Non-SFI NaCl: Do not create unwind tables for libc_free.c

chrome/test/data/nacl/nonsfi/libc_free.c

Index: chrome/test/data/nacl/nonsfi/libc_free.c
diff --git a/chrome/test/data/nacl/nonsfi/libc_free.c b/chrome/test/data/nacl/nonsfi/libc_free.c
index cc8eb839ab039e564b8046bf45244000743b782c..87ff58e0b11577eee583ea4ee037943918494d89 100644
--- a/chrome/test/data/nacl/nonsfi/libc_free.c
+++ b/chrome/test/data/nacl/nonsfi/libc_free.c
@@ -210,6 +210,14 @@ static void HandleMessage(PP_Instance instance, struct PP_Var message) {
   }
 }
 
+#if defined(__arm__)
+// ARM GCC emits references to them. They should not be called unless

[Mark Seaborn, 2014/07/21 22:49:33]

Hmm, where in the code do the references come from?

[hamaji, 2014/07/22 08:17:23]

They are in exidx section. Ah, -funwind-tables is set and dropping this flag
seems to be a better solution.

[Mark Seaborn, 2014/07/22 15:19:48]

Yes, that's what we do for nacl_helper_bootstrap, which also avoids using
libc/libgcc.

+// an exception occurs. We exit with a unique exit code just in case.
+static const int kUnwindExitCode = 2;
+void __aeabi_unwind_cpp_pr0() { __libnacl_irt_basic.exit(kUnwindExitCode); }

[Mark Seaborn, 2014/07/21 22:49:33]

Nit: the function body should be on a separate line.

Just calling __builtin_trap() to exit would also be simpler.

[hamaji, 2014/07/22 08:17:23]

It seems ARM GCC uses abort() to implement __builtin_trap, but anyway, this code
was removed.

+void __aeabi_unwind_cpp_pr1() { __libnacl_irt_basic.exit(kUnwindExitCode); }
+#endif
+
 void _start(uintptr_t info[]) {
   Elf_auxv_t* auxv = nacl_startup_auxv(info);
   grok_auxv(auxv);