Make shared CFG construction library a parameterized module

config/identical-files.json

@@ -486,7 +486,6 @@
   ],
   "CFG": [
     "csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraphImplShared.qll",
-    "ruby/ql/lib/codeql/ruby/controlflow/internal/ControlFlowGraphImplShared.qll",
     "swift/ql/lib/codeql/swift/controlflow/internal/ControlFlowGraphImplShared.qll"
   ],
   "TypeTracker": [
@@ -573,4 +572,4 @@
     "python/ql/lib/semmle/python/security/internal/EncryptionKeySizes.qll",
     "java/ql/lib/semmle/code/java/security/internal/EncryptionKeySizes.qll"
   ]
-}
+}

ruby/ql/consistency-queries/CfgConsistency.ql

@@ -1,8 +1,8 @@
-import codeql.ruby.controlflow.internal.ControlFlowGraphImplShared::Consistency
+import codeql.ruby.controlflow.internal.ControlFlowGraphImpl::Consistency
 import codeql.ruby.AST
 import codeql.ruby.CFG
 import codeql.ruby.controlflow.internal.Completion
-import codeql.ruby.controlflow.internal.ControlFlowGraphImpl
+import codeql.ruby.controlflow.internal.ControlFlowGraphImpl as CfgImpl
 
 /**
  * All `Expr` nodes are `PostOrderTree`s
@@ -14,7 +14,7 @@ query predicate nonPostOrderExpr(Expr e, string cls) {
   not e instanceof Namespace and
   not e instanceof Toplevel and
   exists(AstNode last, Completion c |
-    last(e, last, c) and
+    CfgImpl::last(e, last, c) and
     last != e and
     c instanceof NormalCompletion
   )

ruby/ql/lib/codeql/ruby/ast/Statement.qll

@@ -3,7 +3,7 @@ private import codeql.ruby.CFG
 private import internal.AST
 private import internal.TreeSitter
 private import internal.Variable
-private import codeql.ruby.controlflow.internal.ControlFlowGraphImpl
+private import codeql.ruby.controlflow.internal.ControlFlowGraphImpl as CfgImpl
 
 /**
  * A statement.
@@ -15,10 +15,10 @@ class Stmt extends AstNode, TStmt {
   CfgNodes::AstCfgNode getAControlFlowNode() { result.getNode() = this }
 
   /** Gets a control-flow entry node for this statement, if any */
-  AstNode getAControlFlowEntryNode() { result = getAControlFlowEntryNode(this) }
+  AstNode getAControlFlowEntryNode() { result = CfgImpl::getAControlFlowEntryNode(this) }
 
   /** Gets the control-flow scope of this statement, if any. */
-  CfgScope getCfgScope() { result = getCfgScope(this) }
+  CfgScope getCfgScope() { result = CfgImpl::getCfgScope(this) }
 
   /** Gets the enclosing callable, if any. */
   Callable getEnclosingCallable() { result = this.getCfgScope() }

ruby/ql/lib/codeql/ruby/controlflow/BasicBlocks.qll

@@ -4,7 +4,6 @@ private import codeql.ruby.AST
 private import codeql.ruby.ast.internal.AST
 private import codeql.ruby.ast.internal.TreeSitter
 private import codeql.ruby.controlflow.ControlFlowGraph
-private import internal.ControlFlowGraphImpl
 private import CfgNodes
 private import SuccessorTypes
 

ruby/ql/lib/codeql/ruby/controlflow/CfgNodes.qll

@@ -6,16 +6,16 @@ private import codeql.ruby.dataflow.SSA
 private import codeql.ruby.ast.internal.Constant
 private import codeql.ruby.ast.internal.Literal
 private import ControlFlowGraph
-private import internal.ControlFlowGraphImpl
+private import internal.ControlFlowGraphImpl as CfgImpl
 private import internal.Splitting
 
 /** An entry node for a given scope. */
-class EntryNode extends CfgNode, TEntryNode {
+class EntryNode extends CfgNode, CfgImpl::TEntryNode {
   override string getAPrimaryQlClass() { result = "EntryNode" }
 
   private CfgScope scope;
 
-  EntryNode() { this = TEntryNode(scope) }
+  EntryNode() { this = CfgImpl::TEntryNode(scope) }
 
   final override EntryBasicBlock getBasicBlock() { result = super.getBasicBlock() }
 
