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, 2 insertions, 0 deletions

diff --git a/src/wasm/wasm-s-parser.cpp b/src/wasm/wasm-s-parser.cpp
index f9e3912f7..9b053d5b8 100644
--- a/src/wasm/wasm-s-parser.cpp
+++ b/src/wasm/wasm-s-parser.cpp
@@ -185,9 +185,11 @@ Element* SExpressionParser::parseString() {
     input++;
     std::string str;
     while (1) {
+      if (input[0] == 0) throw ParseException("unterminated string", line, start - lineStart);
       if (input[0] == '"') break;
       if (input[0] == '\\') {
         str += input[0];
+        if (input[1] == 0) throw ParseException("unterminated string escape", line, start - lineStart);
         str += input[1];
         input += 2;
         continue;