Merge pull request #388 from dezgeg/fix-jump-across-function-boundary

KT-4334: Disallow break or continue across a function boundary

compiler/frontend/src/org/jetbrains/jet/lang/cfg/JetControlFlowProcessor.java

@@ -636,6 +636,7 @@ public class JetControlFlowProcessor {
         public void visitBreakExpressionVoid(@NotNull JetBreakExpression expression, CFPContext context) {
             JetElement loop = getCorrespondingLoop(expression);
             if (loop != null) {
+                checkJumpDoesNotCrossFunctionBoundary(expression, loop);
                 builder.jump(builder.getExitPoint(loop));
             }
         }
@@ -644,6 +645,7 @@ public class JetControlFlowProcessor {
         public void visitContinueExpressionVoid(@NotNull JetContinueExpression expression, CFPContext context) {
             JetElement loop = getCorrespondingLoop(expression);
             if (loop != null) {
+                checkJumpDoesNotCrossFunctionBoundary(expression, loop);
                 builder.jump(builder.getEntryPoint(loop));
             }
         }
@@ -672,6 +674,16 @@ public class JetControlFlowProcessor {
             return loop;
         }
 
+        private void checkJumpDoesNotCrossFunctionBoundary(@NotNull JetLabelQualifiedExpression jumpExpression, @NotNull JetElement jumpTarget) {
+            BindingContext bindingContext = trace.getBindingContext();
+
+            FunctionDescriptor labelExprEnclosingFunc = BindingContextUtils.getEnclosingFunctionDescriptor(bindingContext, jumpExpression);
+            FunctionDescriptor labelTargetEnclosingFunc = BindingContextUtils.getEnclosingFunctionDescriptor(bindingContext, jumpTarget);
+            if (labelExprEnclosingFunc != labelTargetEnclosingFunc) {
+                trace.report(BREAK_OR_CONTINUE_JUMPS_ACROSS_FUNCTION_BOUNDARY.on(jumpExpression));
+            }
+        }
+
         @Override
         public void visitReturnExpressionVoid(@NotNull JetReturnExpression expression, CFPContext context) {
             JetExpression returnedExpression = expression.getReturnedExpression();

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java

@@ -431,6 +431,7 @@ public interface Errors {
     DiagnosticFactory0<JetSimpleNameExpression> AMBIGUOUS_LABEL = DiagnosticFactory0.create(ERROR);
 
     DiagnosticFactory0<JetLabelQualifiedExpression> BREAK_OR_CONTINUE_OUTSIDE_A_LOOP = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<JetLabelQualifiedExpression> BREAK_OR_CONTINUE_JUMPS_ACROSS_FUNCTION_BOUNDARY = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory1<JetLabelQualifiedExpression, String> NOT_A_LOOP_LABEL = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory1<JetReturnExpression, String> NOT_A_RETURN_LABEL = DiagnosticFactory1.create(ERROR);
 

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/DefaultErrorMessages.java

@@ -327,6 +327,7 @@ public class DefaultErrorMessages {
         MAP.put(NO_TAIL_CALLS_FOUND, "A function is marked as tail-recursive but no tail calls are found");
         MAP.put(VALUE_PARAMETER_WITH_NO_TYPE_ANNOTATION, "A type annotation is required on a value parameter");
         MAP.put(BREAK_OR_CONTINUE_OUTSIDE_A_LOOP, "'break' and 'continue' are only allowed inside a loop");
+        MAP.put(BREAK_OR_CONTINUE_JUMPS_ACROSS_FUNCTION_BOUNDARY, "'break' or 'continue' jumps across a function boundary");
         MAP.put(NOT_A_LOOP_LABEL, "The label ''{0}'' does not denote a loop", TO_STRING);
         MAP.put(NOT_A_RETURN_LABEL, "The label ''{0}'' does not reference to a context from which we can return", TO_STRING);
 

compiler/frontend/src/org/jetbrains/jet/lang/resolve/BindingContextUtils.java

@@ -236,6 +236,11 @@ public class BindingContextUtils {
         return descriptor;
     }
 
+    public static FunctionDescriptor getEnclosingFunctionDescriptor(@NotNull BindingContext context, @NotNull JetElement element) {
+        JetFunction function = PsiTreeUtil.getParentOfType(element, JetFunction.class);
+        return (FunctionDescriptor)context.get(DECLARATION_TO_DESCRIPTOR, function);
+    }
+
     public static void reportAmbiguousLabel(
             @NotNull BindingTrace trace,
             @NotNull JetSimpleNameExpression targetLabel,

compiler/testData/diagnostics/tests/controlStructures/jumpAcrossFunctionBoundary.kt

@@ -0,0 +1,17 @@
+fun call(f: () -> Unit) = f()
+
+fun f1() {
+    @outer while (true) {
+        call {
+            <!BREAK_OR_CONTINUE_JUMPS_ACROSS_FUNCTION_BOUNDARY!>break@outer<!>
+        }
+    }
+}
+
+fun f2() {
+    do {
+        fun inner() {
+            <!BREAK_OR_CONTINUE_JUMPS_ACROSS_FUNCTION_BOUNDARY!>continue<!>
+        }
+    } while (true)
+}

compiler/testData/diagnostics/tests/incompleteCode/pseudocodeTraverseNextInstructions.kt

@@ -3,6 +3,6 @@ package b
 fun foo() {
     for (i in <!UNRESOLVED_REFERENCE!>collection<!>) {
         <!UNUSED_FUNCTION_LITERAL!>{
-         break
+         <!BREAK_OR_CONTINUE_JUMPS_ACROSS_FUNCTION_BOUNDARY!>break<!>
     }<!>
 }<!SYNTAX!><!>

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -1745,6 +1745,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest("compiler/testData/diagnostics/tests/controlStructures/ForbidStatementAsDirectFunctionBody.kt");
             }
             
+            @TestMetadata("jumpAcrossFunctionBoundary.kt")
+            public void testJumpAcrossFunctionBoundary() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/controlStructures/jumpAcrossFunctionBoundary.kt");
+            }
+            
             @TestMetadata("kt1075.kt")
             public void testKt1075() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/controlStructures/kt1075.kt");