From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- dom/base/JSExecutionContext.h | 171 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 171 insertions(+) create mode 100644 dom/base/JSExecutionContext.h (limited to 'dom/base/JSExecutionContext.h') diff --git a/dom/base/JSExecutionContext.h b/dom/base/JSExecutionContext.h new file mode 100644 index 0000000000..f6bfbdc628 --- /dev/null +++ b/dom/base/JSExecutionContext.h @@ -0,0 +1,171 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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/. */ + +#ifndef DOM_BASE_JSEXECUTIONCONTEXT_H_ +#define DOM_BASE_JSEXECUTIONCONTEXT_H_ + +#include "js/GCVector.h" +#include "js/TypeDecls.h" +#include "js/Value.h" +#include "js/experimental/JSStencil.h" +#include "jsapi.h" +#include "mozilla/Assertions.h" +#include "mozilla/Attributes.h" +#include "mozilla/ProfilerLabels.h" +#include "mozilla/Vector.h" +#include "nsStringFwd.h" +#include "nscore.h" + +class nsIScriptContext; +class nsIScriptElement; +class nsIScriptGlobalObject; +class nsXBLPrototypeBinding; + +namespace mozilla { +union Utf8Unit; + +namespace dom { + +class ScriptLoadContext; + +class MOZ_STACK_CLASS JSExecutionContext final { + // Register stack annotations for the Gecko profiler. + mozilla::AutoProfilerLabel mAutoProfilerLabel; + + JSContext* mCx; + + // Handles switching to our global's realm. + JSAutoRealm mRealm; + + // Set to a valid handle if a return value is expected. + JS::Rooted mRetValue; + + // The compiled script. + JS::Rooted mScript; + + // The compilation options applied throughout + JS::CompileOptions& mCompileOptions; + + // Debug Metadata: Values managed for the benefit of the debugger when + // inspecting code. + // + // For more details see CompilationAndEvaluation.h, and the comments on + // UpdateDebugMetadata + JS::Rooted mDebuggerPrivateValue; + JS::Rooted mDebuggerIntroductionScript; + + // returned value forwarded when we have to interupt the execution eagerly + // with mSkip. + nsresult mRv; + + // Used to skip upcoming phases in case of a failure. In such case the + // result is carried by mRv. + bool mSkip; + + // Should the result be serialized before being returned. + bool mCoerceToString; + + // Encode the bytecode before it is being executed. + bool mEncodeBytecode; + +#ifdef DEBUG + // Should we set the return value. + bool mWantsReturnValue; + + bool mScriptUsed; +#endif + + private: + // Compile a script contained in a SourceText. + template + nsresult InternalCompile(JS::SourceText& aSrcBuf); + + // Instantiate (on main-thread) a JS::Stencil generated by off-thread or + // main-thread parsing or decoding. + nsresult InstantiateStencil(RefPtr&& aStencil, + JS::InstantiationStorage* aStorage = nullptr); + + public: + // Enter compartment in which the code would be executed. The JSContext + // must come from an AutoEntryScript. + // + // The JS engine can associate metadata for the debugger with scripts at + // compile time. The optional last arguments here cover that metadata. + JSExecutionContext( + JSContext* aCx, JS::Handle aGlobal, + JS::CompileOptions& aCompileOptions, + JS::Handle aDebuggerPrivateValue = JS::UndefinedHandleValue, + JS::Handle aDebuggerIntroductionScript = nullptr); + + JSExecutionContext(const JSExecutionContext&) = delete; + JSExecutionContext(JSExecutionContext&&) = delete; + + ~JSExecutionContext() { + // This flag is reset when the returned value is extracted. + MOZ_ASSERT_IF(!mSkip, !mWantsReturnValue); + + // If encoding was started we expect the script to have been + // used when ending the encoding. + MOZ_ASSERT_IF(mEncodeBytecode && mScript && mRv == NS_OK, mScriptUsed); + } + + // The returned value would be converted to a string if the + // |aCoerceToString| is flag set. + JSExecutionContext& SetCoerceToString(bool aCoerceToString) { + mCoerceToString = aCoerceToString; + return *this; + } + + // When set, this flag records and encodes the bytecode as soon as it is + // being compiled, and before it is being executed. The bytecode can then be + // requested by using |JS::FinishIncrementalEncoding| with the mutable + // handle |aScript| argument of |CompileAndExec| or |JoinAndExec|. + JSExecutionContext& SetEncodeBytecode(bool aEncodeBytecode) { + mEncodeBytecode = aEncodeBytecode; + return *this; + } + + // After getting a notification that an off-thread compile/decode finished, + // this function will take the result of the off-thread operation and move it + // to the main thread. + [[nodiscard]] nsresult JoinOffThread(ScriptLoadContext* aContext); + + // Compile a script contained in a SourceText. + nsresult Compile(JS::SourceText& aSrcBuf); + nsresult Compile(JS::SourceText& aSrcBuf); + + // Compile a script contained in a string. + nsresult Compile(const nsAString& aScript); + + // Decode a script contained in a buffer. + nsresult Decode(const JS::TranscodeRange& aBytecodeBuf); + + // Get a successfully compiled script. + JSScript* GetScript(); + + // Get the compiled script if present, or nullptr. + JSScript* MaybeGetScript(); + + // Execute the compiled script and ignore the return value. + [[nodiscard]] nsresult ExecScript(); + + // Execute the compiled script a get the return value. + // + // Copy the returned value into the mutable handle argument. In case of a + // evaluation failure either during the execution or the conversion of the + // result to a string, the nsresult is be set to the corresponding result + // code and the mutable handle argument remains unchanged. + // + // The value returned in the mutable handle argument is part of the + // compartment given as argument to the JSExecutionContext constructor. If the + // caller is in a different compartment, then the out-param value should be + // wrapped by calling |JS_WrapValue|. + [[nodiscard]] nsresult ExecScript(JS::MutableHandle aRetValue); +}; +} // namespace dom +} // namespace mozilla + +#endif /* DOM_BASE_JSEXECUTIONCONTEXT_H_ */ -- cgit v1.2.3