C++: Match const/volatile/signed/unsigned for FullySpecifiedType

Changing a function signature from const to non-const is not recognized as a
changed, and doesn't trigger the "Apply Function Signature Changes" quickfix.

For example:
void func(Foo &var);
void func(Foo &var) {} // Add const before Foo, quickfix is not triggered

Change-Id: I71ae41765d66df69204abd085fdfcfcb2d605f4c
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/3rdparty/cplusplus/FullySpecifiedType.cpp

@@ -216,5 +216,16 @@ void FullySpecifiedType::setFlags(unsigned flags)
 
 bool FullySpecifiedType::match(const FullySpecifiedType &otherTy, Matcher *matcher) const
 {
+    static const unsigned flagsMask = [](){
+        FullySpecifiedType ty;
+        ty.f._isConst = true;
+        ty.f._isVolatile = true;
+        ty.f._isSigned = true;
+        ty.f._isUnsigned = true;
+        return ty._flags;
+    }();
+
+    if ((_flags & flagsMask) != (otherTy._flags & flagsMask))
+        return false;
     return type()->match(otherTy.type(), matcher);
 }

tests/auto/cplusplus/misc/tst_misc.cpp

@@ -51,6 +51,8 @@ private slots:
     void findBreakpoints3();
 
     void astPathOnGeneratedTokens();
+
+    void typeMatcher();
 };
 
 void tst_Misc::diagnosticClient_error()
@@ -244,5 +246,30 @@ void tst_Misc::astPathOnGeneratedTokens()
     }
 }
 
+void tst_Misc::typeMatcher()
+{
+    IntegerType dummyType(IntegerType::Int);
+    FullySpecifiedType type1(&dummyType);
+    FullySpecifiedType type2(&dummyType);
+
+    for (int i = 0; i < (1<<8); ++i) {
+        type1.setConst   (i & (1 << 0));
+        type1.setVolatile(i & (1 << 1));
+        type1.setSigned  (i & (1 << 2));
+        type1.setUnsigned(i & (1 << 3));
+
+        type2.setConst   (i & (1 << 4));
+        type2.setVolatile(i & (1 << 5));
+        type2.setSigned  (i & (1 << 6));
+        type2.setUnsigned(i & (1 << 7));
+
+        const unsigned type1Specifiers = (i & 0x0f);
+        const unsigned type2Specifiers = (i >> 4);
+        const bool sameSpecifiers = type1Specifiers == type2Specifiers;
+        QCOMPARE(type1.match(type2), sameSpecifiers);
+        QCOMPARE(type2.match(type1), sameSpecifiers);
+    }
+}
+
 QTEST_MAIN(tst_Misc)
 #include "tst_misc.moc"