[lldb] [Process/FreeBSDRemote] Correct DS/ES/FS/GS register sizes

[mgorny]

Summary

Fix DS/ES/FS/GS register sizes in getter/setter for FreeBSD. Apparently
only CS and SS registers are specified as 64/32-bit in LLDB, while
the others are specified as 16-bit. This fixes the failing
StandardStartupTest.TestStopReplyContainsThreadPcs lldb-server unittest.

[mgorny]

@labath, yes, I'm convinced already that we need to abstract this away into something more fancy like Linux does.

[emaste]

Agree that even if refactoring is needed correcting these makes sense.

lldb/source/Plugins/Process/FreeBSDRemote/NativeRegisterContextFreeBSD_x86_64.cpp

case lldb_rip_x86_64:
     break;
   case lldb_rflags_x86_64:
     reg_value = (uint64_t)m_gpr.r_rflags;
     break;
   case lldb_cs_x86_64:
     reg_value = (uint64_t)m_gpr.r_cs;
     break;
   case lldb_fs_x86_64:
-    reg_value = (uint64_t)m_gpr.r_fs;
+    reg_value = (uint16_t)m_gpr.r_fs;
     break;
   case lldb_gs_x86_64:
-    reg_value = (uint64_t)m_gpr.r_gs;
+    reg_value = (uint16_t)m_gpr.r_gs;
     break;
   case lldb_ss_x86_64:
     reg_value = (uint64_t)m_gpr.r_ss;
     break;
   case lldb_ds_x86_64:
-    reg_value = (uint64_t)m_gpr.r_ds;
+    reg_value = (uint16_t)m_gpr.r_ds;
     break;
   case lldb_es_x86_64:
-    reg_value = (uint64_t)m_gpr.r_es;
+    reg_value = (uint16_t)m_gpr.r_es;
     break;
 #else
   case lldb_rax_x86_64:
     reg_value = (uint32_t)m_gpr.r_eax;
     break;
   case lldb_rbx_x86_64:
     reg_value = (uint32_t)m_gpr.r_ebx;
     break;
case lldb_rip_x86_64:
     break;
   case lldb_rflags_x86_64:
     reg_value = (uint32_t)m_gpr.r_eflags;
     break;
   case lldb_cs_x86_64:
     reg_value = (uint32_t)m_gpr.r_cs;
     break;
   case lldb_fs_x86_64:
-    reg_value = (uint32_t)m_gpr.r_fs;
+    reg_value = (uint16_t)m_gpr.r_fs;
     break;
   case lldb_gs_x86_64:
-    reg_value = (uint32_t)m_gpr.r_gs;
+    reg_value = (uint16_t)m_gpr.r_gs;
     break;
   case lldb_ss_x86_64:
     reg_value = (uint32_t)m_gpr.r_ss;
     break;
   case lldb_ds_x86_64:
-    reg_value = (uint32_t)m_gpr.r_ds;
+    reg_value = (uint16_t)m_gpr.r_ds;
     break;
   case lldb_es_x86_64:
-    reg_value = (uint32_t)m_gpr.r_es;
+    reg_value = (uint16_t)m_gpr.r_es;
     break;
 #endif
 #if defined(__x86_64__)
 // the 32-bit field carries more detail, so we don't have to reinvent
 // the wheel
 #define FPR_ENV(x) ((struct envxmm32 *)m_fpr.fpr_env)->x
 #else
 #define FPR_ENV(x) ((struct envxmm *)m_fpr.xmm_env)->x
case lldb_rip_x86_64:
     break;
   case lldb_rflags_x86_64:
     m_gpr.r_rflags = reg_value.GetAsUInt64();
     break;
   case lldb_cs_x86_64:
     m_gpr.r_cs = reg_value.GetAsUInt64();
     break;
   case lldb_fs_x86_64:
-    m_gpr.r_fs = reg_value.GetAsUInt64();
+    m_gpr.r_fs = reg_value.GetAsUInt16();
     break;
   case lldb_gs_x86_64:
-    m_gpr.r_gs = reg_value.GetAsUInt64();
+    m_gpr.r_gs = reg_value.GetAsUInt16();
     break;
   case lldb_ss_x86_64:
     m_gpr.r_ss = reg_value.GetAsUInt64();
     break;
   case lldb_ds_x86_64:
-    m_gpr.r_ds = reg_value.GetAsUInt64();
+    m_gpr.r_ds = reg_value.GetAsUInt16();
     break;
   case lldb_es_x86_64:
-    m_gpr.r_es = reg_value.GetAsUInt64();
+    m_gpr.r_es = reg_value.GetAsUInt16();
     break;
 #else
   case lldb_rax_x86_64:
     m_gpr.r_eax = reg_value.GetAsUInt32();
     break;
   case lldb_rbx_x86_64:
     m_gpr.r_ebx = reg_value.GetAsUInt32();
     break;
case lldb_rip_x86_64:
     break;
   case lldb_rflags_x86_64:
     m_gpr.r_eflags = reg_value.GetAsUInt32();
     break;
   case lldb_cs_x86_64:
     m_gpr.r_cs = reg_value.GetAsUInt32();
     break;
   case lldb_fs_x86_64:
-    m_gpr.r_fs = reg_value.GetAsUInt32();
+    m_gpr.r_fs = reg_value.GetAsUInt16();
     break;
   case lldb_gs_x86_64:
-    m_gpr.r_gs = reg_value.GetAsUInt32();
+    m_gpr.r_gs = reg_value.GetAsUInt16();
     break;
   case lldb_ss_x86_64:
     m_gpr.r_ss = reg_value.GetAsUInt32();
     break;
   case lldb_ds_x86_64:
-    m_gpr.r_ds = reg_value.GetAsUInt32();
+    m_gpr.r_ds = reg_value.GetAsUInt16();
     break;
   case lldb_es_x86_64:
-    m_gpr.r_es = reg_value.GetAsUInt32();
+    m_gpr.r_es = reg_value.GetAsUInt16();
     break;
 #endif
   case lldb_fctrl_x86_64:
     FPR_ENV(en_cw) = reg_value.GetAsUInt16();
     break;
   case lldb_fstat_x86_64:
     FPR_ENV(en_sw) = reg_value.GetAsUInt16();
     break;