[Openmp-commits] [openmp] 8eab182 - [RFC][OpenMP][Doc] No backward compatible for libomptarget and plugins

[Shilei Tian via Openmp-commits]

Author: Shilei Tian
Date: 2022-11-04T12:41:09-04:00
New Revision: 8eab182bf2b7683fb5637a01b7664b802c759c2f

URL: https://github.com/llvm/llvm-project/commit/8eab182bf2b7683fb5637a01b7664b802c759c2f
DIFF: https://github.com/llvm/llvm-project/commit/8eab182bf2b7683fb5637a01b7664b802c759c2f.diff

LOG: [RFC][OpenMP][Doc] No backward compatible for libomptarget and plugins

Now we state that backward compatibility is not guaranteed in the document.

Reviewed By: JonChesterfield, dreachem

Differential Revision: https://reviews.llvm.org/D133277

Added: 
    

Modified: 
    openmp/docs/SupportAndFAQ.rst

Removed: 
    


################################################################################
diff  --git a/openmp/docs/SupportAndFAQ.rst b/openmp/docs/SupportAndFAQ.rst
index dc1ad83902d2..8bf0ea56a7ae 100644
--- a/openmp/docs/SupportAndFAQ.rst
+++ b/openmp/docs/SupportAndFAQ.rst
@@ -413,3 +413,17 @@ linkable device image.
    clang++ openmp.cpp -fopenmp --offload-arch=sm_80 -c
    clang++ cuda.cu --offload-new-driver --offload-arch=sm_80 -fgpu-rdc -c
    clang++ openmp.o cuda.o --offload-link -o app
+
+Q: Are libomptarget and plugins backward compatible?
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+No. libomptarget and plugins are now built as LLVM libraries starting from LLVM
+15. Because LLVM libraries are not backward compatible, libomptarget and plugins
+are not as well. Given that fact, the interfaces between 1) the Clang compiler
+and libomptarget, 2) the Clang compiler and device runtime library, and
+3) libomptarget and plugins are not guaranteed to be compatible with an earlier
+version. Users are responsible for ensuring compatibility when not using the
+Clang compiler and runtime libraries from the same build. Nevertheless, in order
+to better support third-party libraries and toolchains that depend on existing
+libomptarget entry points, contributors are discouraged from making
+modifications to them.