LibJS: Stop tracking whether execution context is strict mode or not

This was only used for basic testing, and forced us to plumb this flag
flag in a bunch of places.

Libraries/LibJS/Bytecode/Interpreter.cpp

@@ -249,9 +249,6 @@ ThrowCompletionOr<Value> Interpreter::run(Script& script_record, GC::Ptr<Environ
 
     // 8. Set the PrivateEnvironment of scriptContext to null.
 
-    // NOTE: This isn't in the spec, but we require it.
-    script_context->is_strict_mode = script_record.is_strict_mode();
-
     // 9. Suspend the currently running execution context.
     // 10. Push scriptContext onto the execution context stack; scriptContext is now the running execution context.
     TRY(vm.push_execution_context(*script_context, {}));

Libraries/LibJS/Runtime/AbstractOperations.cpp

@@ -723,9 +723,6 @@ ThrowCompletionOr<Value> perform_eval(VM& vm, Value x, CallerMode strict_caller,
     // 28. Set evalContext's PrivateEnvironment to privateEnv.
     eval_context->private_environment = private_environment;
 
-    // NOTE: This isn't in the spec, but we require it.
-    eval_context->is_strict_mode = strict_eval;
-
     // 29. Push evalContext onto the execution context stack; evalContext is now the running execution context.
     TRY(vm.push_execution_context(*eval_context, {}));
 

Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp

@@ -689,9 +689,6 @@ void ECMAScriptFunctionObject::make_method(Object& home_object)
 // 10.2.1.1 PrepareForOrdinaryCall ( F, newTarget ), https://tc39.es/ecma262/#sec-prepareforordinarycall
 void ECMAScriptFunctionObject::prepare_for_ordinary_call(VM& vm, ExecutionContext& callee_context, Object* new_target)
 {
-    // Non-standard
-    callee_context.is_strict_mode = is_strict_mode();
-
     // 1. Let callerContext be the running execution context.
     // 2. Let calleeContext be a new ECMAScript code execution context.
 

Libraries/LibJS/Runtime/ExecutionContext.cpp

@@ -125,7 +125,6 @@ NonnullOwnPtr<ExecutionContext> ExecutionContext::copy() const
     copy->program_counter = program_counter;
     copy->function_name = function_name;
     copy->this_value = this_value;
-    copy->is_strict_mode = is_strict_mode;
     copy->executable = executable;
     copy->arguments_offset = arguments_offset;
     copy->passed_argument_count = passed_argument_count;

Libraries/LibJS/Runtime/ExecutionContext.h

@@ -95,7 +95,6 @@ public:
 
     u32 arguments_offset { 0 };
     u32 passed_argument_count { 0 };
-    bool is_strict_mode { false };
 
     Span<Value> arguments;
 

Libraries/LibJS/Runtime/NativeFunction.cpp

@@ -151,9 +151,6 @@ ThrowCompletionOr<Value> NativeFunction::internal_call(ExecutionContext& callee_
     //       calling async_block_start which goes through a NativeFunction here.
     callee_context.private_environment = caller_context.private_environment;
 
-    // NOTE: This is a LibJS specific hack for NativeFunction to inherit the strictness of its caller.
-    callee_context.is_strict_mode = caller_context.is_strict_mode;
-
     // </8.> --------------------------------------------------------------------------
 
     // 9. Push calleeContext onto the execution context stack; calleeContext is now the running execution context.
@@ -204,9 +201,6 @@ ThrowCompletionOr<GC::Ref<Object>> NativeFunction::internal_construct(ExecutionC
     callee_context.lexical_environment = caller_context.lexical_environment;
     callee_context.variable_environment = caller_context.variable_environment;
 
-    // NOTE: This is a LibJS specific hack for NativeFunction to inherit the strictness of its caller.
-    callee_context.is_strict_mode = caller_context.is_strict_mode;
-
     // </8.> --------------------------------------------------------------------------
 
     // 9. Push calleeContext onto the execution context stack; calleeContext is now the running execution context.

