template simplifier: specialized member class not recognized causing wrong instantiation (#1876)

Specialized member classes declared outsize the class were not
recognized. This caused the the member class to be instantiated rather
than the specialized class. We already had a test for this but it was
wrong so it went unnoticed.

lib/templatesimplifier.cpp

@@ -89,7 +89,7 @@ TemplateSimplifier::TokenAndName::TokenAndName(Token *tok, const std::string &s,
             throw InternalError(tok, "explicit specialization of alias templates is not permitted", InternalError::SYNTAX);
         }
 
-        isClass(Token::Match(paramEnd->next(), "class|struct|union %name% <|{|:|;"));
+        isClass(Token::Match(paramEnd->next(), "class|struct|union %name% <|{|:|;|::"));
         if (token->strAt(1) == "<" && !isSpecialization()) {
             const Token *end = token->next()->findClosingBracket();
             isVariadic(end && Token::findmatch(token->tokAt(2), "typename|class . . .", end));
@@ -113,8 +113,8 @@ TemplateSimplifier::TokenAndName::TokenAndName(Token *tok, const std::string &s,
             if (tok1)
                 isForwardDeclaration(tok1->str() == ";");
         }
-        // check for member function and adjust scope
+        // check for member class or function and adjust scope
-        if (isFunction() && nameToken->strAt(-1) == "::") {
+        if ((isFunction() || isClass()) && nameToken->strAt(-1) == "::") {
             const Token * start = nameToken;
 
             while (Token::Match(start->tokAt(-2), "%name% ::") ||
@@ -1397,16 +1397,48 @@ bool TemplateSimplifier::getTemplateNamePositionTemplateVariable(const Token *to
     return false;
 }
 
+bool TemplateSimplifier::getTemplateNamePositionTemplateClass(const Token *tok, int &namepos)
+{
+    if (Token::Match(tok, "> class|struct|union %type% :|<|;|{|::")) {
+        namepos = 2;
+        tok = tok->tokAt(2);
+        while (Token::Match(tok, "%type% :: %type%") ||
+               (Token::Match(tok, "%type% <") && Token::Match(tok->next()->findClosingBracket(), "> :: %type%"))) {
+            if (tok->strAt(1) == "::") {
+                tok = tok->tokAt(2);
+                namepos += 2;
+            } else {
+                const Token *end = tok->next()->findClosingBracket();
+                if (!end || !end->tokAt(2)) {
+                    // syntax error
+                    namepos = -1;
+                    return true;
+                }
+                end = end->tokAt(2);
+                do {
+                    tok = tok->next();
+                    namepos += 1;
+                } while (tok && tok != end);
+            }
+        }
+        return true;
+    }
+    return false;
+}
+
 int TemplateSimplifier::getTemplateNamePosition(const Token *tok)
 {
+    // FIXME: tok == ">>" is a tokenizer bug that needs to be fixed
+    assert(tok && (tok->str() == ">" || tok->str() == ">>"));
+
     auto it = mTemplateNamePos.find(tok);
     if (!mSettings->debugtemplate && it != mTemplateNamePos.end()) {
         return it->second;
     }
     // get the position of the template name
     int namepos = 0;
-    if (Token::Match(tok, "> class|struct|union %type% :|<|;|{"))
+    if (getTemplateNamePositionTemplateClass(tok, namepos))
-        namepos = 2;
+        ;
     else if (Token::Match(tok, "> using %name% ="))
         namepos = 2;
     else if (getTemplateNamePositionTemplateVariable(tok, namepos))
@@ -1500,7 +1532,9 @@ void TemplateSimplifier::expandTemplate(
         templateDeclaration.token->insertToken(templateDeclarationToken->strAt(1), "", true);
         templateDeclaration.token->insertToken(newName, "", true);
         templateDeclaration.token->insertToken(";", "", true);
-    } else if ((isFunction && (copy || isSpecialization)) || (isVariable && !isSpecialization)) {
+    } else if ((isFunction && (copy || isSpecialization)) ||
+               (isVariable && !isSpecialization) ||
+               (isClass && isSpecialization && mTemplateSpecializationMap.find(templateDeclaration.token) != mTemplateSpecializationMap.end())) {
         Token * dst = templateDeclaration.token;
         Token * dstStart = dst->previous();
         bool isStatic = false;

lib/templatesimplifier.h

@@ -240,11 +240,19 @@ public:
     int getTemplateNamePosition(const Token *tok);
 
     /**
-     * Get function template name position
+     * Get class template name position
      * @param tok The ">" token e.g. before "class"
      * @param namepos return offset to name
      * @return true if name found, false if not
      * */
+    static bool getTemplateNamePositionTemplateClass(const Token *tok, int &namepos);
+
+    /**
+     * Get function template name position
+     * @param tok The ">" token
+     * @param namepos return offset to name
+     * @return true if name found, false if not
+     * */
     static bool getTemplateNamePositionTemplateFunction(const Token *tok, int &namepos);
 
