misra.py: Handle essential type categories for ternary operations (#2455)

This commit will add feature to detect essential type categories
for operators of ternary operation.

This fixes issues with rule 10.1 and close the following ticket:
https://trac.cppcheck.net/ticket/9543

Author: jubnzv

addons/misra.py

@@ -531,6 +531,28 @@ def isSimpleEscapeSequence(symbols):
     return symbols[1] in ("'", '"', '?', '\\', 'a', 'b', 'f', 'n', 'r', 't', 'v')
 
 
+def isTernaryOperator(token):
+    if not token:
+        return False
+    if not token.astOperand2:
+        return False
+    return token.str == '?' and token.astOperand2.str == ':'
+
+
+def getTernaryOperandsRecursive(token):
+    """Returns list of ternary operands including nested onces."""
+    if not isTernaryOperator(token):
+        return []
+    result = []
+    result += getTernaryOperandsRecursive(token.astOperand2.astOperand1)
+    if token.astOperand2.astOperand1 and not isTernaryOperator(token.astOperand2.astOperand1):
+        result += [token.astOperand2.astOperand1]
+    result += getTernaryOperandsRecursive(token.astOperand2.astOperand2)
+    if token.astOperand2.astOperand2 and not isTernaryOperator(token.astOperand2.astOperand2):
+        result += [token.astOperand2.astOperand2]
+    return result
+
+
 def hasNumericEscapeSequence(symbols):
     """Check that given string contains octal or hexadecimal escape sequences."""
     if '\\' not in symbols:
@@ -1049,20 +1071,25 @@ def misra_10_1(self, data):
         for token in data.tokenlist:
             if not token.isOp:
                 continue
-            e1 = getEssentialTypeCategory(token.astOperand1)
-            e2 = getEssentialTypeCategory(token.astOperand2)
-            if not e1 or not e2:
-                continue
-            if token.str in ('<<', '>>'):
-                if e1 != 'unsigned':
-                    self.reportError(token, 10, 1)
-                elif e2 != 'unsigned' and not token.astOperand2.isNumber:
-                    self.reportError(token, 10, 1)
-            elif token.str in ('~', '&', '|', '^'):
-                e1_et = getEssentialType(token.astOperand1)
-                e2_et = getEssentialType(token.astOperand2)
-                if e1_et == 'char' and e2_et == 'char':
-                    self.reportError(token, 10, 1)
+
+            for t1, t2 in itertools.product(
+                list(getTernaryOperandsRecursive(token.astOperand1) or [token.astOperand1]),
+                list(getTernaryOperandsRecursive(token.astOperand2) or [token.astOperand2]),
+            ):
+                e1 = getEssentialTypeCategory(t1)
+                e2 = getEssentialTypeCategory(t2)
+                if not e1 or not e2:
+                    continue
+                if token.str in ('<<', '>>'):
+                    if e1 != 'unsigned':
+                        self.reportError(token, 10, 1)
+                    elif e2 != 'unsigned' and not token.astOperand2.isNumber:
+                        self.reportError(token, 10, 1)
+                elif token.str in ('~', '&', '|', '^'):
+                    e1_et = getEssentialType(token.astOperand1)
+                    e2_et = getEssentialType(token.astOperand2)
+                    if e1_et == 'char' and e2_et == 'char':
+                        self.reportError(token, 10, 1)
 
     def misra_10_4(self, data):
         op = {'+', '-', '*', '/', '%', '&', '|', '^', '+=', '-=', ':'}

addons/test/misra/misra-test.c

@@ -234,6 +234,32 @@ void misra_10_1(uint8_t u, char c1, char c2) {
   MISRA_10_1_CHAR cd3;
   cd3 = cd1 & cd2; // 10.1
 }
+void misra_10_1_ternary()
+{
+    int a;
+    uint8_t ui8;
+    uint16_t ui16;
+    int8_t i8;
+    int16_t i16;
+
+    a = ui16 << ui16;
+    a = ui16 << (get_bool(42) ? ui16 : ui16);
+    a = ui16 << (get_bool(42) ? ui16 : (get_bool(34) ? ui16 : ui16)); // 10.4
+    a = ui16 << (get_bool(42) ? (get_bool(34) ? ui16 : ui16) : ui16); // 10.4
+    a = ui16 << (get_bool(42) ? i16 : (get_bool(34) ? ui16 : ui16)); // 10.1
+    a = ui16 << (get_bool(42) ? (get_bool(34) ? ui16 : i16) : ui16); // 10.1 10.4
+    a = ui16 << (get_bool(42) ? (get_bool(34) ? ui16 : ui16) : i16); // 10.1
+    a = ui16 << (get_bool(42) ? (get_bool(34) ? ui16 : ui8) : ui8); // 10.4
+    a = ui16 << (get_bool(42) ? (get_bool(34) ? i16 : ui8) : ui8); // 10.1 10.4
+    a = (get_bool(42) ? (get_bool(34) ? ui16 : ui8) : ui8) << ui16; // 10.4
+    a = (get_bool(42) ? (get_bool(34) ? i16 : ui8) : ui8) << ui16; // 10.1 10.4
+    a = (get_bool(42) ? (get_bool(34) ? ui16 : i8) : ui8) << ui16; // 10.1 10.4
+    a = (get_bool(42) ? (get_bool(34) ? ui16 : ui8) : i8) << ui16; // 10.1
+    a = (get_bool(42) ? (get_bool(34) ? ui16 : ui8) : ui8) << (get_bool(19) ? ui16 : ui8); // 10.4
+    a = (get_bool(42) ? (get_bool(34) ? i16 : ui8) : ui8) << (get_bool(19) ? ui16 : ui8); // 10.1 10.4
+    a = (get_bool(42) ? (get_bool(34) ? ui16 : ui8) : ui8) << (get_bool(19) ? i16 : ui8); // 10.1 10.4
+
+}
 
 void misra_10_4(u32 x, s32 y) {
   z = x + 3; // 10.4