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Re: [patch]: Fix memory leak of c-exp.y
- From: Jan Kratochvil <jan dot kratochvil at redhat dot com>
- To: Hui Zhu <teawater at gmail dot com>
- Cc: Thiago Jung Bauermann <bauerman at br dot ibm dot com>, gdb-patches at sourceware dot org
- Date: Tue, 24 Jun 2008 15:35:40 +0200
- Subject: Re: [patch]: Fix memory leak of c-exp.y
- References: <daef60380806232332n429917efu4eec3c7ca1731987@mail.gmail.com>
On Tue, 24 Jun 2008 08:32:44 +0200, teawater wrote:
> ChangeLog:
> 2008-06-21 Hui Zhu <teawater@gmail.com>
> * gdb/c-exp.y: Fix memory leak of function parse_number
Agreed with the fix just IMO the block of code needs more cleanups. [attached]
The leak was brought in by:
http://sourceware.org/ml/gdb-patches/2007-10/msg00395.html
Just please check the GNU Coding Standards document for the ChangeLog style, it
should have been more like:
2008-06-21 Hui Zhu <teawater@gmail.com>
* c-exp.y (parse_number): Fix a memory leak.
Thanks,
Jan
2008-06-24 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix a memory leak found by Hui Zhu <teawater@gmail.com>.
* c-exp.y (parse_number): Move the S and SAVED_CHAR initialization
after the DECFLOAT detection to fix a memory leak. Remove the
redundant NUM initialization. Protect the DECFLOAT detection memory
access before the P block. Restore the P memory content for the
DECFLOAT detection.
--- ./gdb/c-exp.y 9 Jun 2008 19:25:14 -0000 1.45
+++ ./gdb/c-exp.y 24 Jun 2008 13:03:26 -0000
@@ -1118,45 +1118,46 @@ parse_number (p, len, parsed_float, puti
if (parsed_float)
{
/* It's a float since it contains a point or an exponent. */
- char *s = malloc (len);
- int num = 0; /* number of tokens scanned by scanf */
- char saved_char = p[len];
-
- p[len] = 0; /* null-terminate the token */
+ char *s;
+ int num; /* number of tokens scanned by scanf */
+ char saved_char;
/* If it ends at "df", "dd" or "dl", take it as type of decimal floating
point. Return DECFLOAT. */
- if (p[len - 2] == 'd' && p[len - 1] == 'f')
+ if (len >= 2 && p[len - 2] == 'd' && p[len - 1] == 'f')
{
p[len - 2] = '\0';
putithere->typed_val_decfloat.type
= builtin_type (current_gdbarch)->builtin_decfloat;
decimal_from_string (putithere->typed_val_decfloat.val, 4, p);
- p[len] = saved_char;
- return (DECFLOAT);
+ p[len - 2] = 'd';
+ return DECFLOAT;
}
- if (p[len - 2] == 'd' && p[len - 1] == 'd')
+ if (len >= 2 && p[len - 2] == 'd' && p[len - 1] == 'd')
{
p[len - 2] = '\0';
putithere->typed_val_decfloat.type
= builtin_type (current_gdbarch)->builtin_decdouble;
decimal_from_string (putithere->typed_val_decfloat.val, 8, p);
- p[len] = saved_char;
- return (DECFLOAT);
+ p[len - 2] = 'd';
+ return DECFLOAT;
}
- if (p[len - 2] == 'd' && p[len - 1] == 'l')
+ if (len >= 2 && p[len - 2] == 'd' && p[len - 1] == 'l')
{
p[len - 2] = '\0';
putithere->typed_val_decfloat.type
= builtin_type (current_gdbarch)->builtin_declong;
decimal_from_string (putithere->typed_val_decfloat.val, 16, p);
- p[len] = saved_char;
- return (DECFLOAT);
+ p[len - 2] = 'd';
+ return DECFLOAT;
}
+ s = malloc (len);
+ saved_char = p[len];
+ p[len] = 0; /* null-terminate the token */
num = sscanf (p, "%" DOUBLEST_SCAN_FORMAT "%s",
&putithere->typed_val_float.dval, s);
p[len] = saved_char; /* restore the input stream */