Uninitialized variables; Try to remove heuristics for assignment with overloaded <<. That is non-standard behavior for the << operator. Let's see how much FPs we get.

danmar · danmar · commit a2e709a652ed · 2021-05-24T13:17:50.000+02:00
diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
@@ -1242,21 +1242,6 @@ const Token* CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer,
 
         if (valueExpr->valueType() && valueExpr->valueType()->type == ValueType::Type::VOID)
             return nullptr;
-
-        // overloaded << operator to initialize variable?
-        if (Token::simpleMatch(valueExpr->astParent(), "<<") && !valueExpr->astParent()->astParent()) {
-            if (astIsLhs(valueExpr))
-                return nullptr;
-            const Token *lhs = valueExpr->astParent()->astOperand1();
-            if (Token::simpleMatch(lhs, "<<"))
-                return valueExpr;
-            if (Token::simpleMatch(lhs->previous(), "std ::"))
-                return valueExpr;
-            const Variable *var = lhs->variable();
-            if (var && (var->typeStartToken()->isStandardType() || var->typeStartToken()->isEnumType() || Token::simpleMatch(var->typeStartToken(), "std ::")))
-                return valueExpr;
-            return nullptr;
-        }
     }
     if (astIsRhs(derefValue) && isLikelyStreamRead(mTokenizer->isCPP(), derefValue->astParent()))
         return nullptr;
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
@@ -450,10 +450,10 @@ class TestUninitVar : public TestFixture {
 
             checkUninitVar("int a(FArchive &arc) {\n"   // #3060 (initialization through operator<<)
                            "    int *p;\n"
-                           "    arc << p;\n"
+                           "    arc << p;\n" // <- TODO initialization?
                            "    return *p;\n"
                            "}");
-            ASSERT_EQUALS("", errout.str());
+            ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: p\n", errout.str());
 
             checkUninitVar("void a() {\n"
                            "    int ret;\n"
@@ -462,13 +462,13 @@ class TestUninitVar : public TestFixture {
                            "test.c");
             ASSERT_EQUALS("[test.c:3]: (error) Uninitialized variable: ret\n", errout.str());
 
-            // #4320
+            // #4320 says this is a FP. << is overloaded.
             checkUninitVar("int f() {\n"
                            "    int a;\n"
-                           "    a << 1;\n"
+                           "    a << 1;\n"  // <- TODO initialization?
                            "    return a;\n"
                            "}");
-            ASSERT_EQUALS("", errout.str());
+            ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: a\n", errout.str());
 
             // #4673
             checkUninitVar("void f() {\n"
@@ -2871,13 +2871,6 @@ class TestUninitVar : public TestFixture {
                        "    char a = c << 2;\n"
                        "}");
         ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: c\n", errout.str());
-
-        // #4320
-        checkUninitVar("void f() {\n"
-                       "    int a;\n"
-                       "    a << 1;\n"  // there might be a operator<<
-                       "}");
-        ASSERT_EQUALS("", errout.str());
     }
 
     void uninitvar8() {
@@ -4476,10 +4469,11 @@ class TestUninitVar : public TestFixture {
 
             valueFlowUninit("int a(FArchive &arc) {\n"  // #3060 (initialization through operator<<)
                             "    int *p;\n"
-                            "    arc << p;\n"
-                            "    return *p;\n" // fp: should not warn
+                            "    arc << p;\n"  // <- TODO initialization?
+                            "    return *p;\n"
                             "}");
-            TODO_ASSERT_EQUALS("", "[test.cpp:4]: (error) Uninitialized variable: p\n", errout.str());
+            ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: p\n"
+                          "[test.cpp:4]: (error) Uninitialized variable: p\n", errout.str());
 
             // #4320
             valueFlowUninit("void f() {\n"
