Debugger: Fix parsing of octal-encoded gdb escapes

Fixes: QTCREATORBUG-24462
Change-Id: I89153a04eeef6a2e20fefef45e0efa3712ec0997
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/debugger/debuggerprotocol.cpp

@@ -89,104 +89,111 @@ void GdbMi::parseResultOrValue(const QChar *&from, const QChar *to)
     }
 }
 
+// Reads one \ooo entity.
+static bool parseOctalEscapedHelper(const QChar *&from, const QChar *to, QByteArray &buffer)
+{
+    if (to - from < 4)
+        return false;
+    if (*from != '\\')
+        return false;
+
+    const char c1 = from[1].unicode();
+    const char c2 = from[2].unicode();
+    const char c3 = from[3].unicode();
+    if (!isdigit(c1) || !isdigit(c2) || !isdigit(c3))
+        return false;
+
+    buffer += char((c1 - '0') * 64 + (c2 - '0') * 8 + (c3 - '0'));
+    from += 4;
+    return true;
+}
+
+static bool parseHexEscapedHelper(const QChar *&from, const QChar *to, QByteArray &buffer)
+{
+    if (to - from < 4)
+        return false;
+    if (from[0]!= '\\')
+        return false;
+    if (from[1] != 'x')
+        return false;
+
+    const char c1 = from[2].unicode();
+    const char c2 = from[3].unicode();
+    if (!isxdigit(c1) || !isxdigit(c2))
+        return false;
+
+    buffer += char(16 * fromhex(c1) + fromhex(c2));
+    from += 4;
+    return true;
+}
+
+static void parseSimpleEscape(const QChar *&from, const QChar *to, QString &result)
+{
+    if (from == to) {
+        qDebug() << "MI Parse Error, unterminated backslash escape";
+        return;
+    }
+
+    QChar c = *from++;
+    switch (c.unicode()) {
+    case 'a': result += '\a'; break;
+    case 'b': result += '\b'; break;
+    case 'f': result += '\f'; break;
+    case 'n': result += '\n'; break;
+    case 'r': result += '\r'; break;
+    case 't': result += '\t'; break;
+    case 'v': result += '\v'; break;
+    case '"': result += '"'; break;
+    case '\'': result += '\''; break;
+    case '\\': result += '\\'; break;
+    default:
+        qDebug() << "MI Parse Error, unrecognized backslash escape";
+    }
+}
+
+// Reads subsequent \123 or \x12 entities and converts to Utf8,
+// *or* one escaped char, *or* one unescaped char.
+static void parseCharOrEscape(const QChar *&from, const QChar *to, QString &result)
+{
+    QByteArray buffer;
+    while (parseOctalEscapedHelper(from, to, buffer))
+        ;
+    while (parseHexEscapedHelper(from, to, buffer))
+        ;
+
+    if (!buffer.isEmpty())
+        result.append(QString::fromUtf8(buffer));
+    else if (*from == '\\')
+        parseSimpleEscape(++from, to, result);
+    else
+        result += *from++;
+}
+
 QString GdbMi::parseCString(const QChar *&from, const QChar *to)
 {
-    QString result;
+    if (to == from)
+        return QString();
+
     //qDebug() << "parseCString: " << QString(from, to - from);
     if (*from != '"') {
         qDebug() << "MI Parse Error, double quote expected";
         ++from; // So we don't hang
         return QString();
     }
-    const QChar *ptr = from;
-    ++ptr;
-    while (ptr < to) {
-        if (*ptr == '"') {
-            ++ptr;
-            result = QString(from + 1, ptr - from - 2);
-            break;
-        }
-        if (*ptr == '\\') {
-            ++ptr;
-            if (ptr == to) {
-                qDebug() << "MI Parse Error, unterminated backslash escape";
-                from = ptr; // So we don't hang
-                return QString();
-            }
-        }
-        ++ptr;
-    }
-    from = ptr;
 
