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Fix memory leaks in scanners generated by at least Flex 2.5.9 and

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later.  Reported by Paul Eggert in
<http://lists.gnu.org/archive/html/bison-patches/2006-11/msg00014.html>.
* src/flex-scanner.h (yylex_destroy): Define for Flex before 2.5.9.
* src/scan-code.l (translate_action): Don't bother invoking
yy_delete_buffer (YY_CURRENT_BUFFER) before creating the first buffer.
(code_scanner_free): Instead of invoking
yy_delete_buffer (YY_CURRENT_BUFFER) directly, invoke yylex_destroy,
which frees more.
* src/scan-gram.l (gram_scanner_free): Likewise.
* src/scan-skel.l (scan_skel): Likewise.
This commit is contained in:
Joel E. Denny
2006-11-10 05:26:26 +00:00
parent 4502eadc2f
commit 580b892607
5 changed files with 30 additions and 5 deletions
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14
ChangeLog
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@@ -1,3 +1,17 @@
2006-11-10 Joel E. Denny <jdenny@ces.clemson.edu>
Fix memory leaks in scanners generated by at least Flex 2.5.9 and
later. Reported by Paul Eggert in
<http://lists.gnu.org/archive/html/bison-patches/2006-11/msg00014.html>.
* src/flex-scanner.h (yylex_destroy): Define for Flex before 2.5.9.
* src/scan-code.l (translate_action): Don't bother invoking
yy_delete_buffer (YY_CURRENT_BUFFER) before creating the first buffer.
(code_scanner_free): Instead of invoking
yy_delete_buffer (YY_CURRENT_BUFFER) directly, invoke yylex_destroy,
which frees more.
* src/scan-gram.l (gram_scanner_free): Likewise.
* src/scan-skel.l (scan_skel): Likewise.
2006-11-09 Joel E. Denny <jdenny@ces.clemson.edu>
* src/files.c (tr): Change return type to void.

13
src/flex-scanner.h
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@@ -50,6 +50,19 @@ int FLEX_PREFIX (lex_destroy) (void);
# define yytext FLEX_PREFIX (text)
#endif
/* Non-reentrant scanners generated by Flex 2.5.9 and later (and some earlier
versions according to the Flex manual) leak memory if yylex_destroy is not
invoked. However, yylex_destroy is not defined before Flex 2.5.9, so give
an implementation here that at least appears to work with Flex 2.5.4. */
#if !defined(YY_FLEX_MAJOR_VERSION) || YY_FLEX_MAJOR_VERSION < 2 \
|| (YY_FLEX_MAJOR_VERSION == 2 \
&& (!defined(YY_FLEX_MINOR_VERSION) || YY_FLEX_MINOR_VERSION < 5 \
|| (YY_FLEX_MINOR_VERSION == 5 \
&& (!defined(YY_FLEX_SUBMINOR_VERSION) \
|| YY_FLEX_SUBMINOR_VERSION < 9))))
# define yylex_destroy() yy_delete_buffer (YY_CURRENT_BUFFER)
#endif
/* OBSTACK_FOR_STRING -- Used to store all the characters that we need to
keep (to construct ID, STRINGS etc.). Use the following macros to
use it.

4
src/scan-code.l
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@@ -380,8 +380,6 @@ translate_action (int sc_context, symbol_list *rule, char const *a, location l)
if (!initialized)
{
obstack_init (&obstack_for_string);
/* The initial buffer, never used. */
yy_delete_buffer (YY_CURRENT_BUFFER);
yy_flex_debug = 0;
initialized = true;
}
@@ -422,5 +420,5 @@ code_scanner_free (void)
{
obstack_free (&obstack_for_string, 0);
/* Reclaim Flex's buffers. */
yy_delete_buffer (YY_CURRENT_BUFFER);
yylex_destroy ();
}

2
src/scan-gram.l
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@@ -800,5 +800,5 @@ gram_scanner_free (void)
{
obstack_free (&obstack_for_string, 0);
/* Reclaim Flex's buffers. */
yy_delete_buffer (YY_CURRENT_BUFFER);
yylex_destroy ();
}

2
src/scan-skel.l
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@@ -121,5 +121,5 @@ scan_skel (FILE *in)
skel__flex_debug = trace_flag & trace_skeleton;
skel_lex ();
/* Reclaim Flex's buffers. */
yy_delete_buffer (YY_CURRENT_BUFFER);
yylex_destroy ();
}