Behold, more work on relocations. Things are looking pretty good now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30240 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/MachOWriter.h b/include/llvm/CodeGen/MachOWriter.h
index bb20f7b..a5e3520 100644
--- a/include/llvm/CodeGen/MachOWriter.h
+++ b/include/llvm/CodeGen/MachOWriter.h
@@ -344,6 +344,10 @@
/// SectionData - The actual data for this section which we are building
/// up for emission to the file.
DataBuffer SectionData;
+
+ /// RelocBuffer - A buffer to hold the mach-o relocations before we write
+ /// them out at the appropriate location in the file.
+ DataBuffer RelocBuffer;
/// Relocations - The relocations that we have encountered so far in this
/// section that we will need to convert to MachORelocation entries when
@@ -421,7 +425,7 @@
}
MachOSection(const std::string &seg, const std::string §)
- : sectname(sect), segname(seg), addr(0), size(0), offset(0), align(0),
+ : sectname(sect), segname(seg), addr(0), size(0), offset(0), align(2),
reloff(0), nreloc(0), flags(0), reserved1(0), reserved2(0),
reserved3(0) { }
};
@@ -449,10 +453,13 @@
SN->flags = MachOSection::S_REGULAR | Flags;
return *SN;
}
- MachOSection &getTextSection() {
- return getSection("__TEXT", "__text",
- MachOSection::S_ATTR_PURE_INSTRUCTIONS |
- MachOSection::S_ATTR_SOME_INSTRUCTIONS);
+ MachOSection &getTextSection(bool isCode = true) {
+ if (isCode)
+ return getSection("__TEXT", "__text",
+ MachOSection::S_ATTR_PURE_INSTRUCTIONS |
+ MachOSection::S_ATTR_SOME_INSTRUCTIONS);
+ else
+ return getSection("__TEXT", "__text");
}
MachOSection &getBSSSection() {
return getSection("__DATA", "__bss", MachOSection::S_ZEROFILL);
@@ -479,6 +486,12 @@
}
return getSection("__TEXT", "__const");
}
+ MachOSection &getJumpTableSection() {
+ if (TM.getRelocationModel() == Reloc::PIC_)
+ return getTextSection(false);
+ else
+ return getSection("__TEXT", "__const");
+ }
/// MachOSymTab - This struct contains information about the offsets and
/// size of symbol table information.
@@ -563,10 +576,6 @@
/// local symbols first in the list).
std::vector<MachOSym> SymbolTable;
- /// RelocBuffer - A buffer to hold the mach-o relocations before we write
- /// them out at the appropriate location in the file.
- DataBuffer RelocBuffer;
-
/// SymT - A buffer to hold the symbol table before we write it out at the
/// appropriate location in the file.
DataBuffer SymT;
@@ -666,15 +675,31 @@
outbyte(Output, 0);
}
+ void fixhalf(DataBuffer &Output, unsigned short X, unsigned Offset) {
+ unsigned char *P = &Output[Offset];
+ P[0] = (X >> (isLittleEndian ? 0 : 8)) & 255;
+ P[1] = (X >> (isLittleEndian ? 8 : 0)) & 255;
+ }
+ void fixword(DataBuffer &Output, unsigned X, unsigned Offset) {
+ unsigned char *P = &Output[Offset];
+ P[0] = (X >> (isLittleEndian ? 0 : 24)) & 255;
+ P[1] = (X >> (isLittleEndian ? 8 : 16)) & 255;
+ P[2] = (X >> (isLittleEndian ? 16 : 8)) & 255;
+ P[3] = (X >> (isLittleEndian ? 24 : 0)) & 255;
+ }
+
private:
void AddSymbolToSection(MachOSection &MOS, GlobalVariable *GV);
void EmitGlobal(GlobalVariable *GV);
void EmitHeaderAndLoadCommands();
void EmitSections();
void BufferSymbolAndStringTable();
+ void CalculateRelocations(MachOSection &MOS, unsigned RelOffset);
- virtual void GetTargetRelocation(MachOSection &MOS, MachineRelocation &MR,
- uint64_t Addr) = 0;
+ virtual MachineRelocation GetJTRelocation(unsigned Offset,
+ MachineBasicBlock *MBB) = 0;
+ virtual void GetTargetRelocation(MachineRelocation &MR, MachOSection &MOS,
+ unsigned ToIndex) = 0;
};
}
diff --git a/lib/CodeGen/MachOWriter.cpp b/lib/CodeGen/MachOWriter.cpp
index 5ffd978..be21f5c 100644
--- a/lib/CodeGen/MachOWriter.cpp
+++ b/lib/CodeGen/MachOWriter.cpp
@@ -25,6 +25,7 @@
#include "llvm/Module.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachOWriter.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/Target/TargetJITInfo.h"
@@ -50,6 +51,14 @@
/// Relocations - These are the relocations that the function needs, as
/// emitted.
std::vector<MachineRelocation> Relocations;
+
+ /// CPLocations - This is a map of constant pool indices to offsets from the
+ /// start of the section for that constant pool index.
