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, 15 insertions, 0 deletions

diff --git a/lib/MC/MCELF.cpp b/lib/MC/MCELF.cpp
index 4db2846bc3..560cdbc6ab 100644
--- a/lib/MC/MCELF.cpp
+++ b/lib/MC/MCELF.cpp
@@ -52,6 +52,8 @@ unsigned MCELF::GetType(const MCSymbolData &SD) {
   return Type;
 }
 
+// Visibility is stored in the first two bits of st_other
+// st_other values are stored in the second byte of get/setFlags
 void MCELF::SetVisibility(MCSymbolData &SD, unsigned Visibility) {
   assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL ||
          Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED);
@@ -68,4 +70,17 @@ unsigned MCELF::GetVisibility(MCSymbolData &SD) {
   return Visibility;
 }
 
+// Other is stored in the last six bits of st_other
+// st_other values are stored in the second byte of get/setFlags
+void MCELF::setOther(MCSymbolData &SD, unsigned Other) {
+  uint32_t OtherFlags = SD.getFlags() & ~(0x3f << ELF_Other_Shift);
+  SD.setFlags(OtherFlags | (Other << ELF_Other_Shift));
+}
+
+unsigned MCELF::getOther(MCSymbolData &SD) {
+  unsigned Other =
+    (SD.getFlags() & (0x3f << ELF_Other_Shift)) >> ELF_Other_Shift;
+  return Other;
+}
+
 }