Cleaning up unsimplified templates

lib/templatesimplifier.cpp

@@ -212,6 +212,39 @@ void TemplateSimplifier::cleanupAfterSimplify()
     }
 }
 
+void TemplateSimplifier::removeTemplates()
+{
+    for (Token *tok = mTokenList.front(); tok; tok = tok->next()) {
+        if (!Token::simpleMatch(tok, "template <"))
+            continue;
+        if (tok->previous() && !Token::Match(tok->previous(), "[;}]"))
+            continue;
+        Token *endToken = tok;
+        while (nullptr != (endToken = endToken->next())) {
+            if (endToken->str() == ";")
+                break;
+            if (Token::Match(endToken, "[})]]")) {
+                endToken = nullptr;
+                break;
+            }
+            if (Token::Match(endToken, "[<([]") && endToken->link())
+                endToken = endToken->link();
+            else if (endToken->str() == "{") {
+                endToken = endToken->link();
+                break;
+            }
+        }
+        if (!endToken)
+            continue;
+        Token::eraseTokens(tok, endToken);
+        tok = endToken;
+        tok->deletePrevious();
+        if (tok->str() == "}") {
+            tok->str(";");
+            tok->link(nullptr);
+        }
+    }
+}
 
 void TemplateSimplifier::checkComplicatedSyntaxErrorsInTemplates()
 {

lib/templatesimplifier.h

@@ -53,6 +53,12 @@ public:
      */
     void cleanupAfterSimplify();
 
+    /**
+     * Remove templates, can be used after the simplifications to remove
+     * the templates that failed to be expanded.
+     */
+    void removeTemplates();
+
     /**
      */
     void checkComplicatedSyntaxErrorsInTemplates();

lib/tokenize.cpp

@@ -4442,6 +4442,8 @@ bool Tokenizer::simplifyTokenList1(const char FileName[])
         // this function will just fix so that the syntax is corrected.
         validate(); // #6847 - invalid code
         mTemplateSimplifier->cleanupAfterSimplify();
+        if (!mSettings->checkUnusedTemplates)
+            mTemplateSimplifier->removeTemplates();
     }
 
     // Simplify pointer to standard types (C only)

test/testautovariables.cpp

@@ -1867,10 +1867,11 @@ private:
               "}\n"
               "auto g() {\n"
               "    std::vector<int> v;\n"
-              "    return by_value(v.begin());\n"
+              "    return by_value(v.front());\n"
               "}\n");
-        ASSERT_EQUALS(
+        TODO_ASSERT_EQUALS(
             "[test.cpp:7] -> [test.cpp:7] -> [test.cpp:3] -> [test.cpp:3] -> [test.cpp:6] -> [test.cpp:7]: (error) Returning object that points to local variable 'v' that will be invalid when returning.\n",
+            "",
             errout.str());
 
         check("auto by_ref(int& x) {\n"

test/testcondition.cpp

@@ -2079,9 +2079,6 @@ private:
         check("void f1(const std::string &s) { if(s.empty()) if(s.size() > 42) {}} ");
         ASSERT_EQUALS("[test.cpp:1] -> [test.cpp:1]: (warning) Opposite inner 'if' condition leads to a dead code block.\n", errout.str());
 
-        check("template<class T> void f1(const T &s) { if(s.size() > 42) if(s.empty()) {}} ");
-        ASSERT_EQUALS("[test.cpp:1] -> [test.cpp:1]: (warning) Opposite inner 'if' condition leads to a dead code block.\n", errout.str());
-
         check("void f2(const std::wstring &s) { if(s.empty()) if(s.size() > 42) {}} ");
         ASSERT_EQUALS("[test.cpp:1] -> [test.cpp:1]: (warning) Opposite inner 'if' condition leads to a dead code block.\n", errout.str());
 

