Ensure that data-section-based memory reinitialization works correctly.

rkennke · Aug 4, 2020 · ac0f9e1 · ac0f9e1
1 parent 6afa71c
commit ac0f9e1
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Showing 2 changed files with 11 additions and 5 deletions.
diff --git a/wasm/src/org.graalvm.wasm/src/org/graalvm/wasm/BinaryParser.java b/wasm/src/org.graalvm.wasm/src/org/graalvm/wasm/BinaryParser.java
@@ -156,7 +156,7 @@ private void readSymbolSections() {
                     skipCodeSection();
                     break;
                 case Section.DATA:
-                    readDataSection(null);
+                    readDataSection(null, null);
                     break;
                 default:
                     Assert.fail("invalid section ID: " + sectionID);
@@ -1134,7 +1134,7 @@ private void readGlobalSection() {
         }
     }
 
-    private void readDataSection(WasmInstance linkedInstance) {
+    private void readDataSection(WasmContext linkedContext, WasmInstance linkedInstance) {
         int numDataSegments = readVectorLength();
         for (int dataSegmentId = 0; dataSegmentId != numDataSegments; ++dataSegmentId) {
             int memIndex = readUnsignedInt32();
@@ -1166,6 +1166,11 @@ private void readDataSection(WasmInstance linkedInstance) {
             int byteLength = readVectorLength();
 
             if (linkedInstance != null) {
+                if (offsetGlobalIndex != -1) {
+                    int offsetGlobalAddress = linkedInstance.globalAddress(offsetGlobalIndex);
+                    offsetAddress = linkedContext.globals().loadAsInt(offsetGlobalAddress);
+                }
+
                 // Reading of the data segment is called after linking, so initialize the memory
                 // directly.
                 final WasmMemory memory = linkedInstance.memory();
@@ -1493,13 +1498,13 @@ void resetGlobalState(WasmContext context, WasmInstance instance) {
         }
     }
 
-    void resetMemoryState(WasmInstance instance, boolean zeroMemory) {
+    void resetMemoryState(WasmContext context, WasmInstance instance, boolean zeroMemory) {
         final WasmMemory memory = instance.memory();
         if (memory != null && zeroMemory) {
             memory.clear();
         }
         if (tryJumpToSection(Section.DATA)) {
-            readDataSection(instance);
+            readDataSection(context, instance);
         }
     }
 }
diff --git a/wasm/src/org.graalvm.wasm/src/org/graalvm/wasm/Linker.java b/wasm/src/org.graalvm.wasm/src/org/graalvm/wasm/Linker.java
@@ -174,7 +174,7 @@ private static void assignTypeEquivalenceClasses() {
     public void resetModuleState(WasmContext context, WasmInstance instance, byte[] data, boolean zeroMemory) {
         final BinaryParser reader = new BinaryParser(language, instance.module(), data);
         reader.resetGlobalState(context, instance);
-        reader.resetMemoryState(instance, zeroMemory);
+        reader.resetMemoryState(context, instance, zeroMemory);
     }
 
     void resolveGlobalImport(WasmContext context, WasmInstance instance, ImportDescriptor importDescriptor, int globalIndex, byte valueType, byte mutability) {
@@ -208,6 +208,7 @@ void resolveGlobalImport(WasmContext context, WasmInstance instance, ImportDescr
             }
 
             int address = importedInstance.globalAddress(exportedGlobalIndex);
+            System.out.println("Yo! " + globalIndex + " -> " + address);
             instance.setGlobalAddress(globalIndex, address);
         };
         final ImportGlobalSym importGlobalSym = new ImportGlobalSym(instance.name(), importDescriptor);