@@ -25,13 +25,13 @@ class EntryNode extends CfgNode, TEntryNode {
 }
 
 /** An exit node for a given scope, annotated with the type of exit. */
-class AnnotatedExitNode extends CfgNode, TAnnotatedExitNode {
+class AnnotatedExitNode extends CfgNode, CfgImpl::TAnnotatedExitNode {
   override string getAPrimaryQlClass() { result = "AnnotatedExitNode" }
 
   private CfgScope scope;
   private boolean normal;
 
-  AnnotatedExitNode() { this = TAnnotatedExitNode(scope, normal) }
+  AnnotatedExitNode() { this = CfgImpl::TAnnotatedExitNode(scope, normal) }
 
   /** Holds if this node represent a normal exit. */
   final predicate isNormal() { normal = true }
@@ -52,12 +52,12 @@ class AnnotatedExitNode extends CfgNode, TAnnotatedExitNode {
 }
 
 /** An exit node for a given scope. */
-class ExitNode extends CfgNode, TExitNode {
+class ExitNode extends CfgNode, CfgImpl::TExitNode {
   override string getAPrimaryQlClass() { result = "ExitNode" }
 
   private CfgScope scope;
 
-  ExitNode() { this = TExitNode(scope) }
+  ExitNode() { this = CfgImpl::TExitNode(scope) }
 
   final override Location getLocation() { result = scope.getLocation() }
 
@@ -71,14 +71,14 @@ class ExitNode extends CfgNode, TExitNode {
  * (dead) code or not important for control flow, and multiple when there are different
  * splits for the AST node.
  */
-class AstCfgNode extends CfgNode, TElementNode {
+class AstCfgNode extends CfgNode, CfgImpl::TElementNode {
   /** Gets the name of the primary QL class for this node. */
   override string getAPrimaryQlClass() { result = "AstCfgNode" }
 
-  private Splits splits;
+  private CfgImpl::Splits splits;
   AstNode e;
 
-  AstCfgNode() { this = TElementNode(_, e, splits) }
+  AstCfgNode() { this = CfgImpl::TElementNode(_, e, splits) }
 
   final override AstNode getNode() { result = e }
 

ruby/ql/lib/codeql/ruby/controlflow/ControlFlowGraph.qll

@@ -3,7 +3,7 @@
 private import codeql.ruby.AST
 private import codeql.ruby.controlflow.BasicBlocks
 private import SuccessorTypes
-private import internal.ControlFlowGraphImpl
+private import internal.ControlFlowGraphImpl as CfgImpl
 private import internal.Splitting
 private import internal.Completion
 
@@ -15,12 +15,12 @@ private import internal.Completion
  * Note that module declarations are not themselves CFG scopes, as they are part of
  * the CFG of the enclosing top-level or callable.
  */
-class CfgScope extends Scope instanceof CfgScopeImpl {
+class CfgScope extends Scope instanceof CfgImpl::CfgScopeImpl {
   /** Gets the CFG scope that this scope is nested under, if any. */
   final CfgScope getOuterCfgScope() {
     exists(AstNode parent |
       parent = this.getParent() and
-      result = getCfgScope(parent)
+      result = CfgImpl::getCfgScope(parent)
     )
   }
 }
@@ -33,7 +33,7 @@ class CfgScope extends Scope instanceof CfgScopeImpl {
  *
  * Only nodes that can be reached from an entry point are included in the CFG.
  */
-class CfgNode extends TCfgNode {
+class CfgNode extends CfgImpl::TCfgNode {
   /** Gets the name of the primary QL class for this node. */
   string getAPrimaryQlClass() { none() }
 
@@ -53,13 +53,13 @@ class CfgNode extends TCfgNode {
   final predicate isCondition() { exists(this.getASuccessor(any(ConditionalSuccessor bs))) }
 
   /** Gets the scope of this node. */
-  final CfgScope getScope() { result = getNodeCfgScope(this) }
+  final CfgScope getScope() { result = CfgImpl::getNodeCfgScope(this) }
 
   /** Gets the basic block that this control flow node belongs to. */
   BasicBlock getBasicBlock() { result.getANode() = this }
 
   /** Gets a successor node of a given type, if any. */
-  final CfgNode getASuccessor(SuccessorType t) { result = getASuccessor(this, t) }
+  final CfgNode getASuccessor(SuccessorType t) { result = CfgImpl::getASuccessor(this, t) }
 
   /** Gets an immediate successor, if any. */
   final CfgNode getASuccessor() { result = this.getASuccessor(_) }
@@ -78,7 +78,7 @@ class CfgNode extends TCfgNode {
 }
 
