[dpdk-dev] [v5] doc: define qualification criteria for external library

[<jerinj@marvell.com>]

From: Jerin Jacob <jerinj@marvell.com>

Define qualification criteria for external library
based on a techboard meeting minutes [1] and past
learnings from mailing list discussion.

[1]
http://mails.dpdk.org/archives/dev/2019-June/135847.html
https://mails.dpdk.org/archives/dev/2024-January/284849.html

Signed-off-by: Jerin Jacob <jerinj@marvell.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
---
 doc/guides/contributing/index.rst             |  1 +
 .../contributing/library_dependency.rst       | 52 +++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 doc/guides/contributing/library_dependency.rst

v5:
- Added "Dependency nature" section based on Stephen's input

v4:
- Address Thomas comments from https://patches.dpdk.org/project/dpdk/patch/20240105121215.3950532-1-jerinj@marvell.com/

v3:
- Updated the content based on TB discussion which is documented at
https://mails.dpdk.org/archives/dev/2024-January/284849.html

v2:
- Added "Meson build integration" and "Code readability" sections.


diff --git a/doc/guides/contributing/index.rst b/doc/guides/contributing/index.rst
index dcb9b1fbf0..e5a8c2b0a3 100644
--- a/doc/guides/contributing/index.rst
+++ b/doc/guides/contributing/index.rst
@@ -15,6 +15,7 @@ Contributor's Guidelines
     documentation
     unit_test
     new_library
+    library_dependency
     patches
     vulnerability
     stable
diff --git a/doc/guides/contributing/library_dependency.rst b/doc/guides/contributing/library_dependency.rst
new file mode 100644
index 0000000000..94025fdf60
--- /dev/null
+++ b/doc/guides/contributing/library_dependency.rst
@@ -0,0 +1,52 @@
+.. SPDX-License-Identifier: BSD-3-Clause
+   Copyright(c) 2024 Marvell.
+
+External Library dependency
+===========================
+
+This document defines the qualification criteria for external libraries that may be
+used as dependencies in DPDK drivers or libraries.
+
+#. **Documentation:**
+
+   - Must have adequate documentation for the steps to build it.
+   - Must have clear license documentation on distribution and usage aspects of external library.
+
+#. **Free availability:**
+
+   - The library must be freely available to build in either source or binary form.
+   - It shall be downloadable from a direct link. There shall not be any requirement to explicitly
+     login or sign a user agreement.
+
+#. **Usage License:**
+
+   - Both permissive (e.g., BSD-3 or Apache) and non-permissive (e.g., GPLv3) licenses are acceptable.
+   - In the case of a permissive license, automatic inclusion in the build process is assumed.
+     For non-permissive licenses, an additional build configuration option is required.
+
+#. **Distributions License:**
+
+   - No specific constraints beyond documentation.
+
+#. **Compiler compatibility:**
+
+   - The library must be able to compile with a DPDK supported compiler for the given execution
+     environment.
+     For example, for Linux, the library must be able to compile with GCC and/or clang.
+   - Library may be limited to a specific OS.
+
+#. **Meson build integration:**
+
+   - The library must have standard method like ``pkg-config`` for seamless integration with
+     DPDK's build environment.
+
+#. **Code readability:**
+
+   - Optional dependencies should use stubs to minimize ``ifdef`` clutter, promoting improved
+     code readability.
+
+#. **Dependency nature:**
+
+   - The external library dependency should be optional.
+     i.e Missing external library must not impact the core functionality of the DPDK, specific
+     library and/or driver will not built if dependencies are not meet.
-- 
2.43.0