Removed finally blocks handling from code generator

2017-05-03 13:41:42 +05:00
parent 3c84e39360
commit 667b5fb936
1 changed files with 11 additions and 135 deletions
@@ -906,148 +906,24 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
        }
    }

-    /**
-     * The [InnerScope] that includes code generated by [genFinalizeImpl] when leaving it
-     * with `return`, `break`, `continue` or throwing exception.
-     */
-    private abstract inner class FinalizingScope() : CatchingScope() {
-
-        /**
-         * Cache for [genReturn].
-         *
-         * `returnBlocks[func]` contains the [ContinuationBlock] to be used for `return` from `func`;
-         * the block expects return value as its value.
-         */
-        private val returnBlocks = mutableMapOf<CallableDescriptor, ContinuationBlock>()
-
-        // Jump to finalize-and-return instead of simply returning.
-        override fun genReturn(target: CallableDescriptor, value: LLVMValueRef?) {
-            val block = returnBlocks.getOrPut(target) {
-                continuationBlock(target.returnType!!) {
-                    genFinalize()
-                    val returnValue = it.valuePhi // `null` if return type is `Unit`.
-                    outerContext.genReturn(target, returnValue)
-                }
-            }
-
-            jump(block, value)
-        }
-
-        /**
-         * Cache for [genBreak].
-         */
-        private val breakBlocks = mutableMapOf<IrLoop, LLVMBasicBlockRef>()
-
-        // Jump to finalize-and-break instead of simply breaking.
-        override fun genBreak(destination: IrBreak) {
-            val block = breakBlocks.getOrPut(destination.loop) {
-                codegen.basicBlock("finalizeAndBreak") {
-                    genFinalize()
-                    outerContext.genBreak(destination)
-                }
-            }
-
-            codegen.br(block)
-        }
-
-        /**
-         * Cache for [genContinue].
-         *
-         * Note: can't merge with [breakBlocks] because the code for `break` and `continue` is different.
-         */
-        private val continueBlocks = mutableMapOf<IrLoop, LLVMBasicBlockRef>()
-
-        // Jump to finalize-and-continue instead of simply continuing.
-        override fun genContinue(destination: IrContinue) {
-            val block = continueBlocks.getOrPut(destination.loop) {
-                codegen.basicBlock("finalizeAndContinue") {
-                    genFinalize()
-                    outerContext.genContinue(destination)
-                }
-            }
-
-            codegen.br(block)
-        }
-
-        // When an exception is caught, finalize the scope and rethrow the exception.
-        override fun genHandler(exception: LLVMValueRef) {
-            genFinalizeImpl()
-            outerContext.genThrow(exception)
-        }
-
-        private fun genFinalize() {
-            using(outerContext) {
-                this.genFinalizeImpl()
-            }
-        }
-
-        protected abstract fun genFinalizeImpl()
-    }
-
-    /**
-     * Generates the code which gets "finalized" exactly once when completed either normally or abnormally.
-     *
-     * @param code generates the code to be post-dominated by cleanup.
-     * It must jump to given [ContinuationBlock] with its result when completed normally.
-     *
-     * @param finalize generates the cleanup code that must be executed when code generated by [code] is completed.
-     *
-     * @param type Kotlin type of the result of generated code.
-     *
-     * @return the result of the generated code.
-     */
-    private fun genFinalizedBy(finalize: (() -> Unit)?,
-                                   type: KotlinType, code: (ContinuationBlock) -> Unit): LLVMValueRef {
-
-        val scope = if (finalize == null) null else {
-            object : FinalizingScope() {
-                override fun genFinalizeImpl() {
-                    finalize()
-                }
-            }
-        }
-
-        val continuation = continuationBlock(type)
-
-        using(scope) {
-            code(continuation)
-        }
-        codegen.positionAtEnd(continuation.block)
-        finalize?.invoke()
-
-        // TODO: finalize is duplicated many times (just as in C++, Java or Kotlin JVM);
-        // it is very important to optimize this.
-
-        return continuation.value
-    }
-
-    /**
-     * Generates code that is "finalized" by given expression.
-     */
-    private fun genFinalizedBy(finalize: IrExpression?, type: KotlinType,
-                                   code: (ContinuationBlock) -> Unit): LLVMValueRef {
-
-        val finalizeFun: (() -> Unit)? = if (finalize == null) {
-            null
-        } else {
-            { evaluateExpression(finalize) }
-        }
-
-        return genFinalizedBy(finalizeFun, type, code)
-    }
-
    private fun evaluateTry(expression: IrTry): LLVMValueRef {
        // TODO: does basic block order influence machine code order?
        // If so, consider reordering blocks to reduce exception tables size.

-        return genFinalizedBy(expression.finallyExpression, expression.type) { continuation ->
+        assert (expression.finallyExpression == null, { "All finally blocks should've been lowered" })

-            val catchScope = if (expression.catches.isEmpty()) null else CatchScope(expression.catches, continuation)
+        val continuation = continuationBlock(expression.type)

-            using(catchScope) {
-                evaluateExpressionAndJump(expression.tryResult, continuation)
-            }
+        val catchScope = if (expression.catches.isEmpty())
+                             null
+                         else
+                             CatchScope(expression.catches, continuation)
+        using(catchScope) {
+            evaluateExpressionAndJump(expression.tryResult, continuation)
        }
+        codegen.positionAtEnd(continuation.block)
+
+        return continuation.value
    }

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