[llvm] [llvm][docs] Add notes on upstreaming code from downstream projects (PR #129743)

[Andrzej Warzyński via llvm-commits]

https://github.com/banach-space updated https://github.com/llvm/llvm-project/pull/129743

>From 8e3f677495e4d2b8c57c260d7d3cb31fe09fb673 Mon Sep 17 00:00:00 2001
From: Andrzej Warzynski <andrzej.warzynski at arm.com>
Date: Tue, 4 Mar 2025 17:02:39 +0000
Subject: [PATCH 1/3] [llvm][docs] Add notes on upstreaming code from
 downstream projects

For context, see:
* https://discourse.llvm.org/t/code-review-process-when-upstreaming-patches
---
 llvm/docs/CodeReview.rst | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/llvm/docs/CodeReview.rst b/llvm/docs/CodeReview.rst
index 4cfd91435247c..3206d7a93c65c 100644
--- a/llvm/docs/CodeReview.rst
+++ b/llvm/docs/CodeReview.rst
@@ -272,3 +272,19 @@ Developers should participate in code reviews as both reviewers and
 authors. If someone is kind enough to review your code, you should return the
 favor for someone else. Note that anyone is welcome to review and give feedback
 on a patch, but approval of patches should be consistent with the policy above.
+
+Upstreaming Changes to LLVM
+===========================
+
+When upstreaming your own changes from a downstream project to LLVM, simply
+follow the process outlined above.
+
+When upstreaming changes originally written by someone else:  
+
+* Ensure that the original author(s) are aware of and approve the upstreaming
+  of their code, and that they are comfortable with you leading the process.
+* Properly attribute the original changes, e.g., by creating a commit with
+  multiple authors ([GitHub guide](https://docs.github.com/en/pull-requests/committing-changes-to-your-project/creating-and-editing-commits/creating-a-commit-with-multiple-authors)).  
+* Invite the original author(s) to review the changes, but also include
+  additional reviewers. Specifically, an LGTM from a (co-)author does not
+  constitute approval to land a change.

>From 7e513430fd51bf981d32a58cbfa37c8249c19583 Mon Sep 17 00:00:00 2001
From: Andrzej Warzynski <andrzej.warzynski at arm.com>
Date: Tue, 4 Mar 2025 17:21:06 +0000
Subject: [PATCH 2/3] fixup! [llvm][docs] Add notes on upstreaming code from
 downstream projects

but -> and
---
 llvm/docs/CodeReview.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/docs/CodeReview.rst b/llvm/docs/CodeReview.rst
index 3206d7a93c65c..62cf38b87b12a 100644
--- a/llvm/docs/CodeReview.rst
+++ b/llvm/docs/CodeReview.rst
@@ -285,6 +285,6 @@ When upstreaming changes originally written by someone else:
   of their code, and that they are comfortable with you leading the process.
 * Properly attribute the original changes, e.g., by creating a commit with
   multiple authors ([GitHub guide](https://docs.github.com/en/pull-requests/committing-changes-to-your-project/creating-and-editing-commits/creating-a-commit-with-multiple-authors)).  
-* Invite the original author(s) to review the changes, but also include
+* Invite the original author(s) to review the changes, and also include
   additional reviewers. Specifically, an LGTM from a (co-)author does not
   constitute approval to land a change.

>From 945a908014ae549335df647d94eb9c8ae941419c Mon Sep 17 00:00:00 2001
From: Andrzej Warzynski <andrzej.warzynski at arm.com>
Date: Mon, 10 Mar 2025 18:49:26 +0000
Subject: [PATCH 3/3] fixup! fixup! [llvm][docs] Add notes on upstreaming code
 from downstream projects

Include suggestion from Hubert
---
 llvm/docs/CodeReview.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/docs/CodeReview.rst b/llvm/docs/CodeReview.rst
index 62cf38b87b12a..5772fc3f1b150 100644
--- a/llvm/docs/CodeReview.rst
+++ b/llvm/docs/CodeReview.rst
@@ -286,5 +286,5 @@ When upstreaming changes originally written by someone else:
 * Properly attribute the original changes, e.g., by creating a commit with
   multiple authors ([GitHub guide](https://docs.github.com/en/pull-requests/committing-changes-to-your-project/creating-and-editing-commits/creating-a-commit-with-multiple-authors)).  
 * Invite the original author(s) to review the changes, and also include
-  additional reviewers. Specifically, an LGTM from a (co-)author does not
-  constitute approval to land a change.
+  additional reviewers. Specifically, an LGTM from a (co-)author should not be
+  taken as approval to land a change.