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-rw-r--r--lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp458
1 files changed, 288 insertions, 170 deletions
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index 29fced4..eda4cbb 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -41,17 +41,38 @@ class RuntimeDyldImpl {
// 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;
// Master symbol table. As modules are loaded and external symbols are
// resolved, their addresses are stored here.
- StringMap<uint64_t> SymbolTable;
-
- // FIXME: Should have multiple data blocks, one for each loaded chunk of
- // compiled code.
- sys::MemoryBlock Data;
+ StringMap<uint8_t*> SymbolTable;
+
+ // 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.
+ struct RelocationEntry {
+ std::string Target; // Object this relocation is contained in.
+ uint64_t Offset; // Offset into the object 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?
+
+ RelocationEntry(StringRef t, uint64_t offset, uint32_t data, int64_t addend)
+ : Target(t), Offset(offset), Data(data), Addend(addend),
+ isResolved(false) {}
+ };
+ typedef SmallVector<RelocationEntry, 4> RelocationList;
+ StringMap<RelocationList> Relocations;
+
+ // 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 HasError;
std::string ErrorStr;
@@ -65,12 +86,11 @@ class RuntimeDyldImpl {
void extractFunction(StringRef Name, uint8_t *StartAddress,
uint8_t *EndAddress);
- bool resolveRelocation(uint32_t BaseSection, macho::RelocationEntry RE,
- SmallVectorImpl<void *> &SectionBases,
- SmallVectorImpl<StringRef> &SymbolNames);
- bool resolveX86_64Relocation(intptr_t Address, intptr_t Value, bool isPCRel,
+ bool resolveRelocation(uint8_t *Address, uint8_t *Value, bool isPCRel,
+ unsigned Type, unsigned Size);
+ bool resolveX86_64Relocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
unsigned Type, unsigned Size);
- bool resolveARMRelocation(intptr_t Address, intptr_t Value, bool isPCRel,
+ bool resolveARMRelocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
unsigned Type, unsigned Size);
bool loadSegment32(const MachOObject *Obj,
@@ -85,13 +105,15 @@ public:
bool loadObject(MemoryBuffer *InputBuffer);
- uint64_t getSymbolAddress(StringRef Name) {
+ void *getSymbolAddress(StringRef Name) {
// FIXME: Just look up as a function for now. Overly simple of course.
// Work in progress.
- return (uint64_t)Functions.lookup(Name).base();
+ return SymbolTable.lookup(Name);
}
- sys::MemoryBlock getMemoryBlock() { return Data; }
+ void resolveRelocations();
+
+ void reassignSymbolAddress(StringRef Name, uint8_t *Addr);
// Is the linker in an error state?
bool hasError() { return HasError; }
@@ -107,75 +129,41 @@ void RuntimeDyldImpl::extractFunction(StringRef Name, uint8_t *StartAddress,
uint8_t *EndAddress) {
// Allocate memory for the function via the memory manager.
uintptr_t Size = EndAddress - StartAddress + 1;
- uint8_t *Mem = MemMgr->startFunctionBody(Name.data(), Size);
+ uintptr_t AllocSize = Size;
+ uint8_t *Mem = MemMgr->startFunctionBody(Name.data(), AllocSize);
assert(Size >= (uint64_t)(EndAddress - StartAddress + 1) &&
"Memory manager failed to allocate enough memory!");
// Copy the function payload into the memory block.
- memcpy(Mem, StartAddress, EndAddress - StartAddress + 1);
+ memcpy(Mem, StartAddress, Size);
MemMgr->endFunctionBody(Name.data(), Mem, Mem + Size);
// Remember where we put it.
Functions[Name] = sys::MemoryBlock(Mem, Size);
- DEBUG(dbgs() << " allocated to " << Mem << "\n");
+ // Default the assigned address for this symbol to wherever this
+ // allocated it.
+ SymbolTable[Name] = Mem;
+ DEBUG(dbgs() << " allocated to [" << Mem << ", " << Mem + Size << "]\n");
}
bool RuntimeDyldImpl::
-resolveRelocation(uint32_t BaseSection, macho::RelocationEntry RE,
- SmallVectorImpl<void *> &SectionBases,
- SmallVectorImpl<StringRef> &SymbolNames) {
- // struct relocation_info {
- // int32_t r_address;
- // uint32_t r_symbolnum:24,
- // r_pcrel:1,
- // r_length:2,
- // r_extern:1,
- // r_type:4;
- // };
- uint32_t SymbolNum = RE.Word1 & 0xffffff; // 24-bit value
- bool isPCRel = (RE.Word1 >> 24) & 1;
- unsigned Log2Size = (RE.Word1 >> 25) & 3;
- bool isExtern = (RE.Word1 >> 27) & 1;
- unsigned Type = (RE.Word1 >> 28) & 0xf;
- if (RE.Word0 & macho::RF_Scattered)
- return Error("NOT YET IMPLEMENTED: scattered relocations.");
-
- // The address requiring a relocation.
