1 //===-- RuntimeDyld.cpp - Run-time dynamic linker for MC-JIT ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implementation of the MC-JIT runtime dynamic linker.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/ExecutionEngine/RuntimeDyld.h"
15 #include "JITRegistrar.h"
16 #include "ObjectImageCommon.h"
17 #include "RuntimeDyldCheckerImpl.h"
18 #include "RuntimeDyldELF.h"
19 #include "RuntimeDyldImpl.h"
20 #include "RuntimeDyldMachO.h"
21 #include "llvm/Object/ELF.h"
22 #include "llvm/Support/MathExtras.h"
23 #include "llvm/Support/MutexGuard.h"
26 using namespace llvm::object;
28 #define DEBUG_TYPE "dyld"
30 // Empty out-of-line virtual destructor as the key function.
31 RuntimeDyldImpl::~RuntimeDyldImpl() {}
33 // Pin the JITRegistrar's and ObjectImage*'s vtables to this file.
34 void JITRegistrar::anchor() {}
35 void ObjectImage::anchor() {}
36 void ObjectImageCommon::anchor() {}
40 void RuntimeDyldImpl::registerEHFrames() {}
42 void RuntimeDyldImpl::deregisterEHFrames() {}
44 static void dumpSectionMemory(const SectionEntry &S) {
45 dbgs() << "----- Contents of section " << S.Name << " -----";
47 uint8_t *DataAddr = S.Address;
48 uint64_t LoadAddr = S.LoadAddress;
50 unsigned StartPadding = LoadAddr & 7;
51 unsigned BytesRemaining = S.Size;
54 dbgs() << "\n" << format("0x%08x", LoadAddr & ~7) << ":";
55 while (StartPadding--)
59 while (BytesRemaining > 0) {
60 if ((LoadAddr & 7) == 0)
61 dbgs() << "\n" << format("0x%08x", LoadAddr) << ":";
63 dbgs() << " " << format("%02x", *DataAddr);
73 // Resolve the relocations for all symbols we currently know about.
74 void RuntimeDyldImpl::resolveRelocations() {
75 MutexGuard locked(lock);
77 // First, resolve relocations associated with external symbols.
78 resolveExternalSymbols();
80 // Just iterate over the sections we have and resolve all the relocations
81 // in them. Gross overkill, but it gets the job done.
82 for (int i = 0, e = Sections.size(); i != e; ++i) {
83 // The Section here (Sections[i]) refers to the section in which the
84 // symbol for the relocation is located. The SectionID in the relocation
85 // entry provides the section to which the relocation will be applied.
86 uint64_t Addr = Sections[i].LoadAddress;
87 DEBUG(dbgs() << "Resolving relocations Section #" << i << "\t"
88 << format("0x%x", Addr) << "\n");
89 DEBUG(dumpSectionMemory(Sections[i]));
90 resolveRelocationList(Relocations[i], Addr);
95 void RuntimeDyldImpl::mapSectionAddress(const void *LocalAddress,
96 uint64_t TargetAddress) {
97 MutexGuard locked(lock);
98 for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
99 if (Sections[i].Address == LocalAddress) {
100 reassignSectionAddress(i, TargetAddress);
104 llvm_unreachable("Attempting to remap address of unknown section!");
107 static std::error_code getOffset(const SymbolRef &Sym, uint64_t &Result) {
109 if (std::error_code EC = Sym.getAddress(Address))
112 if (Address == UnknownAddressOrSize) {
113 Result = UnknownAddressOrSize;
114 return object_error::success;
117 const ObjectFile *Obj = Sym.getObject();
118 section_iterator SecI(Obj->section_begin());
119 if (std::error_code EC = Sym.getSection(SecI))
122 if (SecI == Obj->section_end()) {
123 Result = UnknownAddressOrSize;
124 return object_error::success;
127 uint64_t SectionAddress;
128 if (std::error_code EC = SecI->getAddress(SectionAddress))
131 Result = Address - SectionAddress;
132 return object_error::success;
