[libc] provide sysexits.h

[nickdesaulniers]

FWICT, sysexits.h is a BSD extension. It's used in llvm when building clang:

In file included from /llvm-project-main/llvm/lib/Support/Signals.cpp:277:
In file included from /llvm-project-main/llvm/lib/Support/Unix/Signals.inc:39:
/llvm-project-main/llvm/include/llvm/Support/ExitCodes.h:30:2: error: Exit code EX_IOERR not available
   30 | #error Exit code EX_IOERR not available
      |  ^

FWICT, it's because llvm-libc doesn't provide sysexits.h. LLVM only cares about EX_IOERR (I think I was involved in this code, a lifetime ago, for detecting writes to broken pipes...)

[llvmbot]

@llvm/issue-subscribers-libc

Author: Nick Desaulniers (nickdesaulniers)

FWICT, sysexits.h is a BSD extension. It's used in llvm when building clang: ``` In file included from /llvm-project-main/llvm/lib/Support/Signals.cpp:277: In file included from /llvm-project-main/llvm/lib/Support/Unix/Signals.inc:39: /llvm-project-main/llvm/include/llvm/Support/ExitCodes.h:30:2: error: Exit code EX_IOERR not available 30 | #error Exit code EX_IOERR not available | ^ ``` FWICT, it's because llvm-libc doesn't provide sysexits.h. LLVM only cares about `EX_IOERR` (I think I was involved in this code, a lifetime ago, for detecting writes to broken pipes...)

[nickdesaulniers]

We just need the 18 defines. Should be easy. #125168 is a good reference for adding a new header. Since these are neither POSIX nor std C, we don't need any POSIX stuff in the yaml for docgen.

https://android.googlesource.com/platform/bionic/+/main/libc/include/sysexits.h has a list of the macro identifiers and values they should have.

[llvmbot]

Hi!

This issue may be a good introductory issue for people new to working on LLVM. If you would like to work on this issue, your first steps are:

1. Check that no other contributor has already been assigned to this issue. If you believe that no one is actually working on it despite an assignment, ping the person. After one week without a response, the assignee may be changed.
2. In the comments of this issue, request for it to be assigned to you, or just create a pull request after following the steps below. Mention this issue in the description of the pull request.
3. Fix the issue locally.
4. Run the test suite locally. Remember that the subdirectories under test/ create fine-grained testing targets, so you can e.g. use make check-clang-ast to only run Clang's AST tests.
5. Create a Git commit.
6. Run git clang-format HEAD~1 to format your changes.
7. Open a pull request to the upstream repository on GitHub. Detailed instructions can be found in GitHub's documentation. Mention this issue in the description of the pull request.

If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: Nick Desaulniers (nickdesaulniers)

FWICT, sysexits.h is a BSD extension. It's used in llvm when building clang: ``` In file included from /llvm-project-main/llvm/lib/Support/Signals.cpp:277: In file included from /llvm-project-main/llvm/lib/Support/Unix/Signals.inc:39: /llvm-project-main/llvm/include/llvm/Support/ExitCodes.h:30:2: error: Exit code EX_IOERR not available 30 | #error Exit code EX_IOERR not available | ^ ``` FWICT, it's because llvm-libc doesn't provide sysexits.h. LLVM only cares about `EX_IOERR` (I think I was involved in this code, a lifetime ago, for detecting writes to broken pipes...)

[ajayrajsaini]

Hi I am interested in contributing to this issue. I understand the problem is related to the missing EX_IOERR definition when sysexits.h is unavailable, and I will add a fallback definition to resolve the build error. can you please assign this to me? Thanks!

[ajayrajsaini]

hi
i am trying to reproduce the error but whem i am building it is building successfully.
I used "cmake -DCMAKE_BUILD_TYPE="Release" -DLLVM_ENABLE_ASSERTIONS=On ../llvm" and "make check-llvm-unit" to build the project please guide me how can i reproduce the error.
and is there any way that i can speed up the build process since currently it is taking hours.

my OS:-
PRETTY_NAME="Ubuntu 24.10"
NAME="Ubuntu"
VERSION_ID="24.10"
VERSION="24.10 (Oracular Oriole)"
VERSION_CODENAME=oracular
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=oracular
LOGO=ubuntu-logo

[nickdesaulniers]

Hi @ajayrajsaini , please take a look at https://libc.llvm.org/getting_started.html for how to build llvm-libc. Once you have hello world compiling, change the example to add #include <sysexits.h> and have main return EX_IOERR.

When you have this issue resolved, hello world with the above modifications should compile without issue (and run).

[ajayrajsaini]

hi @nickdesaulniers i have added sysexits.h containing error codes please review it:-
#126112

[ajayrajsaini]

hi @nickdesaulniers i had moved the header file please review it.
#126112