6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-07-24 08:29:39 +00:00
Code Issues Projects Releases Wiki Activity

MCJIT support for non-function sections.

Browse Source 
Move to a by-section allocation and relocation scheme. This allows
better support for sections which do not contain externally visible
symbols.

Flesh out the relocation address vs. local storage address separation a
bit more as well. Remote process JITs use this to tell the relocation
resolution code where the code will live when it executes.

The startFunctionBody/endFunctionBody interfaces to the JIT and the
memory manager are deprecated. They'll stick around for as long as the
old JIT does, but the MCJIT doesn't use them anymore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148258 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2012-01-16 22:26:39 +00:00
parent 27bf56056b
commit 61425c0a7f
10 changed files with 492 additions and 259 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
include/llvm/ExecutionEngine/JITMemoryManager.h
View File

@ -101,6 +101,22 @@ public:
virtual void endFunctionBody(const Function *F, uint8_t *FunctionStart,
uint8_t *FunctionEnd) = 0;
/// allocateCodeSection - Allocate a memory block of (at least) the given
/// size suitable for executable code. The SectionID is a unique identifier
/// assigned by the JIT and passed through to the memory manager for
/// the instance class to use if it needs to communicate to the JIT about
/// a given section after the fact.
virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) = 0;
/// allocateDataSection - Allocate a memory block of (at least) the given
/// size suitable for data. The SectionID is a unique identifier
/// assigned by the JIT and passed through to the memory manager for
/// the instance class to use if it needs to communicate to the JIT about
/// a given section after the fact.
virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) = 0;
/// allocateSpace - Allocate a memory block of the given size. This method
/// cannot be called between calls to startFunctionBody and endFunctionBody.
virtual uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) = 0;

14
include/llvm/ExecutionEngine/RuntimeDyld.h
View File

@ -35,6 +35,16 @@ public:
RTDyldMemoryManager() {}
virtual ~RTDyldMemoryManager();
/// allocateCodeSection - Allocate a memory block of (at least) the given
/// size suitable for executable code.
virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) = 0;
/// allocateDataSection - Allocate a memory block of (at least) the given
/// size suitable for data.
virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) = 0;
// Allocate ActualSize bytes, or more, for the named function. Return
// a pointer to the allocated memory and update Size to reflect how much
// memory was acutally allocated.
@ -65,9 +75,9 @@ public:
void *getSymbolAddress(StringRef Name);
// Resolve the relocations for all symbols we currently know about.
void resolveRelocations();
// Change the address associated with a symbol when resolving relocations.
// Change the address associated with a section when resolving relocations.
// Any relocations already associated with the symbol will be re-resolved.
void reassignSymbolAddress(StringRef Name, uint8_t *Addr);
void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
StringRef getErrorString();
};

44
lib/ExecutionEngine/JIT/JITMemoryManager.cpp
View File

@ -441,6 +441,50 @@ namespace {
return (uint8_t*)DataAllocator.Allocate(Size, Alignment);
}
/// allocateCodeSection - Allocate memory for a code section.
uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) {
// FIXME: Alignement handling.
FreeRangeHeader* candidateBlock = FreeMemoryList;
FreeRangeHeader* head = FreeMemoryList;
FreeRangeHeader* iter = head->Next;
uintptr_t largest = candidateBlock->BlockSize;
// Search for the largest free block.
while (iter != head) {
if (iter->BlockSize > largest) {
largest = iter->BlockSize;
candidateBlock = iter;
}
iter = iter->Next;
}
largest = largest - sizeof(MemoryRangeHeader);
// If this block isn't big enough for the allocation desired, allocate
// another block of memory and add it to the free list.
if (largest < Size || largest <= FreeRangeHeader::getMinBlockSize()) {
DEBUG(dbgs() << "JIT: Allocating another slab of memory for function.");
candidateBlock = allocateNewCodeSlab((size_t)Size);
}
// Select this candidate block for allocation
CurBlock = candidateBlock;
// Allocate the entire memory block.
FreeMemoryList = candidateBlock->AllocateBlock();
// Release the memory at the end of this block that isn't needed.
FreeMemoryList = CurBlock->TrimAllocationToSize(FreeMemoryList, Size);
return (uint8_t *)(CurBlock + 1);
}
/// allocateDataSection - Allocate memory for a data section.
uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) {
return (uint8_t*)DataAllocator.Allocate(Size, Alignment);
}
/// startExceptionTable - Use startFunctionBody to allocate memory for the
/// function's exception table.
uint8_t* startExceptionTable(const Function* F, uintptr_t &ActualSize) {

10
lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h
View File

@ -31,6 +31,16 @@ public:
// We own the JMM, so make sure to delete it.
~MCJITMemoryManager() { delete JMM; }
uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) {
return JMM->allocateDataSection(Size, Alignment, SectionID);
}
uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) {
return JMM->allocateCodeSection(Size, Alignment, SectionID);
}
// Allocate ActualSize bytes, or more, for the named function. Return
// a pointer to the allocated memory and update Size to reflect how much
// memory was acutally allocated.

