[tz] room for one more (char*) cast?

Thu Jun 19 06:38:40 UTC 2014

enh wrote:
> bionic/libc/tzcode/localtime.c:1357:27: warning: assignment discards
> 'const' qualifier from pointer target type [enabled by default]
>       tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];

Sorry, I don't see how that can happen with the current tzcode; 'sp' is 
of type 'struct state *', so sp->chars is of type 'char *', with no 
'const' qualifier.  Maybe the bionic version has a 'const' that the tz 
version doesn't, a 'const' that should be removed?

I did try a "make CFLAGS='$(GCC_DEBUG_FLAGS)'" on Ubuntu 14.04 and found 
some opportunities for improvement and simplification in this area.  I 
pushed the attached patch to the experimental version on github to 
address the problems I found.  This patch is also tested with my build 
of GCC 4.9.0 on Fedora 20.
-------------- next part --------------
From 99544d30aa2d71c13b42ec9109a4eb1ec53b5c4b Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert at cs.ucla.edu>
Date: Wed, 18 Jun 2014 23:25:57 -0700
Subject: [PATCH] Update to pacify recent GCC's static checking.

These changes pacify gcc 4.8.2-19ubuntu1 on Ubuntu 14.04,
and take advantage of recently-added GCC options when compiling
with GCC_DEBUG_FLAGS.
* Makefile (GCC_DEBUG_FLAGS): Add -Wdeclaration-after-statement,
-Wjump-misses-init, -Wsuggest-attribute=format.
* date.c (copyright, sccsid):
* strftime.c (sccsid):
Remove unused vars.
* date.c (main):
* localtime.c (tzparse):
Remove no-longer-needed uses of INITIALIZE; GCC is smart enough to
figure these out on its own now.
* localtime.c (gmtsub): Redo initialization of gmt_is_set to pacify GCC.
Retry malloc next time even if it failed this time.
* private.h, zdump.c (GNUC_or_lint): Remove, as it provoked a GCC
diagnostic about unused macros in some cases.  Instead, just use
'lint'.  All uses removed.
(TZ_DOMAIN): Don't define unless needed, as otherwise it provokes
a GCC diagnostic about unused macros.
* private.h (INITIALIZE): Simplify accordingly.
* NEWS: Document this.
---
 Makefile    |  6 ++++--
 NEWS        |  2 ++
 date.c      | 14 --------------
 localtime.c |  7 ++++---
 private.h   | 28 +++++++---------------------
 strftime.c  |  6 ------
 zdump.c     | 16 +++-------------
 7 files changed, 20 insertions(+), 59 deletions(-)

diff --git a/Makefile b/Makefile
index 0fab5a3..73147fb 100644
--- a/Makefile
+++ b/Makefile
@@ -134,14 +134,16 @@ LDLIBS=
 GCC_DEBUG_FLAGS = -Dlint -g3 -O3 -fno-common -fstrict-aliasing \
 	-Wall -Wextra \
 	-Wbad-function-cast -Wcast-align -Wcast-qual \
-	-Wformat=2 -Winit-self \
+	-Wdeclaration-after-statement \
+	-Wformat=2 -Winit-self -Wjump-misses-init \
 	-Wmissing-declarations -Wmissing-noreturn -Wmissing-prototypes \
 	-Wnested-externs -Wno-address -Wno-cast-qual \
 	-Wno-format-nonliteral -Wno-sign-compare -Wno-sign-conversion \
 	-Wno-type-limits \
 	-Wno-unused-parameter -Woverlength-strings -Wpointer-arith \
 	-Wshadow -Wstrict-prototypes -Wsuggest-attribute=const \
-	-Wsuggest-attribute=noreturn -Wsuggest-attribute=pure -Wtrampolines \
+	-Wsuggest-attribute=format -Wsuggest-attribute=noreturn \
+	-Wsuggest-attribute=pure -Wtrampolines \
 	-Wwrite-strings
 #
 # If you want to use System V compatibility code, add
diff --git a/NEWS b/NEWS
index ed55089..a2d5010 100644
--- a/NEWS
+++ b/NEWS
@@ -15,6 +15,8 @@ Unreleased, experimental changes
     Error diagnostics of 'zic' and 'yearistype' have been reworded so that
     they no longer use ASCII '-' as if it were a dash.
 
+    Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
+
   Changes affecting documentation and commentary
 
     Documentation and commentary now prefer UTF-8 to US-ASCII,
diff --git a/date.c b/date.c
index 42ed16a..a9ca67f 100644
--- a/date.c
+++ b/date.c
@@ -15,16 +15,6 @@
  * WARRANTIES OF MERCHANT[A]BILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
-#ifndef lint
-char copyright[] =
-"@(#) Copyright (c) 1985, 1987, 1988 The Regents of the University of California.\n\
- All rights reserved.\n";
-#endif /* not lint */
-
-#ifndef lint
-static char sccsid[] = "@(#)date.c	4.23 (Berkeley) 9/20/88";
-#endif /* not lint */
-
 #include "private.h"
 #if HAVE_ADJTIME || HAVE_SETTIMEOFDAY
 #include "sys/time.h"	/* for struct timeval, struct timezone */
@@ -99,10 +89,6 @@ main(const int argc, char *argv[])
 	char *			endarg;
 
