commit 6a36fcf509bc9c4c4b9aa42e90bfd706e0d3db94
parent 3f7e8cab087bf4c20a993c64707c65affe22aa54
Author: Ryan Sepassi <rsepassi@gmail.com>
Date: Fri, 1 May 2026 19:12:16 -0700
Revert "cc/parse: support brace elision in nested aggregate initializers"
This reverts commit 5947945ef1b00beb0744635095b6e1a6259a6a2a.
Diffstat:
3 files changed, 0 insertions(+), 218 deletions(-)
diff --git a/cc/cc.scm b/cc/cc.scm
@@ -5728,107 +5728,12 @@
(cond ((at-punct? ps 'comma) (advance ps)))
(expect-punct ps 'rbrace)
(list p)))))
- ;; Brace elision: when elem is itself an
- ;; aggregate and no inner `{` was given,
- ;; consume that aggregate's worth of
- ;; child initializers from the parent list
- ;; (C99 §6.7.8 ¶22). Otherwise, treat the
- ;; next expression as a scalar piece.
- ((eq? (ctype-kind elem) 'arr)
- (%parse-init-array-noBrace ps elem))
- ((or (eq? (ctype-kind elem) 'struct)
- (eq? (ctype-kind elem) 'union))
- (%parse-init-struct-noBrace ps elem))
(else
(list (%const-init-piece ps elem))))))
(cond ((at-punct? ps 'comma) (advance ps)))
p)))))
(lp (%init-main-prepend-reversed piece acc) (+ count 1))))))))
-;; Brace-elision helpers: consume one aggregate's children without
-;; expecting an enclosing `{` `}`. Used when an aggregate-typed element
-;; appears in an outer list without inner braces, e.g.
-;; `struct S a[2] = {1,2,3,4}`.
-(define (%parse-init-array-noBrace ps ty)
- (let* ((elem (%init-array-elem-type ty))
- (esize (ctype-size elem))
- (decl (%init-array-decl-len ty))
- (final (cond ((< decl 0) 0) (else decl))))
- (let lp ((acc '()) (count 0))
- (cond
- ((>= count final)
- ;; Pad to declared length if shorter (count==final-no-pad).
- (reverse acc))
- ;; Stop early if we hit `}` of an enclosing list.
- ((at-punct? ps 'rbrace) (reverse acc))
- (else
- (let ((p (cond
- ((at-punct? ps 'lbrace)
- (advance ps)
- (cond
- ((eq? (ctype-kind elem) 'arr)
- (let-values (((p _c)
- (%parse-init-array-list ps elem))) p))
- ((or (eq? (ctype-kind elem) 'struct)
- (eq? (ctype-kind elem) 'union))
- (%parse-init-struct-list ps elem))
- (else
- (let ((p (%const-init-piece ps elem)))
- (cond ((at-punct? ps 'comma) (advance ps)))
- (expect-punct ps 'rbrace)
- (list p)))))
- ((eq? (ctype-kind elem) 'arr)
- (%parse-init-array-noBrace ps elem))
- ((or (eq? (ctype-kind elem) 'struct)
- (eq? (ctype-kind elem) 'union))
- (%parse-init-struct-noBrace ps elem))
- (else (list (%const-init-piece ps elem))))))
- (cond ((at-punct? ps 'comma) (advance ps)))
- (lp (append (reverse p) acc) (+ count 1))))))))
-
-(define (%parse-init-struct-noBrace ps ty)
- ;; Brace-elided struct: consume positional initializers for each
- ;; field in declaration order, returning a flat piece list (with
- ;; offset-merge so trailing fields get padded).
