Add a RoundTrip pass (#2516)

This pass writes and reads the module. This shows the effects
of converting to and back from the binary format, and will be
useful in testing dwarf debug support (where we'll need to see
that writing and reading a module preserves debug info properly).

1 files changed, 16 insertions, 2 deletions

diff --git a/src/ir/module-utils.h b/src/ir/module-utils.h
index f2fda908c..e212ae8dc 100644
--- a/src/ir/module-utils.h
+++ b/src/ir/module-utils.h
@@ -105,8 +105,8 @@ inline Event* copyEvent(Event* event, Module& out) {
   return ret;
 }
 
-inline void copyModule(Module& in, Module& out) {
-  // we use names throughout, not raw points, so simple copying is fine
+inline void copyModule(const Module& in, Module& out) {
+  // we use names throughout, not raw pointers, so simple copying is fine
   // for everything *but* expressions
   for (auto& curr : in.functionTypes) {
     out.addFunctionType(make_unique<FunctionType>(*curr));
@@ -136,6 +136,20 @@ inline void copyModule(Module& in, Module& out) {
   out.debugInfoFileNames = in.debugInfoFileNames;
 }
 
+inline void clearModule(Module& wasm) {
+  wasm.functionTypes.clear();
+  wasm.exports.clear();
+  wasm.functions.clear();
+  wasm.globals.clear();
+  wasm.events.clear();
+  wasm.table.segments.clear();
+  wasm.memory.segments.clear();
+  wasm.start = Name();
+  wasm.userSections.clear();
+  wasm.debugInfoFileNames.clear();
+  wasm.updateMaps();
+}
+
 // Renaming
 
 // Rename functions along with all their uses.