Fix #14483: false negative: unusedStructMember (member pointer) (#8228)

Author: ludviggunne

lib/symboldatabase.cpp

@@ -5266,6 +5266,26 @@ const Variable *Scope::getVariable(const std::string &varname) const
 
 static const Token* skipPointers(const Token* tok)
 {
+    const Token *start = tok;
+    bool memberPointer = false;
+    while (tok) {
+        if (Token::simpleMatch(tok, "::")) {
+            tok = tok->next();
+            continue;
+        }
+        if (Token::Match(tok, "%type% ::")) {
+            tok = tok->tokAt(2);
+            memberPointer = true;
+            continue;
+        }
+        if (Token::Match(tok, "%type% <") && tok->linkAt(1)) {
+            tok = tok->linkAt(1)->next();
+            continue;
+        }
+        break;
+    }
+    if (memberPointer && !Token::simpleMatch(tok, "*"))
+        return start;
     while (Token::Match(tok, "*|&|&&") || (Token::Match(tok, "( [*&]") && Token::Match(tok->link()->next(), "(|["))) {
         tok = tok->next();
         if (tok && tok->strAt(-1) == "(" && Token::Match(tok, "%type% ::"))

test/testother.cpp

@@ -10468,7 +10468,7 @@ class TestOther : public TestFixture {
 
         // Member variable pointers
         check("void podMemPtrs() {\n"
-              "    int POD::*memptr;\n"
+              "    const int POD::*memptr;\n"
               "    memptr = &POD::a;\n"
               "    memptr = &POD::b;\n"
               "    if (memptr)\n"

test/testunusedvar.cpp

@@ -77,6 +77,8 @@ class TestUnusedVar : public TestFixture {
         TEST_CASE(structmember29); // #14075
         TEST_CASE(structmember30); // #14131
         TEST_CASE(structmember31); // #14130
+        TEST_CASE(structmember32); // #14483
+        TEST_CASE(structmember33);
         TEST_CASE(structmember_macro);
         TEST_CASE(structmember_template_argument); // #13887 - do not report that member used in template argument is unused
         TEST_CASE(classmember);
@@ -2066,6 +2068,20 @@ class TestUnusedVar : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void structmember32() { // #14483
+        checkStructMemberUsage("struct S {\n"
+                               "  int S::* mp;\n"
+                               "};\n");
+        ASSERT_EQUALS("[test.cpp:2:12]: (style) struct member 'S::mp' is never used. [unusedStructMember]\n", errout_str());
+    }
+
+    void structmember33() {
+        checkStructMemberUsage("struct S {\n"
+                               "  int A::B<int>::C::* mp;\n"
+                               "};\n");
+        ASSERT_EQUALS("[test.cpp:2:23]: (style) struct member 'S::mp' is never used. [unusedStructMember]\n", errout_str());
+    }
+
     void structmember_macro() {
         checkStructMemberUsageP("#define S(n) struct n { int a, b, c; };\n"
                                 "S(unused);\n");