From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 21:33:14 +0200 Subject: Adding upstream version 115.7.0esr. Signed-off-by: Daniel Baumann --- dom/base/nsJSUtils.h | 250 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 250 insertions(+) create mode 100644 dom/base/nsJSUtils.h (limited to 'dom/base/nsJSUtils.h') diff --git a/dom/base/nsJSUtils.h b/dom/base/nsJSUtils.h new file mode 100644 index 0000000000..67682173f4 --- /dev/null +++ b/dom/base/nsJSUtils.h @@ -0,0 +1,250 @@ +/* -*- 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 nsJSUtils_h__ +#define nsJSUtils_h__ + +/** + * This is not a generated file. It contains common utility functions + * invoked from the JavaScript code generated from IDL interfaces. + * The goal of the utility functions is to cut down on the size of + * the generated code itself. + */ + +#include "mozilla/Assertions.h" + +#include "jsapi.h" +#include "js/CompileOptions.h" +#include "js/Conversions.h" +#include "js/SourceText.h" +#include "js/String.h" // JS::{,Lossy}CopyLinearStringChars, JS::CopyStringChars, JS::Get{,Linear}StringLength, JS::MaxStringLength, JS::StringHasLatin1Chars +#include "nsString.h" +#include "xpcpublic.h" + +class nsIScriptContext; +class nsIScriptElement; +class nsIScriptGlobalObject; +class nsXBLPrototypeBinding; + +namespace mozilla { +union Utf8Unit; + +namespace dom { +class AutoJSAPI; +class Element; +} // namespace dom +} // namespace mozilla + +class nsJSUtils { + public: + static bool GetCallingLocation(JSContext* aContext, nsACString& aFilename, + uint32_t* aLineno = nullptr, + uint32_t* aColumn = nullptr); + static bool GetCallingLocation(JSContext* aContext, nsAString& aFilename, + uint32_t* aLineno = nullptr, + uint32_t* aColumn = nullptr); + + /** + * Retrieve the inner window ID based on the given JSContext. + * + * @param JSContext aContext + * The JSContext from which you want to find the inner window ID. + * + * @returns uint64_t the inner window ID. + */ + static uint64_t GetCurrentlyRunningCodeInnerWindowID(JSContext* aContext); + + static nsresult CompileFunction(mozilla::dom::AutoJSAPI& jsapi, + JS::HandleVector aScopeChain, + JS::CompileOptions& aOptions, + const nsACString& aName, uint32_t aArgCount, + const char** aArgArray, + const nsAString& aBody, + JSObject** aFunctionObject); + + static nsresult UpdateFunctionDebugMetadata( + mozilla::dom::AutoJSAPI& jsapi, JS::Handle aFun, + JS::CompileOptions& aOptions, JS::Handle aElementAttributeName, + JS::Handle aPrivateValue); + + static bool IsScriptable(JS::Handle aEvaluationGlobal); + + // Returns false if an exception got thrown on aCx. Passing a null + // aElement is allowed; that wil produce an empty aScopeChain. + static bool GetScopeChainForElement( + JSContext* aCx, mozilla::dom::Element* aElement, + JS::MutableHandleVector aScopeChain); + + static void ResetTimeZone(); + + static bool DumpEnabled(); + + // A helper function that receives buffer pointer, creates ArrayBuffer, and + // convert it to Uint8Array. + // Note that the buffer needs to be created by JS_malloc (or at least can be + // freed by JS_free), as the resulting Uint8Array takes the ownership of the + // buffer. + static JSObject* MoveBufferAsUint8Array(JSContext* aCx, size_t aSize, + mozilla::UniquePtr& aBuffer); +}; + +inline void AssignFromStringBuffer(nsStringBuffer* buffer, size_t len, + nsAString& dest) { + buffer->ToString(len, dest); +} + +template ::value>* = nullptr> +inline bool AssignJSString(JSContext* cx, T& dest, JSString* s) { + size_t len = JS::GetStringLength(s); + static_assert(JS::MaxStringLength < (1 << 30), + "Shouldn't overflow here or in SetCapacity"); + + const char16_t* chars; + if (XPCStringConvert::MaybeGetDOMStringChars(s, &chars)) { + // The characters represent an existing string buffer that we shared with + // JS. We can share that buffer ourselves if the string corresponds to the + // whole buffer; otherwise we have to copy. + if (chars[len] == '\0') { + AssignFromStringBuffer( + nsStringBuffer::FromData(const_cast(chars)), len, dest); + return true; + } + } else if (XPCStringConvert::MaybeGetLiteralStringChars(s, &chars)) { + // The characters represent a literal char16_t string constant + // compiled into libxul; we can just use it as-is. + dest.AssignLiteral(chars, len); + return true; + } + + // We don't bother checking for a dynamic-atom external string, because we'd + // just need to copy out of it anyway. + + if (MOZ_UNLIKELY(!dest.SetLength(len, mozilla::fallible))) { + JS_ReportOutOfMemory(cx); + return false; + } + return JS::CopyStringChars(cx, dest.BeginWriting(), s, len); +} + +// Specialization for UTF8String. +template ::value>* = nullptr> +inline bool AssignJSString(JSContext* cx, T& dest, JSString* s) { + using namespace mozilla; + CheckedInt bufLen(JS::GetStringLength(s)); + // From the contract for JS_EncodeStringToUTF8BufferPartial, to guarantee that + // the whole string is converted. + if (JS::StringHasLatin1Chars(s)) { + bufLen *= 2; + } else { + bufLen *= 3; + } + + if (MOZ_UNLIKELY(!bufLen.isValid())) { + JS_ReportOutOfMemory(cx); + return false; + } + + // Shouldn't really matter, but worth being safe. + const bool kAllowShrinking = true; + + auto handleOrErr = dest.BulkWrite(bufLen.value(), 0, kAllowShrinking); + if (MOZ_UNLIKELY(handleOrErr.isErr())) { + JS_ReportOutOfMemory(cx); + return false; + } + + auto handle = handleOrErr.unwrap(); + + auto maybe = JS_EncodeStringToUTF8BufferPartial(cx, s, handle.AsSpan()); + if (MOZ_UNLIKELY(!maybe)) { + JS_ReportOutOfMemory(cx); + return false; + } + + size_t read; + size_t written; + std::tie(read, written) = *maybe; + + MOZ_ASSERT(read == JS::GetStringLength(s)); + handle.Finish(written, kAllowShrinking); + return true; +} + +inline void AssignJSLinearString(nsAString& dest, JSLinearString* s) { + size_t len = JS::GetLinearStringLength(s); + static_assert(JS::MaxStringLength < (1 << 30), + "Shouldn't overflow here or in SetCapacity"); + dest.SetLength(len); + JS::CopyLinearStringChars(dest.BeginWriting(), s, len); +} + +inline void AssignJSLinearString(nsACString& dest, JSLinearString* s) { + size_t len = JS::GetLinearStringLength(s); + static_assert(JS::MaxStringLength < (1 << 30), + "Shouldn't overflow here or in SetCapacity"); + dest.SetLength(len); + JS::LossyCopyLinearStringChars(dest.BeginWriting(), s, len); +} + +template +class nsTAutoJSLinearString : public nsTAutoString { + public: + explicit nsTAutoJSLinearString(JSLinearString* str) { + AssignJSLinearString(*this, str); + } +}; + +using nsAutoJSLinearString = nsTAutoJSLinearString; +using nsAutoJSLinearCString = nsTAutoJSLinearString; + +template +class nsTAutoJSString : public nsTAutoString { + public: + /** + * nsTAutoJSString should be default constructed, which leaves it empty + * (this->IsEmpty()), and initialized with one of the init() methods below. + */ + nsTAutoJSString() = default; + + bool init(JSContext* aContext, JSString* str) { + return AssignJSString(aContext, *this, str); + } + + bool init(JSContext* aContext, const JS::Value& v) { + if (v.isString()) { + return init(aContext, v.toString()); + } + + // Stringify, making sure not to run script. + JS::Rooted str(aContext); + if (v.isObject()) { + str = JS_NewStringCopyZ(aContext, "[Object]"); + } else { + JS::Rooted rootedVal(aContext, v); + str = JS::ToString(aContext, rootedVal); + } + + return str && init(aContext, str); + } + + bool init(JSContext* aContext, jsid id) { + JS::Rooted v(aContext); + return JS_IdToValue(aContext, id, &v) && init(aContext, v); + } + + bool init(const JS::Value& v); + + ~nsTAutoJSString() = default; +}; + +using nsAutoJSString = nsTAutoJSString; + +// Note that this is guaranteed to be UTF-8. +using nsAutoJSCString = nsTAutoJSString; + +#endif /* nsJSUtils_h__ */ -- cgit v1.2.3