23
lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
View File

@ -25,6 +25,7 @@ namespace llvm {
void RuntimeDyldImpl::extractFunction(StringRef Name, uint8_t *StartAddress,
uint8_t *EndAddress) {
// FIXME: DEPRECATED in favor of by-section allocation.
// Allocate memory for the function via the memory manager.
uintptr_t Size = EndAddress - StartAddress + 1;
uintptr_t AllocSize = Size;
@ -35,21 +36,22 @@ void RuntimeDyldImpl::extractFunction(StringRef Name, uint8_t *StartAddress,
memcpy(Mem, StartAddress, Size);
MemMgr->endFunctionBody(Name.data(), Mem, Mem + Size);
// Remember where we put it.
Functions[Name] = sys::MemoryBlock(Mem, Size);
unsigned SectionID = Sections.size();
Sections.push_back(sys::MemoryBlock(Mem, Size));
// Default the assigned address for this symbol to wherever this
// allocated it.
SymbolTable[Name] = Mem;
SymbolTable[Name] = SymbolLoc(SectionID, 0);
DEBUG(dbgs() << " allocated to [" << Mem << ", " << Mem + Size << "]\n");
}
// Resolve the relocations for all symbols we currently know about.
void RuntimeDyldImpl::resolveRelocations() {
// Just iterate over the symbols in our symbol table and assign their
// addresses.
StringMap<uint8_t*>::iterator i = SymbolTable.begin();
StringMap<uint8_t*>::iterator e = SymbolTable.end();
for (;i != e; ++i)
reassignSymbolAddress(i->getKey(), i->getValue());
// Just iterate over the sections we have and resolve all the relocations
// in them. Gross overkill, but it gets the job done.
for (int i = 0, e = Sections.size(); i != e; ++i) {
reassignSectionAddress(i, SectionLoadAddress[i]);
}
}
//===----------------------------------------------------------------------===//
@ -109,8 +111,9 @@ void RuntimeDyld::resolveRelocations() {
Dyld->resolveRelocations();
}
void RuntimeDyld::reassignSymbolAddress(StringRef Name, uint8_t *Addr) {
Dyld->reassignSymbolAddress(Name, Addr);
void RuntimeDyld::reassignSectionAddress(unsigned SectionID,
uint64_t Addr) {
Dyld->reassignSectionAddress(SectionID, Addr);
}
StringRef RuntimeDyld::getErrorString() {

57
lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
View File

@ -154,17 +154,31 @@ bool RuntimeDyldELF::loadObject(MemoryBuffer *InputBuffer) {
return false;
}
void RuntimeDyldELF::resolveRelocations() {
// FIXME: deprecated. should be changed to use the by-section
// allocation and relocation scheme.
// Just iterate over the symbols in our symbol table and assign their
// addresses.
StringMap<SymbolLoc>::iterator i = SymbolTable.begin();
StringMap<SymbolLoc>::iterator e = SymbolTable.end();
for (;i != e; ++i) {
assert (i->getValue().second == 0 && "non-zero offset in by-function sym!");
reassignSymbolAddress(i->getKey(),
(uint8_t*)Sections[i->getValue().first].base());
}
}
void RuntimeDyldELF::resolveX86_64Relocation(StringRef Name,
uint8_t *Addr,
const RelocationEntry &RE) {
uint8_t *TargetAddr;
if (RE.IsFunctionRelative) {
StringMap<sys::MemoryBlock>::iterator ContainingFunc
= Functions.find(RE.Target);
assert(ContainingFunc != Functions.end()
&& "Function for relocation not found");
TargetAddr = reinterpret_cast<uint8_t*>(ContainingFunc->getValue().base()) +
RE.Offset;
StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(RE.Target);
assert(Loc != SymbolTable.end() && "Function for relocation not found");
TargetAddr =
reinterpret_cast<uint8_t*>(Sections[Loc->second.first].base()) +
Loc->second.second + RE.Offset;
} else {
// FIXME: Get the address of the target section and add that to RE.Offset
assert(0 && ("Non-function relocation not implemented yet!"));
@ -209,12 +223,11 @@ void RuntimeDyldELF::resolveX86Relocation(StringRef Name,
const RelocationEntry &RE) {
uint8_t *TargetAddr;
if (RE.IsFunctionRelative) {
StringMap<sys::MemoryBlock>::iterator ContainingFunc
= Functions.find(RE.Target);
assert(ContainingFunc != Functions.end()
&& "Function for relocation not found");
TargetAddr = reinterpret_cast<uint8_t*>(
ContainingFunc->getValue().base()) + RE.Offset;
StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(RE.Target);
assert(Loc != SymbolTable.end() && "Function for relocation not found");
TargetAddr =
reinterpret_cast<uint8_t*>(Sections[Loc->second.first].base()) +
Loc->second.second + RE.Offset;
} else {
// FIXME: Get the address of the target section and add that to RE.Offset
assert(0 && ("Non-function relocation not implemented yet!"));
@ -266,7 +279,11 @@ void RuntimeDyldELF::resolveRelocation(StringRef Name,
}
void RuntimeDyldELF::reassignSymbolAddress(StringRef Name, uint8_t *Addr) {
SymbolTable[Name] = Addr;
// FIXME: deprecated. switch to reassignSectionAddress() instead.
//
// Actually moving the symbol address requires by-section mapping.
assert(Sections[SymbolTable.lookup(Name).first].base() == (void*)Addr &&
"Unable to relocate section in by-function JIT allocation model!");
RelocationList &Relocs = Relocations[Name];
for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
@ -275,6 +292,20 @@ void RuntimeDyldELF::reassignSymbolAddress(StringRef Name, uint8_t *Addr) {
}
}
// Assign an address to a symbol name and resolve all the relocations
// associated with it.
void RuntimeDyldELF::reassignSectionAddress(unsigned SectionID, uint64_t Addr) {
// The address to use for relocation resolution is not
// the address of the local section buffer. We must be doing
// a remote execution environment of some sort. Re-apply any
// relocations referencing this section with the given address.
//
// Addr is a uint64_t because we can't assume the pointer width
// of the target is the same as that of the host. Just use a generic
// "big enough" type.
assert(0);
}
bool RuntimeDyldELF::isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
StringRef Magic = InputBuffer->getBuffer().slice(0, ELF::EI_NIDENT);
return (memcmp(Magic.data(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;