- intptr_t Address = (intptr_t)SectionBases[BaseSection] + RE.Word0;
-
- // Figure out the target address 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]).
- intptr_t Value;
- if (isExtern) {
- StringRef Name = SymbolNames[SymbolNum];
- if (SymbolTable.lookup(Name)) {
- // The symbol is in our symbol table, so we can resolve it directly.
- Value = (intptr_t)SymbolTable[Name];
- } else {
- return Error("NOT YET IMPLEMENTED: relocations to pre-compiled code.");
- }
- DEBUG(dbgs() << "Resolve relocation(" << Type << ") from '" << Name
- << "' to " << format("0x%x", Address) << ".\n");
- } else {
- // For non-external relocations, the SymbolNum is actual a section number
- // as described above.
- Value = (intptr_t)SectionBases[SymbolNum - 1];
- }
-
- unsigned Size = 1 << Log2Size;
+resolveRelocation(uint8_t *Address, uint8_t *Value, bool isPCRel,
+ unsigned Type, unsigned Size) {
+ // 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(Address, Value, isPCRel, Type, Size);
+ return resolveX86_64Relocation((uintptr_t)Address, (uintptr_t)Value,
+ isPCRel, Type, Size);
case mach::CTM_ARM:
- return resolveARMRelocation(Address, Value, isPCRel, Type, Size);
+ return resolveARMRelocation((uintptr_t)Address, (uintptr_t)Value,
+ isPCRel, Type, Size);
}
llvm_unreachable("");
}
-bool RuntimeDyldImpl::resolveX86_64Relocation(intptr_t Address, intptr_t Value,
- bool isPCRel, unsigned Type,
- unsigned Size) {
+bool RuntimeDyldImpl::
+resolveX86_64Relocation(uintptr_t Address, uintptr_t Value,
+ bool isPCRel, unsigned Type,
+ unsigned Size) {
// If the relocation is PC-relative, the value to be encoded is the
// pointer difference.
if (isPCRel)
@@ -210,7 +198,7 @@ bool RuntimeDyldImpl::resolveX86_64Relocation(intptr_t Address, intptr_t Value,
return false;
}
-bool RuntimeDyldImpl::resolveARMRelocation(intptr_t Address, intptr_t Value,
+bool RuntimeDyldImpl::resolveARMRelocation(uintptr_t Address, uintptr_t Value,
bool isPCRel, unsigned Type,
unsigned Size) {
// If the relocation is PC-relative, the value to be encoded is the
@@ -225,6 +213,7 @@ bool RuntimeDyldImpl::resolveARMRelocation(intptr_t Address, intptr_t Value,
switch(Type) {
default:
+ llvm_unreachable("Invalid relocation type!");
case macho::RIT_Vanilla: {
llvm_unreachable("Invalid relocation type!");
// Mask in the target value a byte at a time (we don't have an alignment
@@ -236,10 +225,6 @@ bool RuntimeDyldImpl::resolveARMRelocation(intptr_t Address, intptr_t Value,
}
break;
}
- case macho::RIT_Pair:
- case macho::RIT_Difference:
- case macho::RIT_ARM_LocalDifference:
- case macho::RIT_ARM_PreboundLazyPointer:
case macho::RIT_ARM_Branch24Bit: {
// Mask the value into the target address. We know instructions are
// 32-bit aligned, so we can do it all at once.
