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/* -*- 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 frontend_FrontendContext_h
#define frontend_FrontendContext_h
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include "mozilla/Attributes.h" // MOZ_STACK_CLASS
#include "mozilla/Maybe.h" // mozilla::Maybe
#include <stddef.h> // size_t
#include "js/AllocPolicy.h" // SystemAllocPolicy, AllocFunction
#include "js/ErrorReport.h" // JSErrorCallback, JSErrorFormatString
#include "js/Vector.h" // Vector
#include "vm/ErrorReporting.h" // CompileError
#include "vm/MallocProvider.h" // MallocProvider
struct JSContext;
namespace js {
class FrontendContext;
namespace frontend {
class NameCollectionPool;
} // namespace frontend
struct FrontendErrors {
FrontendErrors() = default;
// Any errors or warnings produced during compilation. These are reported
// when finishing the script.
mozilla::Maybe<CompileError> error;
Vector<CompileError, 0, SystemAllocPolicy> warnings;
bool overRecursed = false;
bool outOfMemory = false;
bool allocationOverflow = false;
bool hadErrors() const {
return outOfMemory || overRecursed || allocationOverflow || error;
}
};
class FrontendAllocator : public MallocProvider<FrontendAllocator> {
private:
FrontendContext* const fc_;
public:
explicit FrontendAllocator(FrontendContext* fc) : fc_(fc) {}
void* onOutOfMemory(js::AllocFunction allocFunc, arena_id_t arena,
size_t nbytes, void* reallocPtr = nullptr);
void reportAllocationOverflow();
};
class FrontendContext {
private:
FrontendAllocator alloc_;
js::FrontendErrors errors_;
// NameCollectionPool can be either:
// * owned by this FrontendContext, or
// * borrowed from JSContext
frontend::NameCollectionPool* nameCollectionPool_;
bool ownNameCollectionPool_;
protected:
// (optional) Current JSContext to support main-thread-specific
// handling for error reporting, GC, and memory allocation.
//
// Set by setCurrentJSContext.
JSContext* maybeCx_ = nullptr;
public:
FrontendContext()
: alloc_(this),
nameCollectionPool_(nullptr),
ownNameCollectionPool_(false) {}
~FrontendContext();
bool allocateOwnedPool();
frontend::NameCollectionPool& nameCollectionPool() {
MOZ_ASSERT(
nameCollectionPool_,
"Either allocateOwnedPool or setCurrentJSContext must be called");
return *nameCollectionPool_;
}
FrontendAllocator* getAllocator() { return &alloc_; }
void setCurrentJSContext(JSContext* cx);
// Returns JSContext if any.
//
// This can be used only for:
// * Main-thread-specific operation, such as operating on JSAtom
// * Optional operation, such as providing better error message
JSContext* maybeCurrentJSContext() { return maybeCx_; }
enum class Warning { Suppress, Report };
void convertToRuntimeError(JSContext* cx, Warning warning = Warning::Report);
void linkWithJSContext(JSContext* cx);
mozilla::Maybe<CompileError>& maybeError() { return errors_.error; }
Vector<CompileError, 0, SystemAllocPolicy>& warnings() {
return errors_.warnings;
}
// Report CompileErrors
void reportError(js::CompileError&& err);
bool reportWarning(js::CompileError&& err);
// Report FrontendAllocator errors
void* onOutOfMemory(js::AllocFunction allocFunc, arena_id_t arena,
size_t nbytes, void* reallocPtr = nullptr);
void onAllocationOverflow();
void onOutOfMemory();
void onOverRecursed();
void recoverFromOutOfMemory();
const JSErrorFormatString* gcSafeCallback(JSErrorCallback callback,
void* userRef,
const unsigned errorNumber);
// Status of errors reported to this FrontendContext
bool hadOutOfMemory() const { return errors_.outOfMemory; }
bool hadOverRecursed() const { return errors_.overRecursed; }
bool hadAllocationOverflow() const { return errors_.allocationOverflow; }
bool hadErrors() const;
#ifdef __wasi__
void incWasiRecursionDepth();
void decWasiRecursionDepth();
bool checkWasiRecursionLimit();
#endif // __wasi__
private:
void ReportOutOfMemory();
void addPendingOutOfMemory();
};
// Automatically report any pending exception when leaving the scope.
class MOZ_STACK_CLASS AutoReportFrontendContext : public FrontendContext {
// The target JSContext to report the errors to.
JSContext* cx_;
Warning warning_;
public:
explicit AutoReportFrontendContext(JSContext* cx,
Warning warning = Warning::Report)
: FrontendContext(), cx_(cx), warning_(warning) {
setCurrentJSContext(cx_);
MOZ_ASSERT(cx_ == maybeCx_);
}
~AutoReportFrontendContext() {
if (cx_) {
convertToRuntimeErrorAndClear();
}
}
void clearAutoReport() { cx_ = nullptr; }
void convertToRuntimeErrorAndClear() {
convertToRuntimeError(cx_, warning_);
cx_ = nullptr;
}
};
/*
* Explicitly report any pending exception before leaving the scope.
*
* Before an instance of this class leaves the scope, you must call either
* failure() (if there are exceptions to report) or ok() (if there are no
* exceptions to report).
*/
class ManualReportFrontendContext : public FrontendContext {
JSContext* cx_;
#ifdef DEBUG
bool handled_ = false;
#endif
public:
explicit ManualReportFrontendContext(JSContext* cx)
: FrontendContext(), cx_(cx) {
setCurrentJSContext(cx_);
}
~ManualReportFrontendContext() { MOZ_ASSERT(handled_); }
void ok() {
#ifdef DEBUG
handled_ = true;
#endif
}
void failure() {
#ifdef DEBUG
handled_ = true;
#endif
convertToRuntimeError(cx_);
}
};
} // namespace js
#endif /* frontend_FrontendContext_h */
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