Libraries/LibJS/Runtime/ShadowRealm.cpp

@@ -342,9 +342,6 @@ NonnullOwnPtr<ExecutionContext> get_shadow_realm_context(Realm& shadow_realm, bo
     // 10. Set context's PrivateEnvironment to null.
     context->private_environment = nullptr;
 
-    // Non-standard
-    context->is_strict_mode = strict_eval;
-
     // 11. Return context.
     return context;
 }

Libraries/LibJS/Script.cpp

@@ -25,18 +25,15 @@ Result<GC::Ref<Script>, Vector<ParserError>> Script::parse(StringView source_tex
     if (parser.has_errors())
         return parser.errors();
 
-    bool strict_mode = script->is_strict_mode();
-
     // 3. Return Script Record { [[Realm]]: realm, [[ECMAScriptCode]]: script, [[HostDefined]]: hostDefined }.
-    return realm.heap().allocate<Script>(realm, filename, move(script), host_defined, strict_mode);
+    return realm.heap().allocate<Script>(realm, filename, move(script), host_defined);
 }
 
-Script::Script(Realm& realm, StringView filename, NonnullRefPtr<Program> parse_node, HostDefined* host_defined, bool strict_mode)
+Script::Script(Realm& realm, StringView filename, NonnullRefPtr<Program> parse_node, HostDefined* host_defined)
     : m_realm(realm)
     , m_parse_node(move(parse_node))
     , m_filename(filename)
     , m_host_defined(host_defined)
-    , m_strict_mode(strict_mode)
 {
 }
 

Libraries/LibJS/Script.h

@@ -46,10 +46,8 @@ public:
     HostDefined* host_defined() const { return m_host_defined; }
     StringView filename() const LIFETIME_BOUND { return m_filename; }
 
-    [[nodiscard]] bool is_strict_mode() const { return m_strict_mode; }
-
 private:
-    Script(Realm&, StringView filename, NonnullRefPtr<Program>, HostDefined*, bool strict_mode);
+    Script(Realm&, StringView filename, NonnullRefPtr<Program>, HostDefined*);
 
     virtual void visit_edges(Cell::Visitor&) override;
 
@@ -60,8 +58,6 @@ private:
     // Needed for potential lookups of modules.
     ByteString m_filename;
     HostDefined* m_host_defined { nullptr }; // [[HostDefined]]
-
-    bool m_strict_mode { false };
 };
 
 }

Libraries/LibJS/SourceTextModule.cpp

@@ -709,9 +709,6 @@ ThrowCompletionOr<void> SourceTextModule::execute_module(VM& vm, GC::Ptr<Promise
     ExecutionContext* module_context = nullptr;
     ALLOCATE_EXECUTION_CONTEXT_ON_NATIVE_STACK(module_context, registers_and_constants_and_locals_count, 0);
 
-    // NOTE: This is not in the spec but we require it.
-    module_context->is_strict_mode = true;
-
     // 2. Set the Function of moduleContext to null.
 
     // 3. Set the Realm of moduleContext to module.[[Realm]].

Libraries/LibJS/Tests/builtins/ShadowRealm/ShadowRealm.prototype.evaluate.js

@@ -15,12 +15,11 @@ describe("normal behavior", () => {
         // Currently uses a plain JS::GlobalObject, i.e. no TestRunnerGlobalObject functions are available on the
         // shadow realm's global object. This may change in the future, update the test accordingly.
         const shadowRealm = new ShadowRealm();
-        expect(shadowRealm.evaluate("globalThis.isStrictMode")).toBeUndefined();
+        expect(shadowRealm.evaluate("globalThis.markAsGarbage")).toBeUndefined();
     });
 
     test("strict mode behavior", () => {
         const shadowRealm = new ShadowRealm();
-        // NOTE: We don't have access to the isStrictMode() test helper inside the shadow realm, see the comment in the test above.
 
