[llvm-commits] [llvm] r76326 - in /llvm/trunk: include/llvm/Target/TargetELFWriterInfo.h lib/CodeGen/ELF.h lib/CodeGen/ELFCodeEmitter.cpp lib/CodeGen/ELFWriter.cpp lib/CodeGen/ELFWriter.h lib/Target/X86/X86ELFWriterInfo.cpp lib/Target/X86/X86ELFWriterInfo.h
Bruno Cardoso Lopes
bruno.cardoso at gmail.com
Sat Jul 18 12:30:50 PDT 2009
Author: bruno
Date: Sat Jul 18 14:30:09 2009
New Revision: 76326
URL: http://llvm.org/viewvc/llvm-project?rev=76326&view=rev
Log:
Add support to properly reference private symbols on relocation entries.
Use proper relocation type to build relocations for JumpTables (rodata
sections).
Modified:
llvm/trunk/include/llvm/Target/TargetELFWriterInfo.h
llvm/trunk/lib/CodeGen/ELF.h
llvm/trunk/lib/CodeGen/ELFCodeEmitter.cpp
llvm/trunk/lib/CodeGen/ELFWriter.cpp
llvm/trunk/lib/CodeGen/ELFWriter.h
llvm/trunk/lib/Target/X86/X86ELFWriterInfo.cpp
llvm/trunk/lib/Target/X86/X86ELFWriterInfo.h
Modified: llvm/trunk/include/llvm/Target/TargetELFWriterInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetELFWriterInfo.h?rev=76326&r1=76325&r2=76326&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Target/TargetELFWriterInfo.h (original)
+++ llvm/trunk/include/llvm/Target/TargetELFWriterInfo.h Sat Jul 18 14:30:09 2009
@@ -99,7 +99,14 @@
/// getAddendForRelTy - Gets the addend value for an ELF relocation entry
/// based on the target relocation type. If addend is not used returns 0.
- virtual long int getAddendForRelTy(unsigned RelTy) const = 0;
+ virtual long int getDefaultAddendForRelTy(unsigned RelTy) const = 0;
+
+ /// getRelTySize - Returns the size of relocatable field in bits
+ virtual unsigned getRelocationTySize(unsigned RelTy) const = 0;
+
+ /// getJumpTableRelocationTy - Returns the machine relocation type used
+ /// to reference a jumptable.
+ virtual unsigned getJumpTableMachineRelocationTy() const = 0;
};
} // end llvm namespace
Modified: llvm/trunk/lib/CodeGen/ELF.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ELF.h?rev=76326&r1=76325&r2=76326&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ELF.h (original)
+++ llvm/trunk/lib/CodeGen/ELF.h Sat Jul 18 14:30:09 2009
@@ -184,6 +184,13 @@
/// Sym - The symbol to represent this section if it has one.
ELFSym *Sym;
+ /// getSymIndex - Returns the symbol table index of the symbol
+ /// representing this section.
+ unsigned getSymbolTableIndex() const {
+ assert(Sym && "section not present in the symbol table");
+ return Sym->SymTabIdx;
+ }
+
ELFSection(const std::string &name, bool isLittleEndian, bool is64Bit)
: BinaryObject(name, isLittleEndian, is64Bit), Type(0), Flags(0), Addr(0),
Offset(0), Size(0), Link(0), Info(0), Align(0), EntSize(0), Sym(0) {}
Modified: llvm/trunk/lib/CodeGen/ELFCodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ELFCodeEmitter.cpp?rev=76326&r1=76325&r2=76326&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ELFCodeEmitter.cpp (original)
+++ llvm/trunk/lib/CodeGen/ELFCodeEmitter.cpp Sat Jul 18 14:30:09 2009
@@ -20,6 +20,7 @@
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineRelocation.h"
#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetELFWriterInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Support/Debug.h"
@@ -160,6 +161,7 @@
"PIC codegen not yet handled for elf jump tables!");
const TargetAsmInfo *TAI = TM.getTargetAsmInfo();
+ const TargetELFWriterInfo *TEW = TM.getELFWriterInfo();
// Get the ELF Section to emit the jump table
unsigned Align = TM.getTargetData()->getPointerABIAlignment();
@@ -183,9 +185,10 @@
// Each MBB entry in the Jump table section has a relocation entry
// against the current text section.
