================ @@ -1073,6 +1073,28 @@ inputs. Here is some example of ``$``-prefixed options: Language and Target-Independent Features ======================================== +Freestanding Builds +------------------- +Passing the ``-ffreestanding`` flag causes Clang to build for a freestanding +(rather than a hosted) environment. The flag has the following effects: + +* the ``__STDC_HOSTED__`` predefined macro will expand to ``0``, +* builtin functions are disabled (``-fno-builtins``), +* unwind tables are disabled (``fno-asynchronous-unwind-tables -fno-unwind-tables``), and +* allows ``main`` to be used as a regular symbol. + +A freestanding environment is not one which has no C standard library support. ---------------- jyknight wrote:
I summarized the functionality required from a conforming freestanding implementation in a [previous comment](https://github.com/llvm/llvm-project/pull/132232#issuecomment-2741829501) on this PR. I think we should also assume that future C standards may further increase the set of freestanding functions, towards inclusion of any function which doesn't require a runtime environment (e.g. memory allocator, system calls, or other global state). https://github.com/llvm/llvm-project/pull/132232 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
