Mark expressions for correct recognition by "unreachable code"

This commit is contained in:
Andrey Breslav
2013-12-03 21:00:08 +04:00
parent 6a4043c9a0
commit 11fcd64949
15 changed files with 155 additions and 34 deletions
@@ -85,6 +85,8 @@ public interface JetControlFlowBuilder {
void repeatPseudocode(@NotNull Label startLabel, @NotNull Label finishLabel);
// Reading values
void mark(@NotNull JetElement element);
void loadUnit(@NotNull JetExpression expression);
void loadConstant(@NotNull JetExpression expression, @Nullable CompileTimeConstant<?> constant);
void createAnonymousObject(@NotNull JetObjectLiteralExpression expression);
@@ -234,4 +234,9 @@ public abstract class JetControlFlowBuilderAdapter implements JetControlFlowBuil
public void repeatPseudocode(@NotNull Label startLabel, @NotNull Label finishLabel) {
getDelegateBuilder().repeatPseudocode(startLabel, finishLabel);
}
@Override
public void mark(@NotNull JetElement element) {
getDelegateBuilder().mark(element);
}
}
@@ -16,6 +16,7 @@
package org.jetbrains.jet.lang.cfg;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.intellij.openapi.util.Ref;
import com.intellij.psi.PsiElement;
@@ -53,17 +54,17 @@ import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
import org.jetbrains.jet.lexer.JetToken;
import org.jetbrains.jet.lexer.JetTokens;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.*;
import static org.jetbrains.jet.lang.cfg.JetControlFlowBuilder.PredefinedOperation.*;
import static org.jetbrains.jet.lang.diagnostics.Errors.*;
import static org.jetbrains.jet.lexer.JetTokens.*;
public class JetControlFlowProcessor {
private final JetControlFlowBuilder builder;
private final BindingTrace trace;
private final Set<PsiElement> marked = new HashSet<PsiElement>();
public JetControlFlowProcessor(BindingTrace trace) {
this.builder = new JetControlFlowInstructionsGenerator();
@@ -140,6 +141,11 @@ public class JetControlFlowProcessor {
this.inCondition = inCondition;
}
private void mark(JetElement element) {
if (!marked.add(element)) return;
builder.mark(element);
}
public void generateInstructions(@Nullable JetElement element) {
generateInstructions(element, inCondition);
}
@@ -173,6 +179,7 @@ public class JetControlFlowProcessor {
@Override
public void visitParenthesizedExpression(@NotNull JetParenthesizedExpression expression) {
mark(expression);
JetExpression innerExpression = expression.getExpression();
if (innerExpression != null) {
generateInstructions(innerExpression, inCondition);
@@ -243,8 +250,11 @@ public class JetControlFlowProcessor {
public void visitBinaryExpression(@NotNull JetBinaryExpression expression) {
JetSimpleNameExpression operationReference = expression.getOperationReference();
IElementType operationType = operationReference.getReferencedNameElementType();
if (!ImmutableSet.of(ANDAND, OROR, EQ, ELVIS).contains(operationType)) {
mark(expression);
}
JetExpression right = expression.getRight();
if (operationType == JetTokens.ANDAND) {
if (operationType == ANDAND) {
generateInstructions(expression.getLeft(), true);
Label resultLabel = builder.createUnboundLabel();
builder.jumpOnFalse(resultLabel);
@@ -256,7 +266,7 @@ public class JetControlFlowProcessor {
builder.predefinedOperation(expression, AND);
}
}
else if (operationType == JetTokens.OROR) {
else if (operationType == OROR) {
generateInstructions(expression.getLeft(), true);
Label resultLabel = builder.createUnboundLabel();
builder.jumpOnTrue(resultLabel);
@@ -268,7 +278,7 @@ public class JetControlFlowProcessor {
builder.predefinedOperation(expression, OR);
}
}
else if (operationType == JetTokens.EQ) {
else if (operationType == EQ) {
visitAssignment(expression.getLeft(), right, expression);
}
else if (OperatorConventions.ASSIGNMENT_OPERATIONS.containsKey(operationType)) {
