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 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_BINDINGS_EXCEPTION_STATE_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_BINDINGS_EXCEPTION_STATE_H_

#include "base/check.h"
#include "base/compiler_specific.h"
#include "base/dcheck_is_on.h"
#include "base/location.h"
#include "third_party/blink/renderer/platform/bindings/exception_code.h"
#include "third_party/blink/renderer/platform/bindings/exception_context.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
#include "v8/include/v8.h"

namespace blink {

class DummyExceptionStateForTesting;

// ExceptionState is a scope-like class and provides a way to throw an exception
// with an option to cancel it.  An exception message may be auto-generated.
class PLATFORM_EXPORT ExceptionState {
  STACK_ALLOCATED();

 public:
  // A function pointer type that creates a DOMException.
  using CreateDOMExceptionFunction =
      v8::Local<v8::Value> (*)(v8::Isolate*,
                               DOMExceptionCode,
                               const String& sanitized_message,
                               const String& unsanitized_message);

  // Sets the function to create a DOMException. Must be called only once.
  static void SetCreateDOMExceptionFunction(CreateDOMExceptionFunction);

  // If `isolate` is nullptr, this ExceptionState will ignore all exceptions.
  explicit ExceptionState(v8::Isolate* isolate)
      : ExceptionState(isolate, kEmptyContext) {}

  ExceptionState(v8::Isolate* isolate, const ExceptionContext& context)
      : context_(context), isolate_(isolate) {}

  ExceptionState(const ExceptionState&) = delete;
  ExceptionState& operator=(const ExceptionState&) = delete;

  ~ExceptionState() {
    DCHECK(!had_exception_ || !isolate_ || isolate_->HasPendingException());
  }

  // Throws a DOMException due to the given exception code.
  NOINLINE void ThrowDOMException(DOMExceptionCode, const String& message);

  // Throws a constructed DOMException.
  NOINLINE void ThrowDOMException(v8::Local<v8::Value> exception,
                                  DOMExceptionCode code,
                                  const String& message);

  // Throws a DOMException with SECURITY_ERR.
  NOINLINE void ThrowSecurityError(
      const String& sanitized_message,
      const String& unsanitized_message = String());

  // Throws an ECMAScript Error object.
  NOINLINE void ThrowRangeError(const String& message);
  NOINLINE void ThrowTypeError(const String& message);
  NOINLINE void ThrowSyntaxError(const String& message);

  // Throws WebAssembly Error object.
  NOINLINE void ThrowWasmCompileError(const String& message);

  // These overloads reduce the binary code size because the call sites do not
  // need the conversion by String::String(const char*) that is inlined at each
  // call site. As there are many call sites that pass in a const char*, this
  // size optimization is effective (32kb reduction as of June 2018).
  // See also https://crbug.com/849743
  NOINLINE void ThrowDOMException(DOMExceptionCode, const char* message);
  NOINLINE void ThrowSecurityError(const char* sanitized_message,
                                   const char* unsanitized_message = nullptr);
  NOINLINE void ThrowRangeError(const char* message);
  NOINLINE void ThrowTypeError(const char* message);
  NOINLINE void ThrowSyntaxError(const char* message);
  NOINLINE void ThrowWasmCompileError(const char* message);

  // Report the given value as the exception being thrown, but rethrow it
  // immediately via the v8::TryCatch instead of in the destructor.
  NOINLINE void RethrowV8Exception(v8::TryCatch&);

  // Returns true if there is a pending exception.
  bool HadException() const { return had_exception_; }

  // Returns the context of what Web API is currently being executed.
  const ExceptionContext& GetContext() const { return context_; }

  v8::Isolate* GetIsolate() const { return isolate_; }

  ExceptionState& ReturnThis() { return *this; }

  // A helper for correctly asserting no pending v8 exception (which,
  // as it happens, involved properly excluding a termination exception).
  static void AssertNoPendingException(v8::Isolate* isolate) {
    CHECK(!isolate->HasPendingException() || isolate->IsExecutionTerminating());
  }

 protected:
  // Delegated constructor for NonThrowableExceptionState
  enum ForNonthrowable { kNonthrowable };
#if DCHECK_IS_ON()
  ExceptionState(const base::Location& location, ForNonthrowable)
#else
  explicit ExceptionState(ForNonthrowable)
#endif
      : context_(kEmptyContext),
        isolate_(nullptr)
#if DCHECK_IS_ON()
        ,
        location_(location),
        assert_no_exceptions_(true)
#endif
  {
  }