83
lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
View File

@ -16,6 +16,7 @@
#include "llvm/ExecutionEngine/RuntimeDyld.h"
#include "llvm/Object/MachOObject.h"
#include "llvm/ADT/IndexedMap.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Twine.h"
#include "llvm/ADT/SmallVector.h"
@ -40,17 +41,18 @@ protected:
// The MemoryManager to load objects into.
RTDyldMemoryManager *MemMgr;
// FIXME: This all assumes we're dealing with external symbols for anything
// explicitly referenced. I.e., we can index by name and things
// will work out. In practice, this may not be the case, so we
// should find a way to effectively generalize.
// For each function, we have a MemoryBlock of it's instruction data.
StringMap<sys::MemoryBlock> Functions;
// For each section, we have a MemoryBlock of it's data.
// Indexed by SectionID.
SmallVector<sys::MemoryBlock, 32> Sections;
// For each section, the address it will be considered to live at for
// relocations. The same as the pointer the above memory block for hosted
// JITs. Indexed by SectionID.
SmallVector<uint64_t, 32> SectionLoadAddress;
// Master symbol table. As modules are loaded and external symbols are
// resolved, their addresses are stored here.
StringMap<uint8_t*> SymbolTable;
// resolved, their addresses are stored here as a SectionID/Offset pair.
typedef std::pair<unsigned, uint64_t> SymbolLoc;
StringMap<SymbolLoc> SymbolTable;
bool HasError;
std::string ErrorStr;
@ -62,6 +64,9 @@ protected:
return true;
}
uint8_t *getSectionAddress(unsigned SectionID) {
return (uint8_t*)Sections[SectionID].base();
}
void extractFunction(StringRef Name, uint8_t *StartAddress,
uint8_t *EndAddress);
@ -75,12 +80,15 @@ public:
void *getSymbolAddress(StringRef Name) {
// FIXME: Just look up as a function for now. Overly simple of course.
// Work in progress.
return SymbolTable.lookup(Name);
if (SymbolTable.find(Name) == SymbolTable.end())
return 0;
SymbolLoc Loc = SymbolTable.lookup(Name);
return getSectionAddress(Loc.first) + Loc.second;
}
void resolveRelocations();
virtual void resolveRelocations();
virtual void reassignSymbolAddress(StringRef Name, uint8_t *Addr) = 0;
virtual void reassignSectionAddress(unsigned SectionID, uint64_t Addr) = 0;
// Is the linker in an error state?
bool hasError() { return HasError; }
@ -128,6 +136,8 @@ class RuntimeDyldELF : public RuntimeDyldImpl {
StringMap<RelocationList> Relocations;
unsigned Arch;
void resolveRelocations();
void resolveX86_64Relocation(StringRef Name,
uint8_t *Addr,
const RelocationEntry &RE);
@ -150,6 +160,7 @@ public:
bool loadObject(MemoryBuffer *InputBuffer);
void reassignSymbolAddress(StringRef Name, uint8_t *Addr);
void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const;
};
@ -160,30 +171,34 @@ class RuntimeDyldMachO : public RuntimeDyldImpl {
// For each symbol, keep a list of relocations based on it. Anytime
// its address is reassigned (the JIT re-compiled the function, e.g.),
// the relocations get re-resolved.
// The symbol (or section) the relocation is sourced from is the Key
// in the relocation list where it's stored.
struct RelocationEntry {
std::string Target; // Object this relocation is contained in.
uint64_t Offset; // Offset into the object for the relocation.
unsigned SectionID; // Section the relocation is contained in.
uint64_t Offset; // Offset into the section for the relocation.
uint32_t Data; // Second word of the raw macho relocation entry.
int64_t Addend; // Addend encoded in the instruction itself, if any.
bool isResolved; // Has this relocation been resolved previously?
int64_t Addend; // Addend encoded in the instruction itself, if any,
// plus the offset into the source section for
// the symbol once the relocation is resolvable.
RelocationEntry(StringRef t, uint64_t offset, uint32_t data, int64_t addend)
: Target(t), Offset(offset), Data(data), Addend(addend),
isResolved(false) {}
RelocationEntry(unsigned id, uint64_t offset, uint32_t data, int64_t addend)
: SectionID(id), Offset(offset), Data(data), Addend(addend) {}
};
typedef SmallVector<RelocationEntry, 4> RelocationList;
StringMap<RelocationList> Relocations;
// Relocations to sections already loaded. Indexed by SectionID which is the
// source of the address. The target where the address will be writen is
// SectionID/Offset in the relocation itself.
IndexedMap<RelocationList> Relocations;
// Relocations to symbols that are not yet resolved. Must be external
// relocations by definition. Indexed by symbol name.
StringMap<RelocationList> UnresolvedRelocations;
// FIXME: Also keep a map of all the relocations contained in an object. Use
// this to dynamically answer whether all of the relocations in it have
// been resolved or not.
bool resolveRelocation(uint8_t *Address, uint8_t *Value, bool isPCRel,
unsigned Type, unsigned Size);
bool resolveRelocation(uint8_t *Address, uint64_t Value, bool isPCRel,
unsigned Type, unsigned Size, int64_t Addend);
bool resolveX86_64Relocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
unsigned Type, unsigned Size);
unsigned Type, unsigned Size, int64_t Addend);
bool resolveARMRelocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
unsigned Type, unsigned Size);
unsigned Type, unsigned Size, int64_t Addend);
bool loadSegment32(const MachOObject *Obj,
const MachOObject::LoadCommandInfo *SegmentLCI,
@ -191,13 +206,23 @@ class RuntimeDyldMachO : public RuntimeDyldImpl {
bool loadSegment64(const MachOObject *Obj,
const MachOObject::LoadCommandInfo *SegmentLCI,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
bool processSymbols32(const MachOObject *Obj,
SmallVectorImpl<unsigned> &SectionMap,
SmallVectorImpl<StringRef> &SymbolNames,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
bool processSymbols64(const MachOObject *Obj,
SmallVectorImpl<unsigned> &SectionMap,
SmallVectorImpl<StringRef> &SymbolNames,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
void resolveSymbol(StringRef Name);
public:
RuntimeDyldMachO(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
bool loadObject(MemoryBuffer *InputBuffer);
void reassignSymbolAddress(StringRef Name, uint8_t *Addr);
void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
static bool isKnownFormat(const MemoryBuffer *InputBuffer);