+ std::vector<intptr_t> CPLocations;
+
+ /// JTLocations - This is a map of jump table indices to offsets from the
+ /// start of the section for that jump table index.
+ std::vector<intptr_t> JTLocations;
/// MBBLocations - This vector is a mapping from MBB ID's to their address.
/// It is filled in by the StartMachineBasicBlock callback and queried by
@@ -66,19 +75,22 @@
Relocations.push_back(MR);
}
- virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
- if (MBBLocations.size() <= (unsigned)MBB->getNumber())
- MBBLocations.resize((MBB->getNumber()+1)*2);
- MBBLocations[MBB->getNumber()] = getCurrentPCValue();
- }
-
+ void emitConstantPool(MachineConstantPool *MCP);
+ void emitJumpTables(MachineJumpTableInfo *MJTI);
+
virtual intptr_t getConstantPoolEntryAddress(unsigned Index) const {
assert(0 && "CP not implementated yet!");
return 0;
}
virtual intptr_t getJumpTableEntryAddress(unsigned Index) const {
- assert(0 && "JT not implementated yet!");
- return 0;
+ assert(JTLocations.size() > Index && "JT not emitted!");
+ return JTLocations[Index];
+ }
+
+ virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
+ if (MBBLocations.size() <= (unsigned)MBB->getNumber())
+ MBBLocations.resize((MBB->getNumber()+1)*2);
+ MBBLocations[MBB->getNumber()] = getCurrentPCOffset();
}
virtual intptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
@@ -119,7 +131,9 @@
// Upgrade the section alignment if required.
if (MOS->align < Align) MOS->align = Align;
- // Make sure we only relocate to this function's MBBs.
+ // Clear per-function data structures.
+ CPLocations.clear();
+ JTLocations.clear();
MBBLocations.clear();
}
@@ -132,26 +146,31 @@
const GlobalValue *FuncV = F.getFunction();
MachOSym FnSym(FuncV, MOW.Mang->getValueName(FuncV), MOS->Index);
- // FIXME: emit constant pool to appropriate section(s)
- // FIXME: emit jump table to appropriate section
+ // Emit constant pool to appropriate section(s)
+ emitConstantPool(F.getConstantPool());
+
+ // Emit jump tables to appropriate section
+ emitJumpTables(F.getJumpTableInfo());
- // Resolve the function's relocations either to concrete pointers in the case
- // of branches from one block to another, or to target relocation entries.
+ // If we have emitted any relocations to function-specific objects such as
+ // basic blocks, constant pools entries, or jump tables, record their
+ // addresses now so that we can rewrite them with the correct addresses
+ // later.
for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
MachineRelocation &MR = Relocations[i];
+ intptr_t Addr;
if (MR.isBasicBlock()) {
- void *MBBAddr = (void *)getMachineBasicBlockAddress(MR.getBasicBlock());
- MR.setResultPointer(MBBAddr);
- MOW.TM.getJITInfo()->relocate(BufferBegin, &MR, 1, 0);
- } else if (MR.isConstantPoolIndex() || MR.isJumpTableIndex()) {
- // Get the address of the index.
- uint64_t Addr = 0;
- // Generate the relocation(s) for the index.
- MOW.GetTargetRelocation(*MOS, MR, Addr);
- } else {
- // Handle other types later once we've finalized the sections in the file.
- MOS->Relocations.push_back(MR);
+ Addr = getMachineBasicBlockAddress(MR.getBasicBlock());
+ MR.setResultPointer((void *)Addr);
+ } else if (MR.isConstantPoolIndex()) {
+ Addr = getConstantPoolEntryAddress(MR.getConstantPoolIndex());
+ MR.setResultPointer((void *)Addr);
+ } else if (MR.isJumpTableIndex()) {
+ // FIXME: handle PIC codegen
+ Addr = getJumpTableEntryAddress(MR.getJumpTableIndex());
+ MR.setResultPointer((void *)Addr);
}
+ MOS->Relocations.push_back(MR);
}
Relocations.clear();
@@ -160,6 +179,42 @@
return false;
}
+/// emitConstantPool - For each constant pool entry, figure out which section
+/// the constant should live in, allocate space for it, and emit it to the
+/// Section data buffer.
