Fix #14860 FP sizeofwithsilentarraypointer with std::array (cppcheck-opensource#8661)

Author: chrchr-github

lib/checksizeof.cpp

@@ -87,7 +87,7 @@ void CheckSizeofImpl::checkSizeofForArrayParameter()
                 }
 
                 const Variable *var = varTok->variable();
-                if (var && var->isArray() && var->isArgument() && !var->isReference())
+                if (var && var->isArray() && var->isArgument() && !var->isReference() && !(var->isStlType() && var->getTypeName() == "std::array"))
                     sizeofForArrayParameterError(tok);
             }
         }

test/testsizeof.cpp

@@ -334,6 +334,14 @@ class TestSizeof : public TestFixture {
               "}");
         ASSERT_EQUALS("", errout_str());
 
+        check("int f(std::array<int, 2> a) {\n" // #14860
+              "    return sizeof(a);\n"
+              "}\n"
+              "int g(std::string a[2]) {\n"
+              "    return sizeof(a);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:5:12]: (warning) Using 'sizeof' on array given as function argument returns size of a pointer. [sizeofwithsilentarraypointer]\n",
+                      errout_str());
     }
 
     void sizeofForNumericParameter() {