A few fixes for ARMv5TE.

runtime/vm/os_linux.cc

Index: runtime/vm/os_linux.cc
===================================================================
--- runtime/vm/os_linux.cc	(revision 44777)
+++ runtime/vm/os_linux.cc	(working copy)
@@ -507,8 +507,10 @@
 void OS::DebugBreak() {
 #if defined(HOST_ARCH_X64) || defined(HOST_ARCH_IA32)
   asm("int $3");
-#elif defined(HOST_ARCH_ARM)
+#elif defined(HOST_ARCH_ARM) && !defined(__THUMBEL__)
   asm("svc #0x9f0001");  // __ARM_NR_breakpoint

[zra, 2015/03/30 17:25:00]

This is not a valid thumb instruction.

[srdjan, 2015/03/30 17:39:50]

Is there a breakpoint instruction in thumb instruction set?

[zra, 2015/03/30 20:02:05]

After cleanup, only the Intel instruction should be needed.

+#elif defined(HOST_ARCH_ARM) && defined(__THUMBEL__)
+  UNIMPLEMENTED();
 #elif defined(HOST_ARCH_MIPS) || defined(HOST_ARCH_ARM64)
   UNIMPLEMENTED();

[regis, 2015/03/30 18:12:43]

I am wondering how you figured out that this instruction was not available on
Thumb, since we only call this OS::DebugBreak() from the simulator to enter gdb
on Intel platforms.
As Srdjan indicates, an UNIMPLEMENTED is not really solving the problem. On the
other hand, there is no problem to solve so far :-)

Apparently, this is also called from a vm test "CodeImmutability", which I do
not understand.

I think some TODOs to remember to clean up this mess would be good.

[zra, 2015/03/30 20:02:05]

gcc refuses to compile the inline assembly if you pass -mthumb.
TODO added.

 #else