llvm/llvm-project

[libc][POSIX][unistd] implement `alarm`

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#124,654 opened on Jan 27, 2025

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 (13 comments) (0 reactions) (1 assignee)C++ (10,782 forks)batch import
good first issuelibc

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Description

building clang against llvm-libc fails due to the uses of alarm (unistd.h) in llvm/lib/Support/Unix/{Watchdog.inc|Program.inc}

Contributor guide

Research direction
Examine the existing implementation of similar POSIX functions in LLVM's libc, such as sleep or getpid, to understand the pattern. Look at the files llvm/lib/Support/Unix/Watchdog.inc and Program.inc to see how alarm is currently used. Review the issue comments for any implementation hints or discussions. The goal is to add an alarm syscall wrapper to libc that matches the POSIX signature and integrates with LLVM's build system.
Tech stack
ccpp
Domain
build systemapi
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
basic C programmingunderstanding of POSIXfamiliarity with LLVM project structure
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25