Something

mv -f .deps/password.Tpo .deps/password.Po
i686-pc-linux-gnu-g++ -DMYSQL_SERVER -DDEFAULT_MYSQL_HOME="\"/usr\"" -DDATADIR="\"/var/lib/mysql\"" -DSHAREDIR="\"/usr/share/mysql\"" -DHAVE_CONFIG_H -I. -I.. -I../bdb/build_unix -I../innobase/include -I../innobase/include -I../include -I../include -I../regex -I.     -DDBUG_OFF -O2 -march=i686 -pipe -DHAVE_ERRNO_AS_DEFINE=1 -fno-exceptions -fno-strict-aliasing -felide-constructors -fno-rtti -fno-implicit-templates   -fno-implicit-templates -fno-exceptions -fno-rtti -MT hash_filo.o -MD -MP -MF .deps/hash_filo.Tpo -c -o hash_filo.o hash_filo.cc
mv -f .deps/sql_map.Tpo .deps/sql_map.Po
i686-pc-linux-gnu-g++ -DMYSQL_SERVER -DDEFAULT_MYSQL_HOME="\"/usr\"" -DDATADIR="\"/var/lib/mysql\"" -DSHAREDIR="\"/usr/share/mysql\"" -DHAVE_CONFIG_H -I. -I.. -I../bdb/build_unix -I../innobase/include -I../innobase/include -I../include -I../include -I../regex -I.     -DDBUG_OFF -O2 -march=i686 -pipe -DHAVE_ERRNO_AS_DEFINE=1 -fno-exceptions -fno-strict-aliasing -felide-constructors -fno-rtti -fno-implicit-templates   -fno-implicit-templates -fno-exceptions -fno-rtti -MT hostname.o -MD -MP -MF .deps/hostname.Tpo -c -o hostname.o hostname.cc
mv -f .deps/hash_filo.Tpo .deps/hash_filo.Po
i686-pc-linux-gnu-g++ -DMYSQL_SERVER -DDEFAULT_MYSQL_HOME="\"/usr\"" -DDATADIR="\"/var/lib/mysql\"" -DSHAREDIR="\"/usr/share/mysql\"" -DHAVE_CONFIG_H -I. -I.. -I../bdb/build_unix -I../innobase/include -I../innobase/include -I../include -I../include -I../regex -I.     -DDBUG_OFF -O2 -march=i686 -pipe -DHAVE_ERRNO_AS_DEFINE=1 -fno-exceptions -fno-strict-aliasing -felide-constructors -fno-rtti -fno-implicit-templates   -fno-implicit-templates -fno-exceptions -fno-rtti -MT set_var.o -MD -MP -MF .deps/set_var.Tpo -c -o set_var.o set_var.cc
mv -f .deps/mysqld.Tpo .deps/mysqld.Po
i686-pc-linux-gnu-g++ -DMYSQL_SERVER -DDEFAULT_MYSQL_HOME="\"/usr\"" -DDATADIR="\"/var/lib/mysql\"" -DSHAREDIR="\"/usr/share/mysql\"" -DHAVE_CONFIG_H -I. -I.. -I../bdb/build_unix -I../innobase/include -I../innobase/include -I../include -I../include -I../regex -I.     -DDBUG_OFF -O2 -march=i686 -pipe -DHAVE_ERRNO_AS_DEFINE=1 -fno-exceptions -fno-strict-aliasing -felide-constructors -fno-rtti -fno-implicit-templates   -fno-implicit-templates -fno-exceptions -fno-rtti -MT sql_parse.o -MD -MP -MF .deps/sql_parse.Tpo -c -o sql_parse.o sql_parse.cc
mv -f .deps/hostname.Tpo .deps/hostname.Po
/bin/sed -e 's/__attribute__ ((__unused__))//' sql_yacc.cc > sql_yacc.cc-new
/bin/mv sql_yacc.cc-new sql_yacc.cc
Note: The following compile may take a long time.
If it fails, re-run configure with --with-low-memory
i686-pc-linux-gnu-g++ -DMYSQL_SERVER -DDEFAULT_MYSQL_HOME="\"/usr\"" -DDATADIR="\"/var/lib/mysql\"" -DSHAREDIR="\"/usr/share/mysql\"" -DHAVE_CONFIG_H -I. -I.. -I../bdb/build_unix -I../innobase/include -I../innobase/include -I../include -I../include -I../regex -I.     -DDBUG_OFF -O2 -march=i686 -pipe -DHAVE_ERRNO_AS_DEFINE=1 -fno-exceptions -fno-strict-aliasing -felide-constructors -fno-rtti -fno-implicit-templates   -fno-implicit-templates -fno-exceptions -fno-rtti -fno-inline -c sql_yacc.cc
{standard input}: Assembler messages:
{standard input}:9256: Warning: end of file not at end of a line; newline inserted
{standard input}:9689: Error: unbalanced parenthesis in operand 1.
i686-pc-linux-gnu-g++: Internal error: Killed (program cc1plus)
Please submit a full bug report.
See <URL:http://bugs.gentoo.org/> for instructions.
make[4]: *** [sql_yacc.o] Error 1
make[4]: *** Waiting for unfinished jobs....
mv -f .deps/sql_parse.Tpo .deps/sql_parse.Po
mv -f .deps/set_var.Tpo .deps/set_var.Po
make[4]: Leaving directory `/var/tmp/portage/dev-db/mysql-5.0.40/work/mysql/sql'
make[3]: *** [all-recursive] Error 1
make[3]: Leaving directory `/var/tmp/portage/dev-db/mysql-5.0.40/work/mysql/sql'
make[2]: *** [all] Error 2
make[2]: Leaving directory `/var/tmp/portage/dev-db/mysql-5.0.40/work/mysql/sql'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/var/tmp/portage/dev-db/mysql-5.0.40/work/mysql'
make: *** [all] Error 2

!!! ERROR: dev-db/mysql-5.0.40 failed.
Call stack:
  ebuild.sh, line 1614:   Called dyn_compile
  ebuild.sh, line 971:   Called qa_call 'src_compile'
  environment, line 4431:   Called src_compile
  ebuild.sh, line 1304:   Called mysql_src_compile
  mysql.eclass, line 605:   Called die