for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
+ unsigned MachineRelTy = TEW->getJumpTableMachineRelocationTy();
MachineRelocation MR =
MachineRelocation::getBB(JTSection.size(),
- MachineRelocation::VANILLA,
+ MachineRelTy,
MBBs[mi]);
// Offset of JT 'i' in JT section
Modified: llvm/trunk/lib/CodeGen/ELFWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ELFWriter.cpp?rev=76326&r1=76325&r2=76326&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ELFWriter.cpp (original)
+++ llvm/trunk/lib/CodeGen/ELFWriter.cpp Sat Jul 18 14:30:09 2009
@@ -296,8 +296,16 @@
}
}
- if (!GV->hasPrivateLinkage())
+ // Private symbols must never go to the symbol table.
+ unsigned SymIdx = 0;
+ if (GV->hasPrivateLinkage()) {
+ PrivateSyms.push_back(GblSym);
+ SymIdx = PrivateSyms.size()-1;
+ } else {
SymbolList.push_back(GblSym);
+ }
+
+ GblSymLookup[GV] = SymIdx;
}
void ELFWriter::EmitGlobalConstantStruct(const ConstantStruct *CVS,
@@ -394,20 +402,16 @@
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
EmitGlobal(I);
- GblSymLookup[I] = 0;
}
// Emit all pending globals
// TODO: this should be done only for referenced symbols
for (SetVector<GlobalValue*>::const_iterator I = PendingGlobals.begin(),
E = PendingGlobals.end(); I != E; ++I) {
-
// No need to emit the symbol again
if (GblSymLookup.find(*I) != GblSymLookup.end())
continue;
-
EmitGlobal(*I);
- GblSymLookup[*I] = 0;
}
// Emit non-executable stack note
@@ -480,7 +484,8 @@
MRE = Relos.end(); MRI != MRE; ++MRI) {
MachineRelocation &MR = *MRI;
- // Offset from the start of the section containing the symbol
+ // Holds the relocatable field address as an offset from the
+ // beginning of the section where it lives
unsigned Offset = MR.getMachineCodeOffset();
// Symbol index in the symbol table
@@ -498,15 +503,34 @@
if (MR.isGlobalValue()) {
const GlobalValue *G = MR.getGlobalValue();
SymIdx = GblSymLookup[G];
- Addend = TEW->getAddendForRelTy(RelType);
+ if (G->hasPrivateLinkage()) {
+ // If the target uses a section offset in the relocation:
+ // SymIdx + Addend = section sym for global + section offset
+ unsigned SectionIdx = PrivateSyms[SymIdx]->SectionIdx;
+ Addend = PrivateSyms[SymIdx]->Value;
+ SymIdx = SectionList[SectionIdx]->getSymbolTableIndex();
+ } else {
+ Addend = TEW->getDefaultAddendForRelTy(RelType);
+ }
} else {
// Get the symbol index for the section symbol referenced
// by the relocation
unsigned SectionIdx = MR.getConstantVal();
- SymIdx = SectionList[SectionIdx]->Sym->SymTabIdx;
+ SymIdx = SectionList[SectionIdx]->getSymbolTableIndex();
Addend = (uint64_t)MR.getResultPointer();
}
+ // The target without addend on the relocation symbol must be
+ // patched in the relocation place itself to contain the addend
+ if (!HasRelA) {
+ if (TEW->getRelocationTySize(RelType) == 32)
+ S.fixWord32(Addend, Offset);
+ else if (TEW->getRelocationTySize(RelType) == 64)
+ S.fixWord64(Addend, Offset);
+ else
+ llvm_unreachable("don't know howto patch relocatable field");
+ }
+
// Get the relocation entry and emit to the relocation section
ELFRelocation Rel(Offset, SymIdx, RelType, HasRelA, Addend);
EmitRelocation(RelSec, Rel, HasRelA);
Modified: llvm/trunk/lib/CodeGen/ELFWriter.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ELFWriter.h?rev=76326&r1=76325&r2=76326&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ELFWriter.h (original)
+++ llvm/trunk/lib/CodeGen/ELFWriter.h Sat Jul 18 14:30:09 2009
@@ -107,8 +107,8 @@
std::map<std::string, ELFSection*> SectionLookup;
/// GblSymLookup - This is a mapping from global value to a symbol index
- /// in the symbol table. This is useful since relocations symbol references
- /// must be quickly mapped to a symbol table index
+ /// in the symbol table or private symbols list. This is useful since reloc
+ /// symbol references must be quickly mapped to their indices on the lists
std::map<const GlobalValue*, uint32_t> GblSymLookup;
/// SymbolList - This is the list of symbols emitted to the symbol table.