     /**

test/testsimplifytemplate.cpp

@@ -976,7 +976,12 @@ private:
                             "  template<typename T> struct X { T t; };"
                             "};"
                             "template<> struct A::X<int> { int *t; };";
-        ASSERT_EQUALS("struct A { struct X<int> ; } ; struct A :: X<int> { int t ; } ;", tok(code));
+        const char expected[] = "struct A { "
+                                "struct X<int> ; "
+                                "template < typename T > struct X { T t ; } ; "
+                                "} ; "
+                                "struct A :: X<int> { int * t ; } ;";
+        ASSERT_EQUALS(expected, tok(code));
     }
 
     void template41() { // #4710 - const in template instantiation not handled perfectly
@@ -1021,6 +1026,7 @@ private:
                             "    return 0;\n"
                             "}";
         const char expected[] = "struct E<void*> ; "
+                                "struct C<B<A>> ; "
                                 "struct C<A> ; "
                                 "struct D<B<A>> ; "
                                 "int f2<B<A>> ( ) ; "
@@ -1215,7 +1221,8 @@ private:
                             "  enum { value = 1 }; "
                             "};"
                             "const int x = Factorial<4>::value;";
-        const char expected[] = "struct Factorial<4> ; "
+        const char expected[] = "struct Factorial<0> ; "
+                                "struct Factorial<4> ; "
                                 "struct Factorial<3> ; "
                                 "struct Factorial<2> ; "
                                 "struct Factorial<1> ; "
@@ -1342,7 +1349,8 @@ private:
                             "int main () {\n"
                             "    return diagonalGroupTest<4>();\n"
                             "}";
-        const char exp[] = "struct Factorial<4> ; "
+        const char exp[] = "struct Factorial<0> ; "
+                           "struct Factorial<4> ; "
                            "struct Factorial<3> ; "
                            "struct Factorial<2> ; "
                            "struct Factorial<1> ; "
@@ -1576,13 +1584,22 @@ private:
                             "   void foo() { }\n"
                             "};";
         const char exp [] = "template < typename T , typename V , int KeySize = 0 > class Bar ; "
+                            "class Bar<void,void> ; "
                             "class Bar<void,void> { "
                             "} ; "
                             "template < typename K , typename V , int KeySize = 0 > "
                             "class Bar : private Bar<void,void> { "
                             "void foo ( ) { } "
                             "} ;";
-        ASSERT_EQUALS(exp, tok(code));
+        const char act [] = "template < typename T , typename V , int KeySize = 0 > class Bar ; "
+                            "class Bar<void,void> { "
+                            "} ; "
+                            "class Bar<void,void> ; "
+                            "template < typename K , typename V , int KeySize = 0 > "
+                            "class Bar : private Bar<void,void> { "
+                            "void foo ( ) { } "
+                            "} ;";
+        TODO_ASSERT_EQUALS(exp, act, tok(code));
     }
 
     void template71() { // #8821
@@ -1679,7 +1696,8 @@ private:
                             "    std::cout << is_void<char>::value << std::endl;\n"
                             "    std::cout << is_void<void>::value << std::endl;\n"
                             "}";
-        const char exp[] = "struct is_void<char> ; "
+        const char exp[] = "struct is_void<void> ; "
+                           "struct is_void<char> ; "
                            "struct is_void<void> : std :: true_type { } ; "
                            "int main ( ) { "
                            "std :: cout << is_void<char> :: value << std :: endl ; "
@@ -2846,7 +2864,8 @@ private:
                                 "    b.A<>::Print();\n"
                                 "    return 0;\n"
                                 "}";
-            ASSERT_EQUALS("template < typename T0 > class A ; "
+            ASSERT_EQUALS("class A<void> ; "
+                          "template < typename T0 > class A ; "
                           "class A<void> { "
                           "public: "
                           "A<void> ( ) { } "
@@ -3261,6 +3280,7 @@ private:
                             "template class Fred<1>;\n"
                             "}\n";
         ASSERT_EQUALS("namespace NS { "
+                      "struct Barney<1> ; "
                       "template < int type > struct Barney ; "
                       "struct Barney<1> { } ; "
                       "class Fred<1> ; "
@@ -3577,7 +3597,8 @@ private:
             const char code[] = "template<typename T> class C { };\n"
                                 "template<> class C<char> { };\n"
                                 "map<int> m;\n";
-            const char expected[] = "template < typename T > class C { } ; "
+            const char expected[] = "class C<char> ; "
+                                    "template < typename T > class C { } ; "
                                     "class C<char> { } ; "
                                     "map < int > m ;";
             ASSERT_EQUALS(expected, tok(code));
@@ -3587,7 +3608,8 @@ private:
                                 "template<> class C<char> { };\n"
                                 "map<int> m;\n"
                                 "C<int> i;";
-            const char expected[] = "class C<int> ; "
+            const char expected[] = "class C<char> ; "
+                                    "class C<int> ; "
                                     "class C<char> { } ; "
                                     "map < int > m ; "
                                     "C<int> i ; "
@@ -3600,7 +3622,8 @@ private:
                                 "map<int> m;\n"
                                 "C<int> i;\n"
                                 "C<char> c;";
-            const char expected[] = "class C<int> ; "
+            const char expected[] = "class C<char> ; "
+                                    "class C<int> ; "
                                     "class C<char> { } ; "
                                     "map < int > m ; "
                                     "C<int> i ; "