Author: Peter Collingbourne Date: 2025-04-15T13:03:58-07:00 New Revision: a1d52fcdca8bda4fe8c6652b2de83f408f4ad4f2
URL: https://github.com/llvm/llvm-project/commit/a1d52fcdca8bda4fe8c6652b2de83f408f4ad4f2 DIFF: https://github.com/llvm/llvm-project/commit/a1d52fcdca8bda4fe8c6652b2de83f408f4ad4f2.diff LOG: Clarify documentation for -funique-source-file-names. Reviewers: efriedma-quic, teresajohnson Reviewed By: teresajohnson, efriedma-quic Pull Request: https://github.com/llvm/llvm-project/pull/135832 Added: Modified: clang/docs/UsersManual.rst Removed: ################################################################################ diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst index d4656a7e63c99..69256527f40c9 100644 --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -2301,11 +2301,31 @@ are listed below. When enabled, allows the compiler to assume that each object file passed to the linker has been compiled using a unique source file - name. This is useful for reducing link times when doing ThinLTO + path. This is useful for reducing link times when doing ThinLTO in combination with whole-program devirtualization or CFI. - A misuse of this flag will generally result in a duplicate symbol - error at link time. + The full source path passed to the compiler must be unique. This + means that, for example, the following is a usage error: + + .. code-block:: console + + $ cd foo + $ clang -funique-source-file-names -c foo.c + $ cd ../bar + $ clang -funique-source-file-names -c foo.c + $ cd .. + $ clang foo/foo.o bar/foo.o + + but this is not: + + .. code-block:: console + + $ clang -funique-source-file-names -c foo/foo.c + $ clang -funique-source-file-names -c bar/foo.c + $ clang foo/foo.o bar/foo.o + + A misuse of this flag may result in a duplicate symbol error at + link time. .. option:: -fforce-emit-vtables _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
