On 4 Nov 2020, at 17:38, Shawn Webb <shawn.w...@hardenedbsd.org> wrote: > > On Wed, Nov 04, 2020 at 11:26:51AM -0500, Ed Maste wrote: >> On Tue, 3 Nov 2020 at 14:57, Dimitry Andric <d...@freebsd.org> wrote: >>> >>> Author: dim >>> Date: Tue Nov 3 19:57:28 2020 >>> New Revision: 367304 >>> URL: https://svnweb.freebsd.org/changeset/base/367304 >>> >>> Log: >>> Add WITH_LLVM_CXXFILT option to install llvm-cxxfilt as c++filt >> >> A previous argument against the LLVM versions of binutils replacements >> is that they were excessively large, but this does not look like a >> substantial problem here. LLVM's cxxfilt is indeed many times the size >> of ELF Tool Chain's, but still small enough that for a tool chain >> component it's not a concern, in my opinion. >> >> ELF Tool Chain: >> $ size obj/c++filt >> text data bss dec hex filename >> 66966 1008 8400 76374 0x12a56 obj/c++filt >> >> LLVM: >> $ size obj/llvm-cxxfilt >> text data bss dec hex filename >> 378138 1756 9165 389059 0x5efc3 obj/llvm-cxxfilt >> >> A remaining issue is that both nm and addr2line can also demangle C++ >> symbols. > > This brings a question: is there any guidance as to what FreeBSD > considers "too large of a component" for a toolchain component (or any > other various components, like src.git/stand)?
I think this guidance originates from the world of embedded systems, where storage size is a more limiting factor than on recent desktop or server class machines. On my desktops I won't care too much whether an executable is 1M or 100MB, but on a small SD card things add up very quickly! That said, llvm-related tools such as llvm-ar or llvm-cxxfilt are pretty big, mainly because all of them are written in C++ with a lot of templates, and we link the llvm and clang .a files statically into them. It would save some space to stuff all those library files into a shared library, and link the tools against that, but the disadvantage is that it will take a *lot* of memory and CPU time to link that (huge) shared library. I experimented a little with that in the past, and it's very difficult to make it work on 32-bit systems. -Dimitry
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