-    int idx = result.indexOf('\\');
+    ++from; // Skip initial quote.
-    if (idx >= 0) {
+    QString result;
-        QChar *dst = result.data() + idx;
+    result.reserve(to - from);
-        const QChar *src = dst + 1, *end = result.data() + result.length();
+    while (from < to) {
-        do {
+        if (*from == '"') {
-            QChar c = *src++;
+            ++from;
-            switch (c.unicode()) {
+            return result;
-                case 'a': *dst++ = '\a'; break;
+        }
-                case 'b': *dst++ = '\b'; break;
+        parseCharOrEscape(from, to, result);
-                case 'f': *dst++ = '\f'; break;
-                case 'n': *dst++ = '\n'; break;
-                case 'r': *dst++ = '\r'; break;
-                case 't': *dst++ = '\t'; break;
-                case 'v': *dst++ = '\v'; break;
-                case '"': *dst++ = '"'; break;
-                case '\\': *dst++ = '\\'; break;
-                case 'x': {
-                        c = *src++;
-                        int chars = 0;
-                        uchar prod = 0;
-                        while (true) {
-                            uchar val = fromhex(c.unicode());
-                            if (val == UCHAR_MAX)
-                                break;
-                            prod = prod * 16 + val;
-                            if (++chars == 3 || src == end)
-                                break;
-                            c = *src++;
-                        }
-                        if (!chars) {
-                            qDebug() << "MI Parse Error, unrecognized hex escape";
-                            return QString();
-                        }
-                        *dst++ = prod;
-                        break;
-                    }
-                default:
-                    {
-                        int chars = 0;
-                        uchar prod = 0;
-                        forever {
-                            if (c < '0' || c > '7') {
-                                --src;
-                                break;
-                            }
-                            prod = prod * 8 + c.unicode() - '0';
-                            if (++chars == 3 || src == end)
-                                break;
-                            c = *src++;
-                        }
-                        if (!chars) {
-                            qDebug() << "MI Parse Error, unrecognized backslash escape";
-                            return QString();
-                        }
-                        *dst++ = prod;
-                    }
-            }
-            while (src != end) {
-                QChar c = *src++;
-                if (c == '\\')
-                    break;
-                *dst++ = c;
-            }
-        } while (src != end);
-        *dst = 0;
-        result.truncate(dst - result.data());
     }
 
-    return result;
+    qDebug() << "MI Parse Error, unfinished string";
+    return QString();
 }
 
 void GdbMi::parseValue(const QChar *&from, const QChar *to)

tests/auto/debugger/CMakeLists.txt

@@ -32,6 +32,15 @@ add_qtc_test(tst_debugger_gdb
     "${DEBUGGERDIR}/debuggerprotocol.cpp" "${DEBUGGERDIR}/debuggerprotocol.h"
 )
 
+add_qtc_test(tst_debugger_protocol
+  DEPENDS Qt5::Network Utils
+  INCLUDES
+    "${DEBUGGERDIR}"
+  SOURCES
+    "${DEBUGGERDIR}/debuggerprotocol.cpp" "${DEBUGGERDIR}/debuggerprotocol.h"
+    tst_protocol.cpp
+)
+
 add_qtc_test(tst_debugger_offsets
   DEPENDS Qt5::CorePrivate
   INCLUDES "${DEBUGGERDIR}"

tests/auto/debugger/debugger.pro

@@ -12,3 +12,4 @@ SUBDIRS += simplifytypes.pro
 SUBDIRS += dumpers.pro
 SUBDIRS += disassembler.pro
 SUBDIRS += offsets.pro
+SUBDIRS += protocol.pro

tests/auto/debugger/debugger.qbs

@@ -7,6 +7,7 @@ Project {
         "disassembler.qbs",
         "dumpers.qbs",
         "gdb.qbs",
+        "protocol.qbs",
         "offsets.qbs",
         "simplifytypes.qbs",
     ]