         // sloppy mode
         expect(shadowRealm.evaluate("(function() { return !this; })()")).toBe(false);

Libraries/LibJS/Tests/classes/class-strict-mode.js

@@ -1,19 +0,0 @@
-test("constructors are always strict mode", () => {
-    class A {
-        constructor() {
-            expect(isStrictMode()).toBeTrue();
-        }
-    }
-
-    new A();
-});
-
-test("methods are always strict mode", () => {
-    class A {
-        method() {
-            expect(isStrictMode()).toBeTrue();
-        }
-    }
-
-    new A().method();
-});

Libraries/LibJS/Tests/functions/arrow-functions.js

@@ -110,33 +110,6 @@ test("arrow functions in objects", () => {
     expect(foobar.x.z()).toBe(foobar.x);
 });
 
-test("strict mode propagation", () => {
-    (() => {
-        "use strict";
-        expect(isStrictMode()).toBeTrue();
-
-        (() => {
-            expect(isStrictMode()).toBeTrue();
-        })();
-    })();
-
-    (() => {
-        "use strict";
-        expect(isStrictMode()).toBeTrue();
-    })();
-
-    (() => {
-        expect(isStrictMode()).toBeFalse();
-
-        (() => {
-            "use strict";
-            expect(isStrictMode()).toBeTrue();
-        })();
-
-        expect(isStrictMode()).toBeFalse();
-    })();
-});
-
 test("no prototype", () => {
     let foo = () => {};
     expect(foo).not.toHaveProperty("prototype");

Libraries/LibJS/Tests/functions/function-strict-mode.js

@@ -1,64 +1,3 @@
-test("non strict-mode by default", () => {
-    expect(isStrictMode()).toBeFalse();
-});
-
-test("use strict with double quotes", () => {
-    "use strict";
-    expect(isStrictMode()).toBeTrue();
-});
-
-// prettier-ignore
-test("use strict with single quotes", () => {
-    'use strict';
-    expect(isStrictMode()).toBeTrue();
-});
-
-// prettier-ignore
-test("use strict with backticks does not yield strict mode", () => {
-    `use strict`;
-    expect(isStrictMode()).toBeFalse();
-});
-
-// prettier-ignore
-test("use strict with single quotes after statement does not yield strict mode code", () => {
-    ;'use strict';
-    expect(isStrictMode()).toBeFalse();
-});
-
-// prettier-ignore
-test("use strict with double quotes after statement does not yield strict mode code", () => {
-    ;"use strict";
-    expect(isStrictMode()).toBeFalse();
-});
-
-test("use strict interrupted by a line continuation does not yield strict mode code", () => {
-    "use \
-strict";
-    expect(isStrictMode()).toBeFalse();
-});
-
-test("strict mode propagates down the scope chain", () => {
-    "use strict";
-    expect(isStrictMode()).toBeTrue();
-    (function () {
-        expect(isStrictMode()).toBeTrue();
-    })();
-});
-
-test("strict mode does not propagate up the scope chain", () => {
-    expect(isStrictMode()).toBeFalse();
-    (function () {
-        "use strict";
-        expect(isStrictMode()).toBeTrue();
-    })();
-    expect(isStrictMode()).toBeFalse();
-});
-
-test('only the string "use strict" yields strict mode code', () => {
-    "use stric";
-    expect(isStrictMode()).toBeFalse();
-});
-
 test("strict mode does not apply global object to |this|", () => {
     "use strict";
     let functionThis;

Libraries/LibJS/Tests/program-non-strict.js

@@ -1,61 +0,0 @@
-"do not use strict";
-"no really";
-// /\ Valid directives which should not trigger strict mode
-
-test("basic functionality", () => {
-    expect(isStrictMode()).toBeFalse();
-
-    (function () {
-        expect(isStrictMode()).toBeFalse();
-    })();
-
-    (() => {
-        expect(isStrictMode()).toBeFalse();
-    })();
-
-    (() => {
-        expect(isStrictMode()).toBeFalse();
-    })();
-
-    function a() {
-        expect(isStrictMode()).toBeFalse();
-    }
-
-    a();
-
-    eval("expect(isStrictMode()).toBeFalse()");
-});
-
-test("functions with strict mode", () => {
-    expect(isStrictMode()).toBeFalse();
-
-    function a() {
-        "this is allowed trust me";
-        "use strict";
-        expect(isStrictMode()).toBeTrue();
-    }
-
-    a();
-
-    expect(isStrictMode()).toBeFalse();
-
-    (() => {
-        "use strict";
-        expect(isStrictMode()).toBeTrue();
-    })();
-
-    function b() {
-        eval("expect(isStrictMode()).toBeFalse()");
-
-        function nested() {
-            "use strict";
-            eval("expect(isStrictMode()).toBeTrue()");
-        }
-
-        nested();
-
-        eval("expect(isStrictMode()).toBeFalse()");
-    }
-
-    b();
-});

