Comment 84 for bug 1711337

I run firefox 58.02 armhf that comes with ubuntu 16.04 and it crash in same point my custom firefox 58.02 crashed :

Thread 1 "firefox" received signal SIGSEGV, Segmentation fault.
0xf4c3bfc4 in JS::MutableHandle<JS::Value>::set (v=..., this=<synthetic pointer>)
    at /build/firefox-ID1dFf/firefox-58.0.2+build1/obj-arm-linux-gnueabihf/dist/include/js/RootingAPI.h:580
580 /build/firefox-ID1dFf/firefox-58.0.2+build1/obj-arm-linux-gnueabihf/dist/include/js/RootingAPI.h: No such file or directory.
(gdb) diass /r 0xf4c3bfc0,0xf4c3bfd0
Undefined command: "diass". Try "help".
(gdb) disas /r 0xf4c3bfc0,0xf4c3bfd0
Dump of assembler code from 0xf4c3bfc0 to 0xf4c3bfd0:
   0xf4c3bfc0 <js::jit::DoTypeMonitorFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICTypeMonitor_Fallback*, JS::HandleValue, JS::MutableHandleValue)+96>: 00 23 movs r3, #0
   0xf4c3bfc2 <js::jit::DoTypeMonitorFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICTypeMonitor_Fallback*, JS::HandleValue, JS::MutableHandleValue)+98>: 82 46 mov r10, r0
=> 0xf4c3bfc4 <js::jit::DoTypeMonitorFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICTypeMonitor_Fallback*, JS::HandleValue, JS::MutableHandleValue)+100>: c1 e9 00 23 strd r2, r3, [r1]
   0xf4c3bfc8 <js::jit::DoTypeMonitorFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICTypeMonitor_Fallback*, JS::HandleValue, JS::MutableHandleValue)+104>: d9 f8 04 30 ldr.w r3, [r9, #4]
   0xf4c3bfcc <js::jit::DoTypeMonitorFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICTypeMonitor_Fallback*, JS::HandleValue, JS::MutableHandleValue)+108>: 7b 33 adds r3, #123 ; 0x7b
   0xf4c3bfce <js::jit::DoTypeMonitorFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICTypeMonitor_Fallback*, JS::HandleValue, JS::MutableHandleValue)+110>: 00 f0 4b 81 beq.w 0xf4c3c268 <js::jit::DoTypeMonitorFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICTypeMonitor_Fallback*, JS::HandleValue, JS::MutableHandleValue)+776>
End of assembler dump.
(gdb)

The problem is same RootingAPI.h:580 . Ok so in firefox 58.02 we have 2 bugs , this one "RootingAPI.h:580" and the _sk_xor__vfp4 that I hope to get fixed by compiling with clang .

I will get the Firefox 57.04 source from Ubuntu 14 and check if it still crash if I rebuild it with Skjumper build with clang .I want to see if rebuilding SkJumpr generated with clang fix the _sk_xor__vfp4 crash .