@@ -260,6 +245,10 @@ bool RuntimeDyldImpl::resolveARMRelocation(intptr_t Address, intptr_t Value,
case macho::RIT_ARM_ThumbBranch32Bit:
case macho::RIT_ARM_Half:
case macho::RIT_ARM_HalfDifference:
+ case macho::RIT_Pair:
+ case macho::RIT_Difference:
+ case macho::RIT_ARM_LocalDifference:
+ case macho::RIT_ARM_PreboundLazyPointer:
return Error("Relocation type not implemented yet!");
}
return false;
@@ -269,98 +258,137 @@ bool RuntimeDyldImpl::
loadSegment32(const MachOObject *Obj,
const MachOObject::LoadCommandInfo *SegmentLCI,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
- InMemoryStruct<macho::SegmentLoadCommand> Segment32LC;
- Obj->ReadSegmentLoadCommand(*SegmentLCI, Segment32LC);
- if (!Segment32LC)
+ InMemoryStruct<macho::SegmentLoadCommand> SegmentLC;
+ Obj->ReadSegmentLoadCommand(*SegmentLCI, SegmentLC);
+ if (!SegmentLC)
return Error("unable to load segment load command");
- // Map the segment into memory.
- std::string ErrorStr;
- Data = sys::Memory::AllocateRWX(Segment32LC->VMSize, 0, &ErrorStr);
- if (!Data.base())
- return Error("unable to allocate memory block: '" + ErrorStr + "'");
- memcpy(Data.base(), Obj->getData(Segment32LC->FileOffset,
- Segment32LC->FileSize).data(),
- Segment32LC->FileSize);
- memset((char*)Data.base() + Segment32LC->FileSize, 0,
- Segment32LC->VMSize - Segment32LC->FileSize);
-
- // Bind the section indices to addresses and record the relocations we
- // need to resolve.
- typedef std::pair<uint32_t, macho::RelocationEntry> RelocationMap;
- SmallVector<RelocationMap, 64> Relocations;
-
- SmallVector<void *, 16> SectionBases;
- for (unsigned i = 0; i != Segment32LC->NumSections; ++i) {
+ for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) {
InMemoryStruct<macho::Section> Sect;
- Obj->ReadSection(*SegmentLCI, i, Sect);
- if (!Sect)
- return Error("unable to load section: '" + Twine(i) + "'");
-
- // Remember any relocations the section has so we can resolve them later.
- for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
- InMemoryStruct<macho::RelocationEntry> RE;
- Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
- Relocations.push_back(RelocationMap(j, *RE));
- }
-
- // FIXME: Improve check.
-// if (Sect->Flags != 0x80000400)
-// return Error("unsupported section type!");
-
- SectionBases.push_back((char*) Data.base() + Sect->Address);
- }
+ Obj->ReadSection(*SegmentLCI, SectNum, Sect);
+ if (!Sect)
+ return Error("unable to load section: '" + Twine(SectNum) + "'");
- // Bind all the symbols to address. Keep a record of the names for use
- // by relocation resolution.
- 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) + "'");
- // Get the symbol name.
- StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
- SymbolNames.push_back(Name);
-
- // Just skip undefined symbols. They'll be loaded from whatever
- // module they come from (or system dylib) when we resolve relocations
- // involving them.
- if (STE->SectionIndex == 0)
+ // FIXME: For the time being, we're only loading text segments.
+ if (Sect->Flags != 0x80000400)
continue;
- unsigned Index = STE->SectionIndex - 1;
- if (Index >= Segment32LC->NumSections)
- return Error("invalid section index for symbol: '" + Twine() + "'");
-
- // Get the section base address.
- void *SectionBase = SectionBases[Index];
+ // 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);
- // Get the symbol address.
- uint64_t Address = (uint64_t)SectionBase + STE->Value;
+ // 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)
- return Error("unexpected symbol type!");
- if (STE->Flags != 0x0)
- return Error("unexpected symbol type!");
+ // 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.
+ if (STE->Flags != 0x0 && STE->Flags != 0x8)
+ continue;
- DEBUG(dbgs() << "Symbol: '" << Name << "' @ " << Address << "\n");
+ // Remember the symbol.
+ Symbols.push_back(SymbolEntry(STE->Value, Name));
- SymbolTable[Name] = Address;
- }
+ 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());
- // Now resolve any relocations.
- for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
- if (resolveRelocation(Relocations[i].first, Relocations[i].second,
- SectionBases, SymbolNames))
- return true;
- }
+ // If there weren't any functions (odd, but just in case...)
+ if (!Symbols.size())
+ continue;
- // We've loaded the section; now mark the functions in it as executable.
- // FIXME: We really should use the MemoryManager for this.
- sys::Memory::setRangeExecutable(Data.base(), Data.size());
+ // Extract the function data.
+ 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);
+ // Now extract the relocation information for each function and process it.
