Port CFG implementation to public AST interface

ql/src/codeql_ruby/ast/Control.qll

@@ -440,6 +440,9 @@ class ConditionalLoop extends Loop, TConditionalLoop {
     or
     pred = "getCondition" and result = this.getCondition()
   }
+
+  /** Holds if the loop body is entered when the condition is `condValue`. */
+  predicate entersLoopWhenConditionIs(boolean condValue) { none() }
 }
 
 /**
@@ -463,6 +466,12 @@ class WhileExpr extends ConditionalLoop, TWhileExpr {
 
   final override Expr getCondition() { toGenerated(result) = g.getCondition() }
 
+  /**
+   * Holds if the loop body is entered when the condition is `condValue`. For
+   * `while` loops, this holds when `condValue` is true.
+   */
+  final override predicate entersLoopWhenConditionIs(boolean condValue) { condValue = true }
+
   final override string toString() { result = "while ..." }
 }
 
@@ -487,6 +496,12 @@ class UntilExpr extends ConditionalLoop, TUntilExpr {
 
   final override Expr getCondition() { toGenerated(result) = g.getCondition() }
 
+  /**
+   * Holds if the loop body is entered when the condition is `condValue`. For
+   * `until` loops, this holds when `condValue` is false.
+   */
+  final override predicate entersLoopWhenConditionIs(boolean condValue) { condValue = false }
+
   final override string toString() { result = "until ..." }
 }
 
@@ -505,6 +520,12 @@ class WhileModifierExpr extends ConditionalLoop, TWhileModifierExpr {
 
   final override Expr getCondition() { toGenerated(result) = g.getCondition() }
 
+  /**
+   * Holds if the loop body is entered when the condition is `condValue`. For
+   * `while`-modifier loops, this holds when `condValue` is true.
+   */
+  final override predicate entersLoopWhenConditionIs(boolean condValue) { condValue = true }
+
   final override string getAPrimaryQlClass() { result = "WhileModifierExpr" }
 
   final override string toString() { result = "... while ..." }
@@ -525,6 +546,12 @@ class UntilModifierExpr extends ConditionalLoop, TUntilModifierExpr {
 
   final override Expr getCondition() { toGenerated(result) = g.getCondition() }
 
+  /**
+   * Holds if the loop body is entered when the condition is `condValue`. For
+   * `until`-modifier loops, this holds when `condValue` is false.
+   */
+  final override predicate entersLoopWhenConditionIs(boolean condValue) { condValue = false }
+
   final override string getAPrimaryQlClass() { result = "UntilModifierExpr" }
 
   final override string toString() { result = "... until ..." }

ql/src/codeql_ruby/ast/Method.qll

@@ -4,7 +4,7 @@ private import internal.AST
 private import internal.TreeSitter
 
 /** A callable. */
-class Callable extends Expr, CfgScope, TCallable {
+class Callable extends Expr, TCallable {
   /** Gets the number of parameters of this callable. */
   final int getNumberOfParameters() { result = count(this.getAParameter()) }
 

ql/src/codeql_ruby/ast/Module.qll

@@ -47,7 +47,8 @@ class Toplevel extends ModuleBase, TToplevel {
    * Gets the `n`th `BEGIN` block.
    */
   final BeginBlock getBeginBlock(int n) {
-    toGenerated(result) = rank[n](int i, Generated::BeginBlock b | b = g.getChild(i) | b order by i)
+    toGenerated(result) =
+      rank[n + 1](int i, Generated::BeginBlock b | b = g.getChild(i) | b order by i)
   }
 
   /**

ql/src/codeql_ruby/ast/Statement.qll

@@ -15,7 +15,7 @@ class Stmt extends AstNode, TStmt {
   CfgNodes::AstCfgNode getAControlFlowNode() { result.getNode() = this }
 
   /** Gets the control-flow scope of this statement, if any. */
-  CfgScope getCfgScope() { result = getCfgScope(toGenerated(this)) }
+  CfgScope getCfgScope() { result = getCfgScope(this) }
 