135 ObjectImage *RuntimeDyldImpl::loadObject(ObjectImage *InputObject) {
136 MutexGuard locked(lock);
138 std::unique_ptr<ObjectImage> Obj(InputObject);
142 // Save information about our target
143 Arch = (Triple::ArchType)Obj->getArch();
144 IsTargetLittleEndian = Obj->getObjectFile()->isLittleEndian();
146 // Compute the memory size required to load all sections to be loaded
147 // and pass this information to the memory manager
148 if (MemMgr->needsToReserveAllocationSpace()) {
149 uint64_t CodeSize = 0, DataSizeRO = 0, DataSizeRW = 0;
150 computeTotalAllocSize(*Obj, CodeSize, DataSizeRO, DataSizeRW);
151 MemMgr->reserveAllocationSpace(CodeSize, DataSizeRO, DataSizeRW);
154 // Symbols found in this object
155 StringMap<SymbolLoc> LocalSymbols;
156 // Used sections from the object file
157 ObjSectionToIDMap LocalSections;
159 // Common symbols requiring allocation, with their sizes and alignments
160 CommonSymbolMap CommonSymbols;
161 // Maximum required total memory to allocate all common symbols
162 uint64_t CommonSize = 0;
165 DEBUG(dbgs() << "Parse symbols:\n");
166 for (symbol_iterator I = Obj->begin_symbols(), E = Obj->end_symbols(); I != E;
168 object::SymbolRef::Type SymType;
170 Check(I->getType(SymType));
171 Check(I->getName(Name));
173 uint32_t Flags = I->getFlags();
175 bool IsCommon = Flags & SymbolRef::SF_Common;
177 // Add the common symbols to a list. We'll allocate them all below.
178 if (!GlobalSymbolTable.count(Name)) {
180 Check(I->getAlignment(Align));
182 Check(I->getSize(Size));
183 CommonSize += Size + Align;
184 CommonSymbols[*I] = CommonSymbolInfo(Size, Align);
187 if (SymType == object::SymbolRef::ST_Function ||
188 SymType == object::SymbolRef::ST_Data ||
189 SymType == object::SymbolRef::ST_Unknown) {
191 StringRef SectionData;
193 section_iterator SI = Obj->end_sections();
194 Check(getOffset(*I, SectOffset));
195 Check(I->getSection(SI));
196 if (SI == Obj->end_sections())
198 Check(SI->getContents(SectionData));
199 Check(SI->isText(IsCode));
201 findOrEmitSection(*Obj, *SI, IsCode, LocalSections);
202 LocalSymbols[Name.data()] = SymbolLoc(SectionID, SectOffset);
203 DEBUG(dbgs() << "\tOffset: " << format("%p", (uintptr_t)SectOffset)
204 << " flags: " << Flags << " SID: " << SectionID);
205 GlobalSymbolTable[Name] = SymbolLoc(SectionID, SectOffset);
208 DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name << "\n");
211 // Allocate common symbols
213 emitCommonSymbols(*Obj, CommonSymbols, CommonSize, GlobalSymbolTable);
215 // Parse and process relocations
216 DEBUG(dbgs() << "Parse relocations:\n");
217 for (section_iterator SI = Obj->begin_sections(), SE = Obj->end_sections();
219 unsigned SectionID = 0;
221 section_iterator RelocatedSection = SI->getRelocatedSection();
223 relocation_iterator I = SI->relocation_begin();
224 relocation_iterator E = SI->relocation_end();
226 if (I == E && !ProcessAllSections)
230 Check(RelocatedSection->isText(IsCode));
232 findOrEmitSection(*Obj, *RelocatedSection, IsCode, LocalSections);
233 DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n");
236 I = processRelocationRef(SectionID, I, *Obj, LocalSections, LocalSymbols,
239 // If there is an attached checker, notify it about the stubs for this
240 // section so that they can be verified.
242 Checker->registerStubMap(Obj->getImageName(), SectionID, Stubs);
245 // Give the subclasses a chance to tie-up any loose ends.