+void MachOCodeEmitter::emitConstantPool(MachineConstantPool *MCP) {
+}
+
+/// emitJumpTables - Emit all the jump tables for a given jump table info
+/// record to the appropriate section.
+void MachOCodeEmitter::emitJumpTables(MachineJumpTableInfo *MJTI) {
+ const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
+ if (JT.empty()) return;
+
+ bool isPIC = MOW.TM.getRelocationModel() == Reloc::PIC_;
+ assert(!isPIC && "PIC codegen not yet handled for mach-o jump tables!");
+
+ MachOWriter::MachOSection &Sec = MOW.getJumpTableSection();
+
+ for (unsigned i = 0, e = JT.size(); i != e; ++i) {
+ // For each jump table, record its offset from the start of the section,
+ // reserve space for the relocations to the MBBs, and add the relocations.
+ const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
+ JTLocations.push_back(Sec.SectionData.size());
+ for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
+ MachineRelocation MR(MOW.GetJTRelocation(Sec.SectionData.size(),
+ MBBs[mi]));
+ MR.setResultPointer((void *)JTLocations[i]);
+ Sec.Relocations.push_back(MR);
+ MOW.outaddr(Sec.SectionData, 0);
+ }
+ }
+ // FIXME: it really seems like keeping these in sync is redundant, someone
+ // should do something about that (never access section size directly, only
+ // look at buffer size).
+ Sec.size = Sec.SectionData.size();
+}
+
//===----------------------------------------------------------------------===//
// MachOWriter Implementation
//===----------------------------------------------------------------------===//
@@ -294,12 +349,9 @@
// Emit the header and load commands.
EmitHeaderAndLoadCommands();
- // Emit the text and data sections.
+ // Emit the various sections and their relocation info.
EmitSections();
- // Emit the relocation entry data for each section.
- O.write((char*)&RelocBuffer[0], RelocBuffer.size());
-
// Write the symbol table and the string table to the end of the file.
O.write((char*)&SymT[0], SymT.size());
O.write((char*)&StrT[0], StrT.size());
@@ -370,6 +422,7 @@
E = SectionList.end(); I != E; ++I) {
I->addr = currentAddr;
I->offset = currentAddr + SEG.fileoff;
+
// FIXME: do we need to do something with alignment here?
currentAddr += I->size;
}
@@ -380,14 +433,8 @@
for (std::list<MachOSection>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I) {
// calculate the relocation info for this section command
- // FIXME: this could get complicated calculating the address argument, we
- // should probably split this out into its own function.
- for (unsigned i = 0, e = I->Relocations.size(); i != e; ++i)
- GetTargetRelocation(*I, I->Relocations[i], 0);
- if (I->nreloc != 0) {
- I->reloff = currentAddr;
- currentAddr += I->nreloc * 8;
- }
+ CalculateRelocations(*I, currentAddr);
+ currentAddr += I->nreloc * 8;
// write the finalized section command to the output buffer
outstring(FH, I->sectname, 16);
@@ -449,9 +496,13 @@
/// commands, emit the data for each section to the file.
void MachOWriter::EmitSections() {
for (std::list<MachOSection>::iterator I = SectionList.begin(),
- E = SectionList.end(); I != E; ++I) {
+ E = SectionList.end(); I != E; ++I)
+ // Emit the contents of each section
O.write((char*)&I->SectionData[0], I->size);
- }
+ for (std::list<MachOSection>::iterator I = SectionList.begin(),
+ E = SectionList.end(); I != E; ++I)
+ // Emit the relocation entry data for each section.
+ O.write((char*)&I->RelocBuffer[0], I->RelocBuffer.size());
}
/// PartitionByLocal - Simple boolean predicate that returns true if Sym is
@@ -526,6 +577,23 @@
}
}
+/// CalculateRelocations - For each MachineRelocation in the current section,
+/// calculate the index of the section containing the object to be relocated,
+/// and the offset into that section. From this information, create the
+/// appropriate target-specific MachORelocation type and add buffer it to be
+/// written out after we are finished writing out sections.
+void MachOWriter::CalculateRelocations(MachOSection &MOS, unsigned RelOffset) {
+ for (unsigned i = 0, e = MOS.Relocations.size(); i != e; ++i) {
+ // FIXME: calculate the correct offset and section index for relocated
+ // object.
+ // FIXME: somehow convey the fact that the relocation might be external
+ // to the relocating code.
