Ruby: desugar one-line pattern matches

Author: aibaars

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

@@ -478,15 +478,11 @@ class WhenClause extends AstNode, TWhenClause {
  * end
  * ```
  */
-class InClause extends AstNode, TInClause {
-  private Ruby::InClause g;
-
-  InClause() { this = TInClause(g) }
-
+class InClause extends AstNode instanceof InClauseImpl {
   final override string getAPrimaryQlClass() { result = "InClause" }
 
   /** Gets the body of this case-in expression. */
-  final Stmt getBody() { toGenerated(result) = g.getBody() }
+  final Stmt getBody() { result = super.getBody() }
 
   /**
    * Gets the pattern in this case-in expression. In the
@@ -498,7 +494,7 @@ class InClause extends AstNode, TInClause {
    * end
    * ```
    */
-  final CasePattern getPattern() { toGenerated(result) = g.getPattern() }
+  final CasePattern getPattern() { result = super.getPattern() }
 
   /**
    * Gets the pattern guard condition in this case-in expression. In the
@@ -510,7 +506,7 @@ class InClause extends AstNode, TInClause {
    * end
    * ```
    */
-  final Expr getCondition() { toGenerated(result) = g.getGuard().getAFieldOrChild() }
+  final Expr getCondition() { result = super.getCondition() }
 
   /**
    * Holds if the pattern guard in this case-in expression is an `if` condition. For example:
@@ -520,7 +516,7 @@ class InClause extends AstNode, TInClause {
    * end
    * ```
    */
-  predicate hasIfCondition() { g.getGuard() instanceof Ruby::IfGuard }
+  predicate hasIfCondition() { super.hasIfCondition() }
 
   /**
    * Holds if the pattern guard in this case-in expression is an `unless` condition. For example:
@@ -530,12 +526,12 @@ class InClause extends AstNode, TInClause {
    * end
    * ```
    */
-  predicate hasUnlessCondition() { g.getGuard() instanceof Ruby::UnlessGuard }
+  predicate hasUnlessCondition() { super.hasUnlessCondition() }
 
   final override string toString() { result = "in ... then ..." }
 
   final override AstNode getAChild(string pred) {
-    result = super.getAChild(pred)
+    result = AstNode.super.getAChild(pred)
     or
     pred = "getBody" and result = this.getBody()
     or

ruby/ql/lib/codeql/ruby/ast/internal/AST.qll

@@ -97,12 +97,16 @@ private module Cached {
     } or
     TBlockArgument(Ruby::BlockArgument g) or
     TBlockParameter(Ruby::BlockParameter g) or
+    TBooleanLiteralSynth(Ast::AstNode parent, int i, boolean value) {
+      mkSynthChild(BooleanLiteralKind(value), parent, i)
+    } or
     TBraceBlockSynth(Ast::AstNode parent, int i) { mkSynthChild(BraceBlockKind(), parent, i) } or
     TBraceBlockReal(Ruby::Block g) { not g.getParent() instanceof Ruby::Lambda } or
     TBreakStmt(Ruby::Break g) or
     TCaseEqExpr(Ruby::Binary g) { g instanceof @ruby_binary_equalequalequal } or
     TCaseExpr(Ruby::Case g) or
-    TCaseMatch(Ruby::CaseMatch g) or
+    TCaseMatchReal(Ruby::CaseMatch g) or
+    TCaseMatchSynth(Ast::AstNode parent, int i) { mkSynthChild(CaseMatchKind(), parent, i) } or
     TCharacterLiteral(Ruby::Character g) or
     TClassDeclaration(Ruby::Class g) or
     TClassVariableAccessReal(Ruby::ClassVariable g, Ast::ClassVariable v) {
@@ -130,6 +134,7 @@ private module Cached {
     TDoBlock(Ruby::DoBlock g) { not g.getParent() instanceof Ruby::Lambda } or
     TElementReference(Ruby::ElementReference g) or
     TElse(Ruby::Else g) or
+    TElseSynth(Ast::AstNode parent, int i) { mkSynthChild(ElseKind(), parent, i) } or
