Holger Levsen: > Hi Ximin, > > On Tue, Aug 09, 2016 at 02:08:45PM +0200, Ximin Luo wrote: >> Many software packages (e.g. see #833846) like to set optimisation flags >> based >> on autodetecting CPU features of the build machine. > > do you really say/think that *many* packages in *Debian* have that > behaviour? I'd not be surprised about *a few*, but many??!? > > and, do you know a way we could automatically detect/scan for those to > file bugs? Those are all serious bugs… >
I was exaggerating sorry. "some" would match better what I saw myself directly. As for detection, we could get lintian to scan binary packages' pkg-config files and perhaps other code-looking files (i.e. not documentation) for "-march" and "-mcpu" and "-mtune" but this doesn't cover all cases. We could also do the same for build logs. We could also objdump -S binaries and check if they contain illegal instructions. For example that's how I detected the presence of AVX/FMA/SSE4 in linbox, e.g: $ objdump -S /usr/lib/x86_64-linux-gnu/liblinbox.so | grep '\b\(ymm\|zmm\|vfm\)' but I don't know binary to enough detail to suggest a full set of illegal instructions to search for. X -- GPG: ed25519/56034877E1F87C35 GPG: rsa4096/1318EFAC5FBBDBCE https://github.com/infinity0/pubkeys.git
