Pull GetSoftwareBreakpointPCOffset into base class

Summary:
This function encodes the knowledge of whether the PC points to the
breakpoint instruction of the one following it after the breakpoint is
"hit". This behavior mainly(*) depends on the architecture and not on the
OS, so it makes sense for it to be implemented in the base class, where
it can be shared between different implementations (Linux and NetBSD
atm).

(*) It is possible for an OS to expose a different API, perhaps by doing
some fixups in the kernel. In this case, the implementation can override
this function to implement custom behavior.

Reviewers: krytarowski, zturner

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D52532

llvm-svn: 343409

1 files changed, 3 insertions, 22 deletions

diff --git a/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp b/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
index 145d4d881b6..6326691ca87 100644
--- a/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
+++ b/lldb/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
@@ -322,21 +322,6 @@ Status NativeProcessNetBSD::PtraceWrapper(int req, lldb::pid_t pid, void *addr,
   return error;
 }
 
-Status NativeProcessNetBSD::GetSoftwareBreakpointPCOffset(
-    uint32_t &actual_opcode_size) {
-  // FIXME put this behind a breakpoint protocol class that can be
-  // set per architecture.  Need ARM, MIPS support here.
-  static const uint8_t g_i386_opcode[] = {0xCC};
-  switch (m_arch.GetMachine()) {
-  case llvm::Triple::x86_64:
-    actual_opcode_size = static_cast<uint32_t>(sizeof(g_i386_opcode));
-    return Status();
-  default:
-    assert(false && "CPU type not supported!");
-    return Status("CPU type not supported");
-  }
-}
-
 Status
 NativeProcessNetBSD::FixupBreakpointPCAsNeeded(NativeThreadNetBSD &thread) {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_BREAKPOINTS));
@@ -344,13 +329,9 @@ NativeProcessNetBSD::FixupBreakpointPCAsNeeded(NativeThreadNetBSD &thread) {
   // Find out the size of a breakpoint (might depend on where we are in the
   // code).
   NativeRegisterContext& context = thread.GetRegisterContext();
-  uint32_t breakpoint_size = 0;
-  error = GetSoftwareBreakpointPCOffset(breakpoint_size);
-  if (error.Fail()) {
-    LLDB_LOG(log, "GetBreakpointSize() failed: {0}", error);
-    return error;
-  } else
-    LLDB_LOG(log, "breakpoint size: {0}", breakpoint_size);
+  uint32_t breakpoint_size = GetSoftwareBreakpointPCOffset();
+  LLDB_LOG(log, "breakpoint size: {0}", breakpoint_size);
+
   // First try probing for a breakpoint at a software breakpoint location: PC -
   // breakpoint size.
   const lldb::addr_t initial_pc_addr =