--- a/js/src/frontend/BytecodeCompiler.cpp
+++ b/js/src/frontend/BytecodeCompiler.cpp
@@ -46,25 +46,25 @@ class MOZ_STACK_CLASS BytecodeCompiler
     // Construct an object passing mandatory arguments.
     BytecodeCompiler(JSContext* cx,
                      const ReadOnlyCompileOptions& options,
                      SourceBufferHolder& sourceBuffer,
                      HandleScope enclosingScope);
 
     // Call this before calling compile{Global,Eval}Script.
     MOZ_MUST_USE bool prepareScriptParse() {
-        return createSourceAndParser(ParseGoal::Script) && createScript();
+        return createSourceAndParser(ParseGoal::Script) && createCompleteScript();
     }
 
     JSScript* compileGlobalScript(ScopeKind scopeKind);
     JSScript* compileEvalScript(HandleObject environment, HandleScope enclosingScope);
 
     // Call this before calling compileModule.
     MOZ_MUST_USE bool prepareModuleParse() {
-        return createSourceAndParser(ParseGoal::Module) && createScript();
+        return createSourceAndParser(ParseGoal::Module) && createCompleteScript();
     }
 
     ModuleObject* compileModule();
 
     // Call this before calling compileStandaloneFunction.
     MOZ_MUST_USE bool prepareStandaloneFunctionParse(const Maybe<uint32_t>& parameterListEnd) {
         return createSourceAndParser(ParseGoal::Script, parameterListEnd);
     }
@@ -91,20 +91,23 @@ class MOZ_STACK_CLASS BytecodeCompiler
     JSScript* compileScript(HandleObject environment, SharedContext* sc);
     bool checkLength();
     bool createScriptSource(const Maybe<uint32_t>& parameterListEnd);
     bool canLazilyParse();
     bool createParser(ParseGoal goal);
     bool createSourceAndParser(ParseGoal goal,
                                const Maybe<uint32_t>& parameterListEnd = Nothing());
 
-    // If toString{Start,End} are not explicitly passed, assume the script's
-    // offsets in the source used to parse it are the same as what should be
-    // used to compute its Function.prototype.toString() value.
-    bool createScript();
+    // This assumes the created script's offsets in the source used to parse it
+    // are the same as are used to compute its Function.prototype.toString()
+    // value.
+    bool createCompleteScript();
+
+    // This uses explicitly-provided toString offsets as the created script's
+    // offsets in the source.
     bool createScript(uint32_t toStringStart, uint32_t toStringEnd);
 
     using TokenStreamPosition = frontend::TokenStreamPosition<char16_t>;
 
     bool emplaceEmitter(Maybe<BytecodeEmitter>& emitter, SharedContext* sharedContext);
     bool handleParseFailure(const Directives& newDirectives, TokenStreamPosition& startPosition);
     bool deoptimizeArgumentsInEnclosingScripts(JSContext* cx, HandleObject environment);
 
@@ -278,17 +281,17 @@ bool
 BytecodeCompiler::createSourceAndParser(ParseGoal goal,
                                         const Maybe<uint32_t>& parameterListEnd /* = Nothing() */)
 {
     return createScriptSource(parameterListEnd) &&
            createParser(goal);
 }
 
 bool
-BytecodeCompiler::createScript()
+BytecodeCompiler::createCompleteScript()
 {
     return createScript(0, sourceBuffer.length());
 }
 
 bool
 BytecodeCompiler::createScript(uint32_t toStringStart, uint32_t toStringEnd)
 {
     script = JSScript::Create(cx, options,