 /** The type of a control flow successor. */
-class SuccessorType extends TSuccessorType {
+class SuccessorType extends CfgImpl::TSuccessorType {
   /** Gets a textual representation of successor type. */
   string toString() { none() }
 }
@@ -86,7 +86,7 @@ class SuccessorType extends TSuccessorType {
 /** Provides different types of control flow successor types. */
 module SuccessorTypes {
   /** A normal control flow successor. */
-  class NormalSuccessor extends SuccessorType, TSuccessorSuccessor {
+  class NormalSuccessor extends SuccessorType, CfgImpl::TSuccessorSuccessor {
     final override string toString() { result = "successor" }
   }
 
@@ -99,9 +99,9 @@ module SuccessorTypes {
     boolean value;
 
     ConditionalSuccessor() {
-      this = TBooleanSuccessor(value) or
+      this = CfgImpl::TBooleanSuccessor(value) or
-      this = TEmptinessSuccessor(value) or
+      this = CfgImpl::TEmptinessSuccessor(value) or
-      this = TMatchingSuccessor(value)
+      this = CfgImpl::TMatchingSuccessor(value)
     }
 
     /** Gets the Boolean value of this successor. */
@@ -125,7 +125,7 @@ module SuccessorTypes {
    *
    * `x >= 0` has both a `true` successor and a `false` successor.
    */
-  class BooleanSuccessor extends ConditionalSuccessor, TBooleanSuccessor { }
+  class BooleanSuccessor extends ConditionalSuccessor, CfgImpl::TBooleanSuccessor { }
 
   /**
    * An emptiness control flow successor.
@@ -158,7 +158,7 @@ module SuccessorTypes {
    *                     \___/
    * ```
    */
-  class EmptinessSuccessor extends ConditionalSuccessor, TEmptinessSuccessor {
+  class EmptinessSuccessor extends ConditionalSuccessor, CfgImpl::TEmptinessSuccessor {
     override string toString() { if value = true then result = "empty" else result = "non-empty" }
   }
 
@@ -189,7 +189,7 @@ module SuccessorTypes {
    *  puts "one"  puts "not one"
    * ```
    */
-  class MatchingSuccessor extends ConditionalSuccessor, TMatchingSuccessor {
+  class MatchingSuccessor extends ConditionalSuccessor, CfgImpl::TMatchingSuccessor {
     override string toString() { if value = true then result = "match" else result = "no-match" }
   }
 
@@ -207,7 +207,7 @@ module SuccessorTypes {
    * The exit node of `sum` is a `return` successor of the `return x + y`
    * statement.
    */
-  class ReturnSuccessor extends SuccessorType, TReturnSuccessor {
+  class ReturnSuccessor extends SuccessorType, CfgImpl::TReturnSuccessor {
     final override string toString() { result = "return" }
   }
 
@@ -230,7 +230,7 @@ module SuccessorTypes {
    *
    * The node `puts "done"` is `break` successor of the node `break`.
    */
-  class BreakSuccessor extends SuccessorType, TBreakSuccessor {
+  class BreakSuccessor extends SuccessorType, CfgImpl::TBreakSuccessor {
     final override string toString() { result = "break" }
   }
 
@@ -253,7 +253,7 @@ module SuccessorTypes {
    *
    * The node `x >= 0` is `next` successor of the node `next`.
    */
-  class NextSuccessor extends SuccessorType, TNextSuccessor {
+  class NextSuccessor extends SuccessorType, CfgImpl::TNextSuccessor {
     final override string toString() { result = "next" }
   }
 
@@ -278,7 +278,7 @@ module SuccessorTypes {
    *
    * The node `x -= 1` is `redo` successor of the node `redo`.
    */
-  class RedoSuccessor extends SuccessorType, TRedoSuccessor {
+  class RedoSuccessor extends SuccessorType, CfgImpl::TRedoSuccessor {
     final override string toString() { result = "redo" }
   }
 
@@ -302,7 +302,7 @@ module SuccessorTypes {
    *
    * The node `puts "Retry"` is `retry` successor of the node `retry`.
    */
-  class RetrySuccessor extends SuccessorType, TRetrySuccessor {
+  class RetrySuccessor extends SuccessorType, CfgImpl::TRetrySuccessor {
     final override string toString() { result = "retry" }
   }
 