@@ -116,6 +116,10 @@
/// the beginning while non-locals at the end.
std::vector<ELFSym*> SymbolList;
+ /// PrivateSyms - Record private symbols, every symbol here must never be
+ /// present in the SymbolList.
+ std::vector<ELFSym*> PrivateSyms;
+
/// PendingGlobals - List of externally defined symbols that we have been
/// asked to emit, but have not seen a reference to. When a reference
/// is seen, the symbol will move from this list to the SymbolList.
Modified: llvm/trunk/lib/Target/X86/X86ELFWriterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ELFWriterInfo.cpp?rev=76326&r1=76325&r2=76326&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ELFWriterInfo.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ELFWriterInfo.cpp Sat Jul 18 14:30:09 2009
@@ -43,7 +43,7 @@
return R_X86_64_64;
case X86::reloc_picrel_word:
default:
- llvm_unreachable("unknown relocation type");
+ llvm_unreachable("unknown x86_64 machine relocation type");
}
} else {
switch(MachineRelTy) {
@@ -54,22 +54,55 @@
case X86::reloc_absolute_dword:
case X86::reloc_picrel_word:
default:
- llvm_unreachable("unknown relocation type");
+ llvm_unreachable("unknown x86 machine relocation type");
}
}
return 0;
}
-long int X86ELFWriterInfo::getAddendForRelTy(unsigned RelTy) const {
+long int X86ELFWriterInfo::getDefaultAddendForRelTy(unsigned RelTy) const {
if (is64Bit) {
switch(RelTy) {
case R_X86_64_PC32: return -4;
- break;
case R_X86_64_32: return 0;
- break;
+ default:
+ llvm_unreachable("unknown x86_64 relocation type");
+ }
+ } else {
+ switch(RelTy) {
+ case R_386_PC32: return -4;
+ case R_386_32: return 0;
+ default:
+ llvm_unreachable("unknown x86 relocation type");
+ }
+ }
+ return 0;
+}
+
+unsigned X86ELFWriterInfo::getRelocationTySize(unsigned RelTy) const {
+ if (is64Bit) {
+ switch(RelTy) {
+ case R_X86_64_PC32:
+ case R_X86_64_32:
+ return 32;
+ case R_X86_64_64:
+ return 64;
+ default:
+ llvm_unreachable("unknown x86_64 relocation type");
+ }
+ } else {
+ switch(RelTy) {
+ case R_386_PC32:
+ case R_386_32:
+ return 32;
default:
llvm_unreachable("unknown x86 relocation type");
}
}
return 0;
}
+
+unsigned X86ELFWriterInfo::getJumpTableMachineRelocationTy() const {
+ return X86::reloc_absolute_dword;
+}
+
Modified: llvm/trunk/lib/Target/X86/X86ELFWriterInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ELFWriterInfo.h?rev=76326&r1=76325&r2=76326&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ELFWriterInfo.h (original)
+++ llvm/trunk/lib/Target/X86/X86ELFWriterInfo.h Sat Jul 18 14:30:09 2009
@@ -51,7 +51,14 @@
/// getAddendForRelTy - Gets the addend value for an ELF relocation entry
/// based on the target relocation type
- virtual long int getAddendForRelTy(unsigned RelTy) const;
+ virtual long int getDefaultAddendForRelTy(unsigned RelTy) const;
+
+ /// getRelTySize - Returns the size of relocatable field in bits
+ virtual unsigned getRelocationTySize(unsigned RelTy) const;
+
+ /// getJumpTableRelocationTy - Returns the machine relocation type used
+ /// to reference a jumptable.
+ virtual unsigned getJumpTableMachineRelocationTy() const;
};
} // end llvm namespace
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