Work around v8 snapshot serializer bug
See also:
@@ -57,8 +57,25 @@ int main(int argc, char** argv) {
std::string js_source;
CHECK(deno::ReadFileToString(js_fn, &js_source));
+ // Wrap the js_source in an IIFE to work around a bug in the V8 snapshot
+ // serializer. Without it, CreateBlob() triggers the following assert:
+ // Debug check failed : outer_scope_info()->IsScopeInfo() || is_toplevel().
+ // ==== C stack trace ====
+ // v8::internal::SharedFunctionInfo::FlushCompiled
+ // v8::SnapshotCreator::CreateBlob
+ // deno::MakeSnapshot
+ // Avoid misaligning the source map, and ensure that the sourceMappingUrl
+ // comment remains at the last line.
+ auto smu_offset = js_source.rfind("//#");
+ CHECK(smu_offset != std::string::npos);
+ auto wrapped_js_source = "(function() {" + js_source.substr(0, smu_offset) +
+ "\n})();\n" + js_source.substr(smu_offset);
+ // Double check that the source mapping url comment is at the last line.
+ auto last_line = wrapped_js_source.substr(wrapped_js_source.rfind('\n'));
+ CHECK(last_line.find("sourceMappingURL") != std::string::npos);
+
deno_init();
- auto snapshot_blob = deno::MakeSnapshot(js_fn, js_source.c_str());
+ auto snapshot_blob = deno::MakeSnapshot(js_fn, wrapped_js_source.c_str());
std::string snapshot_str(snapshot_blob.data, snapshot_blob.raw_size);
CHECK(deno::WriteDataAsCpp("snapshot", snapshot_out_cc, snapshot_str));