Libraries/LibJS/Tests/program-strict-mode.js

@@ -1,26 +0,0 @@
-"use strict";
-
-test("basic functionality", () => {
-    expect(isStrictMode()).toBeTrue();
-
-    (function () {
-        expect(isStrictMode()).toBeTrue();
-    })();
-
-    (() => {
-        expect(isStrictMode()).toBeTrue();
-    })();
-
-    (() => {
-        "use strict";
-        expect(isStrictMode()).toBeTrue();
-    })();
-
-    function a() {
-        expect(isStrictMode()).toBeTrue();
-    }
-
-    a();
-
-    eval("expect(isStrictMode()).toBeTrue()");
-});

Libraries/LibJS/Tests/strict-mode-blocks.js

@@ -1,25 +0,0 @@
-test("Issue #3641, strict mode should be function- or program-level, not block-level", () => {
-    function func() {
-        expect(isStrictMode()).toBeFalse();
-
-        // prettier-ignore
-        {
-            "use strict";
-            expect(isStrictMode()).toBeFalse();
-        }
-
-        // prettier-ignore
-        if (true) {
-            "use strict";
-            expect(isStrictMode()).toBeFalse();
-        }
-
-        // prettier-ignore
-        do {
-            "use strict";
-            expect(isStrictMode()).toBeFalse();
-        } while (false);
-    }
-
-    func();
-});

Libraries/LibJS/Tests/use-strict-directive.js

@@ -1,61 +0,0 @@
-test("valid 'use strict; directive", () => {
-    expect(
-        (() => {
-            "use strict";
-            return isStrictMode();
-        })()
-    ).toBeTrue();
-    expect(
-        // prettier-ignore
-        (() => {
-            'use strict';
-            return isStrictMode();
-        })()
-    ).toBeTrue();
-});
-
-test("invalid 'use strict; directive", () => {
-    expect(
-        (() => {
-            " use strict ";
-            return isStrictMode();
-        })()
-    ).toBeFalse();
-    expect(
-        (() => {
-            `use strict`;
-            return isStrictMode();
-        })()
-    ).toBeFalse();
-    expect(
-        (() => {
-            "use\
-            strict";
-            return isStrictMode();
-        })()
-    ).toBeFalse();
-    expect(
-        (() => {
-            "use\ strict";
-            return isStrictMode();
-        })()
-    ).toBeFalse();
-    expect(
-        (() => {
-            "use \163trict";
-            return isStrictMode();
-        })()
-    ).toBeFalse();
-    expect(
-        (() => {
-            `"use strict"`;
-            return isStrictMode();
-        })()
-    ).toBeFalse();
-    expect(
-        (() => {
-            "use strict" + 1;
-            return isStrictMode();
-        })()
-    ).toBeFalse();
-});

Tests/LibJS/test-js.cpp

@@ -17,11 +17,6 @@ TEST_ROOT("Libraries/LibJS/Tests");
 
 TESTJS_PROGRAM_FLAG(test262_parser_tests, "Run test262 parser tests", "test262-parser-tests", 0);
 
-TESTJS_GLOBAL_FUNCTION(is_strict_mode, isStrictMode, 0)
-{
-    return JS::Value(vm.running_execution_context().is_strict_mode);
-}
-
 TESTJS_GLOBAL_FUNCTION(can_parse_source, canParseSource)
 {
     auto source = TRY(vm.argument(0).to_string(vm));