[lldb-dev] [LLVMdev] Reusing LLVM Mips instruction info in lldb

[Daniel Sanders]

> -----Original Message-----
> From: David Chisnall [mailto:David.Chisnall at cl.cam.ac.uk]
> Sent: 26 February 2015 17:36
> To: Daniel Sanders
> Cc: Reid Kleckner; Eric Christopher; Keno Fischer; lldb-dev; LLVM Developers
> Mailing List
> Subject: Re: [LLVMdev] [lldb-dev] Reusing LLVM Mips instruction info in lldb
> 
> On 26 Feb 2015, at 17:20, Daniel Sanders <Daniel.Sanders at imgtec.com>
> wrote:
> >
> > > Would you have any objections to making
> lib/Target/*/MCTargetDesc/*MCTargetDesc.h public?
> >
> > One worry that springs to mind is how easy it is to renumber the enum
> values used by the opcodes. If these numbers are public it will be hard to
> have stable releases that add new instructions.
> 
> I don't believe that there's an expectation of ABI stability for the LLVM C++
> interfaces, even in public headers - there's no expectation that you can link
> against any version of LLVM other than the exact version whose headers you
> used, unless you use the C interfaces.  As long as this is not in llvm-c, then it
> shouldn't be an issue.
> 
> David

It's not expected to be stable between major releases like 3.6.0 and 3.7.0, but I believe it is supposed to be stable between, say,  3.6.0 and 3.6.1. 
During the 3.5.1 release we spent a fair bit of time learning how to use a ABI checking tool and Tom Stellard asked me to make a few changes to preserve the ABI compatibility with the 3.5.0 release.