test/testconstructors.cpp

@@ -347,16 +347,6 @@ private:
               "    int x;\n"
               "};");
         ASSERT_EQUALS("", errout.str());
-
-        check("template <class T> struct A {\n"
-              "    A<T>() : x(0) { }\n"
-              "    A<T>(const T & t) : x(t.x) { }\n"
-              "private:\n"
-              "    int x;\n"
-              "    int y;\n"
-              "};");
-        ASSERT_EQUALS("[test.cpp:2]: (warning) Member variable 'A::y' is not initialized in the constructor.\n"
-                      "[test.cpp:3]: (warning) Member variable 'A::y' is not initialized in the constructor.\n", errout.str());
     }
 
     void simple7() { // ticket #4531

test/testgarbage.cpp

@@ -1365,7 +1365,7 @@ private:
         );
 
         // #3449
-        ASSERT_EQUALS("template < typename T > struct A ;\n"
+        ASSERT_EQUALS(";\n"
                       "struct B { template < typename T > struct C } ;\n"
                       "{ } ;",
                       checkCode("template<typename T> struct A;\n"

test/testnullpointer.cpp

@@ -67,7 +67,6 @@ private:
         TEST_CASE(nullpointer24); // #5082 fp: chained assignment
         TEST_CASE(nullpointer25); // #5061
         TEST_CASE(nullpointer26); // #3589
-        TEST_CASE(nullpointer27); // #6568
         TEST_CASE(nullpointer28); // #6491
         TEST_CASE(nullpointer30); // #6392
         TEST_CASE(nullpointer31); // #8482
@@ -1322,20 +1321,6 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
-    void nullpointer27() { // #6568
-        check("template<class Type>\n"
-              "class Foo {\n"
-              "    Foo<Type>& operator = ( Type* );\n"
-              "};\n"
-              "template<class Type>\n"
-              "Foo<Type>& Foo<Type>::operator = ( Type* pointer_ ) {\n"
-              "    pointer_=NULL;\n"
-              "    *pointer_=0;\n"
-              "    return *this;\n"
-              "}");
-        ASSERT_EQUALS("[test.cpp:8]: (error) Null pointer dereference: pointer_\n", errout.str());
-    }
-
     void nullpointer28() { // #6491
         check("typedef struct { int value; } S;\n"
               "int f(const S *s) { \n"

test/testother.cpp

@@ -5005,11 +5005,6 @@ private:
             ASSERT_EQUALS("", errout.str());
         }
 
-        check("template<int n> void foo(unsigned int x) {\n"
-              "if (x <= 0);\n"
-              "}\n");
-        ASSERT_EQUALS("[test.cpp:2]: (style) Checking if unsigned expression 'x' is less than zero.\n", errout.str());
-
         // #8836
         check("uint32_t value = 0xFUL;\n"
               "void f() {\n"
@@ -7457,12 +7452,11 @@ private:
     }
 
     void forwardAndUsed() {
-        check("template<typename T>\n"
+        check("void f(Foo && foo) {\n"
-              "void f(T && t) {\n"
+              "    g(std::forward<Foo>(foo));\n"
-              "    g(std::forward<T>(t));\n"
+              "    Foo s = foo;\n"
-              "    T s = t;\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:4]: (warning) Access of forwarded variable 't'.\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:3]: (warning) Access of forwarded variable 'foo'.\n", errout.str());
     }
 
     void funcArgNamesDifferent() {

test/testsimplifytemplate.cpp

@@ -38,6 +38,7 @@ private:
 
     void run() OVERRIDE {
         settings.addEnabled("portability");
+        settings.checkUnusedTemplates = true;
 
         TEST_CASE(template1);
         TEST_CASE(template2);
@@ -191,6 +192,8 @@ private:
         TEST_CASE(templateTypeDeduction2);
 
         TEST_CASE(simplifyTemplateArgs);
+
+        TEST_CASE(removeTemplates);
     }
 
     std::string tok(const char code[], bool debugwarnings = false, Settings::PlatformType type = Settings::Native) {
@@ -386,7 +389,8 @@ private:
 
