Comment 107 for bug 1711337

Revision history for this message
James Donald (jdonald) wrote :

Ugh, yeah doing some simple helloworld tests confirms these are armhf gcc *defaults*.

> it's what *defines* armhf as armhf.

Defines: This appears true for -march=armv7-a -mfloat-abi=hard. As for -mfpu, adding -mfpu=neon results in some assembly differences, namely using register d16 and above.

> Unless something is explicitly setting those things differently

The Firefox build log has some instances of -mfpu=neon, particularly in Skia. However, Chromium does as well so indeed this is a longshot.

Looks like we're back to the drawing board. Still some hope with changes like building Skia using clang, adding -mthumb, or -fstack-protector-strong, but none of these other differences stand out as something present in both the Chromium and Arch Linux builds.

I think I misunderstood earlier about the intent of looking at Firefox 57's about:buildconfig. As that's technically still a Skia-broken build, we can continue to examine that configuration for other differences vs the Arch Linux one.

> [herrtimson] If there's a chance to get the output of about:buildconfig regardless the segfault at startup, I'm all eager to learn about this.

With broken browsers like Firefox 58 and 59 armhf, find the build config like so:

strings /usr/lib/firefox/omni.ja | grep -A 31 "Built from"