Swift: add NamedPattern.getVarDecl()

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

@@ -222,19 +222,19 @@ predicate catchMatchingPattern(DoCatchStmt s, CaseStmt c, Pattern pattern) {
 
 /** Holds if `sub` is a subpattern of `p`. */
 private predicate isSubPattern(Pattern p, Pattern sub) {
-  sub = p.(BindingPattern).getResolveStep()
+  sub = p.(BindingPattern).getImmediateSubPattern()
   or
-  sub = p.(EnumElementPattern).getSubPattern().getFullyUnresolved()
+  sub = p.(EnumElementPattern).getImmediateSubPattern()
   or
-  sub = p.(IsPattern).getSubPattern().getFullyUnresolved()
+  sub = p.(IsPattern).getImmediateSubPattern()
   or
-  sub = p.(OptionalSomePattern).getFullyUnresolved()
+  sub = p.(OptionalSomePattern).getImmediateSubPattern()
   or
-  sub = p.(ParenPattern).getResolveStep()
+  sub = p.(ParenPattern).getImmediateSubPattern()
   or
-  sub = p.(TuplePattern).getAnElement().getFullyUnresolved()
+  sub = p.(TuplePattern).getImmediateElement(_)
   or
-  sub = p.(TypedPattern).getSubPattern().getFullyUnresolved()
+  sub = p.(TypedPattern).getImmediateSubPattern()
 }
 
 /** Gets the value of `e` if it is a constant value, disregarding conversions. */

swift/ql/lib/codeql/swift/elements/pattern/NamedPattern.qll

@@ -1,5 +1,40 @@
 private import codeql.swift.generated.pattern.NamedPattern
+private import codeql.swift.elements.pattern.BindingPattern
+private import codeql.swift.elements.pattern.EnumElementPattern
+private import codeql.swift.elements.pattern.IsPattern
+private import codeql.swift.elements.pattern.OptionalSomePattern
+private import codeql.swift.elements.pattern.ParenPattern
+private import codeql.swift.elements.pattern.TuplePattern
+private import codeql.swift.elements.pattern.TypedPattern
+private import codeql.swift.elements.decl.VarDecl
+private import codeql.swift.elements.stmt.LabeledConditionalStmt
+private import codeql.swift.elements.stmt.ConditionElement
 
 class NamedPattern extends Generated::NamedPattern {
+  /** Holds if this named pattern has a corresponding `VarDecl` */
+  predicate hasVarDecl() { exists(this.getVarDecl()) }
+
+  /** Gets the `VarDecl` bound by this named pattern, if any. */
+  VarDecl getVarDecl() {
+    isSubPattern*(result.getParentPattern().getFullyUnresolved(), this) and
+    result.getName() = this.getName()
+  }
+
   override string toString() { result = this.getName() }
 }
+
+private predicate isSubPattern(Pattern p, Pattern sub) {
+  sub = p.(BindingPattern).getImmediateSubPattern()
+  or
+  sub = p.(EnumElementPattern).getImmediateSubPattern()
+  or
+  sub = p.(IsPattern).getImmediateSubPattern()
+  or
+  sub = p.(OptionalSomePattern).getImmediateSubPattern()
+  or
+  sub = p.(ParenPattern).getImmediateSubPattern()
+  or
+  sub = p.(TuplePattern).getImmediateElement(_)
+  or
+  sub = p.(TypedPattern).getImmediateSubPattern()
+}

swift/ql/test/extractor-tests/patterns/all.expected

@@ -39,3 +39,23 @@
 | patterns.swift:46:9:46:9 | b |
 | patterns.swift:49:10:49:10 | true |
 | patterns.swift:50:10:50:10 | false |
+| patterns.swift:55:9:55:9 | a |
+| patterns.swift:55:16:55:16 | b |
+| patterns.swift:55:23:55:23 | c |
+| patterns.swift:55:23:55:26 | ... as ... |
+| patterns.swift:57:8:57:20 | let ... |
+| patterns.swift:57:8:57:20 | let ...? |
+| patterns.swift:57:12:57:20 | (...) |
+| patterns.swift:57:13:57:13 | a |
+| patterns.swift:57:16:57:16 | b |
+| patterns.swift:57:19:57:19 | c |
+| patterns.swift:58:13:58:29 | (...) |
+| patterns.swift:58:14:58:14 | =~ ... |
+| patterns.swift:58:17:58:21 | let ... |
+| patterns.swift:58:21:58:21 | b |
+| patterns.swift:58:24:58:28 | let ... |
+| patterns.swift:58:28:58:28 | c |
+| patterns.swift:61:14:61:14 | =~ ... |
+| patterns.swift:62:14:62:18 | let ... |
+| patterns.swift:62:18:62:18 | c |
+| patterns.swift:63:9:63:9 | _ |

