fix #10305

danmar · Sep 12, 2024 · 7cf50ca · 7cf50ca
1 parent 4cf5cc2
commit 7cf50ca
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Showing 2 changed files with 74 additions and 0 deletions.
diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
@@ -1534,7 +1534,14 @@ void CheckUnusedVar::checkStructMemberUsage()
         if (bailout)
             continue;
 
+        // Keep track of number of non-static members encountered so far
+        int nummembs = 0;
+
         for (const Variable &var : scope.varlist) {
+            if (!var.isStatic()) {
+                nummembs++;
+            }
+
             // only warn for variables without side effects
             if (!var.typeStartToken()->isStandardType() && !var.isPointer() && !astIsContainer(var.nameToken()) && !isRecordTypeWithoutSideEffects(var.type()))
                 continue;
@@ -1544,6 +1551,22 @@ void CheckUnusedVar::checkStructMemberUsage()
             // Check if the struct member variable is used anywhere in the file
             bool use = false;
             for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
+                if (Token::Match(tok, "%name% {") && (!tok->previous() || !Token::Match(tok->previous(), "class|struct")) && tok->str() == scope.className) {
+                    const Token *inner = tok->next()->astOperand2();
+                    // Find number of initialized members in braced initalizer
+                    int initmembs = 0;
+                    while (inner) {
+                        initmembs++;
+                        if (!inner->isInitComma()) {
+                            break;
+                        }
+                        inner = inner->astOperand1();
+                    }
+                    if (initmembs >= nummembs) {
+                        use = true;
+                        break;
+                    }
+                }
                 if (Token::Match(tok, ". %name%") && !tok->next()->variable() && !tok->next()->function() && tok->strAt(1) == var.name()) {
                     // not known => assume variable is used
                     use = true;

diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
@@ -70,6 +70,9 @@ class TestUnusedVar : public TestFixture {
         TEST_CASE(structmember23);
         TEST_CASE(structmember24); // #10847
         TEST_CASE(structmember25);
+        TEST_CASE(structmember26); // #10305
+        TEST_CASE(structmember27);
+        TEST_CASE(structmember28);
         TEST_CASE(structmember_macro);
         TEST_CASE(classmember);
 
@@ -1962,6 +1965,54 @@ class TestUnusedVar : public TestFixture {
                       errout_str());
     }
 
+    void structmember26() { // #10305
+        checkStructMemberUsage("struct S {\n"
+                               "    const int* p{};\n"
+                               "};\n"
+                               "struct C {\n"
+                               "    int i{};\n"
+                               "    S f() const {\n"
+                               "        return S{ &i };\n"
+                               "    }\n"
+                               "};\n");
+        ASSERT_EQUALS("", errout_str());
+    }
+
+    void structmember27() {
+        checkStructMemberUsage("struct S {\n"
+                               "    const int* p{};\n"
+                               "    static int* q;\n"
+                               "    const int* r{};\n"
+                               "};\n"
+                               "struct C {\n"
+                               "    int i{};\n"
+                               "    int j{};\n"
+                               "    S f() const {\n"
+                               "        return S{ &i, &j };\n"
+                               "    }\n"
+                               "};\n"
+                               "int *S::q = 0;\n");
+        ASSERT_EQUALS("", errout_str());
+    }
+
+    void structmember28() {
+        checkStructMemberUsage("struct S {\n"
+                               "    const int* p{};\n"
+                               "    static int* q;\n"
+                               "    const int* r{};\n"
+                               "    const int* s{};"
+                               "};\n"
+                               "struct C {\n"
+                               "    int i{};\n"
+                               "    int j{};\n"
+                               "    S f() const {\n"
+                               "        return S{ &i, &j };\n"
+                               "    }\n"
+                               "};\n"
+                               "int *S::q = 0;\n");
+        ASSERT_EQUALS("[test.cpp:5]: (style) struct member 'S::s' is never used.\n", errout_str());
+    }
+
     void structmember_macro() {
         checkStructMemberUsageP("#define S(n) struct n { int a, b, c; };\n"
                                 "S(unused);\n");