246 finalizeLoad(*Obj, LocalSections);
248 return Obj.release();
251 // A helper method for computeTotalAllocSize.
252 // Computes the memory size required to allocate sections with the given sizes,
253 // assuming that all sections are allocated with the given alignment
255 computeAllocationSizeForSections(std::vector<uint64_t> &SectionSizes,
256 uint64_t Alignment) {
257 uint64_t TotalSize = 0;
258 for (size_t Idx = 0, Cnt = SectionSizes.size(); Idx < Cnt; Idx++) {
259 uint64_t AlignedSize =
260 (SectionSizes[Idx] + Alignment - 1) / Alignment * Alignment;
261 TotalSize += AlignedSize;
266 // Compute an upper bound of the memory size that is required to load all
268 void RuntimeDyldImpl::computeTotalAllocSize(ObjectImage &Obj,
270 uint64_t &DataSizeRO,
271 uint64_t &DataSizeRW) {
272 // Compute the size of all sections required for execution
273 std::vector<uint64_t> CodeSectionSizes;
274 std::vector<uint64_t> ROSectionSizes;
275 std::vector<uint64_t> RWSectionSizes;
276 uint64_t MaxAlignment = sizeof(void *);
278 // Collect sizes of all sections to be loaded;
279 // also determine the max alignment of all sections
280 for (section_iterator SI = Obj.begin_sections(), SE = Obj.end_sections();
282 const SectionRef &Section = *SI;
285 Check(Section.isRequiredForExecution(IsRequired));
287 // Consider only the sections that are required to be loaded for execution
289 uint64_t DataSize = 0;
290 uint64_t Alignment64 = 0;
292 bool IsReadOnly = false;
294 Check(Section.getSize(DataSize));
295 Check(Section.getAlignment(Alignment64));
296 Check(Section.isText(IsCode));
297 Check(Section.isReadOnlyData(IsReadOnly));
298 Check(Section.getName(Name));
299 unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
301 uint64_t StubBufSize = computeSectionStubBufSize(Obj, Section);
302 uint64_t SectionSize = DataSize + StubBufSize;
304 // The .eh_frame section (at least on Linux) needs an extra four bytes
306 // with zeroes added at the end. For MachO objects, this section has a
307 // slightly different name, so this won't have any effect for MachO
309 if (Name == ".eh_frame")
312 if (SectionSize > 0) {
313 // save the total size of the section
315 CodeSectionSizes.push_back(SectionSize);
316 } else if (IsReadOnly) {
317 ROSectionSizes.push_back(SectionSize);
319 RWSectionSizes.push_back(SectionSize);
321 // update the max alignment
322 if (Alignment > MaxAlignment) {
323 MaxAlignment = Alignment;
329 // Compute the size of all common symbols
330 uint64_t CommonSize = 0;
331 for (symbol_iterator I = Obj.begin_symbols(), E = Obj.end_symbols(); I != E;
333 uint32_t Flags = I->getFlags();
334 if (Flags & SymbolRef::SF_Common) {
335 // Add the common symbols to a list. We'll allocate them all below.
337 Check(I->getSize(Size));
341 if (CommonSize != 0) {
342 RWSectionSizes.push_back(CommonSize);
345 // Compute the required allocation space for each different type of sections
346 // (code, read-only data, read-write data) assuming that all sections are
347 // allocated with the max alignment. Note that we cannot compute with the
348 // individual alignments of the sections, because then the required size
349 // depends on the order, in which the sections are allocated.
