update ql files and add test.c for RULE-21-13

Author: jeongsoolee09

c/misra/src/rules/RULE-21-13/CtypeFunctionArgNotUnsignedCharOrEof.ql

@@ -12,8 +12,37 @@
 
 import cpp
 import codingstandards.c.misra
+import codingstandards.cpp.ReadErrorsAndEOF
+import semmle.code.cpp.rangeanalysis.SimpleRangeAnalysis
+import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
+import semmle.code.cpp.dataflow.DataFlow // TODO use this...
 
-from
+query predicate isCtypeFunction(Function function) {
+  function.getADeclaration().getAFile().(HeaderFile).getShortName() = "_ctype" // TODO: change it back to `ctype`
+}
+
+query predicate isInUnsignedCharRange(Expr var) {
+  // TODO: shouldn't be an Expr, instead get it as an argument from a FunctionCall that isCtypeFunction
+  exists(UnsignedCharType unsignedChar |
+    // Consider cases where the argument's value is cast to some smaller type, clipping the range.
+    typeLowerBound(unsignedChar) <= lowerBound(var.getFullyConverted()) and
+    upperBound(var.getFullyConverted()) <= typeUpperBound(unsignedChar)
+  )
+}
+
+// Uh oh, this is empty
+query predicate isEOFInvocation(EOFInvocation eof) {
+  any()
+}
+
+/* very early draft */
+query predicate equivToEOF(FunctionCall fc, EOFInvocation eof) {
+  // var is a param of ctypefunctioncall
+  isCtypeFunction(fc.getTarget()) and
+  DataFlow::localFlow(DataFlow::exprNode(eof.getExpr()), DataFlow::exprNode(fc.getArgument(0)))
+}
+from Element x
 where
   not isExcluded(x, StandardLibraryFunctionTypesPackage::ctypeFunctionArgNotUnsignedCharOrEofQuery()) and
-select
+  any()
+select 1

c/misra/src/rules/RULE-21-15/MemcpyMemmoveMemcmpArgNotPointersToCompatibleTypes.ql

@@ -13,7 +13,8 @@
 import cpp
 import codingstandards.c.misra
 
-from
+from Element x
 where
   not isExcluded(x, StandardLibraryFunctionTypesPackage::memcpyMemmoveMemcmpArgNotPointersToCompatibleTypesQuery()) and
-select
+  any()
+select 1

c/misra/test/rules/RULE-21-13/test.c

@@ -0,0 +1,11 @@
+#include <stdio.h>
+#include <ctype.h>
+
+void sample() {
+  unsigned char c1 = 'c';
+  int r1 = isalnum(c1); // compliant
+  unsigned char c2 = EOF;
+  int r2 = isalnum(c2); // compliant
+}
+
+int main() { return 0; }