[Sanitizer] Get the Linux ptrace test working on PowerPC64

[foad]

Summary

The test refers to user_regs_struct.rip so it can only ever have worked
on x86-64. Put this code inside an appropriate #if, and add a similar
case for PowerPC64. (If we do likewise for ARM we can probably remove
the XFAILs, but I have no way of testing that.)

Those changes are enough to get the test working for me on big-endian
PowerPC64 Fedora 19.

[foad]

(Creating a new revision because I forgot to Cc llvm-commits the first time. There are no changes)

[kcc]

• please upload patcehs with full context (easier with 'arc')
• please don't rename the file to .c, instead cast integer to the enum type and file a bug against the linux headers and/or clang -- this warning must not be there.

[foad]

Add casts instead of converting to C.

[foad]

In D6108#7, @kcc wrote:

• please upload patcehs with full context (easier with 'arc')

Done.

• please don't rename the file to .c, instead cast integer to the enum type

Done.

and file a bug against the linux headers and/or clang -- this warning must not be there.

OK, I'll try to find someone to report it to.

[kcc]

test/sanitizer_common/TestCases/Linux/ptrace.cc

36

#endif // x86_64

46

Can you file a bug against clang?
It should not issue a waning here even w/o the explicit cast.
The bug may end up being in the Linux headers, not in clang)

50

#endif // powerpc64

[foad]

Add comments on #endifs.

[kcc]

LGTM

[foad]

Closed by commit rL221337 (authored by @foad).

[foad]

In D6108#7, @kcc wrote:

• please don't rename the file to .c, instead cast integer to the enum type and file a bug against the linux headers and/or clang -- this warning must not be there.

I've filed a bug against the linux headers: https://bugzilla.kernel.org/show_bug.cgi?id=87861

test/sanitizer_common/TestCases/Linux/ptrace.cc

 int main(void) {
   pid_t pid;
   pid = fork();
   if (pid == 0) { // child
     ptrace(PTRACE_TRACEME, 0, NULL, NULL);
     execl("/bin/true", "true", NULL);
   } else {
     wait(NULL);
-    user_regs_struct regs;
     int res;
+
+#if __x86_64__
+    user_regs_struct regs;
     res = ptrace(PTRACE_GETREGS, pid, NULL, &regs);
     assert(!res);
     if (regs.rip)
       printf("%zx\n", regs.rip);
 
     user_fpregs_struct fpregs;
     res = ptrace(PTRACE_GETFPREGS, pid, NULL, &fpregs);
     assert(!res);
     if (fpregs.mxcsr)
       printf("%x\n", fpregs.mxcsr);
+#endif
+
+#if __powerpc64__
+    struct pt_regs regs;
+    res = ptrace((enum __ptrace_request)PTRACE_GETREGS, pid, NULL, &regs);
+    assert(!res);
+    if (regs.nip)
+      printf("%lx\n", regs.nip);
+
+    elf_fpregset_t fpregs;
+    res = ptrace((enum __ptrace_request)PTRACE_GETFPREGS, pid, NULL, &fpregs);
+    assert(!res);
+    if ((elf_greg_t)fpregs[32]) // fpscr
+      printf("%lx\n", (elf_greg_t)fpregs[32]);
+#endif
 
     siginfo_t siginfo;
     res = ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo);
     assert(!res);
     assert(siginfo.si_pid == pid);
 
     ptrace(PTRACE_CONT, pid, NULL, NULL);
 
     wait(NULL);
   }
   return 0;
 }