350 CodeSize = computeAllocationSizeForSections(CodeSectionSizes, MaxAlignment);
351 DataSizeRO = computeAllocationSizeForSections(ROSectionSizes, MaxAlignment);
352 DataSizeRW = computeAllocationSizeForSections(RWSectionSizes, MaxAlignment);
355 // compute stub buffer size for the given section
356 unsigned RuntimeDyldImpl::computeSectionStubBufSize(ObjectImage &Obj,
357 const SectionRef &Section) {
358 unsigned StubSize = getMaxStubSize();
362 // FIXME: this is an inefficient way to handle this. We should computed the
363 // necessary section allocation size in loadObject by walking all the sections
365 unsigned StubBufSize = 0;
366 for (section_iterator SI = Obj.begin_sections(), SE = Obj.end_sections();
368 section_iterator RelSecI = SI->getRelocatedSection();
369 if (!(RelSecI == Section))
372 for (const RelocationRef &Reloc : SI->relocations()) {
374 StubBufSize += StubSize;
378 // Get section data size and alignment
379 uint64_t Alignment64;
381 Check(Section.getSize(DataSize));
382 Check(Section.getAlignment(Alignment64));
384 // Add stubbuf size alignment
385 unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
386 unsigned StubAlignment = getStubAlignment();
387 unsigned EndAlignment = (DataSize | Alignment) & -(DataSize | Alignment);
388 if (StubAlignment > EndAlignment)
389 StubBufSize += StubAlignment - EndAlignment;
393 void RuntimeDyldImpl::emitCommonSymbols(ObjectImage &Obj,
394 const CommonSymbolMap &CommonSymbols,
396 SymbolTableMap &SymbolTable) {
397 // Allocate memory for the section
398 unsigned SectionID = Sections.size();
399 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, sizeof(void *),
400 SectionID, StringRef(), false);
402 report_fatal_error("Unable to allocate memory for common symbols!");
404 Sections.push_back(SectionEntry("<common symbols>", Addr, TotalSize, 0));
405 memset(Addr, 0, TotalSize);
407 DEBUG(dbgs() << "emitCommonSection SectionID: " << SectionID << " new addr: "
408 << format("%p", Addr) << " DataSize: " << TotalSize << "\n");
410 // Assign the address of each symbol
411 for (CommonSymbolMap::const_iterator it = CommonSymbols.begin(),
412 itEnd = CommonSymbols.end(); it != itEnd; ++it) {
413 uint64_t Size = it->second.first;
414 uint64_t Align = it->second.second;
416 it->first.getName(Name);
418 // This symbol has an alignment requirement.
419 uint64_t AlignOffset = OffsetToAlignment((uint64_t)Addr, Align);
421 Offset += AlignOffset;
422 DEBUG(dbgs() << "Allocating common symbol " << Name << " address "
423 << format("%p\n", Addr));
425 Obj.updateSymbolAddress(it->first, (uint64_t)Addr);
426 SymbolTable[Name.data()] = SymbolLoc(SectionID, Offset);
432 unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj,
433 const SectionRef &Section, bool IsCode) {
436 uint64_t Alignment64;
437 Check(Section.getContents(data));
438 Check(Section.getAlignment(Alignment64));
440 unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
446 unsigned PaddingSize = 0;
447 unsigned StubBufSize = 0;
449 Check(Section.isRequiredForExecution(IsRequired));
450 Check(Section.isVirtual(IsVirtual));
451 Check(Section.isZeroInit(IsZeroInit));
452 Check(Section.isReadOnlyData(IsReadOnly));
453 Check(Section.getSize(DataSize));
454 Check(Section.getName(Name));
456 StubBufSize = computeSectionStubBufSize(Obj, Section);
458 // The .eh_frame section (at least on Linux) needs an extra four bytes padded
459 // with zeroes added at the end. For MachO objects, this section has a
460 // slightly different name, so this won't have any effect for MachO objects.
461 if (Name == ".eh_frame")
465 unsigned SectionID = Sections.size();
467 const char *pData = nullptr;
469 // Some sections, such as debug info, don't need to be loaded for execution.
470 // Leave those where they are.
472 Allocate = DataSize + PaddingSize + StubBufSize;
473 Addr = IsCode ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID,
475 : MemMgr->allocateDataSection(Allocate, Alignment, SectionID,
478 report_fatal_error("Unable to allocate section memory!");
480 // Virtual sections have no data in the object image, so leave pData = 0
484 // Zero-initialize or copy the data from the image
485 if (IsZeroInit || IsVirtual)
486 memset(Addr, 0, DataSize);
488 memcpy(Addr, pData, DataSize);
490 // Fill in any extra bytes we allocated for padding
491 if (PaddingSize != 0) {
492 memset(Addr + DataSize, 0, PaddingSize);
493 // Update the DataSize variable so that the stub offset is set correctly.
