ELF symbol table field st_other support,

excluding visibility bits.

Generic STO handling at the Target level.

The st_other field of the ELF symbol table is one
byte in size. The first 2 bytes are used for generic
visibility and are currently handled by llvm.

The other six bits are processor specific and need 
to be set at the target level.

A couple of notes:

The new static methods for accessing and setting the "other"
flags in include/llvm/MC/MCELF.h match the style guide
and not the other methods in the file. I don't like the
inconsistency, but feel I should follow the prescribed 
lowerUpper() convention.

STO_ value definitions are not specified in gnu land as 
consistently as the STT_ and STB_ fields. Probably because
the latter were defined in a standards doc and the former
defined partially in code. I have stuck with the full byte
definition of the flags.

Contributer: Zoran Jovanovic




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175561 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 3 deletions

diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index fb14dc96b3..0b97f2700b 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -546,12 +546,17 @@ void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF,
   bool IsReserved = Data.isCommon() || Data.getSymbol().isAbsolute() ||
     Data.getSymbol().isVariable();
 
+  // Binding and Type share the same byte as upper and lower nibbles
   uint8_t Binding = MCELF::GetBinding(OrigData);
-  uint8_t Visibility = MCELF::GetVisibility(OrigData);
   uint8_t Type = MCELF::GetType(Data);
-
   uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift);
-  uint8_t Other = Visibility;
+
+  // Other and Visibility share the same byte with Visability using the lower
+  // 2 bits
+  uint8_t Visibility = MCELF::GetVisibility(OrigData);
+  uint8_t Other = MCELF::getOther(OrigData) <<
+    (ELF_Other_Shift - ELF_STV_Shift);
+  Other |= Visibility;
 
   uint64_t Value = SymbolValue(Data, Layout);
   uint64_t Size = 0;