Merge pull request #644 from WebAssembly/fix-debug

Fix dce bug in non-parallel mode, which happens in debug mode

5 files changed, 30 insertions, 2 deletions

diff --git a/check.py b/check.py
index 5d9a72ac0..d3f0ea4c6 100755
--- a/check.py
+++ b/check.py
@@ -272,6 +272,9 @@ for t in sorted(os.listdir(os.path.join('test', 'passes'))):
       with open('split.wast', 'w') as o: o.write(module)
       cmd = [os.path.join('bin', 'wasm-opt')] + opts + ['split.wast', '--print']
       actual += run_command(cmd)
+      # also check debug mode output is valid
+      debugged = run_command(cmd + ['--debug'], stderr=subprocess.PIPE)
+      fail_if_not_contained(actual, debugged)
     fail_if_not_identical(actual, open(os.path.join('test', 'passes', passname + '.txt')).read())
 
 print '[ checking asm2wasm testcases... ]\n'
diff --git a/src/passes/DeadCodeElimination.cpp b/src/passes/DeadCodeElimination.cpp
index 9562b2973..de1191131 100644
--- a/src/passes/DeadCodeElimination.cpp
+++ b/src/passes/DeadCodeElimination.cpp
@@ -40,7 +40,12 @@ struct DeadCodeElimination : public WalkerPass<PostWalker<DeadCodeElimination, V
   Pass* create() override { return new DeadCodeElimination; }
 
   // whether the current code is actually reachable
-  bool reachable = true;
+  bool reachable;
+
+  void doWalkFunction(Function* func) {
+    reachable = true;
+    walk(func->body);
+  }
 
   std::set<Name> reachableBreaks;
 
diff --git a/src/passes/pass.cpp b/src/passes/pass.cpp
index e04033d90..f27eccf6a 100644
--- a/src/passes/pass.cpp
+++ b/src/passes/pass.cpp
@@ -149,7 +149,14 @@ void PassRunner::run() {
         std::cerr << ' ';
       }
       before = std::chrono::high_resolution_clock::now();
-      pass->run(this, wasm);
+      if (pass->isFunctionParallel()) {
+        // function-parallel passes should get a new instance per function
+        for (auto& func : wasm->functions) {
+          runPassOnFunction(pass, func.get());
+        }
+      } else {
+        pass->run(this, wasm);
+      }
       auto after = std::chrono::high_resolution_clock::now();
       std::chrono::duration<double> diff = after - before;
       std::cerr << diff.count() << " seconds." << std::endl;
diff --git a/test/passes/dce.txt b/test/passes/dce.txt
index 3d32d9bed..5f287e183 100644
--- a/test/passes/dce.txt
+++ b/test/passes/dce.txt
@@ -236,4 +236,10 @@
     )
     (i32.const 1337)
   )
+  (func $killer
+    (unreachable)
+  )
+  (func $target
+    (i32.const 2000)
+  )
 )
diff --git a/test/passes/dce.wast b/test/passes/dce.wast
index e76607ecd..dcec20cc1 100644
--- a/test/passes/dce.wast
+++ b/test/passes/dce.wast
@@ -193,5 +193,12 @@
     )
     (i32.const 1337)
   )
+  (func $killer
+    (unreachable)
+    (i32.const 1000)
+  )
+  (func $target
+    (i32.const 2000)
+  )
 )