478
lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
View File

@ -22,25 +22,24 @@ using namespace llvm::object;
namespace llvm {
bool RuntimeDyldMachO::
resolveRelocation(uint8_t *Address, uint8_t *Value, bool isPCRel,
unsigned Type, unsigned Size) {
resolveRelocation(uint8_t *Address, uint64_t Value, bool isPCRel,
unsigned Type, unsigned Size, int64_t Addend) {
// This just dispatches to the proper target specific routine.
switch (CPUType) {
default: assert(0 && "Unsupported CPU type!");
case mach::CTM_x86_64:
return resolveX86_64Relocation((uintptr_t)Address, (uintptr_t)Value,
isPCRel, Type, Size);
isPCRel, Type, Size, Addend);
case mach::CTM_ARM:
return resolveARMRelocation((uintptr_t)Address, (uintptr_t)Value,
isPCRel, Type, Size);
isPCRel, Type, Size, Addend);
}
llvm_unreachable("");
}
bool RuntimeDyldMachO::
resolveX86_64Relocation(uintptr_t Address, uintptr_t Value,
bool isPCRel, unsigned Type,
unsigned Size) {
resolveX86_64Relocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
unsigned Type, unsigned Size, int64_t Addend) {
// If the relocation is PC-relative, the value to be encoded is the
// pointer difference.
if (isPCRel)
@ -75,9 +74,9 @@ resolveX86_64Relocation(uintptr_t Address, uintptr_t Value,
return false;
}
bool RuntimeDyldMachO::resolveARMRelocation(uintptr_t Address, uintptr_t Value,
bool isPCRel, unsigned Type,
unsigned Size) {
bool RuntimeDyldMachO::
resolveARMRelocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
unsigned Type, unsigned Size, int64_t Addend) {
// If the relocation is PC-relative, the value to be encoded is the
// pointer difference.
if (isPCRel) {
@ -135,84 +134,63 @@ bool RuntimeDyldMachO::
loadSegment32(const MachOObject *Obj,
const MachOObject::LoadCommandInfo *SegmentLCI,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
// FIXME: This should really be combined w/ loadSegment64. Templatized
// function on the 32/64 datatypes maybe?
InMemoryStruct<macho::SegmentLoadCommand> SegmentLC;
Obj->ReadSegmentLoadCommand(*SegmentLCI, SegmentLC);
if (!SegmentLC)
return Error("unable to load segment load command");
SmallVector<unsigned, 16> SectionMap;
for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) {
InMemoryStruct<macho::Section> Sect;
Obj->ReadSection(*SegmentLCI, SectNum, Sect);
if (!Sect)
return Error("unable to load section: '" + Twine(SectNum) + "'");
// FIXME: For the time being, we're only loading text segments.
// Allocate memory via the MM for the section.
uint8_t *Buffer;
uint32_t SectionID = Sections.size();
if (Sect->Flags != 0x80000400)
continue;
Buffer = MemMgr->allocateCodeSection(Sect->Size, Sect->Align, SectionID);
else
Buffer = MemMgr->allocateDataSection(Sect->Size, Sect->Align, SectionID);
// Address and names of symbols in the section.
typedef std::pair<uint64_t, StringRef> SymbolEntry;
SmallVector<SymbolEntry, 64> Symbols;
// Index of all the names, in this section or not. Used when we're
// dealing with relocation entries.
SmallVector<StringRef, 64> SymbolNames;
for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
InMemoryStruct<macho::SymbolTableEntry> STE;
Obj->ReadSymbolTableEntry(SymtabLC->SymbolTableOffset, i, STE);
if (!STE)
return Error("unable to read symbol: '" + Twine(i) + "'");
if (STE->SectionIndex > SegmentLC->NumSections)
return Error("invalid section index for symbol: '" + Twine(i) + "'");
// Get the symbol name.
StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
SymbolNames.push_back(Name);
DEBUG(dbgs() << "Loading "
<< ((Sect->Flags == 0x80000400) ? "text" : "data")
<< " (ID #" << SectionID << ")"
<< " '" << Sect->SegmentName << ","
<< Sect->Name << "' of size " << Sect->Size
<< " to address " << Buffer << ".\n");
// Just skip symbols not defined in this section.
if ((unsigned)STE->SectionIndex - 1 != SectNum)
continue;
// FIXME: Check the symbol type and flags.
if (STE->Type != 0xF) // external, defined in this section.
continue;
// Flags == 0x8 marks a thumb function for ARM, which is fine as it
// doesn't require any special handling here.
// Flags in the upper nibble we don't care about.
if ((STE->Flags & 0xf) != 0x0 && STE->Flags != 0x8)
continue;
// Remember the symbol.
Symbols.push_back(SymbolEntry(STE->Value, Name));
DEBUG(dbgs() << "Function sym: '" << Name << "' @ " <<
(Sect->Address + STE->Value) << "\n");
}
// Sort the symbols by address, just in case they didn't come in that way.
array_pod_sort(Symbols.begin(), Symbols.end());
// If there weren't any functions (odd, but just in case...)
if (!Symbols.size())
continue;
// Extract the function data.
// Copy the payload from the object file into the allocated buffer.
uint8_t *Base = (uint8_t*)Obj->getData(SegmentLC->FileOffset,
SegmentLC->FileSize).data();
for (unsigned i = 0, e = Symbols.size() - 1; i != e; ++i) {
uint64_t StartOffset = Sect->Address + Symbols[i].first;
uint64_t EndOffset = Symbols[i + 1].first - 1;
DEBUG(dbgs() << "Extracting function: " << Symbols[i].second
<< " from [" << StartOffset << ", " << EndOffset << "]\n");
extractFunction(Symbols[i].second, Base + StartOffset, Base + EndOffset);
}
// The last symbol we do after since the end address is calculated
// differently because there is no next symbol to reference.
uint64_t StartOffset = Symbols[Symbols.size() - 1].first;
uint64_t EndOffset = Sect->Size - 1;
DEBUG(dbgs() << "Extracting function: " << Symbols[Symbols.size()-1].second
<< " from [" << StartOffset << ", " << EndOffset << "]\n");
extractFunction(Symbols[Symbols.size()-1].second,
Base + StartOffset, Base + EndOffset);
memcpy(Buffer, Base + Sect->Address, Sect->Size);
// Now extract the relocation information for each function and process it.
// Remember what got allocated for this SectionID.
Sections.push_back(sys::MemoryBlock(Buffer, Sect->Size));
