[lldb] NFC Add Process methods to Fix.*Address, to simplify this bit clearing across the codebase

[jasonmolenda]

Summary

Right now to clear unaddressable bits (AArch64 TBI or ptrauth, armv7 0th bit setting for arm/thumb) everyone needs to take a Process, get the ABI, then call the method. As David and I had discussed in another patch, this is unnecessary friction that should be simplified.

This patch adds those same methods to Process, so the callers can skip the extra step of getting the ABI when working with these values.

I'm only adding the Process methods in this patch, leaving all the existing callers as-is, I'll look at updating those separately, but new users can start using these methods once they're in place.

[DavidSpickett]

LGTM. Sinking the whole if abi dance into these methods will clean up a lot.

lldb/include/lldb/Target/Process.h

/// \see Process::Notifications
   void SetHighmemCodeAddressMask(lldb::addr_t code_address_mask) {
     m_highmem_code_address_mask = code_address_mask;
   }
 
   void SetHighmemDataAddressMask(lldb::addr_t data_address_mask) {
     m_highmem_data_address_mask = data_address_mask;
   }
 
+  /// Some targets might use bits in a code address to indicate a mode switch,
+  /// ARM uses bit zero to signify a code address is thumb, so any ARM ABI
+  /// plug-ins would strip those bits.
+  /// Or use the high bits to authenticate a pointer value.
+  lldb::addr_t FixCodeAddress(lldb::addr_t pc);
+  lldb::addr_t FixDataAddress(lldb::addr_t pc);
+
+  /// Use this method when you do not know, or do not care what kind of address
+  /// you are fixing. On platforms where there would be a difference between the
+  /// two types, it will pick the safest option.
+  ///
+  /// Its purpose is to signal that no specific choice was made and provide an
+  /// alternative to randomly picking FixCode/FixData address. Which could break
+  /// platforms where there is a difference (only Arm Thumb at this time).
+  lldb::addr_t FixAnyAddress(lldb::addr_t pc);
+
   /// Get the Modification ID of the process.
   ///
   /// \return
   ///     The modification ID of the process.
   ProcessModID GetModID() const { return m_mod_id; }
 
   const ProcessModID &GetModIDRef() const { return m_mod_id; }
 

lldb/source/Target/Process.cpp

 }
 
 lldb::addr_t Process::GetHighmemDataAddressMask() {
   if (uint32_t num_bits_setting = GetHighmemVirtualAddressableBits())
     return ~((1ULL << num_bits_setting) - 1);
   return GetDataAddressMask();
 }
 
+addr_t Process::FixCodeAddress(addr_t addr) {
+  if (ABISP abi_sp = GetABI())
+    addr = abi_sp->FixCodeAddress(addr);
+  return addr;
+}
+
+addr_t Process::FixDataAddress(addr_t addr) {
+  if (ABISP abi_sp = GetABI())
+    addr = abi_sp->FixDataAddress(addr);
+  return addr;
+}
+
+addr_t Process::FixAnyAddress(addr_t addr) {
+  if (ABISP abi_sp = GetABI())
+    addr = abi_sp->FixAnyAddress(addr);
+  return addr;
+}
+
 void Process::DidExec() {
   Log *log = GetLog(LLDBLog::Process);
   LLDB_LOGF(log, "Process::%s()", __FUNCTION__);
 
   Target &target = GetTarget();
   target.CleanupProcess();
   target.ClearModules(false);
   m_dynamic_checkers_up.reset();