Re: Patch: gcc -mno-cygwin support in Boost.Build v2.

From: Vincent N. Virgilio (virgilio_at_[hidden])
Date: 2004-03-31 03:42:35

Hi Volodya,

Comments below.

Vladimir Prus wrote:

> Hi Vincent,
> 
> 
> 
>> rule init ( a1 * : a2 * : a3 * )
>> {
>>+ if $(a2) = nocygwin
>>+ {
>>+ flags gcc.compile OPTIONS : -mno-cygwin ;
>>+ flags gcc.link OPTIONS : -mno-cygwin ;
>>+ }
>>+
>> if $(a1)
>> {
>> local version = $(a1[1]) ;
>>
>>It enables the following line in
>>boost_1_31_0/tools/build/v2/user-config.jam:
>>
>>using gcc : : nocygwin ;
> 
> 
>>I am a complete novice at jam, bjam, and Boost.Build. The above was in
>>support of my first Jamfile, so I figure it must violate at least good
>>style, if nothing else.
> 
> 
> The first question is why "-mno-cygwin" is needed? I guess it causes gcc not 
> to use cygwin runtime? Why do you need this switch?

Right; it eliminates the Cygwin runtime, much like MinGW. Ultimately, I 
want to commercially distribute the build products.

Speaking of MinGW. I tried it first, but couldn't get past a strange 
link error: something about PEX or PE codes. Another fellow posted that 
he fixed same problem by installing the latest MinGW binutils over the 
released MinGW. That didn't work for me. So I took the Cygwin approach.

> 
> 
>>Could an improved version of this be committed to CVS? If not, what are
>>the complications?
> 
> 
> There are two problems:
> 
> 1. It's not possible to specify 'nocygwin' if you also specify the location of 
> the compiler.

There. I knew I was stepping on something.

> 
> 2. I'm not sure that specifying 'nocygwin' in 'using' is good idea. The 
> 'using' util now was used only to specify where to find the compiler, but not 
> what flags it should use. You can put this in your top-level Jamfile:
> 
> project
> : requirements <cflags>-mno-cygwin <linkflags>-mno-cygwin
> ;
> 
> to achieve the same effect. What do you think?

Well then, I misread the mission of the v2/tools directory. I was trying 
to add support for a TOOLS choice, and wound up in the wrong place.

Is there a way to specify the default value of TOOLS in user-config.jam 
or site-config.jam?

Regardless, there is virtue in the above Jamfile flags.

> 
> - Volodya
> 

Thank you,

-- 
Vince