+ GetTargetRelocation(MOS.Relocations[i], MOS, MOS.Index);
+ }
+ if (MOS.nreloc != 0)
+ MOS.reloff = RelOffset;
+}
+
MachOSym::MachOSym(const GlobalValue *gv, std::string name, uint8_t sect) :
GV(gv), GVName(name), n_strx(0), n_type(sect == NO_SECT ? N_UNDF : N_SECT),
n_sect(sect), n_desc(0), n_value(0) {
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index e266c75..91ae641 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -673,7 +673,7 @@
///
void *ConstantPoolBase;
- /// ConstantPool - The constant pool for the current function.
+ /// JumpTable - The jump tables for the current function.
///
MachineJumpTableInfo *JumpTable;
diff --git a/lib/Target/PowerPC/PPCMachOWriter.cpp b/lib/Target/PowerPC/PPCMachOWriter.cpp
index f82ee34..8d6de73 100644
--- a/lib/Target/PowerPC/PPCMachOWriter.cpp
+++ b/lib/Target/PowerPC/PPCMachOWriter.cpp
@@ -31,9 +31,15 @@
Header.cpusubtype = MachOHeader::CPU_SUBTYPE_POWERPC_ALL;
}
- virtual void GetTargetRelocation(MachOSection &MOS, MachineRelocation &MR,
- uint64_t Addr);
+ virtual void GetTargetRelocation(MachineRelocation &MR, MachOSection &MOS,
+ unsigned ToIndex);
+ virtual MachineRelocation GetJTRelocation(unsigned Offset,
+ MachineBasicBlock *MBB);
+ virtual const char *getPassName() const {
+ return "PowerPC Mach-O Writer";
+ }
+
// Constants for the relocation r_type field.
// see <mach-o/ppc/reloc.h>
enum { PPC_RELOC_VANILLA, // generic relocation
@@ -53,73 +59,93 @@
///
void llvm::addPPCMachOObjectWriterPass(FunctionPassManager &FPM,
std::ostream &O, PPCTargetMachine &TM) {
- PPCMachOWriter *EW = new PPCMachOWriter(O, TM);
- FPM.add(EW);
- FPM.add(createPPCCodeEmitterPass(TM, EW->getMachineCodeEmitter()));
+ PPCMachOWriter *MOW = new PPCMachOWriter(O, TM);
+ FPM.add(MOW);
+ FPM.add(createPPCCodeEmitterPass(TM, MOW->getMachineCodeEmitter()));
}
/// GetTargetRelocation - For the MachineRelocation MR, convert it to one or
/// more PowerPC MachORelocation(s), add the new relocations to the
/// MachOSection, and rewrite the instruction at the section offset if required
/// by that relocation type.
-void PPCMachOWriter::GetTargetRelocation(MachOSection &MOS,
- MachineRelocation &MR,
- uint64_t Addr) {
+void PPCMachOWriter::GetTargetRelocation(MachineRelocation &MR,
+ MachOSection &MOS,
+ unsigned ToIndex) {
+ uint64_t Addr = 0;
+
// Keep track of whether or not this is an externally defined relocation.
- uint32_t index = MOS.Index;
bool isExtern = false;
- // Get the address of the instruction to rewrite
- unsigned char *RelocPos = &MOS.SectionData[0] + MR.getMachineCodeOffset();
-
// Get the address of whatever it is we're relocating, if possible.
- if (MR.isGlobalValue()) {
- // determine whether or not its external and then figure out what section
- // we put it in if it's a locally defined symbol.
- } else if (MR.isString()) {
- // lookup in global values?