@@ -286,7 +296,7 @@ public class JetControlFlowProcessor {
generateBothArguments(expression);
}
}
else if (operationType == JetTokens.ELVIS) {
else if (operationType == ELVIS) {
generateInstructions(expression.getLeft(), false);
Label afterElvis = builder.createUnboundLabel();
builder.jumpOnTrue(afterElvis);
@@ -379,6 +389,7 @@ public class JetControlFlowProcessor {
}
private void generateArrayAccess(JetArrayAccessExpression arrayAccessExpression, @Nullable ResolvedCall<?> setResolvedCall) {
mark(arrayAccessExpression);
if (!checkAndGenerateCall(arrayAccessExpression, setResolvedCall)) {
for (JetExpression index : arrayAccessExpression.getIndexExpressions()) {
generateInstructions(index, false);
@@ -390,6 +401,7 @@ public class JetControlFlowProcessor {
@Override
public void visitUnaryExpression(@NotNull JetUnaryExpression expression) {
mark(expression);
JetSimpleNameExpression operationSign = expression.getOperationReference();
IElementType operationType = operationSign.getReferencedNameElementType();
JetExpression baseExpression = expression.getBaseExpression();
@@ -422,6 +434,7 @@ public class JetControlFlowProcessor {
@Override
public void visitIfExpression(@NotNull JetIfExpression expression) {
mark(expression);
JetExpression condition = expression.getCondition();
if (condition != null) {
generateInstructions(condition, true);
@@ -476,6 +489,7 @@ public class JetControlFlowProcessor {
@Override
public void visitTryExpression(@NotNull JetTryExpression expression) {
mark(expression);
JetFinallySection finallyBlock = expression.getFinallyBlock();
final FinallyBlockGenerator finallyBlockGenerator = new FinallyBlockGenerator(finallyBlock);
if (finallyBlock != null) {
@@ -559,6 +573,7 @@ public class JetControlFlowProcessor {
@Override
public void visitWhileExpression(@NotNull JetWhileExpression expression) {
mark(expression);
LoopInfo loopInfo = builder.enterLoop(expression, null, null);
builder.bindLabel(loopInfo.getConditionEntryPoint());
@@ -589,6 +604,7 @@ public class JetControlFlowProcessor {
@Override
public void visitDoWhileExpression(@NotNull JetDoWhileExpression expression) {
mark(expression);
LoopInfo loopInfo = builder.enterLoop(expression, null, null);
builder.bindLabel(loopInfo.getBodyEntryPoint());
@@ -608,6 +624,7 @@ public class JetControlFlowProcessor {
@Override
public void visitForExpression(@NotNull JetForExpression expression) {
mark(expression);
JetExpression loopRange = expression.getLoopRange();
if (loopRange != null) {
generateInstructions(loopRange, false);
@@ -728,6 +745,7 @@ public class JetControlFlowProcessor {
@Override
public void visitBlockExpression(@NotNull JetBlockExpression expression) {
mark(expression);
List<JetElement> statements = expression.getStatements();
for (JetElement statement : statements) {
generateInstructions(statement, false);
@@ -744,6 +762,7 @@ public class JetControlFlowProcessor {
@Override
public void visitFunctionLiteralExpression(@NotNull JetFunctionLiteralExpression expression) {
mark(expression);
JetFunctionLiteral functionLiteral = expression.getFunctionLiteral();
processLocalDeclaration(functionLiteral);
builder.createFunctionLiteral(expression);
@@ -751,6 +770,7 @@ public class JetControlFlowProcessor {
@Override
public void visitQualifiedExpression(@NotNull JetQualifiedExpression expression) {
mark(expression);
JetExpression selectorExpression = expression.getSelectorExpression();
if (selectorExpression != null) {
final Ref<Boolean> error = new Ref<Boolean>(false);
@@ -777,6 +797,7 @@ public class JetControlFlowProcessor {
@Override
public void visitCallExpression(@NotNull JetCallExpression expression) {
mark(expression);
if (!generateCall(expression.getCalleeExpression())) {
for (ValueArgument argument : expression.getValueArguments()) {
