mirror of
https://github.com/MariaDB/server.git
synced 2025-01-16 12:02:42 +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.
93 lines
3.6 KiB
C
93 lines
3.6 KiB
C
/* Copyright (C) 2002-2004 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 */
|
|
|
|
#ifndef _my_getopt_h
|
|
#define _my_getopt_h
|
|
|
|
C_MODE_START
|
|
|
|
#define GET_NO_ARG 1
|
|
#define GET_BOOL 2
|
|
#define GET_INT 3
|
|
#define GET_UINT 4
|
|
#define GET_LONG 5
|
|
#define GET_ULONG 6
|
|
#define GET_LL 7
|
|
#define GET_ULL 8
|
|
#define GET_STR 9
|
|
#define GET_STR_ALLOC 10
|
|
#define GET_DISABLED 11
|
|
#define GET_ENUM 12
|
|
#define GET_SET 13
|
|
#define GET_DOUBLE 14
|
|
|
|
#define GET_ASK_ADDR 128
|
|
#define GET_TYPE_MASK 127
|
|
|
|
enum get_opt_arg_type { NO_ARG, OPT_ARG, REQUIRED_ARG };
|
|
|
|
struct st_typelib;
|
|
|
|
struct my_option
|
|
{
|
|
const char *name; /* Name of the option */
|
|
int id; /* unique id or short option */
|
|
const char *comment; /* option comment, for autom. --help */
|
|
void *value; /* The variable value */
|
|
void *u_max_value; /* The user def. max variable value */
|
|
struct st_typelib *typelib; /* Pointer to possible values */
|
|
ulong var_type; /* Must match the variable type */
|
|
enum get_opt_arg_type arg_type;
|
|
longlong def_value; /* Default value */
|
|
longlong min_value; /* Min allowed value */
|
|
longlong max_value; /* Max allowed value */
|
|
longlong sub_size; /* Subtract this from given value */
|
|
long block_size; /* Value should be a mult. of this */
|
|
void *app_type; /* To be used by an application */
|
|
};
|
|
|
|
typedef my_bool (*my_get_one_option)(int, const struct my_option *, char *);
|
|
typedef void (*my_error_reporter)(enum loglevel level, const char *format, ...);
|
|
/**
|
|
Used to retrieve a reference to the object (variable) that holds the value
|
|
for the given option. For example, if var_type is GET_UINT, the function
|
|
must return a pointer to a variable of type uint. A argument is stored in
|
|
the location pointed to by the returned pointer.
|
|
*/
|
|
typedef void *(*my_getopt_value)(const char *, uint, const struct my_option *,
|
|
int *);
|
|
|
|
extern char *disabled_my_option;
|
|
extern my_bool my_getopt_print_errors;
|
|
extern my_bool my_getopt_skip_unknown;
|
|
extern my_error_reporter my_getopt_error_reporter;
|
|
|
|
extern int handle_options (int *argc, char ***argv,
|
|
const struct my_option *longopts, my_get_one_option);
|
|
extern void my_cleanup_options(const struct my_option *options);
|
|
extern void my_print_help(const struct my_option *options);
|
|
extern void my_print_variables(const struct my_option *options);
|
|
extern void my_getopt_register_get_addr(my_getopt_value);
|
|
|
|
ulonglong getopt_ull_limit_value(ulonglong num, const struct my_option *optp,
|
|
my_bool *fix);
|
|
longlong getopt_ll_limit_value(longlong, const struct my_option *,
|
|
my_bool *fix);
|
|
my_bool getopt_compare_strings(const char *s, const char *t, uint length);
|
|
|
|
C_MODE_END
|
|
|
|
#endif /* _my_getopt_h */
|
|
|