Re: howto configure so that CFLAGS='-g3 -O0' in gcc/Makefile?

[Andrew Haley <aph at redhat dot com>]

Larry Evans wrote:
> On 06/30/09 12:59, Jonathan Wakely wrote:
>> 2009/6/30 Larry Evans:
>>> So... I read `man gcc` which claimed passing "CFLAGS=<options>" on the
>>> command line is how to do this.  Well, since <options> in my case was
>>> '-g3 -O0' I had to pass it as CFLAGS='-g3 oO0'.
>>
>> http://gcc.gnu.org/install/build.html
>>
>> If you wish to use non-default GCC flags when compiling the stage2 and
>> stage3 compilers, set BOOT_CFLAGS on the command line when doing
>> `make'.
>>
> 
> Thanks Jonathan.
> 
> I also noticed the same info here:
> 
>   http://gcc.gnu.org/wiki/DebuggingGCC
> 
> Well, I think what I did that; however, when I got into gdb, I got this:
> 
> #{##################################################
> Current directory is ~/download/gcc/4.4-20090630/build/gcc/
> GNU gdb 6.8-debian
> Copyright (C) 2008 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later
> <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-linux-gnu"...
> Breakpoint 1 at 0x411136: file
> /home/evansl/download/gcc/4.4-20090630/build/../src/gcc/gcc.c, line 7008.
> Function "internal_error" not defined.
> Make breakpoint pending on future shared library load? (y or [n])
> [answered N; input not from terminal]
> Function "exit" not defined.
> Make breakpoint pending on future shared library load? (y or [n])
> [answered N; input not from terminal]
> Function "abort" not defined.
> Make breakpoint pending on future shared library load? (y or [n])
> [answered N; input not from terminal]
> No source file named parser.c.
> Make breakpoint pending on future shared library load? (y or [n])
> [answered N; input not from terminal]
> /home/evansl/download/gcc/4.4-20090630/build/gcc/.gdbinit:13: Error in
> sourced command file:
> No symbol "expand_location" in current context.
> (gdb) run
> Starting program: /home/evansl/download/gcc/4.4-20090630/build/gcc/g++
> -std=gnu++0x bug.dir/bug.cpp
> warning: failed to reevaluate condition for breakpoint 1: No symbol
> "expand_location" in current context.
> warning: failed to reevaluate condition for breakpoint 1: No symbol
> "expand_location" in current context.
> g++: error trying to exec 'cc1plus': execvp: No such file or directory
> 
> Program exited with code 01.
> (gdb)
> #}##################################################
> 
> What am I doing wrong now?  Should I do `make install` also?
> OOPS, tried that and didn't help.

Are you trying to debug the compiler, or the compiler driver?

If the compiler, debug cc1 or cc1plus, not gcc.

If the driver, pass -B/path/to/build/gcc/ to gcc.

Andrew.