Update DIR-4-6 to include size check for typedef

Author: jeongsoolee09

c/misra/src/rules/DIR-4-6/PlainNumericalTypeUsedOverExplicitTypedef.ql

@@ -37,10 +37,23 @@ predicate forbiddenBuiltinNumericUsedInDecl(Variable var, string message) {
   message = "The type " + var.getType() + " is not a fixed-width numeric type."
 }
 
-predicate forbiddenTypedef(TypedefType typedef, string message) {
-  typedef.getBaseType() instanceof BuiltInNumericType and
-  not typedef.getName().regexpMatch("u?(int|float)(4|8|16|32|64|128)_t") and
-  message = "The type " + typedef.getName() + " is not an alias to a fixed-width numeric type."
+// TODO: add some inline comments
+predicate forbiddenTypedef(CTypedefType typedef, string message) {
+  /* If the typedef's name contains an explicit size */
+  (
+    if typedef.getName().regexpMatch("u?(int|float)(4|8|16|32|64|128)_t")
+    then (
+      /* Then the actual type size should match. */
+      not typedef.getSize() * 8 =
+        // times 8 because getSize() gets the size in bytes
+        typedef.getName().regexpCapture("u?(int|float)(4|8|16|32|64|128)_t", 2).toInt() and
+      message = "The typedef type " + typedef.getName() + " does not have its indicated size."
+    ) else (
+      /* Otherwise, the aliased type itself should have an explicit size in its name. */
+      not typedef.getBaseType().getName().regexpMatch("u?(int|float)(4|8|16|32|64|128)_t") and
+      message = "The type " + typedef.getName() + " is not an alias to a fixed-width numeric type."
+    )
+  )
 }
 
 from Element elem, string message

c/misra/test/rules/DIR-4-6/PlainNumericalTypeUsedOverExplicitTypedef.expected

@@ -1,3 +1,5 @@
+| test.c:14:5:14:10 | int4_t | The typedef type int4_t does not have its indicated size. |
+| test.c:16:5:16:11 | uint4_t | The typedef type uint4_t does not have its indicated size. |
 | test.c:27:5:27:26 | _astronomical_number_t | The type _astronomical_number_t is not an alias to a fixed-width numeric type. |
 | test.c:34:15:34:16 | c2 | The type signed char is not a fixed-width numeric type. |
 | test.c:35:17:35:18 | c3 | The type unsigned char is not a fixed-width numeric type. |

c/misra/test/rules/DIR-4-6/test.c

@@ -1,19 +1,19 @@
-typedef signed char int8_t;    // COMPLIANT: exception, typedefs are permitted
-typedef unsigned char uint8_t; // COMPLIANT: exception, typedefs are permitted
+typedef signed char int8_t;      // COMPLIANT: exception, typedefs are permitted
+typedef unsigned char uint8_t;   // COMPLIANT: exception, typedefs are permitted
 
 typedef signed short int16_t;    // COMPLIANT: exception, typedefs are permitted
 typedef unsigned short uint16_t; // COMPLIANT: exception, typedefs are permitted
 
-typedef signed int int32_t;    // COMPLIANT: exception, typedefs are permitted
-typedef unsigned int uint32_t; // COMPLIANT: exception, typedefs are permitted
+typedef signed int int32_t;      // COMPLIANT: exception, typedefs are permitted
+typedef unsigned int uint32_t;   // COMPLIANT: exception, typedefs are permitted
 
-typedef signed long int64_t;    // COMPLIANT: exception, typedefs are permitted
-typedef unsigned long uint64_t; // COMPLIANT: exception, typedefs are permitted
+typedef signed long int64_t;     // COMPLIANT: exception, typedefs are permitted
+typedef unsigned long uint64_t;  // COMPLIANT: exception, typedefs are permitted
 
 typedef signed long long
-    int128_t; // COMPLIANT: exception, typedefs are permitted
+    int4_t;  // NON_COMPLIANT: typedef does not have its indicated size
 typedef unsigned long long
-    uint128_t; // COMPLIANT: exception, typedefs are permitted
+    uint4_t; // NON_COMPLIANT: typedef does not have its indicated size
 
 typedef float float32_t;        // COMPLIANT: exception, typedefs are permitted
 typedef double float64_t;       // COMPLIANT: exception, typedefs are permitted
@@ -28,38 +28,38 @@ typedef int
 
 int            // COMPLIANT: exception, main's return type can be plain int
 main(int argc, // COMPLIANT: exception, argc's type can be plain int
-     char *argv[]) { // COMPLIANT: char is not a basic numeric type
+     char *argv[]) {          // COMPLIANT: char is not a basic numeric type
 
