Draft of RULE-21-15

Author: jeongsoolee09

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

@@ -12,9 +12,17 @@
 
 import cpp
 import codingstandards.c.misra
+import codingstandards.c.Pointers
 
-from Element x
+class MemCmpMoveCpy extends BuiltInFunction {
+  MemCmpMoveCpy() { this.getName().regexpMatch(".+mem(cmp|cpy|move).+") }
+}
+
+from FunctionCall fc
 where
-  not isExcluded(x, StandardLibraryFunctionTypesPackage::memcpyMemmoveMemcmpArgNotPointersToCompatibleTypesQuery()) and
-  any()
-select 1
+  not isExcluded(fc,
+    StandardLibraryFunctionTypesPackage::memcpyMemmoveMemcmpArgNotPointersToCompatibleTypesQuery()) and
+  exists(MemCmpMoveCpy memfun | fc.getTarget() = memfun |
+    fc.getArgument(0).getUnspecifiedType() = fc.getArgument(1).getUnspecifiedType()
+  )
+select fc, fc.getArgument(0).getUnspecifiedType(), fc.getArgument(1).getUnspecifiedType()

c/misra/test/rules/RULE-21-15/test.c

@@ -0,0 +1,25 @@
+#include <string.h>
+
+void sample() {
+  int from1 = 1000000;
+  char to1;
+  memcpy(&from1, &to1, 1); // NON_COMPLIANT, the types are not compatible
+
+  int from2 = 1000000;
+  int to2;
+  memcpy(&from2, &to2, 2); // COMPLIANT
+
+  char from3[] = "string";
+  char to3[6];
+  memmove(from3, to3, 6); // COMPLIANT
+
+  char from4[] = "sstringg";
+  int to4[2];
+  memmove(from4, to4, 8); // NON_COMPLIANT, despite being equal in byte counts
+
+  char from5[] = "STRING";
+  char to5[] = "string";
+  memcmp(from5, to5, 2); // COMPLIANT
+}
+
+int main() { return 0; }