From cb3f2966789ead182db1ecbf7231e3a3b7a5fd38 Mon Sep 17 00:00:00 2001
From: AlexKnauth <alexander@knauth.org>
Date: Mon, 8 Dec 2014 16:34:43 -0500
Subject: [PATCH] support this-syntax in syntax-parse, syntax-parser, etc.

closes PR 14855
---
 pkgs/racket-test/tests/stxparse/test.rkt      | 23 +++++++++++++++++++
 .../collects/syntax/parse/private/parse.rkt   |  9 +++++---
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/pkgs/racket-test/tests/stxparse/test.rkt b/pkgs/racket-test/tests/stxparse/test.rkt
index a22c2b31b6..a1efa55ad5 100644
--- a/pkgs/racket-test/tests/stxparse/test.rkt
+++ b/pkgs/racket-test/tests/stxparse/test.rkt
@@ -2,6 +2,7 @@
 (require rackunit
          syntax/parse
          syntax/parse/debug
+         syntax/parse/define
          "setup.rkt"
          (for-syntax syntax/parse))
 
@@ -576,3 +577,25 @@
                   (syntax->datum #'(let ([x 1] [y 2] [z 3])
                                      (+ x y z))))
     ))
+
+(test-case "this-syntax"
+  (let ()
+    (define-syntax-class identity
+      [pattern _
+               #:with stx this-syntax])
+    (define stx #'(1 2 3))
+    (syntax-parse stx
+      [x:identity
+       (check-eq? this-syntax stx)
+       (check-eq? #'x.stx stx)])
+    ((syntax-parser
+       [x:identity
+        (check-eq? this-syntax stx)
+        (check-eq? #'x.stx stx)])
+     stx)
+    (define-simple-macro (x . _)
+      #:with stx (syntax/loc this-syntax (void))
+      stx)
+    (check-eq? (x) (void))
+    ))
+
diff --git a/racket/collects/syntax/parse/private/parse.rkt b/racket/collects/syntax/parse/private/parse.rkt
index a4fec508c6..aaf92f3102 100644
--- a/racket/collects/syntax/parse/private/parse.rkt
+++ b/racket/collects/syntax/parse/private/parse.rkt
@@ -161,7 +161,8 @@
     [(syntax-parse stx-expr . clauses)
      (quasisyntax/loc stx
        (let ([x (datum->syntax #f stx-expr)])
-         (parse:clauses x clauses body-sequence #,((make-syntax-introducer) stx))))]))
+         (with ([this-syntax x])
+           (parse:clauses x clauses body-sequence #,((make-syntax-introducer) stx)))))]))
 
 (define-syntax (syntax-parser stx)
   (syntax-case stx ()
@@ -169,7 +170,8 @@
      (quasisyntax/loc stx
        (lambda (x)
          (let ([x (datum->syntax #f x)])
-           (parse:clauses x clauses body-sequence #,((make-syntax-introducer) stx)))))]))
+           (with ([this-syntax x])
+             (parse:clauses x clauses body-sequence #,((make-syntax-introducer) stx))))))]))
 
 (define-syntax (syntax-parser/template stx)
   (syntax-case stx ()
@@ -177,7 +179,8 @@
      (quasisyntax/loc stx
        (lambda (x)
          (let ([x (datum->syntax #f x)])
-           (parse:clauses x clauses one-template ctx))))]))
+           (with ([this-syntax x])
+             (parse:clauses x clauses one-template ctx)))))]))
 
 (define-syntax (define/syntax-parse stx)
   (syntax-case stx ()