WASM: fix bugs

core/src/main/java/org/teavm/backend/wasm/WasmTarget.java

@@ -670,9 +670,10 @@ public class WasmTarget implements TeaVMTarget {
         gcIntrinsic.setRegionsAddress(address);
         gcIntrinsic.setRegionMaxCount(regionCount);
 
-        gcMemory -= regionCount * 2;
         address += regionCount * 2;
         address = (address + 4) >> 2 << 2;
+
+        gcMemory = module.getMemorySize() * 65536 - address;
         gcIntrinsic.setHeapAddress(address);
         gcIntrinsic.setAvailableBytes(gcMemory);
     }

core/src/main/java/org/teavm/backend/wasm/generate/WasmGenerator.java

@@ -22,11 +22,6 @@ import org.teavm.backend.wasm.binary.BinaryWriter;
 import org.teavm.backend.wasm.model.WasmFunction;
 import org.teavm.backend.wasm.model.WasmLocal;
 import org.teavm.backend.wasm.model.WasmType;
-import org.teavm.backend.wasm.model.expression.WasmExpression;
-import org.teavm.backend.wasm.model.expression.WasmFloat32Constant;
-import org.teavm.backend.wasm.model.expression.WasmFloat64Constant;
-import org.teavm.backend.wasm.model.expression.WasmInt32Constant;
-import org.teavm.backend.wasm.model.expression.WasmInt64Constant;
 import org.teavm.interop.Export;
 import org.teavm.model.AnnotationReader;
 import org.teavm.model.ClassHolder;
@@ -90,27 +85,6 @@ public class WasmGenerator {
         methodAst.getBody().acceptVisitor(visitor);
         function.getBody().add(visitor.result);
 
-        if (function.getResult() != null) {
-            WasmExpression finalExpr;
-            switch (function.getResult()) {
-                case INT32:
-                    finalExpr = new WasmInt32Constant(0);
-                    break;
-                case INT64:
-                    finalExpr = new WasmInt64Constant(0);
-                    break;
-                case FLOAT32:
-                    finalExpr = new WasmFloat32Constant(0);
-                    break;
-                case FLOAT64:
-                    finalExpr = new WasmFloat64Constant(0);
-                    break;
-                default:
-                    throw new AssertionError();
-            }
-            function.getBody().add(finalExpr);
-        }
-
         AnnotationReader exportAnnot = method.getAnnotations().get(Export.class.getName());
         if (exportAnnot != null) {
             function.setExportName(exportAnnot.getValue("name").getString());

core/src/main/java/org/teavm/backend/wasm/render/WasmRenderer.java

@@ -55,28 +55,24 @@ public class WasmRenderer {
 
     public void render(WasmModule module) {
         visitor.open().append("module");
-        renderMemory(module);
         renderTypes(module);
 
-        for (WasmFunction function : module.getFunctions().values()) {
-            if (function.getImportName() == null) {
-                continue;
-            }
-            lf().renderImport(function);
-        }
         for (WasmFunction function : module.getFunctions().values()) {
             if (function.getImportName() != null) {
-                continue;
+                lf().render(function);
             }
-            lf().render(function);
         }
         for (WasmFunction function : module.getFunctions().values()) {
-            if (function.getExportName() == null) {
+            if (function.getImportName() == null) {
-                continue;
+                lf().render(function);
             }
-            lf().renderExport(function);
         }
+
         renderTable(module);
+        renderMemory(module);
+        renderElement(module);
+        renderData(module);
+
         if (module.getStartFunction() != null) {
             visitor.lf().open().append("start $" + module.getStartFunction().getName()).close().lf();
         }
@@ -85,9 +81,12 @@ public class WasmRenderer {
 
     public void renderMemory(WasmModule module) {
         visitor.lf();
-        visitor.open().append("memory " + module.getMemorySize());
+        visitor.open().append("memory " + module.getMemorySize()).close().lf();
+    }
+
+    public void renderData(WasmModule module) {
         for (WasmMemorySegment segment : module.getSegments()) {
-            visitor.lf().open().append("segment " + segment.getOffset());
+            visitor.lf().open().append("data (i32.const " + segment.getOffset() + ")");
             visitor.indent();
             for (int i = 0; i < segment.getLength(); i += 256) {
                 visitor.lf().append("\"");
@@ -110,26 +109,21 @@ public class WasmRenderer {
             visitor.outdent();
             visitor.close();
         }
-        visitor.close().lf();
-    }
-
-    public void renderImport(WasmFunction function) {
-        String importModule = function.getImportModule();
-        if (importModule == null) {
-            importModule = "";
-        }
-        visitor.open().append("import $" + function.getName() + " \"" + importModule + "\" "
-                + "\"" + function.getImportName() + "\"");
-        renderSignature(function);
-        visitor.close();
-    }
-
-    public void renderExport(WasmFunction function) {
-        visitor.open().append("export \"" + function.getExportName() + "\" $" + function.getName()).close();
     }
 
     public void render(WasmFunction function) {
         visitor.open().append("func $" + function.getName());
+
+        if (function.getImportName() != null) {
+            String importModule = function.getImportModule();
+            if (importModule == null) {
+                importModule = "";
+            }
+            visitor.append(" (import \"" + importModule + "\" \"" + function.getImportName() + "\")");
+        } else if (function.getExportName() != null) {
+            visitor.append(" (export \"" + function.getExportName() + "\")");
+        }
+
         renderSignature(function);
 
         int firstLocalVariable = function.getParameters().size();
@@ -142,6 +136,9 @@ public class WasmRenderer {
             }
             visitor.close();
         }
+        for (WasmExpression part : function.getBody()) {
+            visitor.preprocess(part);
+        }
         for (WasmExpression part : function.getBody()) {
             visitor.line(part);
         }
@@ -195,7 +192,15 @@ public class WasmRenderer {
             return;
         }
 
