:00
parent e28a9c71a8
commit 415f2f1d35
6 changed files with 207 additions and 36 deletions
@@ -76,6 +76,8 @@ internal class CodeGenerator(override val context: Context) : ContextUtils {
    fun load(value: LLVMValueRef, varName: String): LLVMValueRef = LLVMBuildLoad(builder, value, varName)!!
    fun store(value: LLVMValueRef, ptr: LLVMValueRef): LLVMValueRef = LLVMBuildStore(builder, value, ptr)!!

+    fun isConst(value: LLVMValueRef): Boolean = (LLVMIsConstant(value) == 1)
+
    //-------------------------------------------------------------------------//

    fun invoke(llvmFunction: LLVMValueRef?, args: List<LLVMValueRef?>,
@@ -124,6 +126,11 @@ internal class CodeGenerator(override val context: Context) : ContextUtils {
    fun classType(descriptor: ClassDescriptor): LLVMTypeRef = LLVMGetTypeByName(context.llvmModule, descriptor.symbolName)!!
    fun typeInfoValue(descriptor: ClassDescriptor): LLVMValueRef = descriptor.llvmTypeInfoPtr

+    /**
+     * Pointer to type info for given type, or `null` if the type doesn't have corresponding type info.
+     */
+    fun typeInfoValue(type: KotlinType): LLVMValueRef? = type.typeInfoPtr?.llvm
+
    fun param(fn: FunctionDescriptor, i: Int): LLVMValueRef {
        assert (i >= 0 && i < countParams(fn))
        return LLVMGetParam(fn.llvmFunction, i)!!
@@ -12,6 +12,8 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.descriptorUtil.classId
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperClassNotAny
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeUtils

 /**
 * Provides utility methods to the implementer.
@@ -94,6 +96,12 @@ internal interface ContextUtils {
    val ClassDescriptor.typeInfoPtr: ConstPointer
        get() = constPointer(this.llvmTypeInfoPtr)

+    /**
+     * Pointer to type info for this type, or `null` if the type doesn't have corresponding type info.
+     */
+    val KotlinType.typeInfoPtr: ConstPointer?
+        get() = TypeUtils.getClassDescriptor(this)?.typeInfoPtr
+
    /**
     * Returns contents of this [GlobalHash].
     *
@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.descriptorUtil.classId
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 import org.jetbrains.kotlin.resolve.descriptorUtil.getAllSuperclassesWithoutAny
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
@@ -694,12 +695,30 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
    //-------------------------------------------------------------------------//

    private fun evaluateVararg(tmpVariableName: String, value: IrVararg): LLVMValueRef? {
-        val arrayCreationArgs = listOf(codegen.kTheArrayTypeInfo, kImmInt32One, Int32(value.elements.size).llvm)
+        val arguments = value.elements.map {
+            assert (it !is IrSpreadElement)
+            evaluateExpression(codegen.newVar(), it)!!
+        }
+
+        return genCreateArray(tmpVariableName, value.type, arguments)
+    }
+
+    private fun genCreateArray(tmpVariableName: String,
+                               arrayType: KotlinType, elements: List<LLVMValueRef>): LLVMValueRef {
+
+        if (elements.all { codegen.isConst(it) }) {
+            // Note: even if all elements are const, they aren't guaranteed to be statically initialized.
+            // E.g. an element may be a pointer to lazy-initialized object (aka singleton).
+            // However it is guaranteed that all elements are already initialized at this point.
+            return codegen.staticData.createKotlinArray(arrayType, elements)
+        }
+
+        val typeInfo = codegen.typeInfoValue(arrayType)!!
+
+        val arrayCreationArgs = listOf(typeInfo, kImmInt32One, Int32(elements.size).llvm)
        val array = currentCodeContext.genCall(context.allocArrayFunction, arrayCreationArgs, tmpVariableName)
-        value.elements.forEachIndexed { i, it ->
-            val elementValueRaw = evaluateExpression(codegen.newVar(), it)
-            currentCodeContext.genCall(context.setArrayFunction, listOf(array, Int32(i).llvm, elementValueRaw!!), "")
-            return@forEachIndexed
+        elements.forEachIndexed { i, it ->
+            currentCodeContext.genCall(context.setArrayFunction, listOf(array, Int32(i).llvm, it), "")
        }
        return array
    }
@@ -1367,11 +1386,54 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid

    //-------------------------------------------------------------------------//

+    /**
+     * Tries to evaluate given expression with given (already evaluated) arguments in compile time.
+     * Returns `null` on failure.
+     */
+    private fun compileTimeEvaluate(expression: IrMemberAccessExpression, args: List<LLVMValueRef>): LLVMValueRef? {
+        if (!args.all { codegen.isConst(it) }) {
+            return null
+        }
+
+        val function = expression.descriptor
+
+        if (function.fqNameSafe.asString() == "kotlin.collections.listOf" && function.valueParameters.size == 1) {
+            val varargExpression = expression.getValueArgument(0) as? IrVararg
+
+            if (varargExpression != null) {
+                // The function is kotlin.collections.listOf<T>(vararg args: T).
+                // TODO: refer functions more reliably.
+
+                val vararg = args.single()
+
+                if (varargExpression.elements.any { it is IrSpreadElement }) {
+                    return null // not supported yet, see `length` calculation below.
+                }
+                val length = varargExpression.elements.size
+                // TODO: store length in `vararg` itself when more abstract types will be used for values.
+
+                // `elementType` is type argument of function return type:
+                val elementType = function.returnType!!.arguments.single()
+
+                val array = constPointer(vararg)
+                // Note: dirty hack here: `vararg` has type `Array<out E>`, but `createArrayList` expects `Array<E>`;
+                // however `vararg` is immutable, and in current implementation it has type `Array<E>`,
+                // so let's ignore this mismatch currently for simplicity.
+
+                return context.staticData.createArrayList(elementType, array, length).llvm
+            }
+        }
+
+        return null
+    }
+
    private fun evaluateCall(tmpVariableName: String, value: IrMemberAccessExpression): LLVMValueRef {
        logger.log("evaluateCall               : $tmpVariableName = ${ir2string(value)}")

        val args = evaluateExplicitArgs(value)

+        compileTimeEvaluate(value, args)?.let { return it }
+
        when {
            value is IrDelegatingConstructorCall ->
                return delegatingConstructorCall(tmpVariableName, value.descriptor, args)
@@ -57,6 +57,8 @@ internal open class Struct(val type: LLVMTypeRef?, val elements: List<ConstValue

    constructor(type: LLVMTypeRef?, vararg elements: ConstValue) : this(type, elements.toList())

+    constructor(vararg elements: ConstValue) : this(structType(elements.map { it.llvmType }), *elements)
+
    override val llvm = memScoped {
        val values = elements.map { it.llvm }.toTypedArray()
        val valuesNativeArrayPtr = allocArrayOf(*values)[0].ptr
@@ -128,8 +130,10 @@ internal val ContextUtils.kNullArrayHeaderPtr: LLVMValueRef

 internal fun pointerType(pointeeType: LLVMTypeRef) = LLVMPointerType(pointeeType, 0)!!

-internal fun structType(vararg types: LLVMTypeRef): LLVMTypeRef = memScoped {
-    LLVMStructType(allocArrayOf(*types)[0].ptr, types.size, 0)!!
+internal fun structType(vararg types: LLVMTypeRef): LLVMTypeRef = structType(types.toList())
+
+internal fun structType(types: List<LLVMTypeRef>): LLVMTypeRef = memScoped {
+    LLVMStructType(allocArrayOf(types)[0].ptr, types.size, 0)!!
 }

 internal fun ContextUtils.getLlvmFunctionType(function: FunctionDescriptor): LLVMTypeRef {
@@ -15,11 +15,16 @@ internal class StaticData(override val context: Context): ContextUtils {
        companion object {
            fun create(staticData: StaticData, type: LLVMTypeRef, name: String): Global {
                val module = staticData.context.llvmModule
-                if (LLVMGetNamedGlobal(module, name) != null) {
+                if (name != "" && LLVMGetNamedGlobal(module, name) != null) {
                    throw IllegalArgumentException("Global '$name' already exists")
                }