     TElsif(Ruby::Elsif g) or
     TEmptyStmt(Ruby::EmptyStatement g) or
     TEncoding(Ruby::Encoding g) or
@@ -168,7 +173,8 @@ private module Cached {
     TIfReal(Ruby::If g) or
     TIfSynth(Ast::AstNode parent, int i) { mkSynthChild(IfKind(), parent, i) } or
     TIfModifierExpr(Ruby::IfModifier g) or
-    TInClause(Ruby::InClause g) or
+    TInClauseReal(Ruby::InClause g) or
+    TInClauseSynth(Ast::AstNode parent, int i) { mkSynthChild(InClauseKind(), parent, i) } or
     TInstanceVariableAccessReal(Ruby::InstanceVariable g, Ast::InstanceVariable v) {
       InstanceVariableAccess::range(g, v)
     } or
@@ -346,7 +352,7 @@ private module Cached {
         TAssignMulExpr or TAssignRShiftExpr or TAssignSubExpr or TBareStringLiteral or
         TBareSymbolLiteral or TBeginBlock or TBeginExpr or TBitwiseAndExprReal or
         TBitwiseOrExprReal or TBitwiseXorExprReal or TBlockArgument or TBlockParameter or
-        TBraceBlockReal or TBreakStmt or TCaseEqExpr or TCaseExpr or TCaseMatch or
+        TBraceBlockReal or TBreakStmt or TCaseEqExpr or TCaseExpr or TCaseMatchReal or
         TCharacterLiteral or TClassDeclaration or TClassVariableAccessReal or TComplementExpr or
         TComplexLiteral or TDefinedExpr or TDelimitedSymbolLiteral or TDestructuredLeftAssignment or
         TDestructuredParameter or TDivExprReal or TDo or TDoBlock or TElementReference or TElse or
@@ -355,7 +361,7 @@ private module Cached {
         TForwardArgument or TGEExpr or TGTExpr or TGlobalVariableAccessReal or
         THashKeySymbolLiteral or THashLiteral or THashPattern or THashSplatExpr or
         THashSplatNilParameter or THashSplatParameter or THereDoc or TIdentifierMethodCall or
-        TIfReal or TIfModifierExpr or TInClause or TInstanceVariableAccessReal or
+        TIfReal or TIfModifierExpr or TInClauseReal or TInstanceVariableAccessReal or
         TIntegerLiteralReal or TKeywordParameter or TLEExpr or TLShiftExprReal or TLTExpr or
         TLambda or TLeftAssignmentList or TLine or TLocalVariableAccessReal or
         TLogicalAndExprReal or TLogicalOrExprReal or TMethod or TMatchPattern or
@@ -377,14 +383,14 @@ private module Cached {
 
   class TAstNodeSynth =
     TAddExprSynth or TAssignExprSynth or TBitwiseAndExprSynth or TBitwiseOrExprSynth or
-        TBitwiseXorExprSynth or TBraceBlockSynth or TClassVariableAccessSynth or
-        TConstantReadAccessSynth or TConstantWriteAccessSynth or TDivExprSynth or
-        TExponentExprSynth or TGlobalVariableAccessSynth or TIfSynth or
-        TInstanceVariableAccessSynth or TIntegerLiteralSynth or TLShiftExprSynth or
-        TLocalVariableAccessSynth or TLogicalAndExprSynth or TLogicalOrExprSynth or
-        TMethodCallSynth or TModuloExprSynth or TMulExprSynth or TNilLiteralSynth or
-        TRShiftExprSynth or TRangeLiteralSynth or TSelfSynth or TSimpleParameterSynth or
-        TSplatExprSynth or TStmtSequenceSynth or TSubExprSynth;
+        TBitwiseXorExprSynth or TBraceBlockSynth or TBooleanLiteralSynth or TCaseMatchSynth or
+        TClassVariableAccessSynth or TConstantReadAccessSynth or TConstantWriteAccessSynth or
+        TDivExprSynth or TElseSynth or TExponentExprSynth or TGlobalVariableAccessSynth or
+        TIfSynth or TInClauseSynth or TInstanceVariableAccessSynth or TIntegerLiteralSynth or
+        TLShiftExprSynth or TLocalVariableAccessSynth or TLogicalAndExprSynth or