- (let* ((fields (%init-struct-fields ty))
- (size (ctype-size ty)))
- (let lp ((entries '()) (rest fields))
- (cond
- ((null? rest)
- (%merge-init-entries (reverse entries) size))
- ((at-punct? ps 'rbrace)
- (%merge-init-entries (reverse entries) size))
- (else
- (let* ((target (car rest))
- (fname (car target))
- (fty (car (cdr target)))
- (foff (car (cddr target)))
- (piece-list
- (cond
- ((at-punct? ps 'lbrace)
- (advance ps)
- (cond
- ((eq? (ctype-kind fty) 'arr)
- (let-values (((p _c)
- (%parse-init-array-list ps fty))) p))
- ((or (eq? (ctype-kind fty) 'struct)
- (eq? (ctype-kind fty) 'union))
- (%parse-init-struct-list ps fty))
- (else
- (let ((p (%const-init-piece ps fty)))
- (cond ((at-punct? ps 'comma) (advance ps)))
- (expect-punct ps 'rbrace)
- (list p)))))
- ((eq? (ctype-kind fty) 'arr)
- (%parse-init-array-noBrace ps fty))
- ((or (eq? (ctype-kind fty) 'struct)
- (eq? (ctype-kind fty) 'union))
- (%parse-init-struct-noBrace ps fty))
- (else
- (list (%const-init-piece ps fty))))))
- (cond ((at-punct? ps 'comma) (advance ps)))
- (lp (cons (cons foff piece-list) entries) (cdr rest))))))))
-
(define (%piece-bytesize p)
;; Output width of one piece (cf. %cg-init-piece->bv): a bv emits
;; one byte per element; a (label-ref . _) emits an 8-byte slot.
@@ -6062,15 +5967,6 @@
(cg-assign (ps-cg ps)) (cg-pop (ps-cg ps))
(cond ((at-punct? ps 'comma) (advance ps)))
(expect-punct ps 'rbrace))))
- ;; Brace elision: aggregate elem without inner `{` —
- ;; consume that aggregate's worth of children directly
- ;; (C99 §6.7.8 ¶22). Without this, `int a[2][2] = {1,2,3,4}`
- ;; would treat each integer as an entire `int[2]`.
- ((eq? (ctype-kind elem) 'arr)
- (%parse-init-local-array-noBrace ps sm eoff elem))
- ((or (eq? (ctype-kind elem) 'struct)
- (eq? (ctype-kind elem) 'union))
- (%parse-init-local-struct-noBrace ps sm eoff elem))
(else
(%push-frame-elem-lval ps eoff elem)
(parse-expr-bp ps 4) (rval! ps)
@@ -6079,113 +5975,6 @@
(cond ((at-punct? ps 'comma) (advance ps)))
(lp (+ i 1))))))))
-(define (%parse-init-local-array-noBrace ps sm base-off ty)
- ;; Like %parse-init-local-array-list but consumes a fixed number of
- ;; children (= declared length) without expecting an enclosing `}`.
- ;; Pads remaining slots with zero. Caller is the parent list whose
- ;; `}` (or further siblings) follow.
- (let* ((elem (%init-array-elem-type ty))
- (esize (ctype-size elem))
- (decl (%init-array-decl-len ty))
- (final (cond ((< decl 0) 0) (else decl))))
- (let lp ((i 0))
- (cond
- ((>= i final) #t)
- ((at-punct? ps 'rbrace)
- ;; Hit parent `}` early; zero-fill remaining slots.
