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6f3a540c37
strict aliasing violations. Essentially, the problem is that large parts of the server were developed in simpler times (last decades, pre C99 standard) when strict aliasing and compilers supporting such optimizations were rare to non-existent. Thus, when compiling the server with a modern compiler that uses strict aliasing rules to perform optimizations, there are several places in the code that might trigger undefined behavior. As evinced by some recent bugs, GCC does a somewhat good of job misoptimizing such code, but on the other hand also gives warnings about suspicious code. One problem is that the warnings aren't always accurate, yet we can't afford to just shut them off as we might miss real cases. False-positive cases are aggravated mostly by casts that are likely to trigger undefined behavior. The solution is to start a cleanup process focused on fixing and reducing the amount of strict-aliasing related warnings produced by GCC and others compilers. A good deal of noise reduction can be achieved by just removing useless casts that are product of historical cruft and are likely to trigger undefined behavior if dereferenced. client/mysql.cc: Remove now-unnecessary casts. Break up large strings. client/mysql_upgrade.c: Remove now-unnecessary casts. client/mysqladmin.cc: Remove now-unnecessary casts. Break up large strings. client/mysqlbinlog.cc: Remove now-unnecessary casts. client/mysqlcheck.c: Remove now-unnecessary casts. client/mysqldump.c: Remove now-unnecessary casts. client/mysqlimport.c: Remove now-unnecessary casts. client/mysqlshow.c: Remove now-unnecessary casts. client/mysqlslap.c: Remove now-unnecessary casts. client/mysqltest.cc: Remove now-unnecessary casts. extra/comp_err.c: Remove now-unnecessary casts. extra/my_print_defaults.c: Remove now-unnecessary casts. Break up large strings. extra/mysql_waitpid.c: Remove now-unnecessary casts. extra/perror.c: Remove now-unnecessary casts. extra/resolve_stack_dump.c: Remove now-unnecessary casts. extra/resolveip.c: Remove now-unnecessary casts. include/my_getopt.h: Use a void pointer type as the opaque type to avoid problems with type incompatibility -- GCC issues warnings when the type name is not type compatible with a operand. As a side bonus, a explicit cast won't be necessary anymore. include/sslopt-longopts.h: Remove now-unnecessary casts. Break up large strings. mysys/my_getopt.c: Update opaque type and introduce a type definition for the argument to my_getopt_register_get_addr. server-tools/instance-manager/options.cc: Remove now-unnecessary casts. sql/mysqld.cc: Remove now-unnecessary casts. Break up large strings. Update mysql_getopt_value prototype (the old prototype was different from the definition anyway). sql/sql_plugin.cc: The type of a pointer to a function must be compatible with the pointed-to function type, otherwise the behavior is undefined. sql/table.cc: The variable buf pointer to pointer to pointer to constant char could improperly alias a incompatible type in call to fix_type_ pointers. Since this was actually dead code, it is simply removed. sql/unireg.cc: Remove call to get_form_pos. The code creates a new FRM file which is always truncated and writes the form position as 0. Hence, no need to retrieve it, we now for sure it is 0. storage/archive/archive_reader.c: Remove now-unnecessary casts. storage/myisam/ft_nlq_search.c: Read weight directly from the buffer. storage/myisam/fulltext.h: Add explanation about the type duality of a key buffer. Add accessor macro to retrieve a FT float value. storage/myisam/mi_test1.c: Remove now-unnecessary casts. storage/myisam/myisam_ftdump.c: Read weight directly from the buffer. storage/myisam/myisamchk.c: Remove now-unnecessary casts. storage/myisam/myisamlog.c: A pointer to char was used to alias a pointer to pointer to unsigned char, thus violating strict aliasing rules. storage/myisam/myisampack.c: Remove now-unnecessary casts. strings/decimal.c: Remove aliasing violation, printing the value is enough for debugging purposes. tests/mysql_client_test.c: Remove now-unnecessary casts.
117 lines
3 KiB
C
117 lines
3 KiB
C
/* Copyright (C) 2003 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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/* Wait until a program dies */
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#ifndef __NETWARE__
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#include <my_global.h>
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#include <m_string.h>
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#include <my_sys.h>
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#include <my_getopt.h>
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#include <signal.h>
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#include <errno.h>
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static const char *VER= "1.1";
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static char *progname;
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static my_bool verbose;
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void usage(void);
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static struct my_option my_long_options[] =
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{
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{"help", '?', "Display this help and exit.", 0, 0, 0, GET_NO_ARG, NO_ARG, 0,
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0, 0, 0, 0, 0},
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{"help", 'I', "Synonym for -?.", 0, 0, 0, GET_NO_ARG, NO_ARG, 0,
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0, 0, 0, 0, 0},
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{"verbose", 'v',
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"Be more verbose. Give a warning, if kill can't handle signal 0.",
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&verbose, &verbose, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
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{"version", 'V', "Print version information and exit.", 0, 0, 0,
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GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
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{ 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
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};
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static my_bool
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get_one_option(int optid, const struct my_option *opt __attribute__((unused)),
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char *argument __attribute__((unused)))
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{
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switch(optid) {
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case 'V':
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printf("%s version %s by Jani Tolonen\n", progname, VER);
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exit(-1);
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case 'I':
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case '?':
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usage();
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}
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return 0;
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}
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int main(int argc, char *argv[])
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{
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int pid= 0, t= 0, sig= 0;
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progname= argv[0];
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if (handle_options(&argc, &argv, my_long_options, get_one_option))
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exit(-1);
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if (!argv[0] || !argv[1] || (pid= atoi(argv[0])) <= 0 ||
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(t= atoi(argv[1])) <= 0)
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usage();
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for (; t > 0; t--)
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{
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if (kill((pid_t) pid, sig))
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{
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if (errno == EINVAL)
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{
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if (verbose)
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printf("WARNING: kill couldn't handle signal 0, using signal 1.\n");
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sig= 1;
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t++;
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continue;
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}
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return 0;
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}
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sleep(1);
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}
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return 1;
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}
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void usage(void)
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{
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printf("%s version %s by Jani Tolonen\n\n", progname, VER);
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printf("usage: %s [options] #pid #time\n\n", progname);
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printf("Description: Waits for a program, which program id is #pid, to\n");
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printf("terminate within #time seconds. If the program terminates within\n");
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printf("this time, or if the #pid no longer exists, value 0 is returned.\n");
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printf("Otherwise 1 is returned. Both #pid and #time must be positive\n");
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printf("integer arguments.\n\n");
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printf("Options:\n");
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my_print_help(my_long_options);
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exit(-1);
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}
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#else
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#include <stdio.h>
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main()
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{
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fprintf(stderr,"This tool has not been ported to NetWare\n");
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return 0;
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}
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#endif /* __NETWARE__ */
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