[tz] suggestions for potential code improvements?
Kees Dekker
Kees.Dekker at infor.com
Thu Jul 30 14:42:09 UTC 2015
Hi Paul,
Remarks on date.c:
The definitions of static functions oops() and iffy() do not have a declaration (raising e.g. 'oops' undefined; assuming extern returning int in Visual Studio (and probably other compilers). Can you please add two prototypes for these static functions?
BTW. I think the two files that were not correctly patched are the Makefile and date.c. So my comments on date.c may be related to an outdated version.
Remarks for zdump.c:
You said that tzcode supplies its own gmtime_r(). Do you mean the onze in zdump.c itself? That one is only supplied if HAVE_LOCALTIME_R was not set/defined.
Remarks for zic.c:
There are still some inconsistent prototypes: inleap(),inlink(),rulesub(),outzone(),addtt(),yearistype(),byword(), oadd(),tadd(),rpytime(),newabbr(). If you can make them consistent (declaration & definition) it would be great.
Regards,
Kees
-----Original Message-----
From: Kees Dekker
Sent: Thursday, July 30, 2015 15:19
To: 'Paul Eggert'
Cc: Time zone mailing list
Subject: RE: [tz] suggestions for potential code improvements?
Hi Paul,
Thanks again. Sorry for the delay, I was one day off.
Except the patch supplied to Jonathan Lennox, I was able to apply them all. Will I get the latest sources (including all previously sent patches) when I run: git clone https://github.com/eggert/tz.git?
Anyhow, I created a simple example where I found that gcc does not recognize any mismatch in int types (between declaration and definition) with only const qualifiers are added. Also note the strange error regarding the [const] char * mismatch. See example below. Just try to compile with gcc -Wall -Wextra -o <output> <input-c-file-as-copied from this email>. If you find this gcc behavior odd too, I will check whether I can file this to the gcc/gnu.org folks.
#include <stdio.h>
static void f(const int i);
static void g(int i);
static void h(const char *s);
int main(void)
{
f(3);
g(4);
h("A joke");
return 0;
}
static void f(int i)
{
printf("f-Input is: %d\n", i);
}
static void g(const int i)
{
printf("g-Input is: %d\n", i);
}
static void h(char *s)
{
printf("h-Input is: %s\n", s);
}
Regards,
Kees
-----Original Message-----
From: Paul Eggert [mailto:eggert at cs.ucla.edu]
Sent: Wednesday, July 29, 2015 03:46
To: Kees Dekker
Cc: Time zone mailing list
Subject: Re: [tz] suggestions for potential code improvements?
Kees Dekker wrote:
> Both date.c, zdump.c, zic.c contain a number of static functions where the declaration differs from the implementation. This applies to:
> Date.c: wildinput(), oops(), display(), timeout(), iffy().
> Zdump.c: yeartot()
> Zic.c: dolink(),itsdir(),inrule(),inzone(),inzcont().
Thanks, should be fixed in the attached proposed patch (installed on Github).
> I also found that Visual Studio is the compiler that reports (line numbers corrected to match with your sources):
>
> 1>w:\logic\tz\zdump.c(970): error C4295: 'wday_name' : array is too small to include a terminating null character
> 1>w:\logic\tz\zdump.c(974): error C4295: 'mon_name' : array is too small to include a terminating null character
As mentioned earlier there is no bug there. the compiler is merely complaining
about style, and pacifying the compiler will require making the code a little
larger at run-time; so let's leave the code alone.
> Some other remarks of the previous email (like gmtime_r() does not exist on Windows, and regarding conversion errors from size_t to int) also exist in the previously mentioned 3 source files, but I first like to know your thoughts regarding the mail below before I will provide additional feedback.
For warnings about implicit conversions I wouldn't worry unless there is a real
bug. I don't see why MS-Windows' lack of support for gmtime_r is a problem:
tzcode supplies its own gmtime_r implementation and this implementation should work.
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