                val llvmGlobal = LLVMAddGlobal(module, type, name)!!
+
+                if (name == "") {
+                    LLVMSetLinkage(llvmGlobal, LLVMLinkage.LLVMPrivateLinkage)
+                }
+
                return Global(staticData, llvmGlobal)
            }
        }
@@ -2,8 +2,13 @@ package org.jetbrains.kotlin.backend.konan.llvm

 import llvm.*
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.ir.expressions.IrConst
-import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeProjection
+import org.jetbrains.kotlin.types.replace

 private fun StaticData.objHeader(containerOffsetNegative: Int, typeInfo: ConstPointer): Struct {
    assert (containerOffsetNegative >= 0)
@@ -16,41 +21,121 @@ private fun StaticData.arrayHeader(containerOffsetNegative: Int, typeInfo: Const
    return Struct(runtime.arrayHeaderType, objHeader, Int32(length))
 }

+private fun requiredPadding(size: Int, align: Int): Int {
+    val rem = size % align
+    return (align - rem) % align
+}
+
 private fun StaticData.staticContainerHeader(): Struct {
    val CONTAINER_TAG_NOCOUNT = 1 // FIXME: copy-pasted from runtime
-    return Struct(runtime.containerHeaderType, Int32(CONTAINER_TAG_NOCOUNT))
+    val header = Struct(runtime.containerHeaderType, Int32(CONTAINER_TAG_NOCOUNT))
+
+    // ArrayHeader struct is represented as packed in LLVM;
+    // so add explicit padding to container's header to make its objects properly aligned:
+    val llvmSize = LLVMABISizeOfType(llvmTargetData, header.type).toInt()
+    val paddingSize = requiredPadding(llvmSize, 8)
+    val padding = ConstArray(int8Type, ByteArray(paddingSize).map { Int8(it) })
+
+    // TODO: handle such cases more generally by using C types alignments instead of LLVM ones.
+
+    return Struct(header, padding)
 }

 internal fun StaticData.createKotlinStringLiteral(value: IrConst<String>): ConstPointer {
-    val base64Str = value.value.globalHashBase64
-    val valueBytes = value.value.toByteArray(Charsets.UTF_8)
+    val name = "kstr:" + value.value.globalHashBase64
+    val elements = value.value.toByteArray(Charsets.UTF_8).map { Int8(it) }

-    val arrayCount = valueBytes.size
-    val arrayType = LLVMArrayType(int8Type, arrayCount)
+    val objRef = createKotlinArray(value.type, elements)

-    val compositeType = structType(runtime.containerHeaderType, runtime.arrayHeaderType, arrayType)
-
-    // TODO: use C types alignments instead of LLVM ones
-    val global = this.createGlobal(compositeType, "kstrcont:$base64Str")
-    LLVMSetLinkage(global.llvmGlobal, LLVMLinkage.LLVMPrivateLinkage)
-
-    val containerHeader = staticContainerHeader()
-
-    val objHeaderPtr = global.pointer.getElementPtr(1)
-    val containerHeaderPtr = global.pointer.getElementPtr(0)
-    val containerOffsetNegative = objHeaderPtr.sub(containerHeaderPtr)
-
-    val stringClass = value.type.constructor.declarationDescriptor as ClassDescriptor
-    assert (stringClass.fqNameSafe.asString() == "kotlin.String")
-    val arrayHeader = arrayHeader(containerOffsetNegative, stringClass.typeInfoPtr, arrayCount)
-
-    val array = ConstArray(int8Type, valueBytes.map { Int8(it) } )
-
-    global.setInitializer(Struct(compositeType, containerHeader, arrayHeader, array))
-
-    val stringRef = objHeaderPtr.bitcast(getLLVMType(value.type))
-    val res = createAlias("kstr:$base64Str", stringRef)
+    val res = createAlias(name, objRef)
    LLVMSetLinkage(res.llvm, LLVMLinkage.LLVMWeakAnyLinkage)