   /** Gets the enclosing callable, if any. */
   Callable getEnclosingCallable() { result = this.getCfgScope() }

ql/src/codeql_ruby/controlflow/CfgNodes.qll

@@ -67,7 +67,7 @@ class AstCfgNode extends CfgNode, TAstCfgNode {
   private Splits splits;
   private AstNode n;
 
-  AstCfgNode() { this = TAstCfgNode(toGenerated(n), splits) }
+  AstCfgNode() { this = TAstCfgNode(n, splits) }
 
   final override AstNode getNode() { result = n }
 
@@ -132,7 +132,7 @@ abstract private class ExprChildMapping extends Expr {
 
   pragma[noinline]
   private BasicBlock getABasicBlockInScope() {
-    result.getANode() = TAstCfgNode(toGenerated(this.getAChildStar()), _)
+    result.getANode() = TAstCfgNode(this.getAChildStar(), _)
   }
 
   pragma[nomagic]

ql/src/codeql_ruby/controlflow/ControlFlowGraph.qll

@@ -1,8 +1,7 @@
 /** Provides classes representing the control flow graph. */
 
 private import codeql.Locations
-private import codeql_ruby.AST as AST
-private import codeql_ruby.ast.internal.AST as ASTInternal
+private import codeql_ruby.AST
 private import codeql_ruby.controlflow.BasicBlocks
 private import SuccessorTypes
 private import internal.ControlFlowGraphImpl
@@ -10,14 +9,14 @@ private import internal.Splitting
 private import internal.Completion
 
 /** An AST node with an associated control-flow graph. */
-class CfgScope extends AST::AstNode {
-  CfgScope() { ASTInternal::toGenerated(this) instanceof CfgScope::Range_ }
+class CfgScope extends AstNode {
+  CfgScope() { this instanceof CfgScope::Range_ }
 
   /** Gets the CFG scope that this scope is nested under, if any. */
   final CfgScope getOuterCfgScope() {
-    exists(AST::AstNode parent |
+    exists(AstNode parent |
       parent = this.getParent() and
-      result = getCfgScope(ASTInternal::toGenerated(parent))
+      result = getCfgScope(parent)
     )
   }
 }
@@ -35,7 +34,7 @@ class CfgNode extends TCfgNode {
   string toString() { none() }
 
   /** Gets the AST node that this node corresponds to, if any. */
-  AST::AstNode getNode() { none() }
+  AstNode getNode() { none() }
 
   /** Gets the location of this control flow node. */
   Location getLocation() { none() }

