mirror of
https://github.com/MariaDB/server.git
synced 2025-01-17 20:42:30 +01:00
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.
328 lines
7.4 KiB
C
328 lines
7.4 KiB
C
/* Copyright (C) 2000 MySQL AB
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; version 2 of the License.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
|
|
|
|
/* Resolve numeric stack dump produced by mysqld 3.23.30 and later
|
|
versions into symbolic names. By Sasha Pachev <sasha@mysql.com>
|
|
*/
|
|
|
|
#define DONT_USE_RAID
|
|
#include <my_global.h>
|
|
#include <m_ctype.h>
|
|
#include <my_sys.h>
|
|
#include <m_string.h>
|
|
#include <mysql_version.h>
|
|
#include <errno.h>
|
|
#include <my_getopt.h>
|
|
|
|
#define INIT_SYM_TABLE 4096
|
|
#define INC_SYM_TABLE 4096
|
|
#define MAX_SYM_SIZE 128
|
|
#define DUMP_VERSION "1.4"
|
|
#define HEX_INVALID (uchar)255
|
|
|
|
typedef ulong my_long_addr_t ; /* at some point, we need to fix configure
|
|
* to define this for us
|
|
*/
|
|
|
|
typedef struct sym_entry
|
|
{
|
|
char symbol[MAX_SYM_SIZE];
|
|
uchar* addr;
|
|
} SYM_ENTRY;
|
|
|
|
|
|
static char* dump_fname = 0, *sym_fname = 0;
|
|
static DYNAMIC_ARRAY sym_table; /* how do you like this , static DYNAMIC ? */
|
|
static FILE* fp_dump, *fp_sym = 0, *fp_out;
|
|
|
|
static struct my_option my_long_options[] =
|
|
{
|
|
{"help", 'h', "Display this help and exit.",
|
|
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
|
|
{"version", 'V', "Output version information and exit.",
|
|
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
|
|
{"symbols-file", 's', "Use specified symbols file.", &sym_fname,
|
|
&sym_fname, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
|
|
{"numeric-dump-file", 'n', "Read the dump from specified file.",
|
|
&dump_fname, &dump_fname, 0, GET_STR, REQUIRED_ARG,
|
|
0, 0, 0, 0, 0, 0},
|
|
{ 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
|
|
};
|
|
|
|
|
|
static void verify_sort();
|
|
|
|
|
|
#include <help_start.h>
|
|
|
|
static void print_version(void)
|
|
{
|
|
printf("%s Ver %s Distrib %s, for %s (%s)\n",my_progname,DUMP_VERSION,
|
|
MYSQL_SERVER_VERSION,SYSTEM_TYPE,MACHINE_TYPE);
|
|
}
|
|
|
|
|
|
static void usage()
|
|
{
|
|
print_version();
|
|
printf("MySQL AB, by Sasha Pachev\n");
|
|
printf("This software comes with ABSOLUTELY NO WARRANTY\n\n");
|
|
printf("Resolve numeric stack strace dump into symbols.\n\n");
|
|
printf("Usage: %s [OPTIONS] symbols-file [numeric-dump-file]\n",
|
|
my_progname);
|
|
my_print_help(my_long_options);
|
|
my_print_variables(my_long_options);
|
|
printf("\n\
|
|
The symbols-file should include the output from: 'nm --numeric-sort mysqld'.\n\
|
|
The numeric-dump-file should contain a numeric stack trace from mysqld.\n\
|
|
If the numeric-dump-file is not given, the stack trace is read from stdin.\n");
|
|
}
|
|
|
|
#include <help_end.h>
|
|
|
|
|
|
static void die(const char* fmt, ...)
|
|
{
|
|
va_list args;
|
|
va_start(args, fmt);
|
|
fprintf(stderr, "%s: ", my_progname);
|
|
vfprintf(stderr, fmt, args);
|
|
fprintf(stderr, "\n");
|
|
va_end(args);
|
|
exit(1);
|
|
}
|
|
|
|
|
|
static my_bool
|
|
get_one_option(int optid, const struct my_option *opt __attribute__((unused)),
|
|
char *argument __attribute__((unused)))
|
|
{
|
|
switch(optid) {
|
|
case 'V':
|
|
print_version();
|
|
exit(0);
|
|
case '?':
|
|
usage();
|
|
exit(0);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int parse_args(int argc, char **argv)
|
|
{
|
|
int ho_error;
|
|
|
|
if ((ho_error=handle_options(&argc, &argv, my_long_options, get_one_option)))
|
|
exit(ho_error);
|
|
|
|
/*
|
|
The following code is to make the command compatible with the old
|
|
version that required one to use the -n and -s options
|
|
*/
|
|
|
|
if (argc == 2)
|
|
{
|
|
sym_fname= argv[0];
|
|
dump_fname= argv[1];
|
|
}
|
|
else if (argc == 1)
|
|
{
|
|
if (!sym_fname)
|
|
sym_fname = argv[0];
|
|
else if (!dump_fname)
|
|
dump_fname = argv[0];
|
|
else
|
|
{
|
|
usage();