- (let zlp ((k i))
- (cond
- ((>= k final) #t)
- (else
- (let ((off (+ base-off (* k esize))))
- (let zb ((j 0))
- (cond
- ((>= j esize) #t)
- (else
- (%push-frame-elem-lval ps (+ off j) %t-u8)
- (cg-push-imm (ps-cg ps) %t-u8 0)
- (cg-assign (ps-cg ps))
- (cg-pop (ps-cg ps))
- (zb (+ j 1)))))
- (zlp (+ k 1)))))))
- (else
- (let ((eoff (+ base-off (* i esize))))
- (cond
- ((at-punct? ps 'lbrace)
- (advance ps)
- (cond
- ((eq? (ctype-kind elem) 'arr)
- (%parse-init-local-array-list ps sm eoff elem))
- ((or (eq? (ctype-kind elem) 'struct)
- (eq? (ctype-kind elem) 'union))
- (%parse-init-local-struct-list ps sm eoff elem))
- (else
- (%push-frame-elem-lval ps eoff elem)
- (parse-expr-bp ps 4) (rval! ps)
- (cg-cast (ps-cg ps) elem)
- (cg-assign (ps-cg ps)) (cg-pop (ps-cg ps))
- (cond ((at-punct? ps 'comma) (advance ps)))
- (expect-punct ps 'rbrace))))
- ((eq? (ctype-kind elem) 'arr)
- (%parse-init-local-array-noBrace ps sm eoff elem))
- ((or (eq? (ctype-kind elem) 'struct)
- (eq? (ctype-kind elem) 'union))
- (%parse-init-local-struct-noBrace ps sm eoff elem))
- (else
- (%push-frame-elem-lval ps eoff elem)
- (parse-expr-bp ps 4) (rval! ps)
- (cg-cast (ps-cg ps) elem)
- (cg-assign (ps-cg ps)) (cg-pop (ps-cg ps))))
- (cond ((at-punct? ps 'comma) (advance ps)))
- (lp (+ i 1))))))))
-
-(define (%parse-init-local-struct-noBrace ps sm base-off ty)
- ;; Brace-elided struct in auto context: positional inits for each
- ;; field; pad unmentioned tail fields with zero.
- (let ((fields (%init-struct-fields ty)))
- (let lp ((rest fields) (seen '()))
- (cond
- ((or (null? rest) (at-punct? ps 'rbrace))
- (for-each
- (lambda (f)
- (cond ((not (%anon-touched? f seen))
- (%emit-zero-field ps base-off f))))
- fields))
- (else
- (let* ((target (car rest))
- (fname (car target))
- (fty (car (cdr target)))
- (foff (car (cddr target)))
- (eoff (+ base-off foff)))
- (cond
- ((at-punct? ps 'lbrace)
- (advance ps)
- (cond
- ((eq? (ctype-kind fty) 'arr)
- (%parse-init-local-array-list ps sm eoff fty))
- ((or (eq? (ctype-kind fty) 'struct)
- (eq? (ctype-kind fty) 'union))
- (%parse-init-local-struct-list ps sm eoff fty))
- (else
- (%push-frame-elem-lval ps eoff fty)
- (parse-expr-bp ps 4) (rval! ps)
- (cg-cast (ps-cg ps) fty)
- (cg-assign (ps-cg ps)) (cg-pop (ps-cg ps))
- (cond ((at-punct? ps 'comma) (advance ps)))
- (expect-punct ps 'rbrace))))
- ((eq? (ctype-kind fty) 'arr)
- (%parse-init-local-array-noBrace ps sm eoff fty))
- ((or (eq? (ctype-kind fty) 'struct)
- (eq? (ctype-kind fty) 'union))
- (%parse-init-local-struct-noBrace ps sm eoff fty))
- (else
- (%push-frame-elem-lval ps eoff fty)
- (parse-expr-bp ps 4) (rval! ps)
- (cg-cast (ps-cg ps) fty)
- (cg-assign (ps-cg ps)) (cg-pop (ps-cg ps))))
- (cond ((at-punct? ps 'comma) (advance ps)))
- (lp (cdr rest) (cons fname seen))))))))
-
(define (%bv-in-list? bv xs)
(cond ((null? xs) #f)
((equal? bv (car xs)) #t)
diff --git a/tests/cc/241-init-brace-elision-struct-array.c b/tests/cc/241-init-brace-elision-struct-array.c
@@ -1,6 +0,0 @@
-/* Brace elision in nested aggregate init */
-struct S { int a; int b; };
-int main(void) {
- struct S arr[2] = { 1, 2, 3, 4 }; /* no inner braces */
- return arr[0].a + arr[0].b + arr[1].a + arr[1].b; /* 10 */
-}
diff --git a/tests/cc/241-init-brace-elision-struct-array.expected-exit b/tests/cc/241-init-brace-elision-struct-array.expected-exit
@@ -1 +0,0 @@
-10