ql/src/codeql_ruby/controlflow/internal/AstNodes.qll

@@ -1,149 +0,0 @@
-/**
- * Provides various helper classes for AST nodes. The definitions in this file
- * will likely be part of the hand-written user-facing AST layer.
- */
-
-private import codeql_ruby.ast.internal.TreeSitter::Generated
-private import codeql_ruby.controlflow.internal.Completion
-
-class LogicalNotAstNode extends Unary {
-  AstNode operand;
-
-  LogicalNotAstNode() {
-    this.getOperator().toString() in ["!", "not"] and
-    operand = this.getOperand()
-  }
-}
-
-class LogicalAndAstNode extends Binary {
-  AstNode left;
-  AstNode right;
-
-  LogicalAndAstNode() {
-    this.getOperator().toString() in ["&&", "and"] and
-    left = this.getLeft() and
-    right = this.getRight()
-  }
-
-  AstNode getAnOperand() { result in [left, right] }
-}
-
-class LogicalOrAstNode extends Binary {
-  AstNode left;
-  AstNode right;
-
-  LogicalOrAstNode() {
-    this.getOperator().toString() in ["||", "or"] and
-    left = this.getLeft() and
-    right = this.getRight()
-  }
-
-  AstNode getAnOperand() { result in [left, right] }
-}
-
-private class If_or_elisif =
-  @if or @elsif or @conditional or @if_modifier or @unless or @unless_modifier;
-
-class IfElsifAstNode extends AstNode, If_or_elisif {
-  AstNode getConditionNode() { none() }
-
-  AstNode getBranch(boolean b) { none() }
-}
-
-private class IfAstNode extends IfElsifAstNode, If {
-  override AstNode getConditionNode() { result = this.getCondition() }
-
-  override AstNode getBranch(boolean b) {
-    b = true and result = this.getConsequence()
-    or
-    b = false and result = this.getAlternative()
-  }
-}
-
-private class ElsifAstNode extends IfElsifAstNode, Elsif {
-  override AstNode getConditionNode() { result = this.getCondition() }
-
-  override AstNode getBranch(boolean b) {
-    b = true and result = this.getConsequence()
-    or
-    b = false and result = this.getAlternative()
-  }
-}
-
-private class ConditionalAstNode extends IfElsifAstNode, Conditional {
-  override AstNode getConditionNode() { result = this.getCondition() }
-
-  override AstNode getBranch(boolean b) {
-    b = true and result = this.getConsequence()
-    or
-    b = false and result = this.getAlternative()
-  }
-}
-
-private class IfModifierAstNode extends IfElsifAstNode, IfModifier {
-  override AstNode getConditionNode() { result = this.getCondition() }
-
-  override AstNode getBranch(boolean b) { b = true and result = this.getBody() }
-}
-
-private class UnlessAstNode extends IfElsifAstNode, Unless {
-  override AstNode getConditionNode() { result = this.getCondition() }
-
-  override AstNode getBranch(boolean b) {
-    b = false and result = this.getConsequence()
-    or
-    b = true and result = this.getAlternative()
-  }
-}
-
-private class UnlessModifierAstNode extends IfElsifAstNode, UnlessModifier {
-  override AstNode getConditionNode() { result = this.getCondition() }
-
-  override AstNode getBranch(boolean b) { b = false and result = this.getBody() }
-}
-
-private class CondLoop = @while or @while_modifier or @until or @until_modifier;
-
-class ConditionalLoopAstNode extends AstNode, CondLoop {
-  AstNode getConditionNode() { none() }
-
-  AstNode getBodyNode() { none() }
-
-  predicate continueLoop(BooleanCompletion c) { c instanceof TrueCompletion }
-
-  final predicate endLoop(BooleanCompletion c) { continueLoop(c.getDual()) }
-}
-
-private class WhileLoop extends ConditionalLoopAstNode, While {
-  override UnderscoreStatement getConditionNode() { result = this.getCondition() }
-
-  override Do getBodyNode() { result = this.getBody() }
-}
-
-private class WhileModifierLoop extends ConditionalLoopAstNode, WhileModifier {
-  override AstNode getConditionNode() { result = this.getCondition() }
-
-  override UnderscoreStatement getBodyNode() { result = this.getBody() }
-}
-
-private class UntilLoop extends ConditionalLoopAstNode, Until {
-  override UnderscoreStatement getConditionNode() { result = this.getCondition() }
-
-  override Do getBodyNode() { result = this.getBody() }
-
-  override predicate continueLoop(BooleanCompletion c) { c instanceof FalseCompletion }
-}
-
-private class UntilModifierLoop extends ConditionalLoopAstNode, UntilModifier {
-  override AstNode getConditionNode() { result = this.getCondition() }
-
-  override UnderscoreStatement getBodyNode() { result = this.getBody() }
-
-  override predicate continueLoop(BooleanCompletion c) { c instanceof FalseCompletion }
-}
-
-class ParenthesizedStatement extends ParenthesizedStatements {
-  ParenthesizedStatement() { strictcount(int i | exists(this.getChild(i))) = 1 }
-
-  AstNode getChild() { result = this.getChild(0) }
-}

ql/src/codeql_ruby/controlflow/internal/Completion.qll

@@ -49,7 +49,7 @@ private predicate nestedEnsureCompletion(Completion outer, int nestLevel) {
     or
     outer = TExitCompletion()
   ) and
-  nestLevel = any(Trees::RescueEnsureBlockTree t).nestLevel()
+  nestLevel = any(Trees::BodyStmtTree t).getNestLevel()
 }
 
 pragma[noinline]
@@ -206,7 +206,7 @@ private predicate inMatchingContext(AstNode n) {
     w.getPattern(_) = n
   )
   or
-  toGenerated(n).(Trees::DefaultValueParameterTree).hasDefaultValue()
+  n.(Trees::DefaultValueParameterTree).hasDefaultValue()
 }
 
