david@TERA.COM (David Callahan) (11/27/89)
config.g++ sun3-nfp-os4
g++ emits incomplete symbol table information for structures with
anonymous unions.
Example:
----------file: gnu-bug2.c ----------
#include <stream.h>
struct temp {
int i1 ;
union { int a; float b ;} ;
int i2 ;
} ;
main() {
temp t ;
t.a = 4 ;
cout << t.a << "\n" ;
t.b = 2.2 ;
cout << t.b << "\n" ;
}
----------sample compilation--------
g++ -v -o bug -g gnu-bug2.c
gcc version 1.36.1 (based on GCC 1.36)
/usr/local/lib/g++-1.36.1/gcc-cpp -+ -v -undef -D__GNUC__ -D__GNUG__ -D__cplusplus -Dmc68000 -Dsun -Dunix -D__mc68000__ -D__sun__ -D__unix__ -Dmc68020 gnu-bug2.c /usr/tmp/cca02441.cpp
GNU CPP version 1.36
/usr/local/lib/g++-1.36.1/gcc-cc1plus /usr/tmp/cca02441.cpp -quiet -dumpbase gnu-bug2.c -g -version -o /usr/tmp/cca02441.s
GNU C++ version 1.36.1 (based on GCC 1.36) (68k, MIT syntax) compiled by GNU C version 1.36.
default target switches: -m68020 -mc68020 -mbitfield
/usr/local/lib/g++-1.36.1/gcc-as -mc68020 -o gnu-bug2.o /usr/tmp/cca02441.s
/usr/local/lib/g++-1.36.1/gcc-ld -o bug -e start -dc -dp -Bstatic /lib/crt0.o /lib/Fcrt1.o gnu-bug2.o -lg++ /usr/local/lib/g++-1.36.1/gcc-gnulib -lg -lc
---------- Sample (correct) exection ------------
dactyl% bug
4
2.2
dactyl%
---------- Partial debugging information: ------------
dactyl% nm -a bug | grep temp
00000000 - 00 0000 LSYM temp:T211
00000000 - 00 0000 LSYM temp:t211
00000000 - 00 0000 LSYM temp:t211=s12i1:/21,0,32;i2:/21,64,32;;~;
dactyl%
-------------- Sample debugging session ------------
dactyl% gdb bug
gdb bug
GDB 3.4, Copyright (C) 1989 Free Software Foundation, Inc.
There is ABSOLUTELY NO WARRANTY for GDB; type "info warranty" for details.
GDB is free software and you are welcome to distribute copies of it
under certain conditions; type "info copying" to see the conditions.
Reading symbol data from /home/tera/david/Cfront/bug...done.
Type "help" for a list of commands.
(gdb) break main
Reading in symbols for gnu-bug2.c...done.
Breakpoint 1 at 0x22be: file gnu-bug2.c, line 8.
(gdb) run
Starting program: /home/tera/david/Cfront/bug
Bpt 1, main () (gnu-bug2.c line 10)
10 t.a = 4 ;
(gdb) whatis t
type = temp
(gdb) p t
$1 = {i1 = 0, i2 = 0}
(gdb) p t.a
there is no field named a
(gdb) quit
The program is running. Quit anyway? (y or n) y
dactyl%
----------
David Callahan david@tera.com
Tera Computer Co. 400 North 34th Street, Suite 300 Seattle WA, 98103