Tokenizer: improved handling of inner templates. Partial fix for #3226

lib/tokenize.cpp

@@ -2614,8 +2614,11 @@ static unsigned int templateParameters(const Token *tok)
         return 0;
     tok = tok->next();
 
+    unsigned int level = 0;
+
     while (tok) {
-        ++numberOfParameters;
+        if (level == 0)
+            ++numberOfParameters;
 
         // skip std::
         while (Token::Match(tok, "%var% ::"))
@@ -2632,9 +2635,20 @@ static unsigned int templateParameters(const Token *tok)
         if (tok->str() == "*")
             tok = tok->next();
 
+        // inner template
+        if (tok->str() == "<") {
+            ++level;
+            tok = tok->next();
+            continue;
+        }
+
         // ,/>
-        if (tok->str() == ">")
-            return numberOfParameters;
+        while (tok->str() == ">") {
+            if (level == 0)
+                return numberOfParameters;
+            --level;
+            tok = tok->next();
+        }
         if (tok->str() != ",")
             break;
         tok = tok->next();
@@ -2817,6 +2831,32 @@ std::list<Token *> Tokenizer::simplifyTemplatesGetTemplateInstantiations()
                 break;
         } else if (Token::Match(tok->previous(), "[({};=] %var% <") ||
                    Token::Match(tok->tokAt(-2), "[,:] private|protected|public %var% <")) {
+
+            // Add inner template instantiations first => go to the ">"
+            // and then parse backwards, adding all seen instantiations
+            const Token *tok2;
+
+            // goto end ">" token
+            unsigned int level = 0;
+            for (tok2 = tok; tok2; tok2 = tok2->next()) {
+                if (tok2->str() == "<") {
+                    ++level;
+                } else if (tok2->str() == ">") {
+                    if (level <= 1)
+                        break;
+                    --level;
+                }
+            }
+
+            // parse backwards and add template instantiations
+            for (; tok2 && tok2 != tok; tok2 = tok2->previous()) {
+                if (Token::Match(tok2, ", %var% <") &&
+                    templateParameters(tok2->tokAt(2))) {
+                    used.push_back(tok2->next());
+                }
+            }
+
+            // Add outer template..
             if (templateParameters(tok->next()))
                 used.push_back(tok);
         }

test/testsimplifytokens.cpp

@@ -118,6 +118,7 @@ private:
         TEST_CASE(template25);  // #2648 - another test for sizeof template parameter
         TEST_CASE(template26);  // #2721 - passing 'char[2]' as template parameter
         TEST_CASE(template27);  // #3350 - removing unused template in macro call
+        TEST_CASE(template28);
         TEST_CASE(template_unhandled);
         TEST_CASE(template_default_parameter);
         TEST_CASE(template_default_type);
@@ -2102,6 +2103,13 @@ private:
         ASSERT_EQUALS("X ( class Fred ) ;", sizeof_(code));
     }
 
+    void template28() {
+        // #3226 - inner template
+        const char code[] = "template<class A, class B> class Fred {};\n"
+                            "Fred<int,Fred<int,int> > x;\n";
+        ASSERT_EQUALS("; Fred<int,Fred<int,int>> x ; class Fred<int,int> { } class Fred<int,Fred<int,int>> { }", sizeof_(code));
+    }
+
     void template_unhandled() {
         // An unhandled template usage should be simplified..
         ASSERT_EQUALS("; x<int> ( ) ;", sizeof_(";x<int>();"));