@@ -323,7 +323,7 @@ module SuccessorTypes {
    * The exit node of `m` is an exceptional successor of the node
    * `raise "x > 2"`.
    */
-  class RaiseSuccessor extends SuccessorType, TRaiseSuccessor {
+  class RaiseSuccessor extends SuccessorType, CfgImpl::TRaiseSuccessor {
     final override string toString() { result = "raise" }
   }
 
@@ -344,7 +344,7 @@ module SuccessorTypes {
    * The exit node of `m` is an exit successor of the node
    * `exit 1`.
    */
-  class ExitSuccessor extends SuccessorType, TExitSuccessor {
+  class ExitSuccessor extends SuccessorType, CfgImpl::TExitSuccessor {
     final override string toString() { result = "exit" }
   }
 }

ruby/ql/lib/codeql/ruby/controlflow/internal/Completion.qll

@@ -8,7 +8,7 @@ private import codeql.ruby.AST
 private import codeql.ruby.ast.internal.AST
 private import codeql.ruby.ast.internal.Control
 private import codeql.ruby.controlflow.ControlFlowGraph
-private import ControlFlowGraphImpl
+private import ControlFlowGraphImpl as CfgImpl
 private import NonReturning
 private import SuccessorTypes
 
@@ -53,7 +53,7 @@ private predicate nestedEnsureCompletion(TCompletion outer, int nestLevel) {
     or
     outer = TExitCompletion()
   ) and
-  nestLevel = any(Trees::BodyStmtTree t).getNestLevel()
+  nestLevel = any(CfgImpl::Trees::BodyStmtTree t).getNestLevel()
 }
 
 pragma[noinline]
@@ -72,7 +72,7 @@ private predicate completionIsValidForStmt(AstNode n, Completion c) {
 }
 
 private AstNode getARescuableBodyChild() {
-  exists(Trees::BodyStmtTree bst | result = bst.getBodyChild(_, true) |
+  exists(CfgImpl::Trees::BodyStmtTree bst | result = bst.getBodyChild(_, true) |
     exists(bst.getARescue())
     or
     exists(bst.getEnsure())
@@ -247,7 +247,7 @@ private predicate inMatchingContext(AstNode n) {
   or
   n = any(ReferencePattern p).getExpr()
   or
-  n.(Trees::DefaultValueParameterTree).hasDefaultValue()
+  n.(CfgImpl::Trees::DefaultValueParameterTree).hasDefaultValue()
 }
 
 /**

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

@@ -1,74 +0,0 @@
-private import codeql.ruby.AST as RB
-private import ControlFlowGraphImpl as Impl
-private import Completion as Comp
-private import codeql.ruby.ast.internal.Synthesis
-private import Splitting as Splitting
-private import codeql.ruby.CFG as Cfg
-
-/** The base class for `ControlFlowTree`. */
-class ControlFlowTreeBase extends RB::AstNode {
-  ControlFlowTreeBase() { not any(Synthesis s).excludeFromControlFlowTree(this) }
-}
-
-class ControlFlowElement = RB::AstNode;
-
-class Completion = Comp::Completion;
-
-/**
- * Hold if `c` represents normal evaluation of a statement or an
- * expression.
- */
-predicate completionIsNormal(Completion c) { c instanceof Comp::NormalCompletion }
-
-/**
- * Hold if `c` represents simple (normal) evaluation of a statement or an
- * expression.
- */
-predicate completionIsSimple(Completion c) { c instanceof Comp::SimpleCompletion }
-
-/** Holds if `c` is a valid completion for `e`. */
-predicate completionIsValidFor(Completion c, ControlFlowElement e) { c.isValidFor(e) }
-
-class CfgScope = Cfg::CfgScope;
-
-predicate getCfgScope = Impl::getCfgScope/1;
-
-/** Holds if `first` is first executed when entering `scope`. */
-predicate scopeFirst(CfgScope scope, ControlFlowElement first) {
-  scope.(Impl::CfgScopeImpl).entry(first)
-}
-
-/** Holds if `scope` is exited when `last` finishes with completion `c`. */
-predicate scopeLast(CfgScope scope, ControlFlowElement last, Completion c) {
-  scope.(Impl::CfgScopeImpl).exit(last, c)
-}
-
-/** The maximum number of splits allowed for a given node. */
-int maxSplits() { result = 5 }
-
-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::RaiseSuccessor or
-  t instanceof Cfg::SuccessorTypes::ExitSuccessor
-}
-
-class Location = RB::Location;
-
-class Node = Cfg::CfgNode;

ruby/ql/lib/codeql/ruby/controlflow/internal/Splitting.qll

@@ -2,7 +2,7 @@
  * Provides classes and predicates relevant for splitting the control flow graph.
  */
 