// By default, the load address of a section is its memory buffer.
SectionLoadAddress.push_back((uint64_t)Buffer);
// Keep a map of object file section numbers to corresponding SectionIDs
// while processing the file.
SectionMap.push_back(SectionID);
}
// Process the symbol table.
SmallVector<StringRef, 64> SymbolNames;
processSymbols32(Obj, SectionMap, SymbolNames, SymtabLC);
// Process the relocations for each section we're loading.
Relocations.grow(Relocations.size() + SegmentLC->NumSections);
for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) {
InMemoryStruct<macho::Section> Sect;
Obj->ReadSection(*SegmentLCI, SectNum, Sect);
if (!Sect)
return Error("unable to load section: '" + Twine(SectNum) + "'");
for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
InMemoryStruct<macho::RelocationEntry> RE;
Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
@ -222,51 +200,53 @@ loadSegment32(const MachOObject *Obj,
// relocation should be applied. We need to translate that into an
// offset into a function since that's our atom.
uint32_t Offset = RE->Word0;
// Look for the function containing the address. This is used for JIT
// code, so the number of functions in section is almost always going
// to be very small (usually just one), so until we have use cases
// where that's not true, just use a trivial linear search.
unsigned SymbolNum;
unsigned NumSymbols = Symbols.size();
assert(NumSymbols > 0 && Symbols[0].first <= Offset &&
"No symbol containing relocation!");
for (SymbolNum = 0; SymbolNum < NumSymbols - 1; ++SymbolNum)
if (Symbols[SymbolNum + 1].first > Offset)
break;
// Adjust the offset to be relative to the symbol.
Offset -= Symbols[SymbolNum].first;
// Get the name of the symbol containing the relocation.
StringRef TargetName = SymbolNames[SymbolNum];
bool isExtern = (RE->Word1 >> 27) & 1;
// FIXME: Get the relocation addend from the target address.
// FIXME: VERY imporant for internal relocations.
// Figure out the source symbol of the relocation. If isExtern is true,
// this relocation references the symbol table, otherwise it references
// a section in the same object, numbered from 1 through NumSections
// (SectionBases is [0, NumSections-1]).
// FIXME: Some targets (ARM) use internal relocations even for
// externally visible symbols, if the definition is in the same
// file as the reference. We need to convert those back to by-name
// references. We can resolve the address based on the section
// offset and see if we have a symbol at that address. If we do,
// use that; otherwise, puke.
if (!isExtern)
return Error("Internal relocations not supported.");
uint32_t SourceNum = RE->Word1 & 0xffffff; // 24-bit value
StringRef SourceName = SymbolNames[SourceNum];
if (!isExtern) {
assert(SourceNum > 0 && "Invalid relocation section number!");
unsigned SectionID = SectionMap[SourceNum - 1];
unsigned TargetID = SectionMap[SectNum];
DEBUG(dbgs() << "Internal relocation at Section #"
<< TargetID << " + " << Offset
<< " from Section #"
<< SectionID << " (Word1: "
<< format("0x%x", RE->Word1) << ")\n");
// FIXME: Get the relocation addend from the target address.
// Store the relocation information. It will get resolved when
// the section addresses are assigned.
Relocations[SectionID].push_back(RelocationEntry(TargetID,
Offset,
RE->Word1,
0 /*Addend*/));
} else {
StringRef SourceName = SymbolNames[SourceNum];
// Now store the relocation information. Associate it with the source
// symbol.
Relocations[SourceName].push_back(RelocationEntry(TargetName,
Offset,
RE->Word1,
0 /*Addend*/));
DEBUG(dbgs() << "Relocation at '" << TargetName << "' + " << Offset
<< " from '" << SourceName << "(Word1: "
<< format("0x%x", RE->Word1) << ")\n");
// Now store the relocation information. Associate it with the source
// symbol. Just add it to the unresolved list and let the general
// path post-load resolve it if we know where the symbol is.
UnresolvedRelocations[SourceName].push_back(RelocationEntry(SectNum,
Offset,
RE->Word1,
0 /*Addend*/));
DEBUG(dbgs() << "Relocation at Section #" << SectNum << " + " << Offset
<< " from '" << SourceName << "(Word1: "
<< format("0x%x", RE->Word1) << ")\n");
}
}
}
// Resolve the addresses of any symbols that were defined in this segment.
for (int i = 0, e = SymbolNames.size(); i != e; ++i)
resolveSymbol(SymbolNames[i]);
return false;
}
@ -280,77 +260,56 @@ loadSegment64(const MachOObject *Obj,
if (!Segment64LC)
return Error("unable to load segment load command");
SmallVector<unsigned, 16> SectionMap;
for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; ++SectNum) {
InMemoryStruct<macho::Section64> Sect;
Obj->ReadSection64(*SegmentLCI, SectNum, Sect);
if (!Sect)
return Error("unable to load section: '" + Twine(SectNum) + "'");
// FIXME: For the time being, we're only loading text segments.
// Allocate memory via the MM for the section.
uint8_t *Buffer;
uint32_t SectionID = Sections.size();
if (Sect->Flags != 0x80000400)
continue;
Buffer = MemMgr->allocateCodeSection(Sect->Size, Sect->Align, SectionID);
else
Buffer = MemMgr->allocateDataSection(Sect->Size, Sect->Align, SectionID);
// Address and names of symbols in the section.
typedef std::pair<uint64_t, StringRef> SymbolEntry;
SmallVector<SymbolEntry, 64> Symbols;
// Index of all the names, in this section or not. Used when we're
// dealing with relocation entries.
SmallVector<StringRef, 64> SymbolNames;
for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
InMemoryStruct<macho::Symbol64TableEntry> STE;
Obj->ReadSymbol64TableEntry(SymtabLC->SymbolTableOffset, i, STE);
if (!STE)
return Error("unable to read symbol: '" + Twine(i) + "'");
if (STE->SectionIndex > Segment64LC->NumSections)
return Error("invalid section index for symbol: '" + Twine(i) + "'");