JetExpression argumentExpression = argument.getArgumentExpression();
@@ -834,6 +855,7 @@ public class JetControlFlowProcessor {
@Override
public void visitBinaryWithTypeRHSExpression(@NotNull JetBinaryExpressionWithTypeRHS expression) {
mark(expression);
IElementType operationType = expression.getOperationReference().getReferencedNameElementType();
if (operationType == JetTokens.COLON || operationType == JetTokens.AS_KEYWORD || operationType == JetTokens.AS_SAFE) {
generateInstructions(expression.getLeft(), false);
@@ -845,6 +867,7 @@ public class JetControlFlowProcessor {
@Override
public void visitThrowExpression(@NotNull JetThrowExpression expression) {
mark(expression);
JetExpression thrownExpression = expression.getThrownExpression();
if (thrownExpression != null) {
generateInstructions(thrownExpression, false);
@@ -854,6 +877,7 @@ public class JetControlFlowProcessor {
@Override
public void visitArrayAccessExpression(@NotNull JetArrayAccessExpression expression) {
mark(expression);
if (!generateCall(expression)) {
generateArrayAccess(expression, getResolvedCall(expression));
}
@@ -861,11 +885,13 @@ public class JetControlFlowProcessor {
@Override
public void visitIsExpression(@NotNull JetIsExpression expression) {
mark(expression);
generateInstructions(expression.getLeftHandSide(), inCondition);
}
@Override
public void visitWhenExpression(@NotNull JetWhenExpression expression) {
mark(expression);
JetExpression subjectExpression = expression.getSubjectExpression();
if (subjectExpression != null) {
generateInstructions(subjectExpression, inCondition);
@@ -877,6 +903,7 @@ public class JetControlFlowProcessor {
Label nextLabel = null;
for (Iterator<JetWhenEntry> iterator = expression.getEntries().iterator(); iterator.hasNext(); ) {
JetWhenEntry whenEntry = iterator.next();
mark(whenEntry);
boolean isElse = whenEntry.isElse();
if (isElse) {
@@ -917,6 +944,7 @@ public class JetControlFlowProcessor {
@Override
public void visitObjectLiteralExpression(@NotNull JetObjectLiteralExpression expression) {
mark(expression);
JetObjectDeclaration declaration = expression.getObjectDeclaration();
generateInstructions(declaration, inCondition);
@@ -940,6 +968,7 @@ public class JetControlFlowProcessor {
@Override
public void visitStringTemplateExpression(@NotNull JetStringTemplateExpression expression) {
mark(expression);
for (JetStringTemplateEntry entry : expression.getEntries()) {
if (entry instanceof JetStringTemplateEntryWithExpression) {
JetStringTemplateEntryWithExpression entryWithExpression = (JetStringTemplateEntryWithExpression) entry;
@@ -109,6 +109,11 @@ public class JetFlowInformationProvider {
redirectToPrevInstructions(instruction);
}
@Override
public void visitMarkInstruction(MarkInstruction instruction) {
redirectToPrevInstructions(instruction);
}
@Override
public void visitInstruction(Instruction instruction) {
if (instruction instanceof JetElementInstruction) {
@@ -95,4 +95,9 @@ public class InstructionVisitor {
public void visitCompilationErrorInstruction(CompilationErrorInstruction instruction) {
visitInstructionWithNext(instruction);
}
public void visitMarkInstruction(MarkInstruction instruction) {
visitInstructionWithNext(instruction);
}
}
@@ -229,6 +229,11 @@ public class JetControlFlowInstructionsGenerator extends JetControlFlowBuilderAd
return pseudocode;
}
@Override
public void mark(@NotNull JetElement element) {
add(new MarkInstruction(element));
}
@Override
public void returnValue(@NotNull JetExpression returnExpression, @NotNull JetElement subroutine) {
Label exitPoint = getExitPoint(subroutine);
@@ -46,4 +46,20 @@ class CompilationErrorInstruction(
override fun createCopy() = CompilationErrorInstruction(element, message)
override fun toString() = "error(${render(element)}, $message)"
}