-private import codeql.ruby.AST
+private import codeql.ruby.AST as Ast
 private import Completion
 private import ControlFlowGraphImpl
 private import SuccessorTypes
@@ -64,31 +64,36 @@ private module ConditionalCompletionSplitting {
 
   int getNextListOrder() { result = 1 }
 
-  private class ConditionalCompletionSplitImpl extends SplitImpl, ConditionalCompletionSplit {
+  private class ConditionalCompletionSplitImpl extends SplitImpl instanceof ConditionalCompletionSplit
+  {
+    ConditionalCompletion completion;
+
+    ConditionalCompletionSplitImpl() { this = TConditionalCompletionSplit(completion) }
+
     override ConditionalCompletionSplitKind getKind() { any() }
 
     override predicate hasEntry(AstNode pred, AstNode succ, Completion c) {
       succ(pred, succ, c) and
       last(succ, _, completion) and
       (
-        last(succ.(NotExpr).getOperand(), pred, c) and
+        last(succ.(Ast::NotExpr).getOperand(), pred, c) and
         completion.(BooleanCompletion).getDual() = c
         or
-        last(succ.(LogicalAndExpr).getAnOperand(), pred, c) and
+        last(succ.(Ast::LogicalAndExpr).getAnOperand(), pred, c) and
         completion = c
         or
-        last(succ.(LogicalOrExpr).getAnOperand(), pred, c) and
+        last(succ.(Ast::LogicalOrExpr).getAnOperand(), pred, c) and
         completion = c
         or
-        last(succ.(StmtSequence).getLastStmt(), pred, c) and
+        last(succ.(Ast::StmtSequence).getLastStmt(), pred, c) and
         completion = c
         or
-        last(succ.(ConditionalExpr).getBranch(_), pred, c) and
+        last(succ.(Ast::ConditionalExpr).getBranch(_), pred, c) and
         completion = c
       )
       or
       succ(pred, succ, c) and
-      succ instanceof WhenClause and
+      succ instanceof Ast::WhenClause and
       completion = c
     }
 
@@ -144,7 +149,7 @@ module EnsureSplitting {
     /** Holds if this node is the entry node in the `ensure` block it belongs to. */
     predicate isEntryNode() { first(block.getEnsure(), this) }
 
-    BodyStmt getBlock() { result = block }
+    Ast::BodyStmt getBlock() { result = block }
 
     pragma[noinline]
     predicate isEntered(AstNode pred, int nestLevel, Completion c) {
@@ -221,12 +226,12 @@ module EnsureSplitting {
     override string toString() { result = "ensure (" + nestLevel + ")" }
   }
 
-  private class EnsureSplitImpl extends SplitImpl, EnsureSplit {
+  private class EnsureSplitImpl extends SplitImpl instanceof EnsureSplit {
-    override EnsureSplitKind getKind() { result.getNestLevel() = this.getNestLevel() }
+    override EnsureSplitKind getKind() { result.getNestLevel() = super.getNestLevel() }
 
     override predicate hasEntry(AstNode pred, AstNode succ, Completion c) {
-      succ.(EnsureNode).isEntered(pred, this.getNestLevel(), c) and
+      succ.(EnsureNode).isEntered(pred, super.getNestLevel(), c) and
-      this.getType().isSplitForEntryCompletion(c)
+      super.getType().isSplitForEntryCompletion(c)
     }
 
     override predicate hasEntryScope(CfgScope scope, AstNode first) { none() }
@@ -253,8 +258,8 @@ module EnsureSplitting {
      */
     private predicate exit(AstNode pred, Completion c, boolean inherited) {
       exists(Trees::BodyStmtTree block, EnsureSplitType type |
-        this.exit0(pred, block, this.getNestLevel(), c) and
+        this.exit0(pred, block, super.getNestLevel(), c) and
-        type = this.getType()
+        type = super.getType()
       |
         if last(block.getEnsure(), pred, c)
         then
@@ -302,9 +307,9 @@ module EnsureSplitting {
       // split must be able to exit with a `return` completion.
       this.appliesToPredecessor(pred) and
       exists(EnsureSplitImpl outer |
-        outer.getNestLevel() = this.getNestLevel() - 1 and
+        outer.(EnsureSplit).getNestLevel() = super.getNestLevel() - 1 and
         outer.exit(pred, c, inherited) and
-        this.getType() instanceof NormalSuccessor and
+        super.getType() instanceof NormalSuccessor and
         inherited = true
       )
     }
@@ -335,10 +340,10 @@ module EnsureSplitting {
           if en.isEntryNode() and en.getBlock() != pred.(EnsureNode).getBlock()
           then
             // entering a nested `ensure` block
-            en.getNestLevel() > this.getNestLevel()
+            en.getNestLevel() > super.getNestLevel()
           else
             // staying in the same (possibly nested) `ensure` block as `pred`
-            en.getNestLevel() >= this.getNestLevel()
+            en.getNestLevel() >= super.getNestLevel()
         )
     }
   }

