3 files changed, 22 insertions, 1 deletions
diff --git a/src/binaryen-shell.cpp b/src/binaryen-shell.cpp
index 8f99d1295..6e3cc8af2 100644
--- a/src/binaryen-shell.cpp
+++ b/src/binaryen-shell.cpp
@@ -227,6 +227,7 @@ int main(int argc, const char* argv[]) {
       if (passes.size() > 0) {
         if (options.debug) std::cerr << "running passes...\n";
         PassRunner passRunner(&moreModuleAllocations);
+        if (options.debug) passRunner.setDebug(true);
         for (auto& passName : passes) {
           if (passName == "O") {
             passRunner.addDefaultOptimizationPasses();
diff --git a/src/pass.cpp b/src/pass.cpp
index a85643efa..b0d4a316e 100644
--- a/src/pass.cpp
+++ b/src/pass.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include <chrono>
+
 #include <pass.h>
 
 namespace wasm {
@@ -35,7 +37,9 @@ void PassRegistry::registerPass(const char* name, const char *description, Creat
 
 Pass* PassRegistry::createPass(std::string name) {
   if (passInfos.find(name) == passInfos.end()) return nullptr;
-  return passInfos[name].create();
+  auto ret = passInfos[name].create();
+  ret->name = name;
+  return ret;
 }
 
 std::vector<std::string> PassRegistry::getRegisteredNames() {
@@ -66,7 +70,17 @@ void PassRunner::addDefaultOptimizationPasses() {
 void PassRunner::run(Module* module) {
   for (auto pass : passes) {
     currPass = pass;
+    std::chrono::high_resolution_clock::time_point before;
+    if (debug) {
+      std::cerr << "[PassRunner] running pass: " << pass->name << std::endl;
+      before = std::chrono::high_resolution_clock::now();
+    }
     pass->run(this, module);
+    if (debug) {
+      auto after = std::chrono::high_resolution_clock::now();
+      std::chrono::duration<double> diff = after - before;
+      std::cerr << "[PassRunner]   pass took " << diff.count() << " seconds." << std::endl;
+    }
   }
 }
 
diff --git a/src/pass.h b/src/pass.h
index 503c164f9..2c3a09ae6 100644
--- a/src/pass.h
+++ b/src/pass.h
@@ -69,9 +69,12 @@ struct PassRunner {
   MixedArena* allocator;
   std::vector<Pass*> passes;
   Pass* currPass;
+  bool debug = false;
 
   PassRunner(MixedArena* allocator) : allocator(allocator) {}
 
+  void setDebug(bool debug_) { debug = debug_; }
+
   void add(std::string passName) {
     auto pass = PassRegistry::get()->createPass(passName);
     assert(pass);
@@ -112,6 +115,9 @@ public:
   virtual void run(PassRunner* runner, Module* module) = 0;
   // Override this to perform finalization work after the pass runs.
   virtual void finalize(PassRunner* runner, Module* module) {}
+
+  std::string name;
+
 protected:
   Pass() {}
   Pass(Pass &) {}