// Copyright (C) 2017 The Qt Company Ltd. // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only #include "qv4functiontable_p.h" #include "qv4function_p.h" #include #include #include QT_BEGIN_NAMESPACE namespace QV4 { void generateFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef) { // This implements writing of JIT'd addresses so that perf can find the // symbol names. // // Perf expects the mapping to be in a certain place and have certain // content, for more information, see: // https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/jit-interface.txt static bool doProfile = !qEnvironmentVariableIsEmpty("QV4_PROFILE_WRITE_PERF_MAP"); if (Q_UNLIKELY(doProfile)) { static QFile perfMapFile(QString::fromLatin1("/tmp/perf-%1.map") .arg(QCoreApplication::applicationPid())); static const bool isOpen = perfMapFile.open(QIODevice::WriteOnly); if (!isOpen) { qWarning("QV4::JIT::Assembler: Cannot write perf map file."); doProfile = false; } else { const void *address = codeRef->code().executableAddress(); perfMapFile.write(QByteArray::number(reinterpret_cast(address), 16)); perfMapFile.putChar(' '); perfMapFile.write(QByteArray::number(static_cast(codeRef->size()), 16)); perfMapFile.putChar(' '); perfMapFile.write(Function::prettyName(function, address).toUtf8()); perfMapFile.putChar('\n'); perfMapFile.flush(); } } } void destroyFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef) { Q_UNUSED(function); Q_UNUSED(codeRef); // It's not advisable to remove things from the perf map file, as it's primarily used to analyze // a trace after the application has terminated. We want to know about all functions that were // ever jitted then. If the memory ranges overlap, we will have a problem when analyzing the // trace. The JIT should try to avoid this. } size_t exceptionHandlerSize() { return 0; } } // QV4 QT_END_NAMESPACE