    return res
 }
+
+private fun StaticData.createRef(type: KotlinType, objHeaderPtr: ConstPointer): ConstPointer {
+    val llvmType = getLLVMType(type)
+    return if (llvmType != objHeaderPtr.llvmType) {
+        objHeaderPtr.bitcast(llvmType)
+    } else {
+        objHeaderPtr
+    }
+}
+
+internal fun StaticData.createKotlinArray(arrayType: KotlinType, elements: List<LLVMValueRef>) =
+        createKotlinArray(arrayType, elements.map { constValue(it) }).llvm
+
+internal fun StaticData.createKotlinArray(arrayType: KotlinType, elements: List<ConstValue>): ConstPointer {
+
+    val typeInfo = arrayType.typeInfoPtr!!
+
+    val bodyElementType: LLVMTypeRef = elements.firstOrNull()?.llvmType ?: int8Type
+    // (use [0 x i8] as body if there are no elements)
+    val arrayBody = ConstArray(bodyElementType, elements)
+
+    val containerHeader = staticContainerHeader()
+
+    val compositeType = structType(containerHeader.llvmType, runtime.arrayHeaderType, arrayBody.llvmType)
+
+    val global = this.createGlobal(compositeType, "")
+
+    val objHeaderPtr = global.pointer.getElementPtr(1)
+    val containerHeaderPtr = global.pointer.getElementPtr(0)
+    val containerOffsetNegative = objHeaderPtr.sub(containerHeaderPtr)
+    val arrayHeader = arrayHeader(containerOffsetNegative, typeInfo, elements.size)
+
+    global.setInitializer(Struct(compositeType, containerHeader, arrayHeader, arrayBody))
+
+    return createRef(arrayType, objHeaderPtr)
+}
+
+internal fun StaticData.createKotlinObject(type: KotlinType, body: ConstValue): ConstPointer {
+    val typeInfo = type.typeInfoPtr!!
+
+    val containerHeader = staticContainerHeader()
+    val compositeType = structType(containerHeader.llvmType, runtime.objHeaderType, body.llvmType)
+
+    val global = this.createGlobal(compositeType, "")
+
+    val objHeaderPtr = global.pointer.getElementPtr(1)
+    val containerHeaderPtr = global.pointer.getElementPtr(0)
+    val containerOffsetNegative = objHeaderPtr.sub(containerHeaderPtr)
+    val objHeader = objHeader(containerOffsetNegative, typeInfo)
+
+    global.setInitializer(Struct(compositeType, containerHeader, objHeader, body))
+
+    return createRef(type, objHeaderPtr)
+}
+
+private fun StaticData.getArrayListClass(): ClassDescriptor {
+    val module = context.irModule.descriptor
+    val pkg = module.getPackage(FqName.fromSegments(listOf("kotlin", "collections")))
+    val classifier = pkg.memberScope.getContributedClassifier(Name.identifier("ArrayList"),
+            NoLookupLocation.FROM_BACKEND)
+
+    return classifier as ClassDescriptor
+}
+
+/**
+ * Creates static instance of `kotlin.collections.ArrayList<elementType>` with given values of fields.
+ *
+ * @param array value for `array: Array<E>` field.
+ * @param length value for `length: Int` field.
+ */
+internal fun StaticData.createArrayList(elementType: TypeProjection, array: ConstPointer, length: Int): ConstPointer {
+    val arrayListClass = getArrayListClass()
+
+    // type is ArrayList<elementType>:
+    val type = arrayListClass.defaultType.replace(listOf(elementType))
+
+    // FIXME: properly import body type from stdlib
+
+    val body = Struct(
+            array, // array: Array<E>
+            Int32(0), // offset: Int
+            Int32(length), // length: Int
+            NullPointer(kObjHeader) // backing: ArrayList<E>?
+    )
+
+    return createKotlinObject(type, body)
+}