Fix cppcheck-opensource#7959 invalidPrintfArgType_uint false positive (cppcheck-opensource#8534)

Author: chrchr-github

lib/checkio.cpp

@@ -1539,9 +1539,10 @@ CheckIO::ArgumentInfo::ArgumentInfo(const Token * arg, const Settings &settings,
                 if (element && isStdVectorOrString()) { // isStdVectorOrString sets type token if true
                     element = false;    // not really an array element
                 } else if (variableInfo->isEnumType()) {
-                    if (variableInfo->type() && variableInfo->type()->classScope && variableInfo->type()->classScope->enumType)
+                    const bool hasEnumType = variableInfo->type() && variableInfo->type()->classScope && variableInfo->type()->classScope->enumType;
+                    if (hasEnumType && variableInfo->type()->classScope->enumType->isStandardType())
                         typeToken = variableInfo->type()->classScope->enumType;
-                    else {
+                    else if (!hasEnumType) {
                         tempToken = new Token(tok1);
                         tempToken->str("int");
                         typeToken = tempToken;

test/testio.cpp

@@ -3371,6 +3371,20 @@ class TestIO : public TestFixture {
               "}");
         ASSERT_EQUALS("", errout_str());
 
+        check("enum E : uint8_t { E0 }; \n" // #7959
+              "void f(E e) {\n"
+              "    printf(\"%hhu\", e);\n"
+              "}");
+        ASSERT_EQUALS("", errout_str());
+
+        check("enum E : uint8_t { E0 }; \n"
+              "void f(E e) {\n"
+              "    printf(\"%lu\", e);\n"
+              "}");
+        TODO_ASSERT_EQUALS("[test.cpp:3]: (warning) %lu in format string (no. 1) requires 'unsigned long' but the argument type is 'uint8_t'.\n",
+                           "",
+                           errout_str());
+
         check("void f() {\n"
               "    printf(\"%lu\", sizeof(char));\n"
               "}\n", dinit(CheckOptions, $.portability = true, $.platform = Platform::Type::Win64));