3 files changed, 53 insertions, 8 deletions

diff --git a/src/passes/MinifyImportsAndExports.cpp b/src/passes/MinifyImportsAndExports.cpp
index 60dd2cd80..3a4dd8f80 100644
--- a/src/passes/MinifyImportsAndExports.cpp
+++ b/src/passes/MinifyImportsAndExports.cpp
@@ -24,9 +24,12 @@
 //   (import "env" "longname" (func $internal))
 // to
 //   (import "env" "a" (func $internal))
-// "a" is the minified name (note that we only minify the base,
-// not the module).
+// "a" is the minified name. If we also minify module names, then the
+// result could be
+//   (import "a" "a" (func $internal))
 //
+// TODO: check if we can minify names to the empty string "", which is even
+//       shorter than one character.
 
 #include <map>
 #include <string>
@@ -42,11 +45,11 @@
 namespace wasm {
 
 struct MinifyImportsAndExports : public Pass {
-  bool minifyExports;
+  bool minifyExports, minifyModules;
 
 public:
-  explicit MinifyImportsAndExports(bool minifyExports)
-    : minifyExports(minifyExports) {}
+  explicit MinifyImportsAndExports(bool minifyExports, bool minifyModules)
+    : minifyExports(minifyExports), minifyModules(minifyModules) {}
 
 private:
   // Generates minified names that are valid in JS.
@@ -160,7 +163,12 @@ private:
       }
     };
     auto processImport = [&](Importable* curr) {
-      if (curr->module == ENV || curr->module.startsWith("wasi_")) {
+      // Minify all import base names if we are importing modules (which means
+      // we will minify all modules names, so we are not being careful).
+      // Otherwise, assume we just want to minify "normal" imports like env
+      // and wasi, but not special things like asm2wasm or custom user things.
+      if (minifyModules || curr->module == ENV ||
+          curr->module.startsWith("wasi_")) {
         process(curr->base);
       }
     };
@@ -179,13 +187,45 @@ private:
     for (auto& pair : newToOld) {
       std::cout << pair.second.str << " => " << pair.first.str << '\n';
     }
+
+    if (minifyModules) {
+      doMinifyModules(module);
+    }
+  }
+
+  const Name SINGLETON_MODULE_NAME = "a";
+
+  void doMinifyModules(Module* module) {
+    // Minify the module name itself, and also merge all the modules into
+    // one. Assert against overlapping names.
+#ifndef NDEBUG
+    std::set<Name> seenImports;
+#endif
+    auto processImport = [&](Importable* curr) {
+      curr->module = SINGLETON_MODULE_NAME;
+#ifndef NDEBUG
+      assert(seenImports.count(curr->base) == 0);
+      seenImports.insert(curr->base);
+#endif
+    };
+    ModuleUtils::iterImportedGlobals(*module, processImport);
+    ModuleUtils::iterImportedFunctions(*module, processImport);
+    ModuleUtils::iterImportedEvents(*module, processImport);
+    ModuleUtils::iterImportedMemories(*module, processImport);
+    ModuleUtils::iterImportedTables(*module, processImport);
   }
 };
 
-Pass* createMinifyImportsPass() { return new MinifyImportsAndExports(false); }
+Pass* createMinifyImportsPass() {
+  return new MinifyImportsAndExports(false, false);
+}
 
 Pass* createMinifyImportsAndExportsPass() {
-  return new MinifyImportsAndExports(true);
+  return new MinifyImportsAndExports(true, false);
+}
+
+Pass* createMinifyImportsAndExportsAndModulesPass() {
+  return new MinifyImportsAndExports(true, true);
 }
 
 } // namespace wasm
diff --git a/src/passes/pass.cpp b/src/passes/pass.cpp
index 80cc0c1c9..9567d27b6 100644
--- a/src/passes/pass.cpp
+++ b/src/passes/pass.cpp
@@ -185,6 +185,10 @@ void PassRegistry::registerPasses() {
                "minifies both import and export names, and emits a mapping to "
                "the minified ones",
                createMinifyImportsAndExportsPass);
+  registerPass("minify-imports-and-exports-and-modules",
+               "minifies both import and export names, and emits a mapping to "
+               "the minified ones, and minifies the modules as well",
+               createMinifyImportsAndExportsAndModulesPass);
   registerPass("mod-asyncify-always-and-only-unwind",
                "apply the assumption that asyncify imports always unwind, "
                "and we never rewind",
diff --git a/src/passes/passes.h b/src/passes/passes.h
index df5601d2f..868c5b407 100644
--- a/src/passes/passes.h
+++ b/src/passes/passes.h
@@ -63,6 +63,7 @@ Pass* createMergeLocalsPass();
 Pass* createMinifiedPrinterPass();
 Pass* createMinifyImportsPass();
 Pass* createMinifyImportsAndExportsPass();
+Pass* createMinifyImportsAndExportsAndModulesPass();
 Pass* createMetricsPass();
 Pass* createNameListPass();
 Pass* createNoExitRuntimePass();