[mips] Make TTypeEncoding indirect to allow .eh_frame to be read-only.

Summary:
Following on from r209907 which made personality encodings indirect, do the
same for TType encodings. This fixes the case where a try/catch block needs
to generate references to, for example, std::exception in the
.gcc_except_table.

This commit uses DW_EH_PE_sdata8 for N64 as far as is possible at the moment.
However, it is possible to end up with DW_EH_PE_sdata4 when a TargetMachine is
not available. There's no risk of issues with inconsistency here since the
tables are self describing but it does mean there is a small chance of the
PC-relative offset being out of range for particularly large programs.

Reviewers: petarj

Reviewed By: petarj

Subscribers: srhines, joerg, tberghammer, llvm-commits

Differential Revision: http://reviews.llvm.org/D9669

llvm-svn: 238190

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsTargetObjectFile.h b/llvm/lib/Target/Mips/MipsTargetObjectFile.h
index 725f2ffd93d..72338d275f8 100644
--- a/llvm/lib/Target/Mips/MipsTargetObjectFile.h
+++ b/llvm/lib/Target/Mips/MipsTargetObjectFile.h
@@ -41,6 +41,8 @@ class MipsTargetMachine;
 
     MCSection *getSectionForConstant(SectionKind Kind,
                                      const Constant *C) const override;
+
+    unsigned SelectMipsTTypeEncoding() const override;
   };
 } // end namespace llvm