+ for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
+ InMemoryStruct<macho::RelocationEntry> RE;
+ Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
+ if (RE->Word0 & macho::RF_Scattered)
+ return Error("NOT YET IMPLEMENTED: scattered relocations.");
+ // Word0 of the relocation is the offset into the section where the
+ // 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;
+ // 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];
+
+ // FIXME: Get the relocation addend from the target address.
+
+ // 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");
+ }
+ }
return false;
}
@@ -380,51 +408,55 @@ loadSegment64(const MachOObject *Obj,
if (!Sect)
return Error("unable to load section: '" + Twine(SectNum) + "'");
- // FIXME: Improve check.
+ // FIXME: For the time being, we're only loading text segments.
if (Sect->Flags != 0x80000400)
- return Error("unsupported section type!");
+ continue;
// 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() + "'");
+ return Error("invalid section index for symbol: '" + Twine(i) + "'");
+ // Get the symbol name.
+ StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
+ SymbolNames.push_back(Name);
// Just skip symbols not defined in this section.
- if (STE->SectionIndex - 1 != SectNum)
+ if ((unsigned)STE->SectionIndex - 1 != SectNum)
continue;
- // Get the symbol name.
- StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
-
// FIXME: Check the symbol type and flags.
if (STE->Type != 0xF) // external, defined in this section.
- return Error("unexpected symbol type!");
+ continue;
if (STE->Flags != 0x0)
- return Error("unexpected symbol type!");
-
- uint64_t BaseAddress = Sect->Address;
- uint64_t Address = BaseAddress + STE->Value;
+ continue;
// Remember the symbol.
- Symbols.push_back(SymbolEntry(Address, Name));
+ Symbols.push_back(SymbolEntry(STE->Value, Name));
- DEBUG(dbgs() << "Function sym: '" << Name << "' @ " << Address << "\n");
+ 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.
+ // 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.
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 = Symbols[i].first;
+ 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");
@@ -438,8 +470,56 @@ loadSegment64(const MachOObject *Obj,
<< " from [" << StartOffset << ", " << EndOffset << "]\n");
extractFunction(Symbols[Symbols.size()-1].second,
Base + StartOffset, Base + EndOffset);
- }
+ // Now extract the relocation information for each function and process it.
+ for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
+ InMemoryStruct<macho::RelocationEntry> RE;
+ Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
+ if (RE->Word0 & macho::RF_Scattered)
+ return Error("NOT YET IMPLEMENTED: scattered relocations.");
+ // Word0 of the relocation is the offset into the section where the
+ // 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;
+ // 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];
+
+ // FIXME: Get the relocation addend from the target address.
+
+ // 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");
+ }
+ }
return false;
}
@@ -530,6 +610,40 @@ bool RuntimeDyldImpl::loadObject(MemoryBuffer *InputBuffer) {
return false;
}
+// 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());
+}
+
+// Assign an address to a symbol name and resolve all the relocations
+// associated with it.
+void RuntimeDyldImpl::reassignSymbolAddress(StringRef Name, uint8_t *Addr) {
+ // Assign the address in our symbol table.
+ SymbolTable[Name] = Addr;
+
+ RelocationList &Relocs = Relocations[Name];
+ for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
+ RelocationEntry &RE = Relocs[i];
+ uint8_t *Target = SymbolTable[RE.Target] + 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) << ")"
+ << "(" << (isPCRel ? "pcrel" : "absolute")
+ << ", type: " << Type << ", Size: " << Size << ").\n");
+
+ resolveRelocation(Target, Addr, isPCRel, Type, Size);
+ RE.isResolved = true;
+ }
+}
//===----------------------------------------------------------------------===//
// RuntimeDyld class implementation
@@ -545,12 +659,16 @@ bool RuntimeDyld::loadObject(MemoryBuffer *InputBuffer) {
return Dyld->loadObject(InputBuffer);
}
-uint64_t RuntimeDyld::getSymbolAddress(StringRef Name) {
+void *RuntimeDyld::getSymbolAddress(StringRef Name) {
return Dyld->getSymbolAddress(Name);
}
-sys::MemoryBlock RuntimeDyld::getMemoryBlock() {
- return Dyld->getMemoryBlock();
+void RuntimeDyld::resolveRelocations() {
+ Dyld->resolveRelocations();
+}
+
+void RuntimeDyld::reassignSymbolAddress(StringRef Name, uint8_t *Addr) {
+ Dyld->reassignSymbolAddress(Name, Addr);
}
StringRef RuntimeDyld::getErrorString() {
generated by cgit v1.1 at 2025-07-03 20:11:54 +0000