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39
40 #include "qv4functiontable_p.h"
41 #include "qv4function_p.h"
42
43 #include <assembler/MacroAssemblerCodeRef.h>
44
45 #include <QtCore/qfile.h>
46 #include <QtCore/qcoreapplication.h>
47
48 QT_BEGIN_NAMESPACE
49
50 namespace QV4 {
51
generateFunctionTable(Function * function,JSC::MacroAssemblerCodeRef * codeRef)52 void generateFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef)
53 {
54 // This implements writing of JIT'd addresses so that perf can find the
55 // symbol names.
56 //
57 // Perf expects the mapping to be in a certain place and have certain
58 // content, for more information, see:
59 // https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/jit-interface.txt
60 static bool doProfile = !qEnvironmentVariableIsEmpty("QV4_PROFILE_WRITE_PERF_MAP");
61 if (Q_UNLIKELY(doProfile)) {
62 static QFile perfMapFile(QString::fromLatin1("/tmp/perf-%1.map")
63 .arg(QCoreApplication::applicationPid()));
64 static const bool isOpen = perfMapFile.open(QIODevice::WriteOnly);
65 if (!isOpen) {
66 qWarning("QV4::JIT::Assembler: Cannot write perf map file.");
67 doProfile = false;
68 } else {
69 const void *address = codeRef->code().executableAddress();
70 perfMapFile.write(QByteArray::number(reinterpret_cast<quintptr>(address), 16));
71 perfMapFile.putChar(' ');
72 perfMapFile.write(QByteArray::number(static_cast<qsizetype>(codeRef->size()), 16));
73 perfMapFile.putChar(' ');
74 perfMapFile.write(Function::prettyName(function, address).toUtf8());
75 perfMapFile.putChar('\n');
76 perfMapFile.flush();
77 }
78 }
79 }
80
destroyFunctionTable(Function * function,JSC::MacroAssemblerCodeRef * codeRef)81 void destroyFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef)
82 {
83 Q_UNUSED(function);
84 Q_UNUSED(codeRef);
85
86 // It's not advisable to remove things from the perf map file, as it's primarily used to analyze
87 // a trace after the application has terminated. We want to know about all functions that were
88 // ever jitted then. If the memory ranges overlap, we will have a problem when analyzing the
89 // trace. The JIT should try to avoid this.
90 }
91
exceptionHandlerSize()92 size_t exceptionHandlerSize()
93 {
94 return 0;
95 }
96
97 } // QV4
98
99 QT_END_NAMESPACE
100