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authorMark H Weaver <mhw@netris.org>2013-03-31 19:06:51 -0400
committerMark H Weaver <mhw@netris.org>2013-04-04 17:48:37 -0400
commit45c0878b8665182f06a917e391169031c1dc7db6 (patch)
tree8c7dfcacacdc33272d7e5e7c30625397fd607669
parent0426b3f8f8036364aca13c24ef769283937faa3d (diff)
downloadguile-45c0878b8665182f06a917e391169031c1dc7db6.tar.gz
Peeks do not consume EOFs.
Fixes <http://bugs.gnu.org/12216>. * libguile/ports-internal.h (struct scm_port_internal): Add 'pending_eof' flag. * libguile/ports.c (scm_i_set_pending_eof, scm_i_clear_pending_eof): New static functions. (scm_new_port_table_entry): Initialize 'pending_eof'. (scm_i_fill_input): Check for 'pending_eof'. (scm_i_peek_byte_or_eof): Set 'pending_eof' flag before returning EOF. (scm_end_input, scm_unget_byte, scm_seek, scm_truncate): Clear 'pending_eof'. (scm_peek_char): Set 'pending_eof' flag before returning EOF. * test-suite/tests/ports.test ("pending EOF behavior"): Add tests.
-rw-r--r--libguile/ports-internal.h1
-rw-r--r--libguile/ports.c50
-rw-r--r--test-suite/tests/ports.test84
3 files changed, 128 insertions, 7 deletions
diff --git a/libguile/ports-internal.h b/libguile/ports-internal.h
index 73a788f39..333d4fbc8 100644
--- a/libguile/ports-internal.h
+++ b/libguile/ports-internal.h
@@ -48,6 +48,7 @@ struct scm_port_internal
{
scm_t_port_encoding_mode encoding_mode;
scm_t_iconv_descriptors *iconv_descriptors;
+ int pending_eof;
SCM alist;
};
diff --git a/libguile/ports.c b/libguile/ports.c
index eaa204788..f210cdabd 100644
--- a/libguile/ports.c
+++ b/libguile/ports.c
@@ -241,6 +241,18 @@ scm_set_port_input_waiting (scm_t_bits tc, int (*input_waiting) (SCM))
scm_ptobs[SCM_TC2PTOBNUM (tc)].input_waiting = input_waiting;
}
+static void
+scm_i_set_pending_eof (SCM port)
+{
+ SCM_PORT_GET_INTERNAL (port)->pending_eof = 1;
+}
+
+static void
+scm_i_clear_pending_eof (SCM port)
+{
+ SCM_PORT_GET_INTERNAL (port)->pending_eof = 0;
+}
+
SCM
scm_i_port_alist (SCM port)
{
@@ -645,6 +657,7 @@ scm_new_port_table_entry (scm_t_bits tag)
entry->input_cd = pti; /* XXX pointer to the internal port structure */
entry->output_cd = NULL; /* XXX unused */
+ pti->pending_eof = 0;
pti->alist = SCM_EOL;
SCM_SET_CELL_TYPE (z, tag);
@@ -1326,8 +1339,11 @@ get_iconv_codepoint (SCM port, scm_t_wchar *codepoint,
return 0;
}
else
- /* EOF found in the middle of a multibyte character. */
- return EILSEQ;
+ {
+ /* EOF found in the middle of a multibyte character. */
+ scm_i_set_pending_eof (port);
+ return EILSEQ;
+ }
}
buf[input_size++] = byte_read;
@@ -1431,9 +1447,16 @@ static int
scm_i_fill_input (SCM port)
{
scm_t_port *pt = SCM_PTAB_ENTRY (port);
+ scm_t_port_internal *pti = SCM_PORT_GET_INTERNAL (port);
assert (pt->read_pos == pt->read_end);
+ if (pti->pending_eof)
+ {
+ pti->pending_eof = 0;
+ return EOF;
+ }
+
if (pt->read_buf == pt->putback_buf)
{
/* finished reading put-back chars. */
@@ -1489,7 +1512,10 @@ scm_slow_peek_byte_or_eof (SCM port)
if (pt->read_pos >= pt->read_end)
{
if (SCM_UNLIKELY (scm_i_fill_input (port) == EOF))
- return EOF;
+ {
+ scm_i_set_pending_eof (port);
+ return EOF;
+ }
}
return *pt->read_pos;
@@ -1721,6 +1747,7 @@ scm_end_input (SCM port)
long offset;
scm_t_port *pt = SCM_PTAB_ENTRY (port);
+ scm_i_clear_pending_eof (port);
if (pt->read_buf == pt->putback_buf)
{
offset = pt->read_end - pt->read_pos;
@@ -1744,6 +1771,7 @@ scm_unget_byte (int c, SCM port)
{
scm_t_port *pt = SCM_PTAB_ENTRY (port);
+ scm_i_clear_pending_eof (port);
if (pt->read_buf == pt->putback_buf)
/* already using the put-back buffer. */
{
@@ -1915,7 +1943,10 @@ SCM_DEFINE (scm_peek_char, "peek-char", 0, 1, 0,
