Write names of imported functions

1 files changed, 31 insertions, 4 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/WasmBinaryFormat.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/WasmBinaryFormat.java
index f9fceab5..b472eecd 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/WasmBinaryFormat.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/WasmBinaryFormat.java
@@ -6,7 +6,6 @@ import org.shedlang.compiler.backends.wasm.structure.ast.imports.WasmImport;
 import org.shedlang.compiler.backends.wasm.structure.ast.imports.WasmImportDescriptor;
 import org.shedlang.compiler.backends.wasm.structure.ast.types.WasmFuncType;
 import org.shedlang.compiler.backends.wasm.structure.ast.types.WasmValueType;
-import org.shedlang.compiler.util.Action;
 
 import java.io.IOException;
 import java.io.OutputStream;
@@ -49,6 +48,7 @@ public class WasmBinaryFormat {
         writer.writeBytes(WASM_VERSION);
         writeTypeSection(module.types(), writer);
         writeImportSection(module, writer);
+        writeNameSection(module, writer);
 
         outputStream.write(writer.toBytes());
     }
@@ -103,6 +103,21 @@ public class WasmBinaryFormat {
         }
     }
 
+    private static void writeNameSection(WasmModule module, BinaryWriter writer) throws IOException {
+        if (module.imports().size() > 0) {
+            writeSection(SectionType.CUSTOM, writer, () -> {
+                writeString("name", writer);
+                writeSection((byte) 1, writer, () -> {
+                    Leb128Encoding.encodeUnsignedInt32(module.imports().size(), writer);
+                    for (var importIndex = 0; importIndex < module.imports().size(); importIndex++) {
+                        Leb128Encoding.encodeUnsignedInt32(importIndex, writer);
+                        writeString(module.imports().get(importIndex).identifier(), writer);
+                    };
+                });
+            });
+        }
+    }
+
     private static void writeFuncType(WasmFuncType type, BinaryWriter writer) {
         writer.writeByte((byte) 0x60);
         writeValueTypeVector(type.params(), writer);
@@ -126,10 +141,22 @@ public class WasmBinaryFormat {
         writer.writeByte((byte) encoding);
     }
 
+    interface Write {
+        void write() throws IOException;
+    }
+
     private static void writeSection(
         SectionType sectionType,
         BinaryWriter writer,
-        Action writeContent
+        Write writeContent
+    ) throws IOException {
+        writeSection(sectionType.id, writer, writeContent);
+    }
+
+    private static void writeSection(
+        byte id,
+        BinaryWriter writer,
+        Write writeContent
     ) throws IOException {
         // https://webassembly.github.io/spec/core/binary/modules.html#sections
         //
@@ -137,13 +164,13 @@ public class WasmBinaryFormat {
         // * a one-byte section ID
         // * the u32 size of the contents, in bytes
         // * the actual contents
-        writer.writeByte(sectionType.id);
+        writer.writeByte(id);
 
         var sizePosition = writer.position();
         Leb128Encoding.encodePaddedUnsignedInt32(0, writer);
 
         var contentStartPosition = writer.position();
-        writeContent.call();
+        writeContent.write();
         var contentEndPosition = writer.position();
 
         var size = contentEndPosition - contentStartPosition;