// Get the symbol name.
StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
SymbolNames.push_back(Name);
DEBUG(dbgs() << "Loading "
<< ((Sect->Flags == 0x80000400) ? "text" : "data")
<< " (ID #" << SectionID << ")"
<< " '" << Sect->SegmentName << ","
<< Sect->Name << "' of size " << Sect->Size
<< " to address " << Buffer << ".\n");
// Just skip symbols not defined in this section.
if ((unsigned)STE->SectionIndex - 1 != SectNum)
continue;
// FIXME: Check the symbol type and flags.
if (STE->Type != 0xF) // external, defined in this section.
continue;
// Flags in the upper nibble we don't care about.
if ((STE->Flags & 0xf) != 0x0)
continue;
// Remember the symbol.
Symbols.push_back(SymbolEntry(STE->Value, Name));
DEBUG(dbgs() << "Function sym: '" << Name << "' @ " <<
(Sect->Address + STE->Value) << "\n");
}
// Sort the symbols by address, just in case they didn't come in that way.
array_pod_sort(Symbols.begin(), Symbols.end());
// If there weren't any functions (odd, but just in case...)
if (!Symbols.size())
continue;
// Extract the function data.
// Copy the payload from the object file into the allocated buffer.
uint8_t *Base = (uint8_t*)Obj->getData(Segment64LC->FileOffset,
Segment64LC->FileSize).data();
for (unsigned i = 0, e = Symbols.size() - 1; i != e; ++i) {
uint64_t StartOffset = Sect->Address + Symbols[i].first;
uint64_t EndOffset = Symbols[i + 1].first - 1;
DEBUG(dbgs() << "Extracting function: " << Symbols[i].second
<< " from [" << StartOffset << ", " << EndOffset << "]\n");
extractFunction(Symbols[i].second, Base + StartOffset, Base + EndOffset);
}
// The last symbol we do after since the end address is calculated
// differently because there is no next symbol to reference.
uint64_t StartOffset = Symbols[Symbols.size() - 1].first;
uint64_t EndOffset = Sect->Size - 1;
DEBUG(dbgs() << "Extracting function: " << Symbols[Symbols.size()-1].second
<< " from [" << StartOffset << ", " << EndOffset << "]\n");
extractFunction(Symbols[Symbols.size()-1].second,
Base + StartOffset, Base + EndOffset);
memcpy(Buffer, Base + Sect->Address, Sect->Size);
// Now extract the relocation information for each function and process it.
// Remember what got allocated for this SectionID.
Sections.push_back(sys::MemoryBlock(Buffer, Sect->Size));
// By default, the load address of a section is its memory buffer.
SectionLoadAddress.push_back((uint64_t)Buffer);
// Keep a map of object file section numbers to corresponding SectionIDs
// while processing the file.
SectionMap.push_back(SectionID);
}
// Process the symbol table.
SmallVector<StringRef, 64> SymbolNames;
processSymbols64(Obj, SectionMap, SymbolNames, SymtabLC);
// Process the relocations for each section we're loading.
Relocations.grow(Relocations.size() + Segment64LC->NumSections);
for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; ++SectNum) {
InMemoryStruct<macho::Section64> Sect;
Obj->ReadSection64(*SegmentLCI, SectNum, Sect);
if (!Sect)
return Error("unable to load section: '" + Twine(SectNum) + "'");
for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
InMemoryStruct<macho::RelocationEntry> RE;
Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
@ -360,48 +319,142 @@ loadSegment64(const MachOObject *Obj,
// relocation should be applied. We need to translate that into an
// offset into a function since that's our atom.
uint32_t Offset = RE->Word0;
// Look for the function containing the address. This is used for JIT
// code, so the number of functions in section is almost always going
// to be very small (usually just one), so until we have use cases
// where that's not true, just use a trivial linear search.
unsigned SymbolNum;
unsigned NumSymbols = Symbols.size();
assert(NumSymbols > 0 && Symbols[0].first <= Offset &&
"No symbol containing relocation!");
for (SymbolNum = 0; SymbolNum < NumSymbols - 1; ++SymbolNum)
if (Symbols[SymbolNum + 1].first > Offset)
break;
// Adjust the offset to be relative to the symbol.
Offset -= Symbols[SymbolNum].first;
// Get the name of the symbol containing the relocation.
StringRef TargetName = SymbolNames[SymbolNum];
bool isExtern = (RE->Word1 >> 27) & 1;
// FIXME: Get the relocation addend from the target address.
// FIXME: VERY imporant for internal relocations.
// Figure out the source symbol of the relocation. If isExtern is true,
// this relocation references the symbol table, otherwise it references
// a section in the same object, numbered from 1 through NumSections
// (SectionBases is [0, NumSections-1]).
if (!isExtern)
return Error("Internal relocations not supported.");
uint32_t SourceNum = RE->Word1 & 0xffffff; // 24-bit value
StringRef SourceName = SymbolNames[SourceNum];
if (!isExtern) {
assert(SourceNum > 0 && "Invalid relocation section number!");
unsigned SectionID = SectionMap[SourceNum - 1];
unsigned TargetID = SectionMap[SectNum];
DEBUG(dbgs() << "Internal relocation at Section #"
<< TargetID << " + " << Offset
<< " from Section #"
<< SectionID << " (Word1: "
<< format("0x%x", RE->Word1) << ")\n");
// FIXME: Get the relocation addend from the target address.
// Store the relocation information. It will get resolved when
// the section addresses are assigned.
Relocations[SectionID].push_back(RelocationEntry(TargetID,
Offset,
RE->Word1,
0 /*Addend*/));
} else {
StringRef SourceName = SymbolNames[SourceNum];
// Now store the relocation information. Associate it with the source
// symbol.
Relocations[SourceName].push_back(RelocationEntry(TargetName,
Offset,
RE->Word1,
0 /*Addend*/));
DEBUG(dbgs() << "Relocation at '" << TargetName << "' + " << Offset
<< " from '" << SourceName << "(Word1: "
<< format("0x%x", RE->Word1) << ")\n");
// Now store the relocation information. Associate it with the source
// symbol. Just add it to the unresolved list and let the general