         // The expected result..
         const char expected[] = "class A<int> ; "
-                                "void f ( ) { A<int> a ; } ; "
+                                "void f ( ) { A<int> a ; } "
+                                "template < typename T > class B { void g ( ) { A < T > b ; b = A < T > :: h ( ) ; } } ; "
                                 "class A<int> { } ;";
 
         ASSERT_EQUALS(expected, tok(code));
@@ -1385,6 +1389,7 @@ private:
                             "template <class T, unsigned S> C3<T, S>::C3(const C3<T, S> &v) { C1<T *> c1; }\n"
                             "C3<int,6> c3;";
         const char exp[] = "struct C1<int*> ; "
+                           "template < class T > void f ( ) { x = y ? ( C1 < int > :: allocate ( 1 ) ) : 0 ; } "
                            "class C3<int,6> ; "
                            "C3<int,6> c3 ; "
                            "class C3<int,6> { } ; "
@@ -2392,6 +2397,7 @@ private:
                             "template <typename T> class Fred {};\n"
                             "ObjectCache<Fred> _cache;";
         const char exp[] = "class ObjectCache<Fred> ; "
+                           "template < typename T > class Fred { } ; "
                            "ObjectCache<Fred> _cache ; "
                            "class ObjectCache<Fred> { } ;";
         ASSERT_EQUALS(exp, tok(code));
@@ -2499,7 +2505,8 @@ private:
                             "template < class T > struct Unconst < const T & > { } ; "
                             "template < class T > struct Unconst < T * const > { } ; "
                             "template < class T1 , class T2 > struct type_equal { enum Anonymous0 { value = 0 } ; } ; "
-                            "template < class T > struct type_equal < T , T > { enum Anonymous1 { value = 1 } ; } ;";
+                            "template < class T > struct type_equal < T , T > { enum Anonymous1 { value = 1 } ; } ; "
+                            "template < class T > struct template_is_const { enum Anonymous2 { value = ! type_equal < T , Unconst < T > :: type > :: value } ; } ;";
         ASSERT_EQUALS(exp1, tok(code1));
     }
 
@@ -2739,7 +2746,7 @@ private:
         const char code[] = "class Fred {\n"
                             "    template<class T> explicit Fred(T t) { }\n"
                             "}";
-        ASSERT_EQUALS("class Fred { }", tok(code));
+        ASSERT_EQUALS("class Fred { template < class T > explicit Fred ( T t ) { } }", tok(code));
 
         // #3532
         const char code2[] = "class Fred {\n"
@@ -3562,6 +3569,26 @@ private:
         ASSERT_EQUALS("foo<false> = false ; foo<false> ;", tok("template<bool N> foo = N; foo < ( 1 - 1) ? true : false >;"));
     }
 
+    std::string removeTemplates(const char code[]) {
+        Settings settings2;
+        settings2.checkUnusedTemplates = false;
+
+        errout.str("");
+
+        Tokenizer tokenizer(&settings2, this);
+
+        std::istringstream istr(code);
+        tokenizer.tokenize(istr, "test.cpp");
+
+        return tokenizer.tokens()->stringifyList(0, true);
+    }
+
+    void removeTemplates() {
+        // #9057
+        ASSERT_EQUALS(";", removeTemplates("template <typename T> using foo = enable_if_t<is_same<T, int>() && sizeof(int) == 4, int>;\n"
+                                           "template <typename T, typename U = foo<T>> struct bar {};\n"
+                                           "template <typename T> using baz = bar<T>;\n"));
+    }
 };
 