ruby/ql/lib/codeql/ruby/dataflow/internal/SsaImpl.qll

@@ -1,7 +1,7 @@
 private import codeql.ssa.Ssa as SsaImplCommon
 private import codeql.ruby.AST
 private import codeql.ruby.CFG as Cfg
-private import codeql.ruby.controlflow.internal.ControlFlowGraphImplShared as ControlFlowGraphImplShared
+private import codeql.ruby.controlflow.internal.ControlFlowGraphImpl as ControlFlowGraphImpl
 private import codeql.ruby.dataflow.SSA
 private import codeql.ruby.ast.Variable
 private import Cfg::CfgNodes::ExprNodes
@@ -124,7 +124,7 @@ private predicate capturedExitRead(Cfg::AnnotatedExitBasicBlock bb, int i, Local
 private predicate namespaceSelfExitRead(Cfg::AnnotatedExitBasicBlock bb, int i, SelfVariable v) {
   exists(Namespace ns, AstNode last |
     v.getDeclaringScope() = ns and
-    last = ControlFlowGraphImplShared::getAControlFlowExitNode(ns) and
+    last = ControlFlowGraphImpl::getAControlFlowExitNode(ns) and
     if last = ns
     then bb.getNode(i).getAPredecessor().getNode() = last
     else bb.getNode(i).getNode() = last

ruby/ql/lib/ide-contextual-queries/printCfg.ql

@@ -7,7 +7,7 @@
  * @tags ide-contextual-queries/print-cfg
  */
 
-private import codeql.ruby.controlflow.internal.ControlFlowGraphImplShared::TestOutput
+private import codeql.ruby.controlflow.internal.ControlFlowGraphImpl::TestOutput
 private import codeql.IDEContextual
 
 /**

ruby/ql/lib/qlpack.yml

@@ -6,6 +6,7 @@ dbscheme: ruby.dbscheme
 upgrades: upgrades
 library: true
 dependencies:
+  codeql/controlflow: ${workspace}
   codeql/dataflow: ${workspace}
   codeql/mad: ${workspace}
   codeql/regex: ${workspace}

shared/controlflow/qlpack.yml

@@ -2,4 +2,6 @@ name: codeql/controlflow
 version: 0.0.1-dev
 groups: shared
 library: true
+dependencies:
+  codeql/util: ${workspace}
 warnOnImplicitThis: true

shared/util/codeql/util/Location.qll

@@ -0,0 +1,36 @@
+/** Provides classes for working with locations. */
+
+/**
+ * A location as given by a file, a start line, a start column,
+ * an end line, and an end column.
+ *
+ * For more information about locations see [Locations](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+ */
+signature class LocationSig {
+  /** Gets the 1-based line number (inclusive) where this location starts. */
+  int getStartLine();
+
+  /** Gets the 1-based column number (inclusive) where this location starts. */
+  int getStartColumn();
+
+  /** Gets the 1-based line number (inclusive) where this location ends. */
+  int getEndLine();
+
+  /** Gets the 1-based column number (inclusive) where this location ends. */
+  int getEndColumn();
+
+  /** Gets a textual representation of this location. */
+  bindingset[this]
+  string toString();
+
+  /**
+   * Holds if this element is at the specified location.
+   * The location spans column `startColumn` of line `startLine` to
+   * column `endColumn` of line `endLine` in file `filepath`.
+   * For more information, see
+   * [Providing locations in CodeQL queries](https://codeql.github.com/docs/writing-codeql-queries/providing-locations-in-codeql-queries/).
+   */
+  predicate hasLocationInfo(
+    string filePath, int startLine, int startColumn, int endLine, int endColumn
+  );
+}