// path post-load resolve it if we know where the symbol is.
UnresolvedRelocations[SourceName].push_back(RelocationEntry(SectNum,
Offset,
RE->Word1,
0 /*Addend*/));
DEBUG(dbgs() << "Relocation at Section #" << SectNum << " + " << Offset
<< " from '" << SourceName << "(Word1: "
<< format("0x%x", RE->Word1) << ")\n");
}
}
}
// Resolve the addresses of any symbols that were defined in this segment.
for (int i = 0, e = SymbolNames.size(); i != e; ++i)
resolveSymbol(SymbolNames[i]);
return false;
}
bool RuntimeDyldMachO::
processSymbols32(const MachOObject *Obj,
SmallVectorImpl<unsigned> &SectionMap,
SmallVectorImpl<StringRef> &SymbolNames,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
// FIXME: Combine w/ processSymbols64. Factor 64/32 datatype and such.
for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
InMemoryStruct<macho::SymbolTableEntry> STE;
Obj->ReadSymbolTableEntry(SymtabLC->SymbolTableOffset, i, STE);
if (!STE)
return Error("unable to read symbol: '" + Twine(i) + "'");
// Get the symbol name.
StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
SymbolNames.push_back(Name);
// FIXME: Check the symbol type and flags.
if (STE->Type != 0xF) // external, defined in this segment.
continue;
// Flags in the upper nibble we don't care about.
if ((STE->Flags & 0xf) != 0x0)
continue;
// Remember the symbol.
uint32_t SectionID = SectionMap[STE->SectionIndex - 1];
SymbolTable[Name] = SymbolLoc(SectionID, STE->Value);
DEBUG(dbgs() << "Symbol: '" << Name << "' @ "
<< (getSectionAddress(SectionID) + STE->Value)
<< "\n");
}
return false;
}
bool RuntimeDyldMachO::
processSymbols64(const MachOObject *Obj,
SmallVectorImpl<unsigned> &SectionMap,
SmallVectorImpl<StringRef> &SymbolNames,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
InMemoryStruct<macho::Symbol64TableEntry> STE;
Obj->ReadSymbol64TableEntry(SymtabLC->SymbolTableOffset, i, STE);
if (!STE)
return Error("unable to read symbol: '" + Twine(i) + "'");
// Get the symbol name.
StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
SymbolNames.push_back(Name);
// FIXME: Check the symbol type and flags.
if (STE->Type != 0xF) // external, defined in this segment.
continue;
// Flags in the upper nibble we don't care about.
if ((STE->Flags & 0xf) != 0x0)
continue;
// Remember the symbol.
uint32_t SectionID = SectionMap[STE->SectionIndex - 1];
SymbolTable[Name] = SymbolLoc(SectionID, STE->Value);
DEBUG(dbgs() << "Symbol: '" << Name << "' @ "
<< (getSectionAddress(SectionID) + STE->Value)
<< "\n");
}
return false;
}
// resolveSymbol - Resolve any relocations to the specified symbol if
// we know where it lives.
void RuntimeDyldMachO::resolveSymbol(StringRef Name) {
StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(Name);
if (Loc == SymbolTable.end())
return;
RelocationList &Relocs = UnresolvedRelocations[Name];
DEBUG(dbgs() << "Resolving symbol '" << Name << "'\n");
for (int i = 0, e = Relocs.size(); i != e; ++i) {
// Change the relocation to be section relative rather than symbol
// relative and move it to the resolved relocation list.
RelocationEntry Entry = Relocs[i];
Entry.Addend += Loc->second.second;
Relocations[Loc->second.first].push_back(Entry);
}
// FIXME: Keep a worklist of the relocations we've added so that we can
// resolve more selectively later.
Relocs.clear();
}
bool RuntimeDyldMachO::loadObject(MemoryBuffer *InputBuffer) {
// If the linker is in an error state, don't do anything.
if (hasError())
@ -486,31 +539,46 @@ bool RuntimeDyldMachO::loadObject(MemoryBuffer *InputBuffer) {
return true;
}
// Assign the addresses of the sections from the object so that any
// relocations to them get set properly.
// FIXME: This is done directly from the client at the moment. We should
// default the values to the local storage, at least when the target arch
// is the same as the host arch.
return false;
}
// Assign an address to a symbol name and resolve all the relocations
// associated with it.
void RuntimeDyldMachO::reassignSymbolAddress(StringRef Name, uint8_t *Addr) {
// Assign the address in our symbol table.
SymbolTable[Name] = Addr;
void RuntimeDyldMachO::reassignSectionAddress(unsigned SectionID,
uint64_t Addr) {
// The address to use for relocation resolution is not
// the address of the local section buffer. We must be doing
// a remote execution environment of some sort. Re-apply any
// relocations referencing this section with the given address.
//
// Addr is a uint64_t because we can't assume the pointer width
// of the target is the same as that of the host. Just use a generic
// "big enough" type.
RelocationList &Relocs = Relocations[Name];
SectionLoadAddress[SectionID] = Addr;
RelocationList &Relocs = Relocations[SectionID];
for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
RelocationEntry &RE = Relocs[i];
uint8_t *Target = SymbolTable[RE.Target] + RE.Offset;
uint8_t *Target = (uint8_t*)Sections[RE.SectionID].base() + RE.Offset;
bool isPCRel = (RE.Data >> 24) & 1;
unsigned Type = (RE.Data >> 28) & 0xf;
unsigned Size = 1 << ((RE.Data >> 25) & 3);
DEBUG(dbgs() << "Resolving relocation at '" << RE.Target
<< "' + " << RE.Offset << " (" << format("%p", Target) << ")"
<< " from '" << Name << " (" << format("%p", Addr) << ")"
DEBUG(dbgs() << "Resolving relocation at Section #" << RE.SectionID
<< " + " << RE.Offset << " (" << format("%p", Target) << ")"
<< " from Section #" << SectionID << " (" << format("%p", Addr) << ")"
<< "(" << (isPCRel ? "pcrel" : "absolute")
<< ", type: " << Type << ", Size: " << Size << ").\n");
<< ", type: " << Type << ", Size: " << Size << ", Addend: "
<< RE.Addend << ").\n");
resolveRelocation(Target, Addr, isPCRel, Type, Size);
RE.isResolved = true;
resolveRelocation(Target, Addr, isPCRel, Type, Size, RE.Addend);
}
}