 REGISTER_TEST(TestSimplifyTemplate)

test/testsimplifytokens.cpp

@@ -43,7 +43,9 @@ private:
         LOAD_LIB_2(settings_std.library, "std.cfg");
         LOAD_LIB_2(settings_windows.library, "windows.cfg");
         settings0.addEnabled("portability");
+        settings0.checkUnusedTemplates = true;
         settings1.addEnabled("style");
+        settings1.checkUnusedTemplates = true;
         settings_windows.addEnabled("portability");
 
         // Make sure the Tokenizer::simplifyTokenList works.

test/testsimplifytypedef.cpp

@@ -41,6 +41,9 @@ private:
     void run() OVERRIDE {
         settings0.addEnabled("style");
         settings2.addEnabled("style");
+        settings0.checkUnusedTemplates = true;
+        settings1.checkUnusedTemplates = true;
+        settings2.checkUnusedTemplates = true;
 
         TEST_CASE(simplifyTypedef1)
         TEST_CASE(simplifyTypedef2)
@@ -2527,7 +2530,8 @@ private:
                             "template <long, class> struct c; "
                             "template <int g> struct d { enum { e = c<g, b>::f }; };";
         const char exp [] = "class a ; "
-                            "template < long , class > struct c ;";
+                            "template < long , class > struct c ; "
+                            "template < int g > struct d { enum Anonymous0 { e = c < g , int ( a :: * ) > :: f } ; } ;";
         ASSERT_EQUALS(exp, tok(code, false));
     }
 

test/testsimplifyusing.cpp

@@ -41,6 +41,9 @@ private:
     void run() OVERRIDE {
         settings0.addEnabled("style");
         settings2.addEnabled("style");
+        settings0.checkUnusedTemplates = true;
+        settings1.checkUnusedTemplates = true;
+        settings2.checkUnusedTemplates = true;
 
         TEST_CASE(simplifyUsing1);
         TEST_CASE(simplifyUsing2);
@@ -489,7 +492,8 @@ private:
                            "class c { "
                            "int i ; i = 0 ; "
                            "c ( ) { i -- ; } "
-                           "} ;";
+                           "} ; "
+                           "template < class T > class s { } ;";
 
         ASSERT_EQUALS(exp, tok(code, true, Settings::Win64));
     }

test/testsymboldatabase.cpp

@@ -106,6 +106,7 @@ private:
 
     void run() OVERRIDE {
         LOAD_LIB_2(settings1.library, "std.cfg");
+        settings1.checkUnusedTemplates = true;
         settings2.platform(Settings::Unspecified);
 
         TEST_CASE(array);

test/testtokenize.cpp

@@ -47,6 +47,10 @@ private:
     void run() OVERRIDE {
         LOAD_LIB_2(settings_windows.library, "windows.cfg");
 
+        settings0.checkUnusedTemplates = true;
+        settings1.checkUnusedTemplates = true;
+        settings2.checkUnusedTemplates = true;
+
         TEST_CASE(tokenize1);
         TEST_CASE(tokenize2);
         TEST_CASE(tokenize3);

test/testutils.h

@@ -32,6 +32,7 @@ private:
 public:
     explicit givenACodeSampleToTokenize(const char sample[], bool createOnly = false, bool cpp = true)
         : _tokenizer(&_settings, 0) {
+        _settings.checkUnusedTemplates = true;
         std::istringstream iss(sample);
         if (createOnly)
             _tokenizer.list.createTokens(iss, cpp ? "test.cpp" : "test.c");

test/testvarid.cpp

@@ -199,6 +199,7 @@ private:
         errout.str("");
 
         Settings settings;
+        settings.checkUnusedTemplates = true;
         settings.platform(Settings::Unix64);
         settings.standards.c   = Standards::C89;
         settings.standards.cpp = Standards::CPP11;
@@ -218,6 +219,7 @@ private:
         errout.str("");
 
         Settings settings;
+        settings.checkUnusedTemplates = true;
         settings.platform(Settings::Unix64);
         settings.standards.c   = Standards::C89;
         settings.standards.cpp = Standards::CPP11;