494 DataSize += PaddingSize;
497 DEBUG(dbgs() << "emitSection SectionID: " << SectionID << " Name: " << Name
498 << " obj addr: " << format("%p", pData)
499 << " new addr: " << format("%p", Addr)
500 << " DataSize: " << DataSize << " StubBufSize: " << StubBufSize
501 << " Allocate: " << Allocate << "\n");
502 Obj.updateSectionAddress(Section, (uint64_t)Addr);
504 // Even if we didn't load the section, we need to record an entry for it
505 // to handle later processing (and by 'handle' I mean don't do anything
506 // with these sections).
509 DEBUG(dbgs() << "emitSection SectionID: " << SectionID << " Name: " << Name
510 << " obj addr: " << format("%p", data.data()) << " new addr: 0"
511 << " DataSize: " << DataSize << " StubBufSize: " << StubBufSize
512 << " Allocate: " << Allocate << "\n");
515 Sections.push_back(SectionEntry(Name, Addr, DataSize, (uintptr_t)pData));
519 unsigned RuntimeDyldImpl::findOrEmitSection(ObjectImage &Obj,
520 const SectionRef &Section,
522 ObjSectionToIDMap &LocalSections) {
524 unsigned SectionID = 0;
525 ObjSectionToIDMap::iterator i = LocalSections.find(Section);
526 if (i != LocalSections.end())
527 SectionID = i->second;
529 SectionID = emitSection(Obj, Section, IsCode);
530 LocalSections[Section] = SectionID;
535 void RuntimeDyldImpl::addRelocationForSection(const RelocationEntry &RE,
536 unsigned SectionID) {
537 Relocations[SectionID].push_back(RE);
540 void RuntimeDyldImpl::addRelocationForSymbol(const RelocationEntry &RE,
541 StringRef SymbolName) {
542 // Relocation by symbol. If the symbol is found in the global symbol table,
543 // create an appropriate section relocation. Otherwise, add it to
544 // ExternalSymbolRelocations.
545 SymbolTableMap::const_iterator Loc = GlobalSymbolTable.find(SymbolName);
546 if (Loc == GlobalSymbolTable.end()) {
547 ExternalSymbolRelocations[SymbolName].push_back(RE);
549 // Copy the RE since we want to modify its addend.
550 RelocationEntry RECopy = RE;
551 RECopy.Addend += Loc->second.second;
552 Relocations[Loc->second.first].push_back(RECopy);
556 uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr,
557 unsigned AbiVariant) {
558 if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be) {
559 // This stub has to be able to access the full address space,
560 // since symbol lookup won't necessarily find a handy, in-range,
561 // PLT stub for functions which could be anywhere.
562 uint32_t *StubAddr = (uint32_t *)Addr;
564 // Stub can use ip0 (== x16) to calculate address
565 *StubAddr = 0xd2e00010; // movz ip0, #:abs_g3:<addr>
567 *StubAddr = 0xf2c00010; // movk ip0, #:abs_g2_nc:<addr>
569 *StubAddr = 0xf2a00010; // movk ip0, #:abs_g1_nc:<addr>
571 *StubAddr = 0xf2800010; // movk ip0, #:abs_g0_nc:<addr>
573 *StubAddr = 0xd61f0200; // br ip0
576 } else if (Arch == Triple::arm || Arch == Triple::armeb) {
577 // TODO: There is only ARM far stub now. We should add the Thumb stub,
578 // and stubs for branches Thumb - ARM and ARM - Thumb.
