Fix record pattern and pretty-printing

Author: smowton

java/ql/lib/semmle/code/java/Expr.qll

@@ -1672,6 +1672,8 @@ class LocalVariableDeclExpr extends Expr, @localvariabledeclexpr {
     exists(InstanceOfExpr ioe | this.getParent() = ioe | result.isNthChildOf(ioe, 1))
     or
     exists(PatternCase pc | this.getParent() = pc | result.isNthChildOf(pc, -2))
+    or
+    exists(RecordPatternExpr rpe, int index | this.isNthChildOf(rpe, index) and result.isNthChildOf(rpe, -(index + 1)) )
   }
 
   /** Gets the name of the variable declared by this local variable declaration expression. */

java/ql/lib/semmle/code/java/PrettyPrintAst.qll

@@ -1078,12 +1078,30 @@ private class PpRecordPattern extends PpAst, RecordPatternExpr {
     or
     i = 1 and result = "("
     or
-    i = 1 + ((any(int x | x >= 1 and exists(this.getSubPattern(x)))) * 2) and result = ", "
+    i = 1 + ((any(int x | x >= 1 and exists(this.getSubPattern(x)))) * 4) and result = ", "
     or
-    i = 1 + (count(this.getSubPattern(_)) * 2) and result = ")"
+    i = 1 + (count(this.getSubPattern(_)) * 4) and result = ")"
+    or
+    exists(int x, LocalVariableDeclExpr v, int offset | v = this.getSubPattern(x) |
+      i = (offset) + (x * 4) and
+      (
+        offset = 2 and not exists(v.getTypeAccess()) and result = "var"
+        or
+        offset = 3 and result = " "
+      )
+    )
   }
 
   override PpAst getChild(int i) {
-    exists(int x | result = this.getSubPattern(x) | i = 2 + (x * 2))
+    exists(int x, PatternExpr subPattern, int offset | subPattern = this.getSubPattern(x) |
+      i = (offset) + (x * 4) and
+      (
+        result = subPattern.(RecordPatternExpr) and offset = 2
+        or
+        result = subPattern.(LocalVariableDeclExpr).getTypeAccess() and offset = 2
+        or
+        result = subPattern.(LocalVariableDeclExpr) and offset = 4
+      )
+    )
   }
 }

java/ql/test/library-tests/prettyprint/Test.java

@@ -38,6 +38,13 @@ case R(S(int x), String y):
     if (o instanceof String s) { }
     if (o instanceof R(S(int x), String y)) { }
 
+    switch(o) {
+      case R(S(var x), var y) -> { }
+      case null, default -> { }
+    }
+
+    if (o instanceof R(S(var x), var y)) { }
+
   }
 
 }

java/ql/test/library-tests/prettyprint/pp.expected

@@ -46,35 +46,43 @@
 | Test.java:1:14:1:17 | Test | 45 |     switch (o) { |
 | Test.java:1:14:1:17 | Test | 46 |       case String s: |
 | Test.java:1:14:1:17 | Test | 47 |       break; |
-| Test.java:1:14:1:17 | Test | 48 |       case R(S(x), y): |
+| Test.java:1:14:1:17 | Test | 48 |       case R(S(int x), String y): |
 | Test.java:1:14:1:17 | Test | 49 |       break; |
 | Test.java:1:14:1:17 | Test | 50 |       default: |
 | Test.java:1:14:1:17 | Test | 51 |       break; |
 | Test.java:1:14:1:17 | Test | 52 |     } |
 | Test.java:1:14:1:17 | Test | 53 |     switch (o) { |
 | Test.java:1:14:1:17 | Test | 54 |       case String s -> { |
 | Test.java:1:14:1:17 | Test | 55 |       } |
-| Test.java:1:14:1:17 | Test | 56 |       case R(S(x), y) -> { |
+| Test.java:1:14:1:17 | Test | 56 |       case R(S(int x), String y) -> { |
 | Test.java:1:14:1:17 | Test | 57 |       } |
 | Test.java:1:14:1:17 | Test | 58 |       case default -> { |
 | Test.java:1:14:1:17 | Test | 59 |       } |
 | Test.java:1:14:1:17 | Test | 60 |     } |
 | Test.java:1:14:1:17 | Test | 61 |     var a = switch (o) { |
 | Test.java:1:14:1:17 | Test | 62 |       case String s: |
 | Test.java:1:14:1:17 | Test | 63 |       yield 1; |
-| Test.java:1:14:1:17 | Test | 64 |       case R(S(x), y): |
+| Test.java:1:14:1:17 | Test | 64 |       case R(S(int x), String y): |
 | Test.java:1:14:1:17 | Test | 65 |       yield x; |
 | Test.java:1:14:1:17 | Test | 66 |       case default: |
 | Test.java:1:14:1:17 | Test | 67 |       yield 2; |
 | Test.java:1:14:1:17 | Test | 68 |     }; |
 | Test.java:1:14:1:17 | Test | 69 |     var b = switch (o) { |
 | Test.java:1:14:1:17 | Test | 70 |       case String s -> 1; |
-| Test.java:1:14:1:17 | Test | 71 |       case R(S(x), y) -> x; |
+| Test.java:1:14:1:17 | Test | 71 |       case R(S(int x), String y) -> x; |
 | Test.java:1:14:1:17 | Test | 72 |       default -> 2; |
 | Test.java:1:14:1:17 | Test | 73 |     }; |
 | Test.java:1:14:1:17 | Test | 74 |     if (o instanceof String s) { |
 | Test.java:1:14:1:17 | Test | 75 |     } |
-| Test.java:1:14:1:17 | Test | 76 |     if (o instanceof R(S(x), y)) { |
+| Test.java:1:14:1:17 | Test | 76 |     if (o instanceof R(S(int x), String y)) { |
 | Test.java:1:14:1:17 | Test | 77 |     } |
-| Test.java:1:14:1:17 | Test | 78 |   } |
-| Test.java:1:14:1:17 | Test | 79 | } |
+| Test.java:1:14:1:17 | Test | 78 |     switch (o) { |
+| Test.java:1:14:1:17 | Test | 79 |       case R(S(var x), var y) -> { |
+| Test.java:1:14:1:17 | Test | 80 |       } |
+| Test.java:1:14:1:17 | Test | 81 |       case default -> { |
+| Test.java:1:14:1:17 | Test | 82 |       } |
+| Test.java:1:14:1:17 | Test | 83 |     } |
+| Test.java:1:14:1:17 | Test | 84 |     if (o instanceof R(S(var x), var y)) { |
+| Test.java:1:14:1:17 | Test | 85 |     } |
+| Test.java:1:14:1:17 | Test | 86 |   } |
+| Test.java:1:14:1:17 | Test | 87 | } |