 /**

ql/src/codeql_ruby/controlflow/internal/Splitting.qll

@@ -2,9 +2,7 @@
  * Provides classes and predicates relevant for splitting the control flow graph.
  */
 
-private import codeql_ruby.ast.internal.TreeSitter::Generated
-private import codeql_ruby.ast.internal.AST as ASTInternal
-private import codeql_ruby.AST as AST
+private import codeql_ruby.AST
 private import Completion
 private import ControlFlowGraphImpl
 private import SuccessorTypes
@@ -18,13 +16,13 @@ private module Cached {
   cached
   newtype TSplitKind =
     TConditionalCompletionSplitKind() or
-    TEnsureSplitKind(int nestLevel) { nestLevel = any(Trees::RescueEnsureBlockTree t).nestLevel() }
+    TEnsureSplitKind(int nestLevel) { nestLevel = any(Trees::BodyStmtTree t).getNestLevel() }
 
   cached
   newtype TSplit =
     TConditionalCompletionSplit(ConditionalCompletion c) or
     TEnsureSplit(EnsureSplitting::EnsureSplitType type, int nestLevel) {
-      nestLevel = any(Trees::RescueEnsureBlockTree t).nestLevel()
+      nestLevel = any(Trees::BodyStmtTree t).getNestLevel()
     }
 
   cached
@@ -219,28 +217,19 @@ private module ConditionalCompletionSplitting {
       succ(pred, succ, c) and
       last(succ, _, completion) and
       (
-        last(ASTInternal::toGenerated(ASTInternal::fromGenerated(succ).(AST::NotExpr).getOperand()),
-          pred, c) and
+        last(succ.(NotExpr).getOperand(), pred, c) and
         completion.(BooleanCompletion).getDual() = c
         or
-        last(ASTInternal::toGenerated(ASTInternal::fromGenerated(succ)
-                .(AST::LogicalAndExpr)
-                .getAnOperand()), pred, c) and
+        last(succ.(LogicalAndExpr).getAnOperand(), pred, c) and
         completion = c
         or
-        last(ASTInternal::toGenerated(ASTInternal::fromGenerated(succ)
-                .(AST::LogicalOrExpr)
-                .getAnOperand()), pred, c) and
+        last(succ.(LogicalOrExpr).getAnOperand(), pred, c) and
         completion = c
         or
-        last(ASTInternal::toGenerated(ASTInternal::fromGenerated(succ)
-                .(AST::ParenthesizedExpr)
-                .getLastExpr()), pred, c) and
+        last(succ.(ParenthesizedExpr).getLastExpr(), pred, c) and
         completion = c
         or
-        last(ASTInternal::toGenerated(ASTInternal::fromGenerated(succ)
-                .(AST::ConditionalExpr)
-                .getBranch(_)), pred, c) and
+        last(succ.(ConditionalExpr).getBranch(_), pred, c) and
         completion = c
       )
     }
@@ -255,7 +244,7 @@ private module ConditionalCompletionSplitting {
 
     override predicate hasExitScope(CfgScope scope, AstNode last, Completion c) {
       this.appliesTo(last) and
-      succExit(ASTInternal::toGenerated(scope), last, c) and
+      succExit(scope, last, c) and
       if c instanceof ConditionalCompletion then completion = c else any()
     }
 
@@ -288,12 +277,11 @@ module EnsureSplitting {
 
   /** A node that belongs to an `ensure` block. */
   private class EnsureNode extends AstNode {
-    private Trees::RescueEnsureBlockTree block;
+    private Trees::BodyStmtTree block;
 
     EnsureNode() { this = block.getAnEnsureDescendant() }
 
-    /** Gets the immediate block that this node belongs to. */
-    Trees::RescueEnsureBlockTree getBlock() { result = block }
+    int getNestLevel() { result = block.getNestLevel() }
 
