RPCS3/llvm
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm.git synced 2024-11-28 22:20:43 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Document what backwards compatibility we provide for bitcode.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213813 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola 2014-07-23 22:43:22 +00:00
parent a25114b902
commit b74b9541ac
1 changed files with 23 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
docs/DeveloperPolicy.rst
View File

@ -436,6 +436,29 @@ list, development list, or LLVM bug tracker component. If someone sends you
a patch privately, encourage them to submit it to the appropriate list first.
IR Backwards Compatibility
--------------------------
When the IR format has to be changed, keep in mind that we try to maintain some
backwards compatibility. The rules are intended as a balance between convenience
for llvm users and not imposing a big burden on llvm developers:
* The textual format is not backwards compatible. We don't change it too often,
but there are no specific promises.
* The bitcode format produced by a X.Y release will be readable by all following
X.Z releases and the (X+1).0 release.
* Newer releases can ignore features from older releases, but they cannot
miscompile them. For example, if nsw is ever replaced with something else,
dropping it would be a valid way to upgrade the IR.
* Debug metadata is special in that it is currently dropped during upgrades.
* Non-debug metadata is defined to be safe to drop, so a valid way to upgrade
it is to drop it. That is not very user friendly and a bit more effort is
expected, but no promises are made.
.. _copyright-license-patents:
Copyright, License, and Patents