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Add macro-introduction scopes when expanding rename transformers

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This can’t affect scoping, but it can affect `syntax-original?`, which
is important for Check Syntax.
This commit is contained in:
Alexis King 2019-09-14 14:22:42 -05:00 committed by Matthew Flatt
parent c651cedc1f
commit c8652e063a
3 changed files with 40 additions and 12 deletions
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19
pkgs/racket-test-core/tests/racket/macro.rktl
View File

@ -2442,6 +2442,25 @@
(test #t dynamic-require ''syntax-local-value-free-id-context 'result)
;; ----------------------------------------
;; Ensure the expansion of a rename transformer is not `syntax-original?`
(module rename-transformer-introduction-scope racket/base
(require (for-syntax racket/base))
(provide sym free-id=? original?)
(define x #f)
(define-syntax y (make-rename-transformer #'x))
(define-syntax (m stx)
(define expanded-y (syntax-local-introduce (local-expand #'y 'expression '())))
#`(values '#,(syntax-e expanded-y)
'#,(free-identifier=? expanded-y #'x)
'#,(syntax-original? expanded-y)))
(define-values (sym free-id=? original?) (m)))
(test 'x dynamic-require ''rename-transformer-introduction-scope 'sym)
(test #t dynamic-require ''rename-transformer-introduction-scope 'free-id=?)
(test #f dynamic-require ''rename-transformer-introduction-scope 'original?)
;; ----------------------------------------
;; Make sure replacing scopes of binding on reference does not
;; turn a non-`syntax-original?` identifier into a `syntax-original?`

18
racket/src/expander/expand/main.rkt
View File

@ -323,12 +323,7 @@
(cond
[(expand-context-just-once? ctx) exp-s]
[else (expand exp-s re-ctx
#:alternate-id (and (rename-transformer? t)
(syntax-track-origin (transfer-srcloc
(rename-transformer-target-in-context t ctx)
id)
id
id))
#:alternate-id (and (rename-transformer? t) (apply-rename-transformer t id ctx))
#:skip-log? (or (expand-context-only-immediate? ctx)
(rename-transformer? t))
#:fail-non-transformer (and (rename-transformer? t) fail-non-transformer))])]))
@ -485,6 +480,17 @@
;; ----------------------------------------
;; "Apply" a rename transformer, replacing it with its target.
(define (apply-rename-transformer t id ctx)
(define target-id (rename-transformer-target-in-context t ctx))
;; Adding a macro-introduction scope doesn't affect scoping at all, but it can affect
;; whether the result is `syntax-original?`
(define intro-scope (new-scope 'macro))
(define intro-id (add-scope target-id intro-scope))
(syntax-track-origin (transfer-srcloc intro-id id) id id))
;; ----------------------------------------
;; Helper to lookup a binding in an expansion context
(define (lookup b ctx id
#:in [in-s #f]

15
racket/src/racket/src/startup.inc
View File

@ -43558,12 +43558,7 @@ static const char *startup_source =
"((re-ctx195_0) re-ctx_0)"
"((temp196_0)"
"(if(1/rename-transformer? t_0)"
"(syntax-track-origin$1"
"(transfer-srcloc"
"(rename-transformer-target-in-context t_0 ctx_0)"
" id_0)"
" id_0"
" id_0)"
"(apply-rename-transformer t_0 id_0 ctx_0)"
" #f))"
"((temp197_0)"
"(let-values(((or-part_0)(expand-context-only-immediate? ctx_0)))"
@ -43826,6 +43821,14 @@ static const char *startup_source =
"(expand-context/outer-name the-struct_0)))"
" (raise-argument-error 'struct-copy \"expand-context/outer?\" the-struct_0))))))))"
"(define-values"
"(apply-rename-transformer)"
"(lambda(t_0 id_0 ctx_0)"
"(begin"
"(let-values(((target-id_0)(rename-transformer-target-in-context t_0 ctx_0)))"
"(let-values(((intro-scope_0)(new-scope 'macro)))"
"(let-values(((intro-id_0)(add-scope target-id_0 intro-scope_0)))"
"(syntax-track-origin$1(transfer-srcloc intro-id_0 id_0) id_0 id_0)))))))"
"(define-values"
"(lookup62.1)"
"(lambda(in55_0 out-of-context-as-variable?56_0 b59_0 ctx60_0 id61_0)"
"(begin"