Thread: 8.1beta, Subtle bug in COPY in Solaris systems
Hello, First, I'll show the warnings seen when compiling postgres on SunOS 5.6 with gcc 3.2.1 copy.c: In function `GetDecimalFromHex': copy.c:2660: warning: subscript has type `char' copy.c: In function `CopyReadAttributesText': copy.c:2805: warning: subscript has type `char' copy.c:2813: warning: subscript has type `char' Actually this warnings are caused by the isdigit function. On Solaris systems, isdigit is organized as an array lookup, so all the arguments should be casted to unsigned char. 2660c2660 < if (isdigit(hex)) --- > if (isdigit((unsigned char)hex)) 2805c2805 < if (isxdigit(hexchar)) --- > if (isxdigit((unsigned char)hexchar)) 2813c2813 < if (isxdigit(hexchar)) --- > if (isxdigit((unsigned char)hexchar)) Actually that problem cause not only warnings but real bugs too, exploiting that problem. (when the char >128 and is not casted to unsigned, on solaris there will be a negative indices of arrays) For example on SunOS (or any Solaris): test=# CREATE TABLE test0 (xx char(2)); CREATE TABLE test=# copy test0 from stdin; Enter data to be copied followed by a newline. End with a backslash and a period on a line by itself. >> \x3п >> \. test=# select length(xx) from test0;length -------- 1 (1 row) But on NOT Solaris: test=# CREATE TABLE test0 (xx char(2)); CREATE TABLE test=# copy test0 from stdin; Enter data to be copied followed by a newline. End with a backslash and a period on a line by itself. >> \x3п >> \. test=# select length(xx) from test0;length -------- 2 (1 row) I'm not sure that everybody will see that code properly due to encoding differences. But the idea is just feed postgres with "\x3" and one character with the code >128. Regards,Sergey ***************************************************** Sergey E. Koposov Max-Planck Institut fuer Astronomie Web: http://lnfm1.sai.msu.ru/~math E-mail: math@sai.msu.ru
"Sergey E. Koposov" <math@sai.msu.ru> writes:
> 2660c2660
> < if (isdigit(hex))
> ---
> > if (isdigit((unsigned char)hex))
Sigh. We keep fixing these, and they keep creeping back in. I wish
there were a way to get some more-mainstream compiler to warn about
passing chars to the <ctype.h> functions.
Thanks for the report. You only saw the three?
regards, tom lane
On Thu, 1 Sep 2005, Tom Lane wrote:
> "Sergey E. Koposov" <math@sai.msu.ru> writes:
> > 2660c2660
> > < if (isdigit(hex))
> > ---
> > > if (isdigit((unsigned char)hex))
>
> Sigh. We keep fixing these, and they keep creeping back in. I wish
> there were a way to get some more-mainstream compiler to warn about
> passing chars to the <ctype.h> functions.
>
> Thanks for the report. You only saw the three?
In fact, I saw two other warnings, but they should not cause any
problems (at least on my understanding....) :
gcc -O2 -Wall -Wmissing-prototypes -Wpointer-arith -fno-strict-aliasing -DFRONTEND -I. -I../../../src/interfaces/libpq
-I../../../src/include-I/systools/include -c -o psqlscan.o psqlscan.c
In file included from ../../../src/include/c.h:53, from ../../../src/include/postgres_fe.h:21,
from psqlscan.l:40:
../../../src/include/pg_config.h:659:1: warning: "_FILE_OFFSET_BITS" redefined
In file included from /systools/lib/gcc-lib/sparc-sun-solaris2.7/3.2.1/include/stdio.h:36, from
psqlscan.c:13:
/usr/include/sys/feature_tests.h:96:1: warning: this is the location of the previous definition
XXXXXXXXXXXX
gcc -O2 -Wall -Wmissing-prototypes -Wpointer-arith -fno-strict-aliasing -Wno-error -I./../include -I.
-I../../../../src/include-I/systools/include -DMAJOR_VERSION=4 -DMINOR_VERSION=1 -DPATCHLEVEL=1 -c -o preproc.o
preproc.c
In file included from preproc.y:6412:
pgc.c: In function `yylex':
pgc.c:1504: warning: label `find_rule' defined but not used
preproc.y: At top level:
pgc.c:3565: warning: `yy_flex_realloc' defined but not used
With Best Regards, Sergey
*****************************************************
Sergey E. Koposov
Max-Planck Institut fuer Astronomie
Web: http://lnfm1.sai.msu.ru/~math
E-mail: math@sai.msu.ru