C++: Implement alias and side effect models for iterators.

Author: MathiasVP

cpp/ql/lib/semmle/code/cpp/models/implementations/Iterator.qll

@@ -9,6 +9,8 @@ import cpp
 import semmle.code.cpp.models.interfaces.Taint
 import semmle.code.cpp.models.interfaces.DataFlow
 import semmle.code.cpp.models.interfaces.Iterator
+import semmle.code.cpp.models.interfaces.Alias
+import semmle.code.cpp.models.interfaces.SideEffect
 
 /**
  * An instantiation of the `std::iterator_traits` template.
@@ -438,7 +440,9 @@ private class IteratorAssignmentMemberOperatorModel extends IteratorAssignmentMe
  * A `begin` or `end` member function, or a related member function, that
  * returns an iterator.
  */
-private class BeginOrEndFunction extends MemberFunction, TaintFunction, GetIteratorFunction {
+private class BeginOrEndFunction extends MemberFunction, TaintFunction, GetIteratorFunction,
+  AliasFunction, SideEffectFunction
+{
   BeginOrEndFunction() {
     this.hasName([
         "begin", "cbegin", "rbegin", "crbegin", "end", "cend", "rend", "crend", "before_begin",
@@ -456,6 +460,22 @@ private class BeginOrEndFunction extends MemberFunction, TaintFunction, GetItera
     input.isQualifierObject() and
     output.isReturnValue()
   }
+
+  override predicate parameterNeverEscapes(int index) { index = -1 }
+
+  override predicate parameterEscapesOnlyViaReturn(int index) { none() }
+
+  override predicate hasOnlySpecificReadSideEffects() { any() }
+
+  override predicate hasOnlySpecificWriteSideEffects() { any() }
+
+  override predicate hasSpecificWriteSideEffect(ParameterIndex i, boolean buffer, boolean mustWrite) {
+    none()
+  }
+
+  override predicate hasSpecificReadSideEffect(ParameterIndex i, boolean buffer) {
+    i = -1 and buffer = false
+  }
 }
 
 /**