swift/ql/test/extractor-tests/patterns/bound_and_unbound.expected

@@ -0,0 +1,27 @@
+bound
+| patterns.swift:2:9:2:9 | an_int |
+| patterns.swift:3:9:3:9 | a_string |
+| patterns.swift:4:10:4:10 | x |
+| patterns.swift:4:13:4:13 | y |
+| patterns.swift:4:16:4:16 | z |
+| patterns.swift:10:9:10:9 | point |
+| patterns.swift:12:15:12:15 | xx |
+| patterns.swift:12:19:12:19 | yy |
+| patterns.swift:24:9:24:9 | v |
+| patterns.swift:28:19:28:19 | i |
+| patterns.swift:28:22:28:22 | s |
+| patterns.swift:31:9:31:9 | w |
+| patterns.swift:34:14:34:14 | n |
+| patterns.swift:38:9:38:9 | a |
+| patterns.swift:42:14:42:14 | x |
+| patterns.swift:46:9:46:9 | b |
+| patterns.swift:55:9:55:9 | a |
+| patterns.swift:55:16:55:16 | b |
+| patterns.swift:55:23:55:23 | c |
+| patterns.swift:57:13:57:13 | a |
+| patterns.swift:57:19:57:19 | c |
+| patterns.swift:58:21:58:21 | b |
+| patterns.swift:62:18:62:18 | c |
+unbound
+| patterns.swift:57:16:57:16 | b |
+| patterns.swift:58:28:58:28 | c |

swift/ql/test/extractor-tests/patterns/bound_and_unbound.ql

@@ -0,0 +1,11 @@
+import swift
+
+query predicate bound(NamedPattern p) {
+  p.getFile().getBaseName() = "patterns.swift" and
+  p.hasVarDecl()
+}
+
+query predicate unbound(NamedPattern p) {
+  p.getFile().getBaseName() = "patterns.swift" and
+  not p.hasVarDecl()
+}

swift/ql/test/extractor-tests/patterns/patterns.swift

@@ -50,3 +50,16 @@ func switch_patterns() {
     case false: "false"
     }
 }
+
+func bound_and_unbound() {
+    let a = 1, b = 2, c: Int = 3
+
+    if let (a, b, c) = Optional.some((a, b, c)) { _ = (a, c) }
+    if case (a, let b, let c) = (a, b, c) { _ = (b) }
+
+    switch a {
+        case c: "equals c"
+        case let c: "binds c"
+        default: "default"
+    }
+}

