[llvm] r175561 - ELF symbol table field st_other support,
Jack Carter
jcarter at mips.com
Tue Feb 19 13:57:36 PST 2013
Author: jacksprat
Date: Tue Feb 19 15:57:35 2013
New Revision: 175561
URL: http://llvm.org/viewvc/llvm-project?rev=175561&view=rev
Log:
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
Modified:
llvm/trunk/include/llvm/MC/MCELF.h
llvm/trunk/include/llvm/MC/MCELFStreamer.h
llvm/trunk/include/llvm/MC/MCStreamer.h
llvm/trunk/lib/MC/ELFObjectWriter.cpp
llvm/trunk/lib/MC/MCELF.cpp
llvm/trunk/lib/MC/MCELFStreamer.cpp
llvm/trunk/lib/MC/MCStreamer.cpp
Modified: llvm/trunk/include/llvm/MC/MCELF.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCELF.h?rev=175561&r1=175560&r2=175561&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCELF.h (original)
+++ llvm/trunk/include/llvm/MC/MCELF.h Tue Feb 19 15:57:35 2013
@@ -28,6 +28,8 @@ class MCELF {
static unsigned GetType(const MCSymbolData &SD);
static void SetVisibility(MCSymbolData &SD, unsigned Visibility);
static unsigned GetVisibility(MCSymbolData &SD);
+ static void setOther(MCSymbolData &SD, unsigned Other);
+ static unsigned getOther(MCSymbolData &SD);
};
}
Modified: llvm/trunk/include/llvm/MC/MCELFStreamer.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCELFStreamer.h?rev=175561&r1=175560&r2=175561&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCELFStreamer.h (original)
+++ llvm/trunk/include/llvm/MC/MCELFStreamer.h Tue Feb 19 15:57:35 2013
@@ -65,6 +65,8 @@ public:
virtual void EmitCOFFSymbolType(int Type);
virtual void EndCOFFSymbolDef();
+ virtual MCSymbolData &getOrCreateSymbolData(MCSymbol *Symbol);
+
virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
Modified: llvm/trunk/include/llvm/MC/MCStreamer.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCStreamer.h?rev=175561&r1=175560&r2=175561&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCStreamer.h (original)
+++ llvm/trunk/include/llvm/MC/MCStreamer.h Tue Feb 19 15:57:35 2013
@@ -16,6 +16,7 @@
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCWin64EH.h"
@@ -286,6 +287,9 @@ namespace llvm {
/// a Thumb mode function (ARM target only).
virtual void EmitThumbFunc(MCSymbol *Func) = 0;
+ /// getOrCreateSymbolData - Get symbol data for given symbol.
+ virtual MCSymbolData &getOrCreateSymbolData(MCSymbol *Symbol);
+
/// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
///
/// This corresponds to an assembler statement such as:
Modified: llvm/trunk/lib/MC/ELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/ELFObjectWriter.cpp?rev=175561&r1=175560&r2=175561&view=diff
==============================================================================
--- llvm/trunk/lib/MC/ELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/ELFObjectWriter.cpp Tue Feb 19 15:57:35 2013
@@ -546,12 +546,17 @@ void ELFObjectWriter::WriteSymbol(MCData
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;
Modified: llvm/trunk/lib/MC/MCELF.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCELF.cpp?rev=175561&r1=175560&r2=175561&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCELF.cpp (original)
+++ llvm/trunk/lib/MC/MCELF.cpp Tue Feb 19 15:57:35 2013
@@ -52,6 +52,8 @@ unsigned MCELF::GetType(const MCSymbolDa
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(MCSymbolDa
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;
+}
+
}
Modified: llvm/trunk/lib/MC/MCELFStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCELFStreamer.cpp?rev=175561&r1=175560&r2=175561&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCELFStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCELFStreamer.cpp Tue Feb 19 15:57:35 2013
@@ -504,6 +504,10 @@ void MCELFStreamer::EmitThumbFunc(MCSymb
llvm_unreachable("Generic ELF doesn't support this directive");
}
+MCSymbolData &MCELFStreamer::getOrCreateSymbolData(MCSymbol *Symbol) {
+ return getAssembler().getOrCreateSymbolData(*Symbol);
+}
+
void MCELFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
llvm_unreachable("ELF doesn't support this directive");
}
Modified: llvm/trunk/lib/MC/MCStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCStreamer.cpp?rev=175561&r1=175560&r2=175561&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCStreamer.cpp Tue Feb 19 15:57:35 2013
@@ -620,3 +620,8 @@ void MCStreamer::Finish() {
FinishImpl();
}
+
+MCSymbolData &MCStreamer::getOrCreateSymbolData(MCSymbol *Symbol) {
+ report_fatal_error("Not supported!");
+ return *(static_cast<MCSymbolData*> (NULL));
+}
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