--- a/js/src/jsapi-tests/moz.build
+++ b/js/src/jsapi-tests/moz.build
@@ -22,17 +22,16 @@ UNIFIED_SOURCES += [
     'testDateToLocaleString.cpp',
     'testDebugger.cpp',
     'testDeepFreeze.cpp',
     'testDefineGetterSetterNonEnumerable.cpp',
     'testDefineProperty.cpp',
     'testDefinePropertyIgnoredAttributes.cpp',
     'testDeflateStringToUTF8Buffer.cpp',
     'testDifferentNewTargetInvokeConstructor.cpp',
-    'testEnclosingFunction.cpp',
     'testErrorCopying.cpp',
     'testException.cpp',
     'testExternalArrayBuffer.cpp',
     'testExternalStrings.cpp',
     'testFindSCCs.cpp',
     'testForceLexicalInitialization.cpp',
     'testForOfIterator.cpp',
     'testForwardSetProperty.cpp',

deleted file mode 100644
--- a/js/src/jsapi-tests/testEnclosingFunction.cpp
+++ /dev/null
@@ -1,68 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
- * vim: set ts=8 sts=4 et sw=4 tw=99:
- *
- * Test script cloning.
- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "jsfriendapi.h"
-
-#include "jsapi-tests/tests.h"
-
-using namespace js;
-
-static JSFunction* foundFun = nullptr;
-
-static bool
-CheckEnclosing(JSContext* cx, unsigned argc, Value* vp)
-{
-    CallArgs args = CallArgsFromVp(argc, vp);
-
-    foundFun = js::GetOutermostEnclosingFunctionOfScriptedCaller(cx);
-
-    args.rval().set(UndefinedValue());
-    return true;
-}
-
-BEGIN_TEST(test_enclosingFunction)
-{
-    CHECK(JS_DefineFunction(cx, global, "checkEnclosing", CheckEnclosing, 0, 0));
-
-    EXEC("checkEnclosing()");
-    CHECK(foundFun == nullptr);
-
-    RootedFunction fun(cx);
-
-    JS::CompileOptions options(cx);
-    options.setFileAndLine(__FILE__, __LINE__);
-
-    const char s1chars[] = "checkEnclosing()";
-    JS::AutoObjectVector emptyScopeChain(cx);
-    CHECK(JS::CompileFunction(cx, emptyScopeChain, options, "s1", 0, nullptr, s1chars,
-                              strlen(s1chars), &fun));
-    CHECK(fun);
-    CHECK(JS_DefineProperty(cx, global, "s1", fun, JSPROP_ENUMERATE));
-    EXEC("s1()");
-    CHECK(foundFun == fun);
-
-    const char s2chars[] = "return function() { checkEnclosing() }";
-    CHECK(JS::CompileFunction(cx, emptyScopeChain, options, "s2", 0, nullptr, s2chars,
-                              strlen(s2chars), &fun));
-    CHECK(fun);
-    CHECK(JS_DefineProperty(cx, global, "s2", fun, JSPROP_ENUMERATE));
-    EXEC("s2()()");
-    CHECK(foundFun == fun);
-
-    const char s3chars[] = "return function() { { let x; function g() { checkEnclosing() } return g() } }";
-    CHECK(JS::CompileFunction(cx, emptyScopeChain, options, "s3", 0, nullptr, s3chars,
-                              strlen(s3chars), &fun));
-    CHECK(fun);
-    CHECK(JS_DefineProperty(cx, global, "s3", fun, JSPROP_ENUMERATE));
-    EXEC("s3()()");
-    CHECK(foundFun == fun);
-
-    return true;
-}
-END_TEST(test_enclosingFunction)

--- a/js/src/jsfriendapi.cpp
+++ b/js/src/jsfriendapi.cpp
@@ -414,44 +414,16 @@ js::IsObjectInContextCompartment(JSObjec
 
 JS_FRIEND_API(bool)
 js::RunningWithTrustedPrincipals(JSContext* cx)
 {
     return cx->runningWithTrustedPrincipals();
 }
 
