moc: Fix infinite recursion in macro substitution

When performing macro argument substitution, one should keep the set of
macro to exclude, else we can enter an infinite recursion.

Testcase:
 #define M1(A) A
 #define M2 M1(M2)

Task-number: QTBUG-29759
Change-Id: I564bbfed65e1c8599592eaf12c6d67285d2fd9ce
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>

src/tools/moc/preprocessor.cpp

@@ -1,6 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2013 Olivier Goffart <ogoffart@woboq.org>
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the tools applications of the Qt Toolkit.
@@ -536,12 +537,14 @@ static Symbols tokenize(const QByteArray &input, int lineNum = 1, TokenizeMode m
     return symbols;
 }
 
-Symbols Preprocessor::macroExpand(Preprocessor *that, Symbols &toExpand, int &index, int lineNum, bool one)
+Symbols Preprocessor::macroExpand(Preprocessor *that, Symbols &toExpand, int &index,
+                                  int lineNum, bool one, const QSet<QByteArray> &excludeSymbols)
 {
     SymbolStack symbols;
     SafeSymbols sf;
     sf.symbols = toExpand;
     sf.index = index;
+    sf.excludedSymbols = excludeSymbols;
     symbols.push(sf);
 
     Symbols result;
@@ -664,7 +667,7 @@ Symbols Preprocessor::macroExpandIdentifier(Preprocessor *that, SymbolStack &sym
                     if (i == macro.symbols.size() - 1 || macro.symbols.at(i + 1).token != PP_HASHHASH) {
                         Symbols arg = arguments.at(index);
                         int idx = 1;
-                        expansion += macroExpand(that, arg, idx, lineNum, false);
+                        expansion += macroExpand(that, arg, idx, lineNum, false, symbols.excludeSymbols());
                     } else {
                         expansion += arguments.at(index);
                     }

src/tools/moc/preprocessor.h

@@ -85,7 +85,8 @@ public:
 
     void substituteUntilNewline(Symbols &substituted);
     static Symbols macroExpandIdentifier(Preprocessor *that, SymbolStack &symbols, int lineNum, QByteArray *macroName);
-    static Symbols macroExpand(Preprocessor *that, Symbols &toExpand, int &index, int lineNum, bool one);
+    static Symbols macroExpand(Preprocessor *that, Symbols &toExpand, int &index, int lineNum, bool one,
+                               const QSet<QByteArray> &excludeSymbols = QSet<QByteArray>());
 
     int evaluateCondition();
 

src/tools/moc/symbols.h

@@ -1,6 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2013 Olivier Goffart <ogoffart@woboq.com>
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the tools applications of the Qt Toolkit.
@@ -134,6 +135,7 @@ typedef QVector<Symbol> Symbols;
 struct SafeSymbols {
     Symbols symbols;
     QByteArray expandedMacro;
+    QSet<QByteArray> excludedSymbols;
     int index;
 };
 
@@ -159,6 +161,7 @@ public:
     inline QByteArray unquotedLexem() { return symbol().unquotedLexem(); }
 
     bool dontReplaceSymbol(const QByteArray &name);
+    QSet<QByteArray> excludeSymbols();
 };
 
 inline bool SymbolStack::test(Token token)
@@ -178,12 +181,22 @@ inline bool SymbolStack::test(Token token)
 inline bool SymbolStack::dontReplaceSymbol(const QByteArray &name)
 {
     for (int i = 0; i < size(); ++i) {
-        if (name == at(i).expandedMacro)
+        if (name == at(i).expandedMacro || at(i).excludedSymbols.contains(name))
             return true;
     }
     return false;
 }
 
+inline QSet<QByteArray> SymbolStack::excludeSymbols()
+{
+    QSet<QByteArray> set;
+    for (int i = 0; i < size(); ++i) {
+        set << at(i).expandedMacro;
+        set += at(i).excludedSymbols;
+    }
+    return set;
+}
+
 QT_END_NAMESPACE
 
 #endif // SYMBOLS_H

tests/auto/tools/moc/parse-defines.h

@@ -76,6 +76,9 @@
 
 #endif
 
+#define PD_ADD_SUFFIX(x)  PD_DEFINE1(x,_SUFFIX)
+#define PD_DEFINE_ITSELF PD_ADD_SUFFIX(PD_DEFINE_ITSELF)
+
 PD_BEGIN_NAMESPACE
 
 class PD_CLASSNAME : public QObject
@@ -128,6 +131,8 @@ public slots:
     void conditionSlot() {}
 #endif
 
+    void PD_DEFINE_ITSELF(int) {}
+
 };
 
 #undef QString

tests/auto/tools/moc/tst_moc.cpp

@@ -2772,7 +2772,6 @@ void tst_Moc::parseDefines()
         }
         if (!qstrcmp(mci.name(), "TestString2")) {
             ++count;
-            qDebug() << mci.value();
             QVERIFY(!qstrcmp(mci.value(), "ParseDefine"));
         }
         if (!qstrcmp(mci.name(), "TestString3")) {
@@ -2781,6 +2780,9 @@ void tst_Moc::parseDefines()
         }
     }
     QVERIFY(count == 3);
+
+    index = mo->indexOfSlot("PD_DEFINE_ITSELF_SUFFIX(int)");
+    QVERIFY(index != -1);
 }
 
 void tst_Moc::preprocessorOnly()