1 files changed, 30 insertions, 12 deletions

diff --git a/src/passes/LogExecution.cpp b/src/passes/LogExecution.cpp
index 1b90842bc..f1d48012f 100644
--- a/src/passes/LogExecution.cpp
+++ b/src/passes/LogExecution.cpp
@@ -39,9 +39,18 @@ namespace wasm {
 Name LOGGER("log_execution");
 
 struct LogExecution : public WalkerPass<PostWalker<LogExecution>> {
+  // The module name the logger function is imported from.
+  IString loggerModule;
+
   // Adds calls to new imports.
   bool addsEffects() override { return true; }
 
+  void run(Module* module) override {
+    auto& options = getPassOptions();
+    loggerModule = options.getArgumentOrDefault("log-execution", "");
+    super::run(module);
+  }
+
   void visitLoop(Loop* curr) { curr->body = makeLogCall(curr->body); }
 
   void visitReturn(Return* curr) { replaceCurrent(makeLogCall(curr)); }
@@ -63,23 +72,32 @@ struct LogExecution : public WalkerPass<PostWalker<LogExecution>> {
     auto import =
       Builder::makeFunction(LOGGER, Signature(Type::i32, Type::none), {});
 
-    // Import the log function from import "env" if the module
-    // imports other functions from that name.
-    for (auto& func : curr->functions) {
-      if (func->imported() && func->module == ENV) {
-        import->module = func->module;
-        break;
-      }
-    }
-
-    // If not, then pick the import name of the first function we find.
-    if (!import->module) {
+    if (loggerModule != "") {
+      import->module = loggerModule;
+    } else {
+      // Import the log function from import "env" if the module
+      // imports other functions from that name.
       for (auto& func : curr->functions) {
-        if (func->imported()) {
+        if (func->imported() && func->module == ENV) {
           import->module = func->module;
           break;
         }
       }
+
+      // If not, then pick the import name of the first function we find.
+      if (!import->module) {
+        for (auto& func : curr->functions) {
+          if (func->imported()) {
+            import->module = func->module;
+            break;
+          }
+        }
+      }
+
+      // If no function was found, use ENV.
+      if (!import->module) {
+        import->module = ENV;
+      }
     }
 
     import->base = LOGGER;