SERVER-27873 Dump a JavaScript backtrace of any code running in SpiderMonkey in hang_analyzer.py

1 files changed, 16 insertions, 1 deletions

diff --git a/src/mongo/scripting/mozjs/implscope.cpp b/src/mongo/scripting/mozjs/implscope.cpp
index eb393f3703d..fe4e68209e4 100644
--- a/src/mongo/scripting/mozjs/implscope.cpp
+++ b/src/mongo/scripting/mozjs/implscope.cpp
@@ -96,7 +96,7 @@ bool closeToMaxMemory() {
 }
 }  // namespace
 
-MONGO_TRIVIALLY_CONSTRUCTIBLE_THREAD_LOCAL MozJSImplScope* kCurrentScope;
+MONGO_TRIVIALLY_CONSTRUCTIBLE_THREAD_LOCAL MozJSImplScope* kCurrentScope = nullptr;
 
 struct MozJSImplScope::MozJSEntry {
     MozJSEntry(MozJSImplScope* scope)
@@ -938,5 +938,20 @@ const std::string& MozJSImplScope::getParentStack() const {
     return _parentStack;
 }
 
+std::string MozJSImplScope::buildStackString() {
+    JS::RootedObject stack(_context);
+
+    if (!JS::CaptureCurrentStack(_context, &stack)) {
+        return {};
+    }
+
+    JS::RootedString out(_context);
+    if (JS::BuildStackString(_context, stack, &out)) {
+        return JSStringWrapper(_context, out.get()).toString();
+    } else {
+        return {};
+    }
+}
+
 }  // namespace mozjs
 }  // namespace mongo