Validate finalization (#1014)

* validate that types are properly finalized, when in pass-debug mode (BINARYEN_PASS_DEBUG env var): check after each pass is run that the type of each node is equal to the proper type (when finalizing it, i.e., fully recomputing the type).

* fix many fuzz bugs found by that.

* in particular, fix dce bugs with type changes not being fully updated during code removal. add a new TypeUpdater helper class that lets a pass update types efficiently, by the helper tracking deps between blocks and branches etc., and updating/propagating type changes only as necessary.

1 files changed, 7 insertions, 6 deletions

diff --git a/src/passes/pass.cpp b/src/passes/pass.cpp
index 7b4a896eb..2fb0d5c3b 100644
--- a/src/passes/pass.cpp
+++ b/src/passes/pass.cpp
@@ -166,11 +166,7 @@ static void dumpWast(Name name, Module* wasm) {
 }
 
 void PassRunner::run() {
-  // BINARYEN_PASS_DEBUG is a convenient commandline way to log out the toplevel passes, their times,
-  //                     and validate between each pass.
-  //                     (we don't recurse pass debug into sub-passes, as it doesn't help anyhow and
-  //                     also is bad for e.g. printing which is a pass)
-  static const int passDebug = getenv("BINARYEN_PASS_DEBUG") ? atoi(getenv("BINARYEN_PASS_DEBUG")) : 0;
+  static const int passDebug = getPassDebug();
   if (!isNested && (options.debug || passDebug)) {
     // for debug logging purposes, run each pass in full before running the other
     auto totalTime = std::chrono::duration<double>(0);
@@ -212,7 +208,7 @@ void PassRunner::run() {
         if (passDebug >= 2) {
           std::cerr << "Last pass (" << pass->name << ") broke validation. Here is the module before: \n" << moduleBefore.str() << "\n";
         } else {
-          std::cerr << "Last pass (" << pass->name << ") broke validation. Run with BINARYEN_PASS_DEBUG=2 in the env to see the earlier state (FIXME: this is broken, need to prevent recursion of the print pass\n";
+          std::cerr << "Last pass (" << pass->name << ") broke validation. Run with BINARYEN_PASS_DEBUG=2 in the env to see the earlier state, or 3 to dump byn-* files for each pass\n";
         }
         abort();
       }
@@ -300,4 +296,9 @@ void PassRunner::runPassOnFunction(Pass* pass, Function* func) {
   instance->runFunction(this, wasm, func);
 }
 
+int PassRunner::getPassDebug() {
+  static const int passDebug = getenv("BINARYEN_PASS_DEBUG") ? atoi(getenv("BINARYEN_PASS_DEBUG")) : 0;
+  return passDebug;
+}
+
 } // namespace wasm