579 uint32_t *StubAddr = (uint32_t *)Addr;
580 *StubAddr = 0xe51ff004; // ldr pc,<label>
581 return (uint8_t *)++StubAddr;
582 } else if (Arch == Triple::mipsel || Arch == Triple::mips) {
583 uint32_t *StubAddr = (uint32_t *)Addr;
584 // 0: 3c190000 lui t9,%hi(addr).
585 // 4: 27390000 addiu t9,t9,%lo(addr).
586 // 8: 03200008 jr t9.
588 const unsigned LuiT9Instr = 0x3c190000, AdduiT9Instr = 0x27390000;
589 const unsigned JrT9Instr = 0x03200008, NopInstr = 0x0;
591 *StubAddr = LuiT9Instr;
593 *StubAddr = AdduiT9Instr;
595 *StubAddr = JrT9Instr;
597 *StubAddr = NopInstr;
599 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
600 // Depending on which version of the ELF ABI is in use, we need to
601 // generate one of two variants of the stub. They both start with
602 // the same sequence to load the target address into r12.
603 writeInt32BE(Addr, 0x3D800000); // lis r12, highest(addr)
604 writeInt32BE(Addr+4, 0x618C0000); // ori r12, higher(addr)
605 writeInt32BE(Addr+8, 0x798C07C6); // sldi r12, r12, 32
606 writeInt32BE(Addr+12, 0x658C0000); // oris r12, r12, h(addr)
607 writeInt32BE(Addr+16, 0x618C0000); // ori r12, r12, l(addr)
608 if (AbiVariant == 2) {
609 // PowerPC64 stub ELFv2 ABI: The address points to the function itself.
610 // The address is already in r12 as required by the ABI. Branch to it.
611 writeInt32BE(Addr+20, 0xF8410018); // std r2, 24(r1)
612 writeInt32BE(Addr+24, 0x7D8903A6); // mtctr r12
613 writeInt32BE(Addr+28, 0x4E800420); // bctr
615 // PowerPC64 stub ELFv1 ABI: The address points to a function descriptor.
616 // Load the function address on r11 and sets it to control register. Also
617 // loads the function TOC in r2 and environment pointer to r11.
618 writeInt32BE(Addr+20, 0xF8410028); // std r2, 40(r1)
619 writeInt32BE(Addr+24, 0xE96C0000); // ld r11, 0(r12)
620 writeInt32BE(Addr+28, 0xE84C0008); // ld r2, 0(r12)
621 writeInt32BE(Addr+32, 0x7D6903A6); // mtctr r11
622 writeInt32BE(Addr+36, 0xE96C0010); // ld r11, 16(r2)
623 writeInt32BE(Addr+40, 0x4E800420); // bctr
626 } else if (Arch == Triple::systemz) {
627 writeInt16BE(Addr, 0xC418); // lgrl %r1,.+8
628 writeInt16BE(Addr+2, 0x0000);
629 writeInt16BE(Addr+4, 0x0004);
630 writeInt16BE(Addr+6, 0x07F1); // brc 15,%r1
631 // 8-byte address stored at Addr + 8
633 } else if (Arch == Triple::x86_64) {
635 *(Addr+1) = 0x25; // rip
636 // 32-bit PC-relative address of the GOT entry will be stored at Addr+2
637 } else if (Arch == Triple::x86) {
638 *Addr = 0xE9; // 32-bit pc-relative jump.
643 // Assign an address to a symbol name and resolve all the relocations
644 // associated with it.
645 void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID,
647 // The address to use for relocation resolution is not
648 // the address of the local section buffer. We must be doing
649 // a remote execution environment of some sort. Relocations can't
650 // be applied until all the sections have been moved. The client must
651 // trigger this with a call to MCJIT::finalize() or
652 // RuntimeDyld::resolveRelocations().
654 // Addr is a uint64_t because we can't assume the pointer width
655 // of the target is the same as that of the host. Just use a generic
656 // "big enough" type.