 JS_FRIEND_API(JSFunction*)
-js::GetOutermostEnclosingFunctionOfScriptedCaller(JSContext* cx)
-{
-    ScriptFrameIter iter(cx);
-
-    // Skip eval frames.
-    while (!iter.done() && iter.isEvalFrame())
-        ++iter;
-
-    if (iter.done())
-        return nullptr;
-
-    if (!iter.isFunctionFrame())
-        return nullptr;
-
-    if (iter.compartment() != cx->compartment())
-        return nullptr;
-
-    RootedFunction curr(cx, iter.callee(cx));
-    for (ScopeIter si(curr->nonLazyScript()); si; si++) {
-        if (si.kind() == ScopeKind::Function)
-            curr = si.scope()->as<FunctionScope>().canonicalFunction();
-    }
-
-    assertSameCompartment(cx, curr);
-    return curr;
-}
-
-JS_FRIEND_API(JSFunction*)
 js::DefineFunctionWithReserved(JSContext* cx, JSObject* objArg, const char* name, JSNative call,
                                unsigned nargs, unsigned attrs)
 {
     RootedObject obj(cx, objArg);
     MOZ_ASSERT(!cx->runtime()->isAtomsCompartment(cx->compartment()));
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj);
     JSAtom* atom = Atomize(cx, name, strlen(name));

--- a/js/src/jsfriendapi.h
+++ b/js/src/jsfriendapi.h
@@ -662,28 +662,16 @@ JS_FRIEND_API(void)
 AssertSameCompartment(JSObject* objA, JSObject* objB);
 #else
 inline void AssertSameCompartment(JSObject* objA, JSObject* objB) {}
 #endif
 
 JS_FRIEND_API(void)
 NotifyAnimationActivity(JSObject* obj);
 
-/**
- * Return the outermost enclosing function (script) of the scripted caller.
- * This function returns nullptr in several cases:
- *  - no script is running on the context
- *  - the caller is in global or eval code
- * In particular, this function will "stop" its outermost search at eval() and
- * thus it will really return the outermost enclosing function *since the
- * innermost eval*.
- */
-JS_FRIEND_API(JSFunction*)
-GetOutermostEnclosingFunctionOfScriptedCaller(JSContext* cx);
-
 JS_FRIEND_API(JSFunction*)
 DefineFunctionWithReserved(JSContext* cx, JSObject* obj, const char* name, JSNative call,
                            unsigned nargs, unsigned attrs);
 
 JS_FRIEND_API(JSFunction*)
 NewFunctionWithReserved(JSContext* cx, JSNative call, unsigned nargs, unsigned flags,
                         const char* name);
 
@@ -2836,24 +2824,16 @@ typedef long
  * Gecko must call SetJitExceptionFilter before any JIT code is compiled and
  * only once per process.
  */
 extern JS_FRIEND_API(void)
 SetJitExceptionHandler(JitExceptionHandler handler);
 #endif
 
 /**
- * Get the nearest enclosing with environment object for a given function. If
- * the function is not scripted or is not enclosed by a with scope, returns
- * the global.
- */
-extern JS_FRIEND_API(JSObject*)
-GetNearestEnclosingWithEnvironmentObjectForFunction(JSFunction* fun);
-
-/**
  * Get the first SavedFrame object in this SavedFrame stack whose principals are
  * subsumed by the cx's principals. If there is no such frame, return nullptr.
  *
  * Do NOT pass a non-SavedFrame object here.
  *
  * The savedFrame and cx do not need to be in the same compartment.
  */
 extern JS_FRIEND_API(JSObject*)

--- a/js/src/vm/EnvironmentObject.cpp
+++ b/js/src/vm/EnvironmentObject.cpp
@@ -3090,33 +3090,16 @@ js::GetDebugEnvironmentForFrame(JSContex
 
 JSObject*
 js::GetDebugEnvironmentForGlobalLexicalEnvironment(JSContext* cx)
 {
     EnvironmentIter ei(cx, &cx->global()->lexicalEnvironment(), &cx->global()->emptyGlobalScope());
     return GetDebugEnvironment(cx, ei);
 }
 
-// See declaration and documentation in jsfriendapi.h
-JS_FRIEND_API(JSObject*)
-js::GetNearestEnclosingWithEnvironmentObjectForFunction(JSFunction* fun)
-{
-    if (!fun->isInterpreted())
-        return &fun->global();
-
-    JSObject* env = fun->environment();
-    while (env && !env->is<WithEnvironmentObject>())
-        env = env->enclosingEnvironment();
-
-    if (!env)
-        return &fun->global();
-
-    return &env->as<WithEnvironmentObject>().object();
-}
-
 bool
 js::CreateObjectsForEnvironmentChain(JSContext* cx, AutoObjectVector& chain,
                                      HandleObject terminatingEnv, MutableHandleObject envObj)
 {
 #ifdef DEBUG
     for (size_t i = 0; i < chain.length(); ++i) {
         assertSameCompartment(cx, chain[i]);
         MOZ_ASSERT(!chain[i]->is<GlobalObject>());