
<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="">Hi,<div class=""><br class=""></div><div class=""><div class="">In sanitizer code we have two notions of stack unwinders: fast and slow. [1] In the context of sanitizers, stack unwinding is most often for printing error reports that include a stack trace.</div><div class=""><br class=""></div><div class="">I am currently trying to fix an issue that is related to some platforms (Darwin) only supporting the fast unwinder, but calling code not being aware of that possibility.</div><div class="">My mental model was that platforms are required to at least support one kind of unwinder, so I turned a runtime check [2] into a compile time assert [3]. Apparently this is not the case.</div></div><div class=""><br class=""></div><div class="">What do (or should) we do on platforms without supported unwinders? </div><div class="">Or is my mental model correct, and this a runtime (instead of compile time) check for other reasons? Compilation/build system convenience?</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">Julian</div><div class=""><br class=""></div><div class="">[1] <a href="https://github.com/llvm/llvm-project/blob/fcbd7f64953b04f42dd59f606e45dc8e88a27548/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h#L21" class="">https://github.com/llvm/llvm-project/blob/fcbd7f64953b04f42dd59f606e45dc8e88a27548/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h#L21</a></div><div class=""><div class="">[2] <a href="https://github.com/llvm/llvm-project/blob/fcbd7f64953b04f42dd59f606e45dc8e88a27548/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc#L78" class="">https://github.com/llvm/llvm-project/blob/fcbd7f64953b04f42dd59f606e45dc8e88a27548/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc#L78</a></div></div><div class=""><div class="">[3] <a href="https://github.com/llvm/llvm-project/blob/fcbd7f64953b04f42dd59f606e45dc8e88a27548/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h#L21" class="">https://github.com/llvm/llvm-project/blob/fcbd7f64953b04f42dd59f606e45dc8e88a27548/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h#L21</a></div></div><div class=""><br class=""></div></body></html>