glibcspecific

glibcspecific refers to code, interfaces, or behavior that relies on the GNU C Library (glibc) rather than being portable across different C libraries. Glibc is the predominant C library on Linux and provides the standard C API, a broad set of POSIX interfaces, and numerous GNU extensions. Code described as glibcspecific may depend on these extensions or on glibc’s particular semantics, which can reduce portability to systems that use other libc implementations such as musl or uClibc.

Typical glibcspecific features include GNU extensions and non-POSIX APIs. Examples commonly cited are asprintf and vasprintf, the GNU version of strerror_r, getprogname and setprogname, and malloc_usable_size. Such functions and behaviors may not be available or behave differently in other libc implementations. Additionally, glibc uses symbol versioning to manage ABI compatibility, which can influence how binaries link against different glibc versions and affect runtime compatibility across systems with older or newer glibc runtimes.

From a development perspective, identifying glibcspecific code is important for portability analysis. If cross-platform compatibility is a goal, developers may avoid glibc-only APIs or guard them behind runtime or build-time checks, using feature tests or conditional compilation. Documentation and build systems can help by clearly marking glibc-dependent components and by providing alternatives or fallbacks for non-glibc environments. Overall, glibcspecific code trades portability for access to a richer or more convenient API surface provided by glibc.