|
|
exit(1);
|
|
}
|
|
}
|
|
else if (argc != 0 || !sym_fname)
|
|
{
|
|
usage();
|
|
exit(1);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void open_files()
|
|
{
|
|
fp_out = stdout;
|
|
fp_dump = stdin;
|
|
|
|
if (dump_fname && !(fp_dump = my_fopen(dump_fname, O_RDONLY, MYF(MY_WME))))
|
|
die("Could not open %s", dump_fname);
|
|
/* if name not given, assume stdin*/
|
|
|
|
if (!sym_fname)
|
|
die("Please run nm --numeric-sort on mysqld binary that produced stack \
|
|
trace dump and specify the path to it with -s or --symbols-file");
|
|
if (!(fp_sym = my_fopen(sym_fname, O_RDONLY, MYF(MY_WME))))
|
|
die("Could not open %s", sym_fname);
|
|
|
|
}
|
|
|
|
static uchar hex_val(char c)
|
|
{
|
|
uchar l;
|
|
if (my_isdigit(&my_charset_latin1,c))
|
|
return c - '0';
|
|
l = my_tolower(&my_charset_latin1,c);
|
|
if (l < 'a' || l > 'f')
|
|
return HEX_INVALID;
|
|
return (uchar)10 + ((uchar)c - (uchar)'a');
|
|
}
|
|
|
|
static my_long_addr_t read_addr(char** buf)
|
|
{
|
|
uchar c;
|
|
char* p = *buf;
|
|
my_long_addr_t addr = 0;
|
|
|
|
while((c = hex_val(*p++)) != HEX_INVALID)
|
|
addr = (addr << 4) + c;
|
|
|
|
*buf = p;
|
|
return addr;
|
|
}
|
|
|
|
static int init_sym_entry(SYM_ENTRY* se, char* buf)
|
|
{
|
|
char* p, *p_end;
|
|
se->addr = (uchar*)read_addr(&buf);
|
|
|
|
if (!se->addr)
|
|
return -1;
|
|
while (my_isspace(&my_charset_latin1,*buf++))
|
|
/* empty */;
|
|
|
|
while (my_isspace(&my_charset_latin1,*buf++))
|
|
/* empty - skip more space */;
|
|
--buf;
|
|
/* now we are on the symbol */
|
|
for (p = se->symbol, p_end = se->symbol + sizeof(se->symbol) - 1;
|
|
*buf != '\n' && *buf && p < p_end; ++buf,++p)
|
|
*p = *buf;
|
|
*p = 0;
|
|
if (!strcmp(se->symbol, "gcc2_compiled."))
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
static void init_sym_table()
|
|
{
|
|
char buf[512];
|
|
if (my_init_dynamic_array(&sym_table, sizeof(SYM_ENTRY), INIT_SYM_TABLE,
|
|
INC_SYM_TABLE))
|
|
die("Failed in my_init_dynamic_array() -- looks like out of memory problem");
|
|
|
|
while (fgets(buf, sizeof(buf), fp_sym))
|
|
{
|
|
SYM_ENTRY se;
|
|
if (init_sym_entry(&se, buf))
|
|
continue;
|
|
if (insert_dynamic(&sym_table, (uchar*)&se))
|
|
die("insert_dynamic() failed - looks like we are out of memory");
|
|
}
|
|
|
|
verify_sort();
|
|
}
|
|
|
|
static void clean_up()
|
|
{
|
|
delete_dynamic(&sym_table);
|
|
}
|
|
|
|
static void verify_sort()
|
|
{
|
|
uint i;
|
|
uchar* last = 0;
|
|
|
|
for (i = 0; i < sym_table.elements; i++)
|
|
{
|
|
SYM_ENTRY se;
|
|
get_dynamic(&sym_table, (uchar*)&se, i);
|
|
if (se.addr < last)
|
|
die("sym table does not appear to be sorted, did you forget \
|
|
--numeric-sort arg to nm? trouble addr = %p, last = %p", se.addr, last);
|
|
last = se.addr;
|
|
}
|
|
}
|
|
|
|
|
|
static SYM_ENTRY* resolve_addr(uchar* addr, SYM_ENTRY* se)
|
|
{
|
|
uint i;
|
|
get_dynamic(&sym_table, (uchar*)se, 0);
|
|
if (addr < se->addr)
|
|
return 0;
|
|
|
|
for (i = 1; i < sym_table.elements; i++)
|
|
{
|
|
get_dynamic(&sym_table, (uchar*)se, i);
|
|
if (addr < se->addr)
|
|
{
|
|
get_dynamic(&sym_table, (uchar*)se, i - 1);
|
|
return se;
|
|
}
|
|
}
|
|
|
|
return se;
|
|
}
|
|
|
|
|
|
static void do_resolve()
|
|
{
|
|
char buf[1024], *p;
|
|
while (fgets(buf, sizeof(buf), fp_dump))
|
|
{
|
|
/* skip bracket */
|
|
p= (p= strchr(buf, '[')) ? p+1 : buf;
|
|
/* skip space */
|
|
while (my_isspace(&my_charset_latin1,*p))
|
|
++p;
|
|
|
|
if (*p++ == '0' && *p++ == 'x')
|
|
{
|
|
SYM_ENTRY se ;
|
|
uchar* addr = (uchar*)read_addr(&p);
|
|
if (resolve_addr(addr, &se))
|
|
fprintf(fp_out, "%p %s + %d\n", addr, se.symbol,
|
|
(int) (addr - se.addr));
|
|
else
|
|
fprintf(fp_out, "%p (?)\n", addr);
|
|
|
|
}
|
|
else
|
|
{
|
|
fputs(buf, fp_out);
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
int main(int argc, char** argv)
|
|
{
|
|
MY_INIT(argv[0]);
|
|
parse_args(argc, argv);
|
|
open_files();
|
|
init_sym_table();
|
|
do_resolve();
|
|
clean_up();
|
|
return 0;
|
|
}
|