Re: declaring and defining virtual function in header file

[Peter.Schauer]

> c++ -O2 lib.cpp -c

This line is causing the problem.
Try
c++ -g -O2 lib.cpp -c
and you should get better results.

GDB cannot display the proper line number for modules compiled without -g.
GDB also does not step into functions compiled without -g and executes
a `next' (step over) instead, which explains why you end up back in `main'
after a step into `problem'.

> Hi!
> 
> I think i found a very strange problem/bug:
> 
> (using 
> -gdb version 4.16, 418 and to 5.0 configured for 'i586-pc-linux-gnu' and  
> solaris
> - gcc version 2.95.2 19991024 (release)
> )
> 
> i wonder if it is an bug of gdb or gcc. (Or maybe it isn't a bug???)
> 
> Here's an example: (The very important part is in Class.h)
> use the following commands on the files enclosed at the end of this mail:
> 
> c++ -O2 lib.cpp -c
> c++ -g -c cctest.cpp 
> c++ -o ttt cctest.o lib.o
> 
> Execute binary 'ttt'. The output looks like this:
> | 0x80485e0
> | 0x8048660
> | this is function no_problem
> | this is function problem
> 
> 
> 
> now start gdb ('gdb ttt')
> use the 'info line *' command on both of the addresses. The output looks 
> like 
> this:
> 
> | (gdb) info line * 0x80485e0
> | Line 6 of "cctest.cpp" starts at address 0x80485e0 <no_problem__Fv>
> |    and ends at 0x80485e6 <no_problem__Fv+6>.
> 
> 
> 
> Everything's fine with this information
> 
> | (gdb) info line * 0x8048660
> | Line 23 of "cctest.cpp" starts at address 0x8048652 <main+66>
> |    and ends at 0x80486c0 <__tf4Test>.  
> 
> 
> 
> Oops: There is wrong line,file and symbol name information for the second 
> address. 
> try to step into the function 'problem'. 
> 
> without the keyword 'virtual' or/and without the function body of 
> Test::cctest() everything's fine! What's wrong?
> 
> Best regards
> Henning Moll

-- 
Peter Schauer                   address@hidden