5 files changed, 30 insertions, 22 deletions

diff --git a/src/asm2wasm.h b/src/asm2wasm.h
index 6ed13b79a..fe9bd0f3f 100644
--- a/src/asm2wasm.h
+++ b/src/asm2wasm.h
@@ -649,19 +649,24 @@ void Asm2WasmBuilder::processAsm(Ref ast) {
       type = WasmType::f64;
     }
     if (type != WasmType::none) {
-      // we need imported globals to be mutable, but wasm doesn't support that yet, so we must
-      // import an immutable and create a mutable global initialized to its value
-      import->name = Name(std::string(import->name.str) + "$asm2wasm$import");
+      // this is a global
       import->kind = ExternalKind::Global;
       import->globalType = type;
       mappedGlobals.emplace(name, type);
-      {
-        auto global = new Global();
-        global->name = name;
-        global->type = type;
-        global->init = builder.makeGetGlobal(import->name, type);
-        global->mutable_ = true;
-        wasm.addGlobal(global);
+      // tableBase and memoryBase are used as segment/element offsets, and must be constant;
+      // otherwise, an asm.js import of a constant is mutable, e.g. STACKTOP
+      if (name != "tableBase" && name != "memoryBase") {
+        // we need imported globals to be mutable, but wasm doesn't support that yet, so we must
+        // import an immutable and create a mutable global initialized to its value
+        import->name = Name(std::string(import->name.str) + "$asm2wasm$import");
+        {
+          auto global = new Global();
+          global->name = name;
+          global->type = type;
+          global->init = builder.makeGetGlobal(import->name, type);
+          global->mutable_ = true;
+          wasm.addGlobal(global);
+        }
       }
     } else {
       import->kind = ExternalKind::Function;
@@ -1059,8 +1064,8 @@ void Asm2WasmBuilder::processAsm(Ref ast) {
   wasm.table.exists = true;
   wasm.table.imported = true;
 
-  // Import memory offset
-  {
+  // Import memory offset, if not already there
+  if (!wasm.checkImport("memoryBase") && !wasm.checkGlobal("memoryBase")) {
     auto* import = new Import;
     import->name = Name("memoryBase");
     import->module = Name("env");
@@ -1070,8 +1075,8 @@ void Asm2WasmBuilder::processAsm(Ref ast) {
     wasm.addImport(import);
   }
 
-  // Import table offset
-  {
+  // Import table offset, if not already there
+  if (!wasm.checkImport("tableBase") && !wasm.checkGlobal("tableBase")) {
     auto* import = new Import;
     import->name = Name("tableBase");
     import->module = Name("env");
diff --git a/src/binaryen-c.cpp b/src/binaryen-c.cpp
index dc68d8439..c618f9d14 100644
--- a/src/binaryen-c.cpp
+++ b/src/binaryen-c.cpp
@@ -808,6 +808,7 @@ void BinaryenSetMemory(BinaryenModuleRef module, BinaryenIndex initial, Binaryen
   auto* wasm = (Module*)module;
   wasm->memory.initial = initial;
   wasm->memory.max = maximum;
+  wasm->memory.exists = true;
   if (exportName) {
     auto memoryExport = make_unique<Export>();
     memoryExport->name = exportName;
diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index c6fca0256..3c847809f 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -698,15 +698,15 @@ struct PrintSExpression : public Visitor<PrintSExpression> {
       visitImport(child.get());
       o << maybeNewLine;
     }
-    if (curr->table.exists) {
-      visitTable(&curr->table); // Prints its own newlines
-    }
-    visitMemory(&curr->memory);
     for (auto& child : curr->globals) {
       doIndent(o, indent);
       visitGlobal(child.get());
       o << maybeNewLine;
     }
+    if (curr->table.exists) {
+      visitTable(&curr->table); // Prints its own newlines
+    }
+    visitMemory(&curr->memory);
     for (auto& child : curr->exports) {
       doIndent(o, indent);
       visitExport(child.get());
diff --git a/src/wasm-binary.h b/src/wasm-binary.h
index 3f5b799fe..75733a6b5 100644
--- a/src/wasm-binary.h
+++ b/src/wasm-binary.h
@@ -690,6 +690,7 @@ public:
   void readFunctions();
 
   std::map<Export*, Index> exportIndexes;
+  std::vector<Export*> exportOrder;
   void readExports();
 
   Expression* readExpression();
diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 65bf0a268..6b5878904 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -1281,6 +1281,7 @@ void WasmBinaryBuilder::readExports() {
     curr->kind = (ExternalKind)getU32LEB();
     auto index = getU32LEB();
     exportIndexes[curr] = index;
+    exportOrder.push_back(curr);
   }
 }
 
@@ -1383,16 +1384,16 @@ void WasmBinaryBuilder::processFunctions() {
     wasm.start = getFunctionIndexName(startIndex);
   }
 
-  for (auto& iter : exportIndexes) {
-    Export* curr = iter.first;
+  for (auto* curr : exportOrder) {
+    auto index = exportIndexes[curr];
     switch (curr->kind) {
       case ExternalKind::Function: {
-        curr->value = getFunctionIndexName(iter.second);
+        curr->value = getFunctionIndexName(index);
         break;
       }
       case ExternalKind::Table: curr->value = Name::fromInt(0); break;
       case ExternalKind::Memory: curr->value = Name::fromInt(0); break;
-      case ExternalKind::Global: curr->value = getGlobalName(iter.second); break;
+      case ExternalKind::Global: curr->value = getGlobalName(index); break;
       default: WASM_UNREACHABLE();
     }
     wasm.addExport(curr);