Reland emitting of DataCount section (#2027)

This reverts commit cb2d63586c08a3dd194d2b733ceb3f5051c081f8.
The issues with feature validation were mostly resolved in #1993, and
this PR finishes the job by adding feature flags to wasm-as to avoid
emitting the DataCount section when bulk-memory is not enabled.

1 files changed, 3 insertions, 8 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index d6091e93c..f3642203d 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -317,14 +317,9 @@ void WasmBinaryWriter::writeDataCount() {
   if (!wasm->features.hasBulkMemory() || !wasm->memory.segments.size()) {
     return;
   }
-
-  // TODO(tlively): re-enable writing the data count once the default feature
-  // set is no longer All, which causes validation errors in Emscripten due to
-  // the presence of an unrecognized section.
-
-  // auto start = startSection(BinaryConsts::Section::DataCount);
-  // o << U32LEB(wasm->memory.segments.size());
-  // finishSection(start);
+  auto start = startSection(BinaryConsts::Section::DataCount);
+  o << U32LEB(wasm->memory.segments.size());
+  finishSection(start);
 }
 
 void WasmBinaryWriter::writeDataSegments() {