Swift: merge ControlFlowGraphParameter into ControlFlowGraphImplSpecific

Author: Robert Marsh

swift/ql/lib/codeql/swift/controlflow/internal/AstControlFlowTrees.qll

@@ -1,6 +1,6 @@
 private import swift
 private import Completion
-private import ControlFlowGraphParameter::CfgImpl
+private import ControlFlowGraphImplSpecific::CfgImpl
 private import ControlFlowElements
 
 abstract class AstControlFlowTree extends ControlFlowTree {

swift/ql/lib/codeql/swift/controlflow/internal/ControlFlowGraphImpl.qll

@@ -36,7 +36,7 @@ private import codeql.swift.controlflow.ControlFlowGraph
 private import codeql.swift.generated.Synth
 private import Completion
 private import Scope
-import ControlFlowGraphParameter::CfgImpl
+import ControlFlowGraphImplSpecific::CfgImpl
 private import ControlFlowElements
 private import AstControlFlowTrees
 

swift/ql/lib/codeql/swift/controlflow/internal/ControlFlowGraphImplSpecific.qll

@@ -1,7 +1,18 @@
+/**
+ * Provides the `CfgImpl` module that is used to construct the basic successor relation on control
+ * flow elements, and the `CfgInput` module that is used to construct `CgfImpl`.
+ *
+ * See `ControlFlowGraphImpl.qll` for the auxiliary classes and predicates that map AST elements to
+ * control flow elements and sequence their children.
+ */
+
 private import swift as S
+import codeql.controlflow.Cfg
+import codeql.util.Unit
+private import Completion as C
 private import ControlFlowGraphImpl as Impl
 import Completion
-private import codeql.swift.controlflow.ControlFlowGraph as CFG
+private import codeql.swift.controlflow.ControlFlowGraph as Cfg
 private import Splitting as Splitting
 private import Scope
 import ControlFlowElements
@@ -10,13 +21,72 @@ import AstControlFlowTrees
 /** The base class for `ControlFlowTree`. */
 class ControlFlowTreeBase = ControlFlowElement;
 
-class CfgScope = CFG::CfgScope;
+class CfgScope = Cfg::CfgScope;
 
 predicate getCfgScope = Impl::getCfgScope/1;
 
 /** Gets the maximum number of splits allowed for a given node. */
-int maxSplits() { result = 5 }
-
 class Location = S::Location;
 
-class Node = CFG::ControlFlowNode;
+class Node = Cfg::ControlFlowNode;
+
+ module CfgInput implements InputSig<Location> {
+   class AstNode = ControlFlowElement;
+ 
+   class Completion = C::Completion;
+ 
+   predicate completionIsNormal = C::completionIsNormal/1;
+ 
+   predicate completionIsSimple = C::completionIsSimple/1;
+ 
+   predicate completionIsValidFor = C::completionIsValidFor/2;
+ 
+   /** An AST node with an associated control-flow graph. */
+   class CfgScope extends S::Locatable instanceof Impl::CfgScope::Range_ { }
+ 
+   CfgScope getCfgScope(AstNode n) { result = scopeOfAst(n.asAstNode()) }
+ 
+   class SplitKindBase = Splitting::TSplitKind;
+ 
+   class Split = Splitting::Split;
+ 
+   class SuccessorType = Cfg::SuccessorType;
+ 
+   /** Gets a successor type that matches completion `c`. */
+   SuccessorType getAMatchingSuccessorType(Completion c) { result = c.getAMatchingSuccessorType() }
+ 
+   /**
+    * Hold if `c` represents simple (normal) evaluation of a statement or an
+    * expression.
+    */
+   predicate successorTypeIsSimple(SuccessorType t) {
+     t instanceof Cfg::SuccessorTypes::NormalSuccessor
+   }
+ 
+   /** Holds if `t` is an abnormal exit type out of a CFG scope. */
+   predicate isAbnormalExitType(SuccessorType t) {
+     t instanceof Cfg::SuccessorTypes::ExceptionSuccessor
+   }
+ 
+   /** Hold if `t` represents a conditional successor type. */
+   predicate successorTypeIsCondition(SuccessorType t) {
+     t instanceof Cfg::SuccessorTypes::BooleanSuccessor or
+     t instanceof Cfg::SuccessorTypes::BreakSuccessor or
+     t instanceof Cfg::SuccessorTypes::ContinueSuccessor or
+     t instanceof Cfg::SuccessorTypes::MatchingSuccessor or
+     t instanceof Cfg::SuccessorTypes::EmptinessSuccessor
+   }
+ 
+   /** Holds if `first` is first executed when entering `scope`. */
+   predicate scopeFirst(CfgScope scope, AstNode first) {
+     scope.(Impl::CfgScope::Range_).entry(first)
+   }
+ 
+   /** Holds if `scope` is exited when `last` finishes with completion `c`. */
+   predicate scopeLast(CfgScope scope, AstNode last, Completion c) {
+     scope.(Impl::CfgScope::Range_).exit(last, c)
+   }
+ }
+ 
+ module CfgImpl = Make<Location, CfgInput>;
+ 

swift/ql/lib/codeql/swift/controlflow/internal/ControlFlowGraphParameter.qll

@@ -7,7 +7,7 @@ private import Completion
 private import ControlFlowGraphImpl
 private import AstControlFlowTrees
 private import ControlFlowElements
-private import ControlFlowGraphParameter
+private import ControlFlowGraphImplSpecific::CfgInput as CfgInput
 
 cached
 private module Cached {