// This instruciton is used to let the dead code detector know the syntactic structure of unreachable code
// otherwise only individual parts of expression would be reported as unreachable
// e.g. for (i in foo) {} -- only i and foo would be marked unreachable
class MarkInstruction(
element: JetElement
) : InstructionWithNext(element) {
override fun accept(visitor: InstructionVisitor) {
visitor.visitMarkInstruction(this)
}
override fun createCopy() = MarkInstruction(element)
override fun toString() = "mark(${render(element)})"
}
@@ -2,32 +2,28 @@
fun illegalWhenBlock(a: Any): Any {
when(a) {
is Int -> return a
is String -> return a
}
}
---------------------
L0:
<START>
<START>
v(a: Any)
w(a)
r(a)
jmp?(L4) NEXT:[jmp?(L6), r(a)]
w(a)
mark({ when(a) { is Int -> return a } })
mark(when(a) { is Int -> return a })
r(a)
mark(is Int -> return a)
jmp?(L4) NEXT:[<END>, r(a)]
L3:
r(a)
ret(*) L1 NEXT:[<END>]
- jmp(L2) NEXT:[<END>] PREV:[]
L4:
jmp?(L6) NEXT:[<END>, r(a)] PREV:[jmp?(L4)]
L5:
r(a)
ret(*) L1 NEXT:[<END>]
- jmp(L2) PREV:[]
r(a)
ret(*) L1 NEXT:[<END>]
- jmp(L2) PREV:[]
L1:
L2:
L6:
<END> NEXT:[<SINK>] PREV:[ret(*) L1, jmp?(L6), ret(*) L1]
L4:
<END> NEXT:[<SINK>] PREV:[jmp?(L4), ret(*) L1]
error:
<ERROR> PREV:[]
<ERROR> PREV:[]
sink:
<SINK> PREV:[<ERROR>, <END>]
<SINK> PREV:[<ERROR>, <END>]
=====================
-1
View File
@@ -1,6 +1,5 @@
fun illegalWhenBlock(a: Any): Any {
when(a) {
is Int -> return a
is String -> return a
}
}
@@ -137,9 +137,9 @@ fun tf() : Int {
}
fun failtest(<!UNUSED_PARAMETER!>a<!> : Int) : Int {
if (fail() || <!UNREACHABLE_CODE!>true<!>) {
if (fail() || <!UNREACHABLE_CODE!>true<!>) <!UNREACHABLE_CODE!>{
}
}<!>
<!UNREACHABLE_CODE!>return 1<!>
}
@@ -0,0 +1,55 @@
fun foo(<!UNUSED_PARAMETER!>a<!>: Any) {}
fun bar(<!UNUSED_PARAMETER!>a<!>: Any, <!UNUSED_PARAMETER!>b<!>: Any) {}
fun test(arr: Array<Int>) {
while (true) {
<!UNREACHABLE_CODE!>foo<!>(break)
}
while (true) {
<!UNREACHABLE_CODE!>bar<!>(arr, break)
}
while (true) {
<!UNREACHABLE_CODE!>arr[break]<!>
}
while (true) {
<!UNREACHABLE_CODE!>arr[1]<!> = break
}
while (true) {
break
<!UNREACHABLE_CODE!>foo(1)<!>
}
while (true) {
var <!UNUSED_VARIABLE!>x<!> = 1
break
<!UNREACHABLE_CODE!>x = 2<!>
}
while (true) {
var <!UNUSED_VARIABLE!>x<!> = 1
<!UNREACHABLE_CODE!>x = break<!>
}
// TODO: bug, should be fixed in CFA
while (true) {
if (1 > 2 && break && 2 > 3) {
}
}
// TODO: bug, should be fixed in CFA
while (true) {
if (1 > 2 || break || 2 > 3) {
}
}
while (true) {
<!USELESS_ELVIS!>break<!> ?: <!UNREACHABLE_CODE!>null<!>
}
}
@@ -7,5 +7,4 @@ fun main(args: Array<String>) {
}
}
// callback is unused due to KT-4233
fun test<R>(<!UNUSED_PARAMETER!>callback<!>: (R) -> Unit):Unit = <!UNREACHABLE_CODE!>callback(null!!)<!>
fun test<R>(callback: (R) -> Unit):Unit = <!UNREACHABLE_CODE!>callback<!>(null!!)
@@ -9,9 +9,9 @@ fun test(a: Int) {
bar(a, <!NULL_FOR_NONNULL_TYPE!>null<!>)
}
fun test1(a: Int) {
<!UNREACHABLE_CODE!>foo(a, throw Exception())<!>
<!UNREACHABLE_CODE!>foo<!>(a, throw Exception())
}
fun test2(a: Int) {
<!UNREACHABLE_CODE!>bar(a, throw Exception())<!>
<!UNREACHABLE_CODE!>bar<!>(a, throw Exception())
}
@@ -1562,6 +1562,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
doTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/uninitializedInLocalDeclarations.kt");
}
@TestMetadata("unreachableCode.kt")
public void testUnreachableCode() throws Exception {
doTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/unreachableCode.kt");
}
}
@TestMetadata("compiler/testData/diagnostics/tests/controlStructures")
+2 -2
View File
@@ -136,9 +136,9 @@ fun tf() : Int {
}
fun failtest(<warning>a</warning> : Int) : Int {
if (fail() || <warning>true</warning>) {
if (fail() || <warning>true</warning>) <warning>{
}
}</warning>
<warning>return 1</warning>
}