Add local names to WASM object file

4 files changed, 64 insertions, 12 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/modules/WasmFunction.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/modules/WasmFunction.java
index 50ad805b..0f295e90 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/modules/WasmFunction.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/modules/WasmFunction.java
@@ -7,8 +7,17 @@ import org.shedlang.compiler.backends.wasm.structure.ast.types.WasmValueType;
 import java.util.List;
 
 public record WasmFunction(
-    WasmFuncType type,
-    List<WasmValueType> locals,
+    List<WasmLocal> params,
+    List<WasmLocal> locals,
+    List<WasmValueType> resultTypes,
     List<WasmInstruction> body
 ) {
+    public WasmFuncType type() {
+        return new WasmFuncType(
+            params.stream()
+                .map(param -> param.type())
+                .toList(),
+            resultTypes
+        );
+    }
 }
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/modules/WasmLocal.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/modules/WasmLocal.java
new file mode 100644
index 00000000..d9813336
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/modules/WasmLocal.java
@@ -0,0 +1,6 @@
+package org.shedlang.compiler.backends.wasm.structure.ast.modules;
+
+import org.shedlang.compiler.backends.wasm.structure.ast.types.WasmValueType;
+
+public record WasmLocal(String name, WasmValueType type) {
+}
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatModules.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatModules.java
index 58ae08a8..4f684f8f 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatModules.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatModules.java
@@ -215,7 +215,7 @@ public class WasmBinaryFormatModules {
             function.locals(),
             local -> {
                 Leb128Encoding.encodeUnsignedInt32(1, writer);
-                writeValueType(local, writer);
+                writeValueType(local.type(), writer);
             },
             writer
         );
@@ -257,7 +257,7 @@ public class WasmBinaryFormatModules {
         writeTableSection(module, writer);
         writeMemorySection(module, writer);
         writeCodeSection(module, writer);
-        writeNameSection(module, writer);
+        writeNameSection(module, indexTable, writer);
 
         outputStream.write(writer.toBytes());
     }
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatNameSection.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatNameSection.java
index 67caa7c6..50c98879 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatNameSection.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatNameSection.java
@@ -1,6 +1,7 @@
 package org.shedlang.compiler.backends.wasm.structure.binary;
 
 import org.shedlang.compiler.backends.wasm.structure.BinaryWriter;
+import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmLocal;
 import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmModule;
 import org.shedlang.compiler.backends.wasm.structure.ast.modules.WasmImportDescriptor;
 import org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatModules.SectionId;
@@ -23,13 +24,16 @@ public class WasmBinaryFormatNameSection {
 
     // == Name Section ==
 
-    static void writeNameSection(WasmModule module, BinaryWriter writer) throws IOException {
-        if (module.imports().size() > 0) {
-            writeSection(SectionId.CUSTOM, writer, () -> {
-                writeString("name", writer);
-                writeNameSectionFunctionNameSubsection(module, writer);
-            });
-        }
+    static void writeNameSection(
+        WasmModule module,
+        WasmIndexTable indexTable,
+        BinaryWriter writer
+    ) throws IOException {
+        writeSection(SectionId.CUSTOM, writer, () -> {
+            writeString("name", writer);
+            writeFunctionNameSubsection(module, writer);
+            writeLocalNameSubsection(module, indexTable, writer);
+        });
     }
 
     // == Subsections ==
@@ -71,7 +75,7 @@ public class WasmBinaryFormatNameSection {
 
     // == Function Names ==
 
-    private static void writeNameSectionFunctionNameSubsection(WasmModule module, BinaryWriter writer) throws IOException {
+    private static void writeFunctionNameSubsection(WasmModule module, BinaryWriter writer) throws IOException {
         writeNameSubsection(NameSubsectionId.FUNCTION_NAMES, writer, () -> {
             var importedFunctions = module.imports().stream()
                 .flatMap(import_ -> switch (import_.descriptor()) {
@@ -83,4 +87,37 @@ public class WasmBinaryFormatNameSection {
             writeNameMap(writer, importedFunctions);
         });
     }
+
+    // == Local Names ==
+
+    private static void writeLocalNameSubsection(
+        WasmModule module,
+        WasmIndexTable indexTable,
+        BinaryWriter writer
+    ) throws IOException {
+        writeNameSubsection(NameSubsectionId.LOCAL_NAMES, writer, () -> {
+            writeVec(
+                module.functions(),
+                function -> {
+                    var funcIndex = indexTable.funcIndex(function.type());
+                    writeFuncIndex(funcIndex, writer);
+
+                    var names = Stream.concat(
+                        function.params().stream(),
+                        function.locals().stream()
+                    ).map(WasmLocal::name).toList();
+
+                    writeVec(
+                        names,
+                        (nameIndex, name) -> {
+                            Leb128Encoding.encodeUnsignedInt32(nameIndex, writer);
+                            writeString(name, writer);
+                        },
+                        writer
+                    );
+                },
+                writer
+            );
+        });
+    }
 }