657 Sections[SectionID].LoadAddress = Addr;
660 void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs,
662 for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
663 const RelocationEntry &RE = Relocs[i];
664 // Ignore relocations for sections that were not loaded
665 if (Sections[RE.SectionID].Address == nullptr)
667 resolveRelocation(RE, Value);
671 void RuntimeDyldImpl::resolveExternalSymbols() {
672 while (!ExternalSymbolRelocations.empty()) {
673 StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin();
675 StringRef Name = i->first();
676 if (Name.size() == 0) {
677 // This is an absolute symbol, use an address of zero.
678 DEBUG(dbgs() << "Resolving absolute relocations."
680 RelocationList &Relocs = i->second;
681 resolveRelocationList(Relocs, 0);
684 SymbolTableMap::const_iterator Loc = GlobalSymbolTable.find(Name);
685 if (Loc == GlobalSymbolTable.end()) {
686 // This is an external symbol, try to get its address from
688 Addr = MemMgr->getSymbolAddress(Name.data());
689 // The call to getSymbolAddress may have caused additional modules to
690 // be loaded, which may have added new entries to the
691 // ExternalSymbolRelocations map. Consquently, we need to update our
692 // iterator. This is also why retrieval of the relocation list
693 // associated with this symbol is deferred until below this point.
694 // New entries may have been added to the relocation list.
695 i = ExternalSymbolRelocations.find(Name);
697 // We found the symbol in our global table. It was probably in a
698 // Module that we loaded previously.
699 SymbolLoc SymLoc = Loc->second;
700 Addr = getSectionLoadAddress(SymLoc.first) + SymLoc.second;
703 // FIXME: Implement error handling that doesn't kill the host program!
705 report_fatal_error("Program used external function '" + Name +
706 "' which could not be resolved!");
708 updateGOTEntries(Name, Addr);
709 DEBUG(dbgs() << "Resolving relocations Name: " << Name << "\t"
710 << format("0x%lx", Addr) << "\n");
711 // This list may have been updated when we called getSymbolAddress, so
712 // don't change this code to get the list earlier.
713 RelocationList &Relocs = i->second;
714 resolveRelocationList(Relocs, Addr);
717 ExternalSymbolRelocations.erase(i);
721 //===----------------------------------------------------------------------===//
722 // RuntimeDyld class implementation
723 RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {
724 // FIXME: There's a potential issue lurking here if a single instance of
725 // RuntimeDyld is used to load multiple objects. The current implementation
726 // associates a single memory manager with a RuntimeDyld instance. Even
727 // though the public class spawns a new 'impl' instance for each load,
728 // they share a single memory manager. This can become a problem when page
729 // permissions are applied.
732 ProcessAllSections = false;
736 RuntimeDyld::~RuntimeDyld() { delete Dyld; }
738 static std::unique_ptr<RuntimeDyldELF>
739 createRuntimeDyldELF(RTDyldMemoryManager *MM, bool ProcessAllSections,
740 RuntimeDyldCheckerImpl *Checker) {
741 std::unique_ptr<RuntimeDyldELF> Dyld(new RuntimeDyldELF(MM));
742 Dyld->setProcessAllSections(ProcessAllSections);
743 Dyld->setRuntimeDyldChecker(Checker);
747 static std::unique_ptr<RuntimeDyldMachO>
748 createRuntimeDyldMachO(Triple::ArchType Arch, RTDyldMemoryManager *MM,
749 bool ProcessAllSections, RuntimeDyldCheckerImpl *Checker) {
750 std::unique_ptr<RuntimeDyldMachO> Dyld(RuntimeDyldMachO::create(Arch, MM));
751 Dyld->setProcessAllSections(ProcessAllSections);
752 Dyld->setRuntimeDyldChecker(Checker);