     /** Holds if this node is the entry node in the `ensure` block it belongs to. */
     predicate isEntryNode() { first(block.getEnsure(), this) }
@@ -366,7 +354,7 @@ module EnsureSplitting {
   pragma[noinline]
   private predicate hasEntry0(AstNode pred, EnsureNode succ, int nestLevel, Completion c) {
     succ.isEntryNode() and
-    nestLevel = succ.getBlock().nestLevel() and
+    nestLevel = succ.getNestLevel() and
     succ(pred, succ, c)
   }
 
@@ -389,11 +377,9 @@ module EnsureSplitting {
     }
 
     pragma[noinline]
-    private predicate exit0(
-      AstNode pred, Trees::RescueEnsureBlockTree block, int nestLevel, Completion c
-    ) {
+    private predicate exit0(AstNode pred, Trees::BodyStmtTree block, int nestLevel, Completion c) {
       this.appliesToPredecessor(pred) and
-      nestLevel = block.nestLevel() and
+      nestLevel = block.getNestLevel() and
       block.lastInner(pred, c)
     }
 
@@ -402,9 +388,7 @@ module EnsureSplitting {
      * `inherited` indicates whether `c` is an inherited completion from the
      * body.
      */
-    private predicate exit(
-      Trees::RescueEnsureBlockTree block, AstNode pred, Completion c, boolean inherited
-    ) {
+    private predicate exit(Trees::BodyStmtTree block, AstNode pred, Completion c, boolean inherited) {
       exists(EnsureSplitType type |
         exit0(pred, block, this.getNestLevel(), c) and
         type = this.getType()
@@ -472,7 +456,7 @@ module EnsureSplitting {
     }
 
     override predicate hasExitScope(CfgScope scope, AstNode last, Completion c) {
-      succExit(ASTInternal::toGenerated(scope), last, c) and
+      succExit(scope, last, c) and
       (
         exit(_, last, c, _)
         or
@@ -488,10 +472,10 @@ module EnsureSplitting {
           if en.isEntryNode()
           then
             // entering a nested `ensure` block
-            en.getBlock().nestLevel() > this.getNestLevel()
+            en.getNestLevel() > this.getNestLevel()
           else
             // staying in the same (possibly nested) `ensure` block as `pred`
-            en.getBlock().nestLevel() >= this.getNestLevel()
+            en.getNestLevel() >= this.getNestLevel()
         )
     }
   }
@@ -517,7 +501,7 @@ class Splits extends TSplits {
 
 private predicate succEntrySplitsFromRank(CfgScope pred, AstNode succ, Splits splits, int rnk) {
   splits = TSplitsNil() and
-  succEntry(ASTInternal::toGenerated(pred), succ) and
+  succEntry(pred, succ) and
   rnk = 0
   or
   exists(SplitImpl head, Splits tail | succEntrySplitsCons(pred, succ, head, tail, rnk) |
@@ -540,7 +524,7 @@ private predicate succEntrySplitsCons(
 pragma[noinline]
 predicate succEntrySplits(CfgScope pred, AstNode succ, Splits succSplits, SuccessorType t) {
   exists(int rnk |
-    succEntry(ASTInternal::toGenerated(pred), succ) and
+    succEntry(pred, succ) and
     t instanceof NormalSuccessor and
     succEntrySplitsFromRank(pred, succ, succSplits, rnk)
   |
@@ -559,7 +543,7 @@ predicate succExitSplits(AstNode last, Splits predSplits, CfgScope scope, Succes
   exists(Reachability::SameSplitsBlock b, Completion c | last = b.getANode() |
     b.isReachable(predSplits) and
     t = c.getAMatchingSuccessorType() and
-    succExit(ASTInternal::toGenerated(scope), last, c) and
+    succExit(scope, last, c) and
     forall(SplitImpl predSplit | predSplit = predSplits.getASplit() |
       predSplit.hasExitScope(scope, last, c)
     )

ql/src/codeql_ruby/dataflow/internal/SsaImpl.qll

@@ -49,7 +49,7 @@ private predicate capturedExitRead(AnnotatedExitBasicBlock bb, int i, LocalVaria
   i = bb.length()
 }
 
-private CfgScope getCaptureOuterCfgScope(Callable scope) {
+private CfgScope getCaptureOuterCfgScope(CfgScope scope) {
   result = scope.getOuterCfgScope() and
   (
     scope instanceof Block