<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">On Aug 5, 2020, at 4:11 PM, Leonard Chan via cfe-dev <<a href="mailto:cfe-dev@lists.llvm.org" class="">cfe-dev@lists.llvm.org</a>> wrote:<br class=""><div><blockquote type="cite" class=""><br class="Apple-interchange-newline"><div class=""><span style="caret-color: rgb(0, 0, 0); font-family: Arial; font-size: 14.666666984558105px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: pre-wrap; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">The flag would look something like `-fc++-abi=` and override the default C++ ABI selected by the target. It's up to the user to make sure that the ABI and target combination makes sense.</span><br class="Apple-interchange-newline"></div></blockquote></div><br class=""><div class="">I like this idea and I know people in the retrocomputing and alt-OS community would find it useful. (Example: Haiku binary compatibility with BeOS is currently implemented by using a very old GCC. This would allow easier experimentation with implementing a compatible ABI in a modern compiler.)</div><div class=""><br class=""></div><div class="">Should it be specific to the C++ ABI though? Or should there be an equivalent for C ABI? (Example: The LLVM 68000 back-end that's in progress currently targets the SVR4 ABI, but users of the compiler will definitely want support for Amiga, Atari, classic Mac OS, Sun, HP, etc. ABIs.) I suppose for C this is implied by the target triple, but it might be useful to have a separate switch for it.</div><div class=""><br class=""></div><div class=""> -- Chris</div><div class=""><br class=""></div></body></html>