756 ObjectImage *RuntimeDyld::loadObject(std::unique_ptr<ObjectFile> InputObject) {
757 std::unique_ptr<ObjectImage> InputImage;
759 ObjectFile &Obj = *InputObject;
761 if (InputObject->isELF()) {
762 InputImage.reset(RuntimeDyldELF::createObjectImageFromFile(std::move(InputObject)));
764 Dyld = createRuntimeDyldELF(MM, ProcessAllSections, Checker).release();
765 } else if (InputObject->isMachO()) {
766 InputImage.reset(RuntimeDyldMachO::createObjectImageFromFile(std::move(InputObject)));
768 Dyld = createRuntimeDyldMachO(
769 static_cast<Triple::ArchType>(InputImage->getArch()),
770 MM, ProcessAllSections, Checker).release();
772 report_fatal_error("Incompatible object format!");
774 if (!Dyld->isCompatibleFile(&Obj))
775 report_fatal_error("Incompatible object format!");
777 Dyld->loadObject(InputImage.get());
778 return InputImage.release();
781 ObjectImage *RuntimeDyld::loadObject(ObjectBuffer *InputBuffer) {
782 std::unique_ptr<ObjectImage> InputImage;
783 sys::fs::file_magic Type = sys::fs::identify_magic(InputBuffer->getBuffer());
786 case sys::fs::file_magic::elf_relocatable:
787 case sys::fs::file_magic::elf_executable:
788 case sys::fs::file_magic::elf_shared_object:
789 case sys::fs::file_magic::elf_core:
790 InputImage.reset(RuntimeDyldELF::createObjectImage(InputBuffer));
792 Dyld = createRuntimeDyldELF(MM, ProcessAllSections, Checker).release();
794 case sys::fs::file_magic::macho_object:
795 case sys::fs::file_magic::macho_executable:
796 case sys::fs::file_magic::macho_fixed_virtual_memory_shared_lib:
797 case sys::fs::file_magic::macho_core:
798 case sys::fs::file_magic::macho_preload_executable:
799 case sys::fs::file_magic::macho_dynamically_linked_shared_lib:
800 case sys::fs::file_magic::macho_dynamic_linker:
801 case sys::fs::file_magic::macho_bundle:
802 case sys::fs::file_magic::macho_dynamically_linked_shared_lib_stub:
803 case sys::fs::file_magic::macho_dsym_companion:
804 InputImage.reset(RuntimeDyldMachO::createObjectImage(InputBuffer));
806 Dyld = createRuntimeDyldMachO(
807 static_cast<Triple::ArchType>(InputImage->getArch()),
808 MM, ProcessAllSections, Checker).release();
810 case sys::fs::file_magic::unknown:
811 case sys::fs::file_magic::bitcode:
812 case sys::fs::file_magic::archive:
813 case sys::fs::file_magic::coff_object:
814 case sys::fs::file_magic::coff_import_library:
815 case sys::fs::file_magic::pecoff_executable:
816 case sys::fs::file_magic::macho_universal_binary:
817 case sys::fs::file_magic::windows_resource:
818 report_fatal_error("Incompatible object format!");
821 if (!Dyld->isCompatibleFormat(InputBuffer))
822 report_fatal_error("Incompatible object format!");
824 Dyld->loadObject(InputImage.get());
825 return InputImage.release();
828 void *RuntimeDyld::getSymbolAddress(StringRef Name) {
831 return Dyld->getSymbolAddress(Name);
834 uint64_t RuntimeDyld::getSymbolLoadAddress(StringRef Name) {
837 return Dyld->getSymbolLoadAddress(Name);
840 void RuntimeDyld::resolveRelocations() { Dyld->resolveRelocations(); }
842 void RuntimeDyld::reassignSectionAddress(unsigned SectionID, uint64_t Addr) {
843 Dyld->reassignSectionAddress(SectionID, Addr);
846 void RuntimeDyld::mapSectionAddress(const void *LocalAddress,
847 uint64_t TargetAddress) {
848 Dyld->mapSectionAddress(LocalAddress, TargetAddress);
851 bool RuntimeDyld::hasError() { return Dyld->hasError(); }
853 StringRef RuntimeDyld::getErrorString() { return Dyld->getErrorString(); }
855 void RuntimeDyld::registerEHFrames() {
857 Dyld->registerEHFrames();
860 void RuntimeDyld::deregisterEHFrames() {
862 Dyld->deregisterEHFrames();
865 } // end namespace llvm