Fix #12485 Regression: FN: unusedStructMember (#6079)

danmar · Mar 4, 2024 · 0ab4257 · 0ab4257
1 parent 3a31d83
commit 0ab4257
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Showing 3 changed files with 21 additions and 4 deletions.
diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
@@ -1613,7 +1613,7 @@ bool CheckUnusedVar::isRecordTypeWithoutSideEffects(const Type* type)
 
     // Is there a member variable with possible side effects
     for (const Variable& var : type->classScope->varlist) {
-        withoutSideEffects = isVariableWithoutSideEffects(var);
+        withoutSideEffects = isVariableWithoutSideEffects(var, type);
         if (!withoutSideEffects) {
             return withoutSideEffects;
         }
@@ -1623,10 +1623,10 @@ bool CheckUnusedVar::isRecordTypeWithoutSideEffects(const Type* type)
     return (withoutSideEffects = true);
 }
 
-bool CheckUnusedVar::isVariableWithoutSideEffects(const Variable& var)
+bool CheckUnusedVar::isVariableWithoutSideEffects(const Variable& var, const Type* type)
 {
     const Type* variableType = var.type();
-    if (variableType) {
+    if (variableType && variableType != type) {
         if (!isRecordTypeWithoutSideEffects(variableType))
             return false;
     } else {

diff --git a/lib/checkunusedvar.h b/lib/checkunusedvar.h
@@ -73,7 +73,7 @@ class CPPCHECKLIB CheckUnusedVar : public Check {
     void checkStructMemberUsage();
 
     bool isRecordTypeWithoutSideEffects(const Type* type);
-    bool isVariableWithoutSideEffects(const Variable& var);
+    bool isVariableWithoutSideEffects(const Variable& var, const Type* type = nullptr);
     bool isEmptyType(const Type* type);
     bool isFunctionWithoutSideEffects(const Function& func, const Token* functionUsageToken,
                                       std::list<const Function*> checkedFuncs);

diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
@@ -69,6 +69,7 @@ class TestUnusedVar : public TestFixture {
         TEST_CASE(structmember22); // #11016
         TEST_CASE(structmember23);
         TEST_CASE(structmember24); // #10847
+        TEST_CASE(structmember25);
         TEST_CASE(structmember_macro);
         TEST_CASE(classmember);
 
@@ -1957,6 +1958,22 @@ class TestUnusedVar : public TestFixture {
         ASSERT_EQUALS("", errout.str());
     }
 
+    void structmember25() {
+        checkStructMemberUsage("struct S {\n" // #12485
+                               "    S* p;\n"
+                               "    int i;\n"
+                               "};\n"
+                               "struct T {\n"
+                               "    S s;\n"
+                               "    int j;\n"
+                               "};\n");
+        ASSERT_EQUALS("[test.cpp:2]: (style) struct member 'S::p' is never used.\n"
+                      "[test.cpp:3]: (style) struct member 'S::i' is never used.\n"
+                      "[test.cpp:6]: (style) struct member 'T::s' is never used.\n"
+                      "[test.cpp:7]: (style) struct member 'T::j' is never used.\n",
+                      errout.str());
+    }
+
     void structmember_macro() {
         checkStructMemberUsageP("#define S(n) struct n { int a, b, c; };\n"
                                 "S(unused);\n");