- } else {
- assert((MR.isConstantPoolIndex() || MR.isJumpTableIndex()) &&
- "Unhandled MachineRelocation type!");
- }
-
+ if (!isExtern)
+ Addr = (uintptr_t)MR.getResultPointer();
+
switch ((PPC::RelocationType)MR.getRelocationType()) {
default: assert(0 && "Unknown PPC relocation type!");
- case PPC::reloc_pcrel_bx:
- case PPC::reloc_pcrel_bcx:
case PPC::reloc_absolute_low_ix:
assert(0 && "Unhandled PPC relocation type!");
break;
+ case PPC::reloc_vanilla:
+ {
+ // FIXME: need to handle 64 bit vanilla relocs
+ MachORelocation VANILLA(MR.getMachineCodeOffset(), ToIndex, false, 2,
+ isExtern, PPC_RELOC_VANILLA);
+ outword(MOS.RelocBuffer, VANILLA.r_address);
+ outword(MOS.RelocBuffer, VANILLA.getPackedFields());
+ }
+ MOS.nreloc += 1;
+ fixword(MOS.SectionData, Addr, MR.getMachineCodeOffset());
+ break;
+ case PPC::reloc_pcrel_bx:
+ Addr -= MR.getMachineCodeOffset();
+ Addr >>= 2;
+ Addr & 0xFFFFFF;
+ Addr <<= 2;
+ Addr |= (MOS.SectionData[MR.getMachineCodeOffset()] << 24);
+ fixword(MOS.SectionData, Addr, MR.getMachineCodeOffset());
+ break;
+ case PPC::reloc_pcrel_bcx:
+ Addr -= MR.getMachineCodeOffset();
+ Addr &= 0xFFFC;
+ fixhalf(MOS.SectionData, Addr, MR.getMachineCodeOffset() + 2);
+ break;
case PPC::reloc_absolute_high:
{
- MachORelocation HA16(MR.getMachineCodeOffset(), index, false, 2, isExtern,
- PPC_RELOC_HA16);
+ MachORelocation HA16(MR.getMachineCodeOffset(), ToIndex, false, 2,
+ isExtern, PPC_RELOC_HA16);
MachORelocation PAIR(Addr & 0xFFFF, 0xFFFFFF, false, 2, isExtern,
PPC_RELOC_PAIR);
- outword(RelocBuffer, HA16.r_address);
- outword(RelocBuffer, HA16.getPackedFields());
- outword(RelocBuffer, PAIR.r_address);
- outword(RelocBuffer, PAIR.getPackedFields());
+ outword(MOS.RelocBuffer, HA16.r_address);
+ outword(MOS.RelocBuffer, HA16.getPackedFields());
+ outword(MOS.RelocBuffer, PAIR.r_address);
+ outword(MOS.RelocBuffer, PAIR.getPackedFields());
}
+ printf("ha16: %x\n", (unsigned)Addr);
MOS.nreloc += 2;
Addr += 0x8000;
- *(unsigned *)RelocPos &= 0xFFFF0000;
- *(unsigned *)RelocPos |= ((Addr >> 16) & 0xFFFF);
+ fixhalf(MOS.SectionData, Addr >> 16, MR.getMachineCodeOffset() + 2);
break;
case PPC::reloc_absolute_low:
{
- MachORelocation LO16(MR.getMachineCodeOffset(), index, false, 2, isExtern,
- PPC_RELOC_LO16);
+ MachORelocation LO16(MR.getMachineCodeOffset(), ToIndex, false, 2,
+ isExtern, PPC_RELOC_LO16);
MachORelocation PAIR(Addr >> 16, 0xFFFFFF, false, 2, isExtern,
PPC_RELOC_PAIR);
- outword(RelocBuffer, LO16.r_address);
- outword(RelocBuffer, LO16.getPackedFields());
- outword(RelocBuffer, PAIR.r_address);
- outword(RelocBuffer, PAIR.getPackedFields());
+ outword(MOS.RelocBuffer, LO16.r_address);
+ outword(MOS.RelocBuffer, LO16.getPackedFields());
+ outword(MOS.RelocBuffer, PAIR.r_address);
+ outword(MOS.RelocBuffer, PAIR.getPackedFields());
}
+ printf("lo16: %x\n", (unsigned)Addr);
MOS.nreloc += 2;
- *(unsigned *)RelocPos &= 0xFFFF0000;
- *(unsigned *)RelocPos |= (Addr & 0xFFFF);
+ fixhalf(MOS.SectionData, Addr, MR.getMachineCodeOffset() + 2);
break;
}
}
+
+MachineRelocation PPCMachOWriter::GetJTRelocation(unsigned Offset,
+ MachineBasicBlock *MBB) {
+ // FIXME: do something about PIC
+ return MachineRelocation::getBB(Offset, PPC::reloc_vanilla, MBB);
+}
+
diff --git a/lib/Target/PowerPC/PPCRelocations.h b/lib/Target/PowerPC/PPCRelocations.h
index 21c688d..261622f 100644
--- a/lib/Target/PowerPC/PPCRelocations.h
+++ b/lib/Target/PowerPC/PPCRelocations.h
@@ -25,6 +25,10 @@
namespace llvm {
namespace PPC {
enum RelocationType {
+ // reloc_vanilla - A standard relocation, where the address of the
+ // relocated object completely overwrites the address of the relocation.
+ reloc_vanilla,
+
// reloc_pcrel_bx - PC relative relocation, for the b or bl instructions.
reloc_pcrel_bx,