 	INITIALIZE(dousg);
-	INITIALIZE(minuteswest);
-	INITIALIZE(dsttime);
-	INITIALIZE(adjust);
-	INITIALIZE(t);
 #ifdef LC_ALL
 	(void) setlocale(LC_ALL, "");
 #endif /* defined(LC_ALL) */
diff --git a/localtime.c b/localtime.c
index ec0715d..e2cf5c2 100644
--- a/localtime.c
+++ b/localtime.c
@@ -944,7 +944,6 @@ tzparse(const char *name, register struct state *const sp,
 	register int			load_result;
 	static struct ttinfo		zttinfo;
 
-	INITIALIZE(dstname);
 	stdname = name;
 	if (lastditch) {
 		stdlen = strlen(name);	/* length of standard zone name */
@@ -1368,11 +1367,13 @@ gmtsub(const time_t *const timep, const int_fast32_t offset,
 	register struct tm *	result;
 
 	if (!gmt_is_set) {
-		gmt_is_set = TRUE;
 #ifdef ALL_STATE
 		gmtptr = malloc(sizeof *gmtptr);
+		gmt_is_set = gmtptr != NULL;
+#else
+		gmt_is_set = TRUE;
 #endif /* defined ALL_STATE */
-		if (gmtptr != NULL)
+		if (gmt_is_set)
 			gmtload(gmtptr);
 	}
 	result = timesub(timep, offset, gmtptr, tmp);
diff --git a/private.h b/private.h
index be0c8c2..42bf6e6 100644
--- a/private.h
+++ b/private.h
@@ -352,25 +352,11 @@ static time_t const time_t_max =
 ** INITIALIZE(x)
 */
 
-#ifndef GNUC_or_lint
 #ifdef lint
-#define GNUC_or_lint
-#endif /* defined lint */
-#ifndef lint
-#ifdef __GNUC__
-#define GNUC_or_lint
-#endif /* defined __GNUC__ */
-#endif /* !defined lint */
-#endif /* !defined GNUC_or_lint */
-
-#ifndef INITIALIZE
-#ifdef GNUC_or_lint
-#define INITIALIZE(x)	((x) = 0)
-#endif /* defined GNUC_or_lint */
-#ifndef GNUC_or_lint
-#define INITIALIZE(x)
-#endif /* !defined GNUC_or_lint */
-#endif /* !defined INITIALIZE */
+# define INITIALIZE(x)	((x) = 0)
+#else
+# define INITIALIZE(x)
+#endif
 
 /*
 ** For the benefit of GNU folk...
@@ -386,9 +372,9 @@ static time_t const time_t_max =
 #endif /* !HAVE_GETTEXT */
 #endif /* !defined _ */
 
-#ifndef TZ_DOMAIN
-#define TZ_DOMAIN "tz"
-#endif /* !defined TZ_DOMAIN */
+#if !defined TZ_DOMAIN && defined TZ_DOMAINDIR
+# define TZ_DOMAIN "tz"
+#endif
 
 #if HAVE_INCOMPATIBLE_CTIME_R
 #undef asctime_r
diff --git a/strftime.c b/strftime.c
index e9b60e1..9fbb1ec 100644
--- a/strftime.c
+++ b/strftime.c
@@ -24,12 +24,6 @@
 ** WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
 
-#ifndef LIBC_SCCS
-#ifndef lint
-static const char	sccsid[] = "@(#)strftime.c	5.4 (Berkeley) 3/14/89";
-#endif /* !defined lint */
-#endif /* !defined LIBC_SCCS */
-
 #include "tzfile.h"
 #include "fcntl.h"
 #include "locale.h"
diff --git a/zdump.c b/zdump.c
index 0b74c4c..f3e2a24 100644
--- a/zdump.c
+++ b/zdump.c
@@ -167,16 +167,6 @@ enum { SECSPER400YEARS_FITS = SECSPERLYEAR <= INTMAX_MAX / 400 };
 #include "libintl.h"
 #endif /* HAVE_GETTEXT */
 
-#ifndef GNUC_or_lint
-#ifdef lint
-#define GNUC_or_lint
-#else /* !defined lint */
-#ifdef __GNUC__
-#define GNUC_or_lint
-#endif /* defined __GNUC__ */
-#endif /* !defined lint */
-#endif /* !defined GNUC_or_lint */
-
 #if 2 < __GNUC__ || (__GNUC__ == 2 && 96 <= __GNUC_MINOR__)
 # define ATTRIBUTE_PURE __attribute__ ((__pure__))
 #else
@@ -197,9 +187,9 @@ enum { SECSPER400YEARS_FITS = SECSPERLYEAR <= INTMAX_MAX / 400 };
 #endif /* !HAVE_GETTEXT */
 #endif /* !defined _ */
 
-#ifndef TZ_DOMAIN
-#define TZ_DOMAIN "tz"
-#endif /* !defined TZ_DOMAIN */
+#if !defined TZ_DOMAIN && defined TZ_DOMAINDIR
+# define TZ_DOMAIN "tz"
+#endif
 
 extern char **	environ;
 extern int	getopt(int argc, char * const argv[],
-- 
1.9.1

