[LLVMdev] Built LLVM 1.8 on VC8, invalid iterator issue/fix, some questions

[Morten Ofstad]

srhilber at ncsu.edu wrote:
> Hello,
> 
> I've managed to get LLVM 1.8 to build properly with MSVC8 with some
> effort. Most of the changes necessary were very minor C++ usage issues;
> for instance, VC8 can't deal with prototyping something that's really a
> class as 'struct Foo;' or vice versa (it creates issues with matching
> function signatures during linking.) Additionally, I had to do quite a few
> updates to the included VC7.1 project file after doing an upgrade to a VC8
> project (the project file appears to be somewhat out of date.)

I did the same thing a while ago, and submitted some patches. The problem with structs and classes crop up every now and 
again when someone adds new code, I fixed lots of these when LLVM was first ported to VC7 (which has the same issue).

> However, there appears to be some issue with using an invalid iterator in
> the X86 backend that appears when I build with VC8. I've managed to fix it
> by duplicating the std::vector in question before iterating through it,
> but I'm too new to the code to be able to say whether it's the "right"
> fix.

The VC8 STL implementation is basically asserting everything when running in debug mode - I submitted patches for an 
issue where it checks that the operator < is antisymmetric ( given a < b it would assert(! b < a) ) which doesn't work 
if the operator is implemented so it can only compare your class to an int and not the other way around. Sometimes it's 
a bit too restrictive, but usually the code it complains about will benefit from a cleanup anyway.

You were asking if a VC8 port is desired, and the answer is definitly 'yes' - patches for VC8 have already been accepted 
and at least I'm using the VC8 port (... of release 1.5) I will upgrade to the current release when I have some free 
time, but the 1.5 release is working fine for us so at the moment it's one of those "don't fix what isn't broken" 
situations.

m.