| 1 | // Copyright (C) 2017 The Qt Company Ltd. |
|---|---|
| 2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
| 3 | |
| 4 | #include "qv4functiontable_p.h" |
| 5 | #include "qv4function_p.h" |
| 6 | |
| 7 | #include <assembler/MacroAssemblerCodeRef.h> |
| 8 | |
| 9 | #include <QtCore/qfile.h> |
| 10 | #include <QtCore/qcoreapplication.h> |
| 11 | |
| 12 | QT_BEGIN_NAMESPACE |
| 13 | |
| 14 | namespace QV4 { |
| 15 | |
| 16 | void generateFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef) |
| 17 | { |
| 18 | // This implements writing of JIT'd addresses so that perf can find the |
| 19 | // symbol names. |
| 20 | // |
| 21 | // Perf expects the mapping to be in a certain place and have certain |
| 22 | // content, for more information, see: |
| 23 | // https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/jit-interface.txt |
| 24 | static bool doProfile = !qEnvironmentVariableIsEmpty(varName: "QV4_PROFILE_WRITE_PERF_MAP"); |
| 25 | if (Q_UNLIKELY(doProfile)) { |
| 26 | static QFile perfMapFile(QString::fromLatin1(ba: "/tmp/perf-%1.map") |
| 27 | .arg(a: QCoreApplication::applicationPid())); |
| 28 | static const bool isOpen = perfMapFile.open(flags: QIODevice::WriteOnly); |
| 29 | if (!isOpen) { |
| 30 | qWarning(msg: "QV4::JIT::Assembler: Cannot write perf map file."); |
| 31 | doProfile = false; |
| 32 | } else { |
| 33 | const void *address = codeRef->code().executableAddress(); |
| 34 | perfMapFile.write(data: QByteArray::number(reinterpret_cast<quintptr>(address), base: 16)); |
| 35 | perfMapFile.putChar(c: ' '); |
| 36 | perfMapFile.write(data: QByteArray::number(static_cast<qsizetype>(codeRef->size()), base: 16)); |
| 37 | perfMapFile.putChar(c: ' '); |
| 38 | perfMapFile.write(data: Function::prettyName(function, address).toUtf8()); |
| 39 | perfMapFile.putChar(c: '\n'); |
| 40 | perfMapFile.flush(); |
| 41 | } |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | void destroyFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef) |
| 46 | { |
| 47 | Q_UNUSED(function); |
| 48 | Q_UNUSED(codeRef); |
| 49 | |
| 50 | // It's not advisable to remove things from the perf map file, as it's primarily used to analyze |
| 51 | // a trace after the application has terminated. We want to know about all functions that were |
| 52 | // ever jitted then. If the memory ranges overlap, we will have a problem when analyzing the |
| 53 | // trace. The JIT should try to avoid this. |
| 54 | } |
| 55 | |
| 56 | size_t exceptionHandlerSize() |
| 57 | { |
| 58 | return 0; |
| 59 | } |
| 60 | |
| 61 | } // QV4 |
| 62 | |
| 63 | QT_END_NAMESPACE |
| 64 |