result = SCM_BOOL_F;
}
else if (c == EOF)
- result = SCM_EOF_VAL;
+ {
+ scm_i_set_pending_eof (port);
+ result = SCM_EOF_VAL;
+ }
else
result = SCM_MAKE_CHAR (c);
@@ -2014,7 +2045,10 @@ SCM_DEFINE (scm_seek, "seek", 3, 0, 0,
SCM_MISC_ERROR ("port is not seekable",
scm_cons (fd_port, SCM_EOL));
else
- rv = ptob->seek (fd_port, off, how);
+ {
+ scm_i_clear_pending_eof (fd_port);
+ rv = ptob->seek (fd_port, off, how);
+ }
return scm_from_off_t_or_off64_t (rv);
}
else /* file descriptor?. */
@@ -2103,14 +2137,16 @@ SCM_DEFINE (scm_truncate_file, "truncate-file", 1, 1, 0,
off_t_or_off64_t c_length = scm_to_off_t_or_off64_t (length);
scm_t_port *pt = SCM_PTAB_ENTRY (object);
scm_t_ptob_descriptor *ptob = scm_ptobs + SCM_PTOBNUM (object);
-
+
if (!ptob->truncate)
SCM_MISC_ERROR ("port is not truncatable", SCM_EOL);
+
+ scm_i_clear_pending_eof (object);
if (pt->rw_active == SCM_PORT_READ)
scm_end_input (object);
else if (pt->rw_active == SCM_PORT_WRITE)
ptob->flush (object);
-
+
ptob->truncate (object, c_length);
rv = 0;
}
diff --git a/test-suite/tests/ports.test b/test-suite/tests/ports.test
index 886ab2418..7b6ee22a8 100644
--- a/test-suite/tests/ports.test
+++ b/test-suite/tests/ports.test
@@ -1110,6 +1110,90 @@
(char-ready?))))))
+;;;; pending-eof behavior
+
+(with-test-prefix "pending EOF behavior"
+ ;; Make a test port that will produce the given sequence. Each
+ ;; element of 'lst' may be either a character or #f (which means EOF).
+ (define (test-soft-port . lst)
+ (make-soft-port
+ (vector (lambda (c) #f) ; write char
+ (lambda (s) #f) ; write string
+ (lambda () #f) ; flush
+ (lambda () ; read char
+ (let ((c (car lst)))
+ (set! lst (cdr lst))
+ c))
+ (lambda () #f)) ; close
+ "rw"))
+
+ (define (call-with-port p proc)
+ (dynamic-wind
+ (lambda () #f)
+ (lambda () (proc p))
+ (lambda () (close-port p))))
+
+ (define (call-with-test-file str proc)
+ (let ((filename (test-file)))
+ (dynamic-wind
+ (lambda () (call-with-output-file filename
+ (lambda (p) (display str p))))
+ (lambda () (call-with-input-file filename proc))
+ (lambda () (delete-file (test-file))))))
+
+ (pass-if "peek-char does not swallow EOF (soft port)"
+ (call-with-port (test-soft-port #\a #f #\b)
+ (lambda (p)
+ (and (char=? #\a (peek-char p))
+ (char=? #\a (read-char p))
+ (eof-object? (peek-char p))
+ (eof-object? (read-char p))
+ (char=? #\b (peek-char p))
+ (char=? #\b (read-char p))))))
+
+ (pass-if "unread clears pending EOF (soft port)"
+ (call-with-port (test-soft-port #\a #f #\b)
+ (lambda (p)
+ (and (char=? #\a (read-char p))
+ (eof-object? (peek-char p))
+ (begin (unread-char #\u p)
+ (char=? #\u (read-char p)))))))
+
+ (pass-if "unread clears pending EOF (string port)"
+ (call-with-input-string "a"
+ (lambda (p)
+ (and (char=? #\a (read-char p))
+ (eof-object? (peek-char p))
+ (begin (unread-char #\u p)
+ (char=? #\u (read-char p)))))))
+
+ (pass-if "unread clears pending EOF (file port)"
+ (call-with-test-file
+ "a"
+ (lambda (p)
+ (and (char=? #\a (read-char p))
+ (eof-object? (peek-char p))
+ (begin (unread-char #\u p)
+ (char=? #\u (read-char p)))))))
+
+ (pass-if "seek clears pending EOF (string port)"
+ (call-with-input-string "a"
+ (lambda (p)
+ (and (char=? #\a (read-char p))
+ (eof-object? (peek-char p))
+ (begin (seek p 0 SEEK_SET)
+ (char=? #\a (read-char p)))))))
+
+ (pass-if "seek clears pending EOF (file port)"
+ (call-with-test-file
+ "a"
+ (lambda (p)
+ (and (char=? #\a (read-char p))
+ (eof-object? (peek-char p))
+ (begin (seek p 0 SEEK_SET)
+ (char=? #\a (read-char p))))))))
+
+
;;;; Close current-input-port, and make sure everyone can handle it.
(with-test-prefix "closing current-input-port"