tests/auto/debugger/protocol.pro

@@ -0,0 +1,46 @@
+QT = core network
+
+msvc: QTC_LIB_DEPENDS += utils
+include(../qttest.pri)
+
+DEBUGGERDIR = $$IDE_SOURCE_TREE/src/plugins/debugger
+UTILSDIR = $$IDE_SOURCE_TREE/src/libs/utils
+
+INCLUDEPATH += $$DEBUGGERDIR
+
+SOURCES += \
+    tst_protocol.cpp \
+    $$DEBUGGERDIR/debuggerprotocol.cpp
+
+HEADERS += \
+    $$DEBUGGERDIR/debuggerprotocol.h
+
+!msvc {
+    SOURCES += \
+        $$UTILSDIR/environment.cpp \
+        $$UTILSDIR/fileutils.cpp \
+        $$UTILSDIR/hostosinfo.cpp \
+        $$UTILSDIR/namevaluedictionary.cpp \
+        $$UTILSDIR/namevalueitem.cpp \
+        $$UTILSDIR/qtcassert.cpp \
+        $$UTILSDIR/qtcprocess.cpp \
+        $$UTILSDIR/processhandle.cpp \
+        $$UTILSDIR/savefile.cpp \
+
+    HEADERS += \
+        $$UTILSDIR/environment.h \
+        $$UTILSDIR/fileutils.h \
+        $$UTILSDIR/hostosinfo.h \
+        $$UTILSDIR/namevaluedictionary.h \
+        $$UTILSDIR/namevalueitem.h \
+        $$UTILSDIR/qtcassert.h \
+        $$UTILSDIR/qtcprocess.h \
+        $$UTILSDIR/processhandle.h \
+        $$UTILSDIR/savefile.h \
+
+    macos: {
+         HEADERS += $$UTILSDIR/fileutils_mac.h
+         OBJECTIVE_SOURCES += $$UTILSDIR/fileutils_mac.mm
+         LIBS += -framework Foundation
+    }
+}

tests/auto/debugger/protocol.qbs

@@ -0,0 +1,17 @@
+import qbs
+
+QtcAutotest {
+    name: "debugger protocol autotest"
+    Depends { name: "Utils" }
+    Depends { name: "Qt.network" } // For QHostAddress
+    Group {
+        name: "Sources from Debugger plugin"
+        prefix: project.debuggerDir
+        files: "debuggerprotocol.cpp"
+    }
+    Group {
+        name: "Test sources"
+        files: "tst_protocol.cpp"
+    }
+    cpp.includePaths: base.concat([project.debuggerDir])
+}

tests/auto/debugger/tst_protocol.cpp

@@ -0,0 +1,92 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include <debuggerprotocol.h>
+
+#include <QtTest>
+
+//TESTED_COMPONENT=src/plugins/debugger
+
+class tst_protocol : public QObject
+{
+    Q_OBJECT
+
+public:
+    tst_protocol() {}
+
+private slots:
+    void parseCString();
+    void parseCString_data();
+};
+
+void tst_protocol::parseCString()
+{
+    QFETCH(QString, input);
+    QFETCH(QString, expected);
+
+    const QChar *from = input.begin();
+    const QChar *to = input.end();
+    QString parsed = Debugger::Internal::GdbMi::parseCString(from, to);
+
+    QCOMPARE(parsed, expected);
+}
+
+void tst_protocol::parseCString_data()
+{
+    QTest::addColumn<QString>("input");
+    QTest::addColumn<QString>("expected");
+
+    QTest::newRow("empty")
+        << ""
+        << "";
+
+    QTest::newRow("unquoted")
+        << "irgendwas"
+        << "";
+
+    QTest::newRow("plain")
+        << R"("plain")"
+        << "plain";
+
+    // This is expected to throw several warnings
+    //  "MI Parse Error, unrecognized backslash escape"
+    QChar escapes[] = {'\a', '\b', '\f', '\n', '\r', '\t', '\v', '"', '\'', '\\'};
+    QTest::newRow("escaped")
+        << R"("\a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\y\z\"\'\\")"
+        << QString(escapes, sizeof(escapes)/sizeof(escapes[0]));
+
+    QTest::newRow("octal")
+        << R"("abc\303\244\303\251def\303\261")"
+        << R"(abcäédefñ)";
+
+    QTest::newRow("hex")
+        << R"("abc\xc3\xa4\xc3\xa9def\xc3\xb1")"
+        << R"(abcäédefñ)";
+}
+
+QTEST_APPLESS_MAIN(tst_protocol);
+
+#include "tst_protocol.moc"
+