From 63384e359a97234d99070c473d55f38c0a9c1801 Mon Sep 17 00:00:00 2001
From: Volker Berlin <volker.berlin@googlemail.com>
Date: Sat, 21 Mar 2020 21:16:10 +0100
Subject: [PATCH] fix do while with multiple conditions
---
.../jwebassembly/module/BranchManger.java | 29 ++++++++++++++++++-
.../runtime/ControlFlowOperators.java | 12 ++++++++
2 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/src/de/inetsoftware/jwebassembly/module/BranchManger.java b/src/de/inetsoftware/jwebassembly/module/BranchManger.java
index 725dc4a..9fe5580 100644
--- a/src/de/inetsoftware/jwebassembly/module/BranchManger.java
+++ b/src/de/inetsoftware/jwebassembly/module/BranchManger.java
@@ -328,9 +328,18 @@ class BranchManger {
int startPos = startBlock.nextPosition;
if( startPos > endPos ) {
// the condition in a do while(condition) loop
- parent.add( new BranchNode( startPos, startPos, WasmBlockOperator.BR_IF, null, 0 ) );
+ int breakDeep = calculateContinueDeep( parent, endPos );
+ for( int idx = 0; idx < instructions.size(); idx++ ) {
+ WasmInstruction instr = instructions.get( idx );
+ int codePos = instr.getCodePosition();
+ if( codePos >= startPos ) {
+ instructions.add( idx, new WasmBlockInstruction( WasmBlockOperator.BR_IF, breakDeep, startPos - 1, startBlock.lineNumber ) );
+ break;
+ }
+ }
return;
}
+
BranchNode branch = null;
for( ; i < parsedOperations.size(); i++ ) {
ParsedBlock parsedBlock = parsedOperations.get( i );
@@ -462,6 +471,24 @@ class BranchManger {
}
}
+ /**
+ * Calculate the break deep for a continue in a do while(condition) loop.
+ *
+ * @param parent
+ * current branch
+ * @param startPos
+ * the start position of the loop
+ * @return the deep count
+ */
+ private int calculateContinueDeep( BranchNode parent, int startPos ) {
+ int deep = 0;
+ while( parent != null && parent.startPos > startPos ) {
+ deep++;
+ parent = parent.parent;
+ }
+ return deep;
+ }
+
/**
* Calculate the deep of a break. A GOTO or IF in Java can jump out multiple loops. We need to calculate how many levels we need to jump.
*
diff --git a/test/de/inetsoftware/jwebassembly/runtime/ControlFlowOperators.java b/test/de/inetsoftware/jwebassembly/runtime/ControlFlowOperators.java
index b2389d4..aa96dd1 100644
--- a/test/de/inetsoftware/jwebassembly/runtime/ControlFlowOperators.java
+++ b/test/de/inetsoftware/jwebassembly/runtime/ControlFlowOperators.java
@@ -50,6 +50,7 @@ public class ControlFlowOperators extends AbstractBaseTest {
addParam( list, script, "switchDirect" );
addParam( list, script, "endlessLoop" );
addParam( list, script, "doWhileLoop" );
+ addParam( list, script, "doWhileLoopTwoConditions" );
addParam( list, script, "doWhileLoopWithBreak" );
addParam( list, script, "whileLoop" );
addParam( list, script, "forLoop" );
@@ -292,6 +293,17 @@ public class ControlFlowOperators extends AbstractBaseTest {
return d;
}
+ @Export
+ static int doWhileLoopTwoConditions() {
+ int val = 42;
+ int shift = 1;
+ do {
+ val >>>= shift;
+ } while (val > 7 && shift > 0);
+
+ return val;
+ }
+
@Export
static double doWhileLoopWithBreak() {
int a = 0;