[SystemZ] Define DWARF encoding

This is another patch in preparation for adding the SystemZ target.
It defines the appropriate values for DWARF encodings; the intent
is to be compatible with what GCC currently does on the target.

Patch by Richard Sandiford.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181201 91177308-0d34-0410-b5e6-96231b3b80d8

lib/MC/MCObjectFileInfo.cpp

@@ -295,6 +295,15 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
       dwarf::DW_EH_PE_udata8;
+  } else if (T.getArch() == Triple::systemz) {
+    // All currently-defined code models guarantee that 4-byte PC-relative
+    // values will be in range.
+    PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
+      dwarf::DW_EH_PE_sdata4;
+    LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+    FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
+    TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
+      dwarf::DW_EH_PE_sdata4;
   }
 
   // Solaris requires different flags for .eh_frame to seemingly every other