+        TLogicalOrExprSynth or TMethodCallSynth or TModuloExprSynth or TMulExprSynth or
+        TNilLiteralSynth or TRShiftExprSynth or TRangeLiteralSynth or TSelfSynth or
+        TSimpleParameterSynth or TSplatExprSynth or TStmtSequenceSynth or TSubExprSynth;
 
   /**
    * Gets the underlying TreeSitter entity for a given AST node. This does not
@@ -426,7 +432,7 @@ private module Cached {
     n = TBreakStmt(result) or
     n = TCaseEqExpr(result) or
     n = TCaseExpr(result) or
-    n = TCaseMatch(result) or
+    n = TCaseMatchReal(result) or
     n = TCharacterLiteral(result) or
     n = TClassDeclaration(result) or
     n = TClassVariableAccessReal(result, _) or
@@ -467,7 +473,7 @@ private module Cached {
     n = TIdentifierMethodCall(result) or
     n = TIfModifierExpr(result) or
     n = TIfReal(result) or
-    n = TInClause(result) or
+    n = TInClauseReal(result) or
     n = TInstanceVariableAccessReal(result, _) or
     n = TIntegerLiteralReal(result) or
     n = TKeywordParameter(result) or
@@ -567,8 +573,12 @@ private module Cached {
     or
     result = TBitwiseXorExprSynth(parent, i)
     or
+    result = TBooleanLiteralSynth(parent, i, _)
+    or
     result = TBraceBlockSynth(parent, i)
     or
+    result = TCaseMatchSynth(parent, i)
+    or
     result = TClassVariableAccessSynth(parent, i, _)
     or
     result = TConstantReadAccessSynth(parent, i, _)
@@ -577,12 +587,16 @@ private module Cached {
     or
     result = TDivExprSynth(parent, i)
     or
+    result = TElseSynth(parent, i)
+    or
     result = TExponentExprSynth(parent, i)
     or
     result = TGlobalVariableAccessSynth(parent, i, _)
     or
     result = TIfSynth(parent, i)
     or
+    result = TInClauseSynth(parent, i)
+    or
     result = TInstanceVariableAccessSynth(parent, i, _)
     or
     result = TIntegerLiteralSynth(parent, i, _)
@@ -673,8 +687,12 @@ TAstNodeReal fromGenerated(Ruby::AstNode n) { n = toGenerated(result) }
 
 class TCall = TMethodCall or TYieldCall;
 
+class TCaseMatch = TCaseMatchReal or TCaseMatchSynth;
+
 class TCase = TCaseExpr or TCaseMatch;
 
+class TInClause = TInClauseReal or TInClauseSynth;
+
 class TMethodCall =
   TMethodCallSynth or TIdentifierMethodCall or TRegularMethodCall or TElementReference or
       TSuperCall or TUnaryOperation or TBinaryOperation;
@@ -685,7 +703,7 @@ class TConstantAccess =
   TTokenConstantAccess or TScopeResolutionConstantAccess or TNamespace or
       TConstantReadAccessSynth or TConstantWriteAccessSynth;
 
-class TControlExpr = TConditionalExpr or TCaseExpr or TCaseMatch or TLoop;
+class TControlExpr = TConditionalExpr or TCaseExpr or TCaseMatchReal or TCaseMatchSynth or TLoop;
 
 class TConditionalExpr =
   TIfExpr or TUnlessExpr or TIfModifierExpr or TUnlessModifierExpr or TTernaryIfExpr;
@@ -711,8 +729,9 @@ class TExpr =
 class TSplatExpr = TSplatExprReal or TSplatExprSynth;
 
 class TStmtSequence =
-  TBeginBlock or TEndBlock or TThen or TElse or TDo or TEnsure or TStringInterpolationComponent or
-      TBlock or TBodyStmt or TParenthesizedExpr or TStmtSequenceSynth;
+  TBeginBlock or TEndBlock or TThen or TElse or TElseSynth or TDo or TEnsure or
+      TStringInterpolationComponent or TBlock or TBodyStmt or TParenthesizedExpr or
+      TStmtSequenceSynth;
 
 class TBodyStmt = TBeginExpr or TModuleBase or TMethod or TLambda or TDoBlock or TSingletonMethod;
 
@@ -727,7 +746,7 @@ class TNumericLiteral = TIntegerLiteral or TFloatLiteral or TRationalLiteral or
 
