Currently, the "official" (by way of being de-facto) directory structure for a build tree is 'PCBuild/.' for x86 builds and 'PCBuild/amd64' for x64 platforms. I believe this might cause problems for people trying to port their applications to 64bit platforms. My proposal is that we change this subtly - that both 'PCBuild/x86', and 'PCBuild/amd64' exist, while 'PCBuild/.' is always the 'native' platform - ie, that 'PCBuild/.' be a copy of one of the platform subdirectories.
Can you explain what you mean by "native platform"? I usually perform cross-builds for amd64, so would then this directory remain empty?
The rationale is fairly simple: I'm quite certain that this new directory layout will break existing "native only" build processes (ie, those that aren't aware of cross-compilation). I'm quite certain that Mozilla will break, for example, and no cross-compilation process exists that I am aware of. Existing build tools already know about the PCBuild directory, and are focused almost exclusively towards native compilation - all such tools on non-x86 platforms are currently broken.
The reverse may also be true: some tools may expect PCbuild to contain always x86 binaries, even on AMD64 - as they don't support non-x86 at all. Those tools might break if PCbuild suddenly starts containing AMD64 binaries. If this is all about *just* Mozilla, then I'd be much more in favour than if it was for some theoretical package. So if Mozilla builds with that kind of setup, and works correctly - go for it. If you have to fix Mozilla anyway, consider fixing it so it looks in the amd64 directory. Regards, Martin