Fixed #10480 (FP: misra-c2012-10.4 (char))

Author: danmar

addons/misra.py

@@ -443,8 +443,11 @@ def getEssentialTypeCategory(expr):
             return expr.valueType.sign
     if expr.valueType and expr.valueType.typeScope and expr.valueType.typeScope.className:
         return "enum<" + expr.valueType.typeScope.className + ">"
-    if expr.variable:
-        typeToken = expr.variable.typeStartToken
+    vartok = expr
+    while simpleMatch(vartok, '[') or (vartok and vartok.str == '*' and vartok.astOperand2 is None):
+        vartok = vartok.astOperand1
+    if vartok and vartok.variable:
+        typeToken = vartok.variable.typeStartToken
         while typeToken and typeToken.isName:
             if typeToken.str == 'char' and not typeToken.isSigned and not typeToken.isUnsigned:
                 return 'char'

addons/test/misra/misra-test-avr8.c

@@ -1,6 +1,14 @@
 // To test:
 // ~/cppcheck/cppcheck --addon=misra --platform=avr8 misra-test-avr8.c
 
+static void misra_10_4(void)
+{
+    // #10480
+    char buf[1] = {'f'};
+    const char c = '0';
+    signed int x = buf[0] - c;
+}
+
 static void misra_12_2(void) {
   a = (((uint64_t)0xFF) << 32);
 }