 class TIntegerLiteral = TIntegerLiteralReal or TIntegerLiteralSynth;
 
-class TBooleanLiteral = TTrueLiteral or TFalseLiteral;
+class TBooleanLiteral = TTrueLiteral or TFalseLiteral or TBooleanLiteralSynth;
 
 class TStringTextComponentNonRegexp =
   TStringTextComponentNonRegexpStringOrHeredocContent or

ruby/ql/lib/codeql/ruby/ast/internal/Control.qll

@@ -21,10 +21,10 @@ class CaseWhenClause extends CaseExprImpl, TCaseExpr {
   }
 }
 
-class CaseMatch extends CaseExprImpl, TCaseMatch {
+class CaseMatch extends CaseExprImpl, TCaseMatchReal {
   private Ruby::CaseMatch g;
 
-  CaseMatch() { this = TCaseMatch(g) }
+  CaseMatch() { this = TCaseMatchReal(g) }
 
   final override Expr getValue() { toGenerated(result) = g.getValue() }
 
@@ -34,3 +34,53 @@ class CaseMatch extends CaseExprImpl, TCaseMatch {
     n = count(g.getClauses(_)) and toGenerated(result) = g.getElse()
   }
 }
+
+class CaseMatchSynth extends CaseExprImpl, TCaseMatchSynth {
+  CaseMatchSynth() { this = TCaseMatchSynth(_, _) }
+
+  final override Expr getValue() { synthChild(this, 0, result) }
+
+  final override AstNode getBranch(int n) { n >= 0 and synthChild(this, n + 1, result) }
+}
+
+abstract class InClauseImpl extends AstNode, TInClause {
+  abstract Stmt getBody();
+
+  abstract CasePattern getPattern();
+
+  Expr getCondition() { none() }
+
+  predicate hasIfCondition() { none() }
+
+  predicate hasUnlessCondition() { none() }
+}
+
+class InClauseReal extends InClauseImpl, TInClauseReal {
+  private Ruby::InClause g;
+
+  InClauseReal() { this = TInClauseReal(g) }
+
+  final override Stmt getBody() { toGenerated(result) = g.getBody() }
+
+  final override CasePattern getPattern() { toGenerated(result) = g.getPattern() }
+
+  final override Expr getCondition() { toGenerated(result) = g.getGuard().getAFieldOrChild() }
+
+  final override predicate hasIfCondition() { g.getGuard() instanceof Ruby::IfGuard }
+
+  final override predicate hasUnlessCondition() { g.getGuard() instanceof Ruby::UnlessGuard }
+}
+
+class InClauseSynth extends InClauseImpl, TInClauseSynth {
+  InClauseSynth() { this = TInClauseSynth(_, _) }
+
+  final override Stmt getBody() { synthChild(this, 1, result) }
+
+  final override CasePattern getPattern() { synthChild(this, 0, result) }
+
+  final override Expr getCondition() { none() }
+
+  final override predicate hasIfCondition() { none() }
+
+  final override predicate hasUnlessCondition() { none() }
+}

ruby/ql/lib/codeql/ruby/ast/internal/Expr.qll

@@ -29,6 +29,14 @@ class Else extends StmtSequence, TElse {
   final override string toString() { result = "else ..." }
 }
 
+class ElseSynth extends StmtSequence, TElseSynth {
+  ElseSynth() { this = TElseSynth(_, _) }
+
+  override Stmt getStmt(int n) { synthChild(this, n, result) }
+
+  final override string toString() { result = "else ..." }
+}
+
 class Do extends StmtSequence, TDo {
   private Ruby::Do g;
 

ruby/ql/lib/codeql/ruby/ast/internal/Literal.qll

@@ -149,6 +149,12 @@ class FalseLiteral extends BooleanLiteralImpl, TFalseLiteral {
   final override boolean getValue() { result = false }
 }
 
+class BooleanLiteralSynth extends BooleanLiteralImpl, TBooleanLiteralSynth {
+  final override string toString() { result = this.getValue().toString() }
+
+  final override boolean getValue() { this = TBooleanLiteralSynth(_, _, result) }
+}
+
 class EncodingLiteralImpl extends Expr, TEncoding {
   private Ruby::Encoding g;