  // Delegated constructor for DummyExceptionStateForTesting
  explicit ExceptionState(DummyExceptionStateForTesting& dummy_derived);

  static constexpr ExceptionContext kEmptyContext{};

 private:
  void SetExceptionInfo(ExceptionCode, const String&);
  // Since DOMException is defined in core/, we need a dependency injection in
  // order to create a DOMException in platform/.
  static CreateDOMExceptionFunction s_create_dom_exception_func_;

  // The context represents what Web API is currently being executed.
  // In most cases, this is `kEmptyContext`. In the cases where
  // the generated bindings provide a non-empty context, the caller is
  // responsible for ensuring `context_` outlives this object.
  ExceptionContext context_;

  v8::Isolate* const isolate_;

  bool had_exception_ = false;
  bool swallow_all_exceptions_ = false;

#if DCHECK_IS_ON()
  base::Location location_;
  bool assert_no_exceptions_ = false;
#endif
};

// Syntactic sugar for creating an ExceptionState that will throw as soon as
// the function it's passed to returns.
// This is useful for when a v8::TryCatch is on the stack.
class PassThroughException {
  STACK_ALLOCATED();

 public:
  explicit PassThroughException(v8::Isolate* isolate)
      : exception_state_(isolate) {}

  operator ExceptionState&() & = delete;
  operator ExceptionState&() && { return exception_state_; }

 private:
  ExceptionState exception_state_;
};

// NonThrowableExceptionState never allow call sites to throw an exception.
// Should be used if an exception must not be thrown.
class PLATFORM_EXPORT NonThrowableExceptionState final : public ExceptionState {
 public:
#if DCHECK_IS_ON()
  explicit NonThrowableExceptionState(
      base::Location location = base::Location::Current())
      : ExceptionState(location, kNonthrowable) {}
#else
  NonThrowableExceptionState() : ExceptionState(kNonthrowable) {}
#endif
};

// DummyExceptionStateForTesting ignores all thrown exceptions. Syntactic sugar
// for ExceptionState(nullptr)
class PLATFORM_EXPORT DummyExceptionStateForTesting final
    : public ExceptionState {
 public:
  DummyExceptionStateForTesting() : ExceptionState(*this) {}

  ExceptionCode Code() const { return code_; }
  template <typename T>
  T CodeAs() const {
    return static_cast<T>(Code());
  }
  const String& Message() const { return message_; }

 private:
  friend class ExceptionState;
  ExceptionCode code_ = 0;
  String message_;
};

class PLATFORM_EXPORT TryRethrowScope {
  STACK_ALLOCATED();

 public:
  TryRethrowScope(v8::Isolate* isolate, ExceptionState& exception_state)
      : try_catch_(isolate), exception_state_(exception_state) {}

  ~TryRethrowScope() {
    if (try_catch_.HasCaught()) [[unlikely]] {
      exception_state_.RethrowV8Exception(try_catch_);
    }
  }

  bool HasCaught() const { return try_catch_.HasCaught(); }
  v8::Local<v8::Value> GetException() const { return try_catch_.Exception(); }

  static v8::Local<v8::Value> TakeException(v8::TryCatch& try_catch) {
    v8::Local<v8::Value> result = try_catch.Exception();
    try_catch.Reset();
    return result;
  }

  v8::Local<v8::Value> TakeException() { return TakeException(try_catch_); }

 private:
  v8::TryCatch try_catch_;
  ExceptionState& exception_state_;
};

// Syntax sugar for ExceptionState(nullptr)
// This can be used as a default value of an ExceptionState parameter like this:
//
//     Node* removeChild(Node*, ExceptionState& = IGNORE_EXCEPTION);
#define IGNORE_EXCEPTION (::blink::ExceptionState(nullptr).ReturnThis())
#define IGNORE_EXCEPTION_FOR_TESTING IGNORE_EXCEPTION

// Syntax sugar for NonThrowableExceptionState.
// This can be used as a default value of an ExceptionState parameter like this:
//
//     Node* removeChild(Node*, ExceptionState& = ASSERT_NO_EXCEPTION);
#if DCHECK_IS_ON()
#define ASSERT_NO_EXCEPTION (::blink::NonThrowableExceptionState().ReturnThis())
#else
#define ASSERT_NO_EXCEPTION IGNORE_EXCEPTION
#endif
}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_BINDINGS_EXCEPTION_STATE_H_