initialize binary writer debug info even without a source map, as debug info may exist without a source map (#1733)

2 files changed, 6 insertions, 1 deletions

diff --git a/src/wasm-binary.h b/src/wasm-binary.h
index 2a455b808..3dac4de06 100644
--- a/src/wasm-binary.h
+++ b/src/wasm-binary.h
@@ -721,6 +721,7 @@ public:
   void writeLateUserSections();
   void writeUserSection(const UserSection& section);
 
+  void initializeDebugInfo();
   void writeSourceMapProlog();
   void writeSourceMapEpilog();
   void writeDebugLocation(const Function::DebugLocation& loc);
diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 153894906..97e70aeab 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -44,6 +44,7 @@ void WasmBinaryWriter::write() {
 
   writeEarlyUserSections();
 
+  initializeDebugInfo();
   if (sourceMap) {
     writeSourceMapProlog();
   }
@@ -484,8 +485,11 @@ void WasmBinaryWriter::writeSymbolMap() {
   file.close();
 }
 
-void WasmBinaryWriter::writeSourceMapProlog() {
+void WasmBinaryWriter::initializeDebugInfo() {
   lastDebugLocation = { 0, /* lineNumber = */ 1, 0 };
+}
+
+void WasmBinaryWriter::writeSourceMapProlog() {
   *sourceMap << "{\"version\":3,\"sources\":[";
   for (size_t i = 0; i < wasm->debugInfoFileNames.size(); i++) {
     if (i > 0) *sourceMap << ",";