-  char c1 = 1;          // COMPLIANT: char is not a basic numeric type
-  signed char c2 = 1;   // NON_COMPLIANT: use typedef int8_t
-  unsigned char c3 = 1; // NON_COMPLIANT: use typedef uint8_t
-  int8_t c4 = 1;        // COMPLIANT: typedef used instead
+  char c1 = 1;                // COMPLIANT: char is not a basic numeric type
+  signed char c2 = 1;         // NON_COMPLIANT: use typedef int8_t
+  unsigned char c3 = 1;       // NON_COMPLIANT: use typedef uint8_t
+  int8_t c4 = 1;              // COMPLIANT: typedef used instead
 
-  short s1 = 1;          // NON_COMPLIANT: short is a basic numeric type
-  signed short s2 = 1;   // NON_COMPLIANT: use typedef int16_t
-  unsigned short s3 = 1; // NON_COMPLIANT: use typedef uint16_t
-  int16_t s4 = 1;        // COMPLIANT: typedef used instead
+  short s1 = 1;               // NON_COMPLIANT: short is a basic numeric type
+  signed short s2 = 1;        // NON_COMPLIANT: use typedef int16_t
+  unsigned short s3 = 1;      // NON_COMPLIANT: use typedef uint16_t
+  int16_t s4 = 1;             // COMPLIANT: typedef used instead
 
-  int i1 = 1;          // NON_COMPLIANT: int is a basic numeric type
-  signed int i2 = 1;   // NON_COMPLIANT: use typedef int32_t
-  unsigned int i3 = 1; // NON_COMPLIANT: use typedef uint32_t
-  int32_t i4 = 1;      // COMPLIANT: typedef used instead
+  int i1 = 1;                 // NON_COMPLIANT: int is a basic numeric type
+  signed int i2 = 1;          // NON_COMPLIANT: use typedef int32_t
+  unsigned int i3 = 1;        // NON_COMPLIANT: use typedef uint32_t
+  int32_t i4 = 1;             // COMPLIANT: typedef used instead
 
-  long l1 = 1;          // NON_COMPLIANT: int is a basic numeric type
-  signed long l2 = 1;   // NON_COMPLIANT: use typedef int64_t
-  unsigned long l3 = 1; // NON_COMPLIANT: use typedef uint64_t
-  int64_t l4 = 1;       // COMPLIANT: typedef used instead
+  long l1 = 1;                // NON_COMPLIANT: int is a basic numeric type
+  signed long l2 = 1;         // NON_COMPLIANT: use typedef int64_t
+  unsigned long l3 = 1;       // NON_COMPLIANT: use typedef uint64_t
+  int64_t l4 = 1;             // COMPLIANT: typedef used instead
 
   long long ll1 = 1;          // NON_COMPLIANT: int is a basic numeric type
-  signed long long ll2 = 1;   // NON_COMPLIANT: use typedef int128_t
-  unsigned long long ll3 = 1; // NON_COMPLIANT: use typedef uint128_t
-  int128_t ll4 = 1;           // COMPLIANT: typedef used instead
+  signed long long ll2 = 1;   // NON_COMPLIANT: use typedef int64_t
+  unsigned long long ll3 = 1; // NON_COMPLIANT: use typedef uint64_t
+  int64_t ll4 = 1;            // COMPLIANT: typedef used instead
 
   float f1 = 1; // NON_COMPLIANT: float is a basic numeric type, use a typedef
-  float32_t f2 = 1; // COMPLIANT: typedef used instead
+  float32_t f2 = 1;    // COMPLIANT: typedef used instead
 
-  double d1 = 1;    // NON_COMPLIANT: int is a basic numeric type
-  float64_t d2 = 1; // COMPLIANT: typedef used instead
+  double d1 = 1;       // NON_COMPLIANT: int is a basic numeric type
+  float64_t d2 = 1;    // COMPLIANT: typedef used instead
 
   long double ld1 = 1; // NON_COMPLIANT: int is a basic numeric type
   float128_t ld2 = 1;  // COMPLIANT: typedef used instead