Fixed #2597 (False positive: Buffer access out-of-bounds for u_char, uint*_t, ...)

lib/checkbufferoverrun.cpp

@@ -992,7 +992,7 @@ void CheckBufferOverrun::checkScope(const Token *tok, const std::vector<std::str
         }
 
         // Check function call..
-        if (Token::Match(tok, "%var% ("))
+        if (Token::Match(tok, "%var% (") && total_size > 0)
         {
             // No varid => function calls are not handled
             if (varid == 0)

test/testbufferoverrun.cpp

@@ -135,6 +135,7 @@ private:
         TEST_CASE(buffer_overrun_16);
         TEST_CASE(buffer_overrun_17); // ticket #2548
         TEST_CASE(buffer_overrun_18); // ticket #2576 - for, calculation with loop variable
+        TEST_CASE(buffer_overrun_19); // #2597 - class member with unknown type
         TEST_CASE(buffer_overrun_bailoutIfSwitch);  // ticket #2378 : bailoutIfSwitch
 
         // It is undefined behaviour to point out of bounds of an array
@@ -1891,6 +1892,20 @@ private:
                            errout.str());
     }
 
+    void buffer_overrun_19() // #2597 - class member with unknown type
+    {
+        check("class A {\n"
+              "public:\n"
+              "    u8 buf[10];\n"
+              "    A();"
+              "};\n"
+              "\n"
+              "A::A() {\n"
+              "    memset(buf, 0, 10);\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void buffer_overrun_bailoutIfSwitch()
     {
         // No false positive