Re: [BBv2] [msvc] Remove call to vcvars.bat

From: Reece Dunn (msclrhd_at_[hidden])
Date: 2005-10-04 01:27:35

David Abrahams wrote:
> Reece Dunn <msclrhd_at_[hidden]> writes:
> 
>>The attached patch is the first attempt at removing the need to call 
>>vcvars.bat.
> 
> Why is that a good thing?

This is a good thing because:

* We remove the need to invoke cmd / call a batch file, which would 
(should) give a performance increase as we are no longer executing 
vcvars.bat each time the compiler or linker is invoked.

* The user doesn't need to specify the vcvars.bat for 
msvc-8.0/x86-amd64 as this is a known configuration, so the user just says:

using msvc : 8.0 ;

and:

$ bjam release msvc-8.0 architecture=ia64

This is a bad thing because:

* The user can no longer pass a custom vcvars.bat to set up, for 
example, embedded VC++. Note, though, that the setup should be such that 
these configurations should work - maybe we need to pass the path, 
include and library lists instead of the setup/vcvars, or use a default 
generic setup configuration.

* How do we tell bjam that embedded VC++ 4.0 is VC 6.0 for arm/sh?

* There is currently a slight load-time delay that I believe is due to 
the memory allocation issues that Rene has mentioned. When this is 
improved, this load-time should decrease. However, there should be a 
slight increase in each compile/link call that would even out the 
load-time delay on a large build.

- Reece