MySQL Bugs: #88634: Compile warning on 5.6.38 optimized build

Bug #88634	Compile warning on 5.6.38 optimized build
Submitted:	24 Nov 2017 4:26	Modified:	19 Nov 2018 15:12
Reporter:	Roel Van de Paar	Email Updates:
Status:	Won't fix	Impact on me:	None
Category:	MySQL Server: Compiling	Severity:	S3 (Non-critical)
Version:	5.6.38	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
[ 76%] Building CXX object sql/CMakeFiles/sql.dir/sql_planner.cc.o
/git/mysql-server-copy_opt/sql/sql_planner.cc: In member function ‘void Optimize_table_order::best_access_path(JOIN_TAB*, table_map, uint, bool, double, POSITION*, POSITION*)’:
/git/mysql-server-copy_opt/sql/sql_planner.cc:335:52: warning: ‘loose_scan_opt.Loose_scan_opt::best_max_loose_keypart’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       pos->loosescan_parts= best_max_loose_keypart + 1;
                                                    ^
/git/mysql-server-copy_opt/sql/sql_planner.cc:431:18: note: ‘loose_scan_opt.Loose_scan_opt::best_max_loose_keypart’ was declared here
   Loose_scan_opt loose_scan_opt;
                  ^
/git/mysql-server-copy_opt/sql/sql_planner.cc:333:54: warning: ‘loose_scan_opt.Loose_scan_opt::best_loose_scan_start_key’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       pos->key=             best_loose_scan_start_key;
                                                      ^
/git/mysql-server-copy_opt/sql/sql_planner.cc:431:18: note: ‘loose_scan_opt.Loose_scan_opt::best_loose_scan_start_key’ was declared here
   Loose_scan_opt loose_scan_opt;
                  ^
/git/mysql-server-copy_opt/sql/sql_planner.cc:332:52: warning: ‘loose_scan_opt.Loose_scan_opt::best_loose_scan_records’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       pos->records_read=    best_loose_scan_records;
                                                    ^
/git/mysql-server-copy_opt/sql/sql_planner.cc:431:18: note: ‘loose_scan_opt.Loose_scan_opt::best_loose_scan_records’ was declared here
   Loose_scan_opt loose_scan_opt;
                  ^
/git/mysql-server-copy_opt/sql/sql_planner.cc:334:48: warning: ‘loose_scan_opt.Loose_scan_opt::best_loose_scan_key’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       pos->loosescan_key=   best_loose_scan_key;
                                                ^
/git/mysql-server-copy_opt/sql/sql_planner.cc:431:18: note: ‘loose_scan_opt.Loose_scan_opt::best_loose_scan_key’ was declared here
   Loose_scan_opt loose_scan_opt;
                  ^
[ 76%] Building CXX object sql/CMakeFiles/sql.dir/sql_plugin.cc.o
[ 76%] Building CXX object sql/CMakeFiles/sql.dir/sql_prepare.cc.o

How to repeat:
Centos 7 x64, 7.4.1708 (not sure if it matters)

cmake . -DWITH_ZLIB=system -DBUILD_CONFIG=mysql_release -DFEATURE_SET=community -DWITH_EMBEDDED_SERVER=OFF -DENABLE_DOWNLOADS=1 -DDOWNLOAD_BOOST=1 -DWITH_BOOST=/tmp -DWITH_SSL=system -DWITH_PAM=ON

Hello Roel,

Thank you for the report.

Thanks,
Umesh

https://bugs.mysql.com/bug.php?id=77637

Posted by developer:
 
Thank you for bringing this to our attention! Such issues, including this one, are fixed as they are encountered but only on the latest development branch (trunk). And as such fixes are not normally backported to GA releases, we need to close this bug.