-        visitor.lf().open().append("table");
+        visitor.lf().open().append("table " + module.getFunctionTable().size() + " anyfunc").close().lf();
+    }
+
+    private void renderElement(WasmModule module) {
+        if (module.getFunctionTable().isEmpty()) {
+            return;
+        }
+
+        visitor.lf().open().append("elem (i32.const 0)");
         for (WasmFunction function : module.getFunctionTable()) {
             visitor.lf().append("$" + function.getName());
         }

core/src/main/java/org/teavm/backend/wasm/render/WasmRenderingVisitor.java

@@ -29,6 +29,7 @@ import org.teavm.backend.wasm.model.expression.WasmBreak;
 import org.teavm.backend.wasm.model.expression.WasmCall;
 import org.teavm.backend.wasm.model.expression.WasmConditional;
 import org.teavm.backend.wasm.model.expression.WasmConversion;
+import org.teavm.backend.wasm.model.expression.WasmDefaultExpressionVisitor;
 import org.teavm.backend.wasm.model.expression.WasmDrop;
 import org.teavm.backend.wasm.model.expression.WasmExpression;
 import org.teavm.backend.wasm.model.expression.WasmExpressionVisitor;
@@ -71,6 +72,35 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
     List<WasmSignature> signatureList = new ArrayList<>();
     Map<WasmSignature, Integer> signatureMap = new HashMap<>();
 
+    void preprocess(WasmExpression expression) {
+        expression.acceptVisitor(new WasmDefaultExpressionVisitor() {
+            @Override
+            public void visit(WasmBranch expression) {
+                super.visit(expression);
+                register(expression.getTarget());
+            }
+
+            @Override
+            public void visit(WasmBreak expression) {
+                super.visit(expression);
+                register(expression.getTarget());
+            }
+
+            @Override
+            public void visit(WasmSwitch expression) {
+                super.visit(expression);
+                for (WasmBlock target : expression.getTargets()) {
+                    register(target);
+                }
+                register(expression.getDefaultTarget());
+            }
+
+            private void register(WasmBlock block) {
+                blockIdentifiers.computeIfAbsent(block, key -> "block_" + blockIdentifiers.size());
+            }
+        });
+    }
+
     void clear() {
         blockIdentifiers.clear();
         usedIdentifiers.clear();
@@ -135,13 +165,18 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
 
     @Override
     public void visit(WasmBlock expression) {
-        renderBlock(expression, expression.isLoop() ? "loop" : "block");
+        renderBlock(expression, expression.isLoop() ? "loop" : "block", true);
     }
 
-    private void renderBlock(WasmBlock block, String name) {
+    private void renderBlock(WasmBlock block, String name, boolean signature) {
-        String id = getIdentifier("@block");
+        open().append(name);
-        blockIdentifiers.put(block, id);
+        String id = blockIdentifiers.get(block);
-        open().append(name + " $" + id);
+        if (id != null) {
+            append(" $" + id);
+        }
+        if (signature && block.getType() != null) {
+            append(" " + type(block.getType()));
+        }
         for (WasmExpression part : block.getBody()) {
             line(part);
         }
@@ -183,14 +218,19 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
     @Override
     public void visit(WasmConditional expression) {
         open().append("if");
+
+        if (expression.getType() != null) {
+            append(" " + type(expression.getType()));
+        }
+
         line(expression.getCondition());
 
         lf();
-        renderBlock(expression.getThenBlock(), "then");
+        renderBlock(expression.getThenBlock(), "then", false);
 
         if (!expression.getElseBlock().getBody().isEmpty()) {
             lf();
-            renderBlock(expression.getElseBlock(), "else");
+            renderBlock(expression.getElseBlock(), "else", false);
         }
 
         close();
@@ -343,7 +383,7 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
 
     @Override
     public void visit(WasmCall expression) {
-        open().append(expression.isImported() ? "call_import" : "call").append(" $" + expression.getFunctionName());
+        open().append("call").append(" $" + expression.getFunctionName());
         for (WasmExpression argument : expression.getArguments()) {
             line(argument);
         }

core/src/main/java/org/teavm/runtime/GC.java

@@ -70,12 +70,15 @@ public final class GC {
             next = currentChunk.toAddress().add(size);
         }
         int freeSize = current.size;
-        currentChunk = next.toStructure();
         freeSize -= size;
         if (freeSize > 0) {
-            currentChunk.classReference = 0;
+            currentChunk = next.toStructure();
             currentChunk.size = freeSize;
+        } else {
+            freeMemory -= size;
+            getAvailableChunkIfPossible(currentChunk.size + 1);
         }
+        currentChunk.classReference = 0;
         freeMemory -= size;
         return current;
     }
@@ -89,6 +92,9 @@ public final class GC {
     }
 
     private static boolean getAvailableChunkIfPossible(int size) {
+        if (freeChunks == 0) {
+            return false;
+        }
         while (true) {
             if (currentChunk.toAddress().add(size) == currentChunkLimit) {
                 break;