swift/ql/test/library-tests/ast/PrintAst.expected

@@ -5509,6 +5509,95 @@ patterns.swift:
 #   34|     Type = Int
 #   42| [ConcreteVarDecl] x
 #   42|     Type = String
+#   54| [ConcreteFuncDecl] bound_and_unbound()
+#   54|     InterfaceType = () -> ()
+#   54|   getBody(): [BraceStmt] { ... }
+#   55|     getElement(0): [PatternBindingDecl] var ... = ...
+#   55|       getInit(0): [IntegerLiteralExpr] 1
+#   55|       getInit(1): [IntegerLiteralExpr] 2
+#   55|       getInit(2): [IntegerLiteralExpr] 3
+#   55|       getPattern(0): [NamedPattern] a
+#   55|       getPattern(1): [NamedPattern] b
+#   55|       getPattern(2): [TypedPattern] ... as ...
+#   55|         getSubPattern(): [NamedPattern] c
+#   55|         getTypeRepr(): [TypeRepr] Int
+#   55|     getElement(1): [ConcreteVarDecl] a
+#   55|         Type = Int
+#   55|     getElement(2): [ConcreteVarDecl] b
+#   55|         Type = Int
+#   55|     getElement(3): [ConcreteVarDecl] c
+#   55|         Type = Int
+#   57|     getElement(4): [IfStmt] if ... then { ... }
+#   57|       getCondition(): [StmtCondition] StmtCondition
+#   57|         getElement(0): [ConditionElement] let ...? = ... 
+#   57|           getPattern(): [OptionalSomePattern] let ...?
+#   57|             getSubPattern(): [TuplePattern] (...)
+#   57|               getElement(0): [NamedPattern] a
+#   57|               getElement(1): [NamedPattern] b
+#   57|               getElement(2): [NamedPattern] c
+#   57|             getSubPattern().getFullyUnresolved(): [BindingPattern] let ...
+#   57|           getInitializer(): [CallExpr] call to ...
+#   57|             getFunction(): [MethodLookupExpr] .some
+#   57|               getBase(): [TypeExpr] Optional<(Int, Int, Int)>.Type
+#   57|                 getTypeRepr(): [TypeRepr] Optional<(Int, Int, Int)>
+#   57|               getMethodRef(): [DeclRefExpr] some
+#   57|             getArgument(0): [Argument] : (...)
+#   57|               getExpr(): [TupleExpr] (...)
+#   57|                 getElement(0): [DeclRefExpr] a
+#   57|                 getElement(1): [DeclRefExpr] b
+#   57|                 getElement(2): [DeclRefExpr] c
+#   57|       getThen(): [BraceStmt] { ... }
+#   57|         getElement(0): [AssignExpr]  ... = ...
+#   57|           getDest(): [DiscardAssignmentExpr] _
+#   57|           getSource(): [TupleExpr] (...)
+#   57|             getElement(0): [DeclRefExpr] a
+#   57|             getElement(1): [DeclRefExpr] c
+#   58|     getElement(5): [IfStmt] if ... then { ... }
+#   58|       getCondition(): [StmtCondition] StmtCondition
+#   58|         getElement(0): [ConditionElement] (...) = ... 
+#   58|           getPattern(): [TuplePattern] (...)
+#   58|             getElement(0): [ExprPattern] =~ ...
+#   58|               getSubExpr(): [DeclRefExpr] a
+#   58|             getElement(1): [NamedPattern] b
+#   58|             getElement(1).getFullyUnresolved(): [BindingPattern] let ...
+#   58|             getElement(2): [NamedPattern] c
+#   58|             getElement(2).getFullyUnresolved(): [BindingPattern] let ...
+#   58|           getInitializer(): [TupleExpr] (...)
+#   58|             getElement(0): [DeclRefExpr] a
+#   58|             getElement(1): [DeclRefExpr] b
+#   58|             getElement(2): [DeclRefExpr] c
+#   58|       getThen(): [BraceStmt] { ... }
+#   58|         getElement(0): [AssignExpr]  ... = ...
+#   58|           getDest(): [DiscardAssignmentExpr] _
+#   58|           getSource(): [DeclRefExpr] b
+#   58|           getSource().getFullyConverted(): [ParenExpr] (...)
+#   60|     getElement(6): [SwitchStmt] switch a { ... }
+#   60|       getExpr(): [DeclRefExpr] a
+#   61|       getCase(0): [CaseStmt] case ...
+#   61|         getBody(): [BraceStmt] { ... }
+#   61|           getElement(0): [StringLiteralExpr] equals c
+#   61|         getLabel(0): [CaseLabelItem] =~ ...
+#   61|           getPattern(): [ExprPattern] =~ ...
+#   61|             getSubExpr(): [DeclRefExpr] c
+#   62|       getCase(1): [CaseStmt] case ...
+#   62|         getBody(): [BraceStmt] { ... }
+#   62|           getElement(0): [StringLiteralExpr] binds c
+#   62|         getLabel(0): [CaseLabelItem] c
+#   62|           getPattern(): [NamedPattern] c
+#   62|           getPattern().getFullyUnresolved(): [BindingPattern] let ...
+#   63|       getCase(2): [CaseStmt] case ...
+#   63|         getBody(): [BraceStmt] { ... }
+#   63|           getElement(0): [StringLiteralExpr] default
+#   63|         getLabel(0): [CaseLabelItem] _
+#   63|           getPattern(): [AnyPattern] _
+#   57| [ConcreteVarDecl] a
+#   57|     Type = Int
+#   57| [ConcreteVarDecl] c
+#   57|     Type = Int
+#   58| [ConcreteVarDecl] b
+#   58|     Type = Int
+#   62| [ConcreteVarDecl] c
+#   62|     Type = Int
 statements.swift:
 #    1| [ConcreteFuncDecl] loop()
 #    1|     InterfaceType = () -> ()

swift/ql/test/library-tests/ast/patterns.swift

@@ -50,3 +50,16 @@ func switch_patterns() {
     case false: "false"
     }
 }
+
+func bound_and_unbound() {
+    let a = 1, b = 2, c: Int = 3
+
+    if let (a, b, c) = Optional.some((a, b, c)) { _ = (a, c) }
+    if case (a, let b, let c) = (a, b, c) { _ = (b) }
+
+    switch a {
+        case c: "equals c"
+        case let c: "binds c"
+        default: "default"
+    }
+}