18
tools/llvm-rtdyld/llvm-rtdyld.cpp
View File

@ -51,12 +51,30 @@ EntryPoint("entry",
class TrivialMemoryManager : public RTDyldMemoryManager {
public:
SmallVector<sys::MemoryBlock, 16> FunctionMemory;
SmallVector<sys::MemoryBlock, 16> DataMemory;
uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID);
uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID);
uint8_t *startFunctionBody(const char *Name, uintptr_t &Size);
void endFunctionBody(const char *Name, uint8_t *FunctionStart,
uint8_t *FunctionEnd);
};
uint8_t *TrivialMemoryManager::allocateCodeSection(uintptr_t Size,
unsigned Alignment,
unsigned SectionID) {
return (uint8_t*)sys::Memory::AllocateRWX(Size, 0, 0).base();
}
uint8_t *TrivialMemoryManager::allocateDataSection(uintptr_t Size,
unsigned Alignment,
unsigned SectionID) {
return (uint8_t*)sys::Memory::AllocateRWX(Size, 0, 0).base();
}
uint8_t *TrivialMemoryManager::startFunctionBody(const char *Name,
uintptr_t &Size) {
return (uint8_t*)sys::Memory::AllocateRWX(Size, 0, 0).base();

8
unittests/ExecutionEngine/JIT/JITTest.cpp
View File

@ -113,6 +113,14 @@ public:
EndFunctionBodyCall(F, FunctionStart, FunctionEnd));
Base->endFunctionBody(F, FunctionStart, FunctionEnd);
}
virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) {
return Base->allocateDataSection(Size, Alignment, SectionID);
}
virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID) {
return Base->allocateCodeSection(Size, Alignment, SectionID);
}
virtual uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) {
return Base->allocateSpace(Size, Alignment);
}