Re: [jamboost] Re: build.bat change to help debug bjam crashes

From: Rene Rivera (grafik666_at_[hidden])
Date: 2003-07-15 11:12:33

[2003-07-15] Vladimir Prus wrote:

>David Abrahams wrote:
>> Beman Dawes <bdawes_at_[hidden]> writes:
>> > At 05:55 PM 7/14/2003, David Abrahams wrote:
>> > >...
>> > >
>> > >Sorry, please try again.
>> >
>> > Ouch! The startup phase before the compiles actually start took 30
>> > minutes, versus maybe 10 or 15 seconds in release mode.
>> >
>> > I wouldn't mind, except it didn't decide to crash this run:-(
>> >
>> > Oh well, maybe we'll get lucky soon:-)
>>
>> OK, I leave "release with debug symbols" to Rene. Rene, I think we
>> ought to consider building that way by default. Emacs does, FWIW.
>
>This leaves us with a question: why such terrible performnace difference.
Bjam 
>has no inline function, nothing extraordinary, just plain old C. And the 
>biggest time confumer in debug build, according to gprof, is
assert_invariant 
>for string, which should be compiled out with NDEBUG. That's strange.

It is strange. All I can think of is that there are some somewhat large
functions, and some files with interrelated functions in it. Perhaps the
global optimizer is doing a good job ;-)

Anyway, I've made some change to build.jam to make it easy to add different
options for such things.

I only added the "--symbols" option support to GCC, so if someone else could
do some of the other toolsets. Or perhaps just the toolset Beman is using,
as I don't have more time to work on this right now.

Enjoy.

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