VLAs were added to satisfy the FORTRAN crowd, who are used to efficiently instantiating huge arrays on the stack. AFAIU, you can't catch stack overflow in FORTR

VLAs were added to satisfy the FORTRAN crowd, who are used to efficiently instantiating huge arrays on the stack. AFAIU, you can't catch stack overflow in FORTRAN either. That doesn't mean that they're not safe, so long as the program reliably terminates[1]. And you can catch stack overflow, it's just not easy, and made especially difficult from a software architecture perspective because neither C nor POSIX support per-thread signal handlers, so catching stack overflow requires cooperation across components and libraries. (Fortunately, POSIX does provide per-thread signal stacks via sigaltstack(2). And I suppose it should be possible to write a shared library that interposes pthread_create and signal/sigaction to support per-thread signal handlers.) TL;DR: VLAs are fine if you're doing something you might otherwise be doing in FORTRAN. Otherwise, just don't. It's trivial to use GNU obstacks or to write your own, as I do. Just don't go down the rabbit whole of trying to solve all allocation needs; it's not a solvable problem. [1] Sadly, before Stack Clash was published neither GCC nor clang/LLVM did this :(