[libc][cpio] Add cpio.h header.

[siya100]

[libc][docs] add cpio to documentation and include related functi…
These changes ensure that the cpio header is documented properly
with respect to the issue (#122006 ).

Changes:

1. cpio.yaml: Created a new YAML file for cpio with functions
   and related macros.
2. CMakeLists.txt: Added cpio to the documentation
   directories.
3. index.rst: Included cpio in the documentation index.

[github-actions]

Thank you for submitting a Pull Request (PR) to the LLVM Project!

This PR will be automatically labeled and the relevant teams will be notified.

If you wish to, you can add reviewers by using the "Reviewers" section on this page.

If this is not working for you, it is probably because you do not have write permissions for the repository. In which case you can instead tag reviewers by name in a comment by using @ followed by their GitHub username.

If you have received no comments on your PR for a week, you can request a review by "ping"ing the PR by adding a comment “Ping”. The common courtesy "ping" rate is once a week. Please remember that you are asking for valuable time from other developers.

If you have further questions, they may be answered by the LLVM GitHub User Guide.

You can also ask questions in a comment on this PR, on the LLVM Discord or on the forums.

[llvmbot]

@llvm/pr-subscribers-libc

Author: None (siya100)

Changes

[libc][docs] add cpio to documentation and include related functi…
These changes ensure that the cpio header is documented properly
with respect to the issue (#122006 ).

Changes:

1. cpio.yaml: Created a new YAML file for cpio with functions
   and related macros.
2. CMakeLists.txt: Added cpio to the documentation
   directories.
3. index.rst: Included cpio in the documentation index.

---

Full diff: https://github.com/llvm/llvm-project/pull/123798.diff

3 Files Affected:

• (modified) libc/docs/CMakeLists.txt (+1)
• (modified) libc/docs/headers/index.rst (+1)
• (added) libc/utils/docgen/cpio.yaml (+31)

diff --git a/libc/docs/CMakeLists.txt b/libc/docs/CMakeLists.txt
index f88d7c27f9f6b3..b2ead3ffc5e657 100644
--- a/libc/docs/CMakeLists.txt
+++ b/libc/docs/CMakeLists.txt
@@ -37,6 +37,7 @@ if (SPHINX_FOUND)
       aio
       arpa/inet
       assert
+      cpio
       ctype
       errno
       fenv
diff --git a/libc/docs/headers/index.rst b/libc/docs/headers/index.rst
index 858b2142defa92..e457df558b1398 100644
--- a/libc/docs/headers/index.rst
+++ b/libc/docs/headers/index.rst
@@ -8,6 +8,7 @@ Implementation Status
    arpa/inet
    assert
    complex
+   cpio
    ctype
    errno
    fenv
diff --git a/libc/utils/docgen/cpio.yaml b/libc/utils/docgen/cpio.yaml
new file mode 100644
index 00000000000000..d2371c9efb9d3f
--- /dev/null
+++ b/libc/utils/docgen/cpio.yaml
@@ -0,0 +1,31 @@
+functions:
+  cpio_open:
+    in-latest-posix: ''
+  cpio_create:
+    in-latest-posix: ''
+  cpio_read:
+    in-latest-posix: ''
+  cpio_write:
+    in-latest-posix: ''
+  cpio_close:
+    in-latest-posix: ''
+macros:
+  CPIO_ACCESS:
+    in-latest-posix: ''
+  CPIO_CREATE:
+    in-latest-posix: ''
+  CPIO_EXTRACT:
+    in-latest-posix: ''
+  CPIO_LINK:
+    in-latest-posix: ''
+  CPIO_RENAME:
+    in-latest-posix: ''
+  CPIO_SYMLINK:
+    in-latest-posix: ''
+  CPIO_DELETE:
+    in-latest-posix: ''
+  CPIO_TRUNCATE:
+    in-latest-posix: ''
+  CPIO_UNLINK:
+    in-latest-posix: ''
+

[nickdesaulniers]

Thanks for the patch. Something funny is going on here with this header.
https://pubs.opengroup.org/onlinepubs/9799919799/ doesn't show any of these functions or macros you listed...were they removed from posix?

[nickdesaulniers]

Strange; these aren't in the latest posix either. Where did you find this list of funcitons?

[siya100]

have made the changes @nickdesaulniers can you review

[nickdesaulniers]

LGTM; thanks for the patch! Do you need us to merge this for you?

[siya100]

LGTM; thanks for the patch! Do you need us to merge this for you?

[siya100]

yess

[github-actions]

@siya100 Congratulations on having your first Pull Request (PR) merged into the LLVM Project!

Your changes will be combined with recent changes from other authors, then tested by our build bots. If there is a problem with a build, you may receive a report in an email or a comment on this PR.

Please check whether problems have been caused by your change specifically, as the builds can include changes from many authors. It is not uncommon for your change to be included in a build that fails due to someone else's changes, or infrastructure issues.

How to do this, and the rest of the post-merge process, is covered in detail here.

If your change does cause a problem, it may be reverted, or you can revert it yourself. This is a normal part of LLVM development. You can fix your changes and open a new PR to merge them again.

If you don't get any reports, no action is required from you. Your changes are working as expected, well done!

[ldionne]

Should that be here?

I came to this review because that user posted a comment that looked suspiciously like spam and saw they had contributed to LLVM in this PR. From one of their comments, it looks like this user may be contributing AI-generated stuff. There's nothing wrong with that in theory, but I'd advise doing careful review of these diffs. If you think I'm being needlessly careful here, feel free to let me know.

[nickdesaulniers]

https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/cpio.h.html

The <cpio.h> header shall define the following symbolic constant as a string:
MAGIC "070707"

[ldionne]

Ah, thanks, I missed that!

[siya100]

heyy can you please tell mw where i am lacking or how i can modify the yaml file