MCLinker upstream commit 0459e386785c.
Change-Id: Ide6790f5a354b7fcc03d812d6c8cf43b1e309ba3
diff --git a/lib/Object/ObjectLinker.cpp b/lib/Object/ObjectLinker.cpp
new file mode 100644
index 0000000..93fdb20
--- /dev/null
+++ b/lib/Object/ObjectLinker.cpp
@@ -0,0 +1,442 @@
+//===- ObjectLinker.cpp ---------------------------------------------------===//
+//
+// The MCLinker Project
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include <mcld/Object/ObjectLinker.h>
+
+#include <mcld/LinkerConfig.h>
+#include <mcld/Module.h>
+#include <mcld/InputTree.h>
+#include <mcld/MC/InputBuilder.h>
+#include <mcld/LD/LDSection.h>
+#include <mcld/LD/LDContext.h>
+#include <mcld/LD/Archive.h>
+#include <mcld/LD/ArchiveReader.h>
+#include <mcld/LD/ObjectReader.h>
+#include <mcld/LD/DynObjReader.h>
+#include <mcld/LD/GroupReader.h>
+#include <mcld/LD/ObjectWriter.h>
+#include <mcld/LD/DynObjWriter.h>
+#include <mcld/LD/ExecWriter.h>
+#include <mcld/LD/ResolveInfo.h>
+#include <mcld/LD/Layout.h>
+#include <mcld/LD/RelocData.h>
+#include <mcld/Support/RealPath.h>
+#include <mcld/Support/MemoryArea.h>
+#include <mcld/Support/MsgHandling.h>
+#include <mcld/Target/TargetLDBackend.h>
+#include <mcld/Fragment/FragmentLinker.h>
+#include <mcld/Object/ObjectBuilder.h>
+
+#include <llvm/Support/Casting.h>
+
+using namespace llvm;
+using namespace mcld;
+
+ObjectLinker::ObjectLinker(const LinkerConfig& pConfig,
+ Module& pModule,
+ InputBuilder& pInputBuilder,
+ TargetLDBackend& pLDBackend)
+ : m_Config(pConfig),
+ m_Module(pModule),
+ m_InputBuilder(pInputBuilder),
+ m_pLinker(NULL),
+ m_LDBackend(pLDBackend),
+ m_pObjectReader(NULL),
+ m_pDynObjReader(NULL),
+ m_pArchiveReader(NULL),
+ m_pObjectWriter(NULL),
+ m_pDynObjWriter(NULL),
+ m_pExecWriter(NULL),
+ m_pGroupReader(NULL)
+{
+ // set up soname
+ if (!m_Config.options().soname().empty()) {
+ m_Module.setName(m_Config.options().soname());
+ }
+}
+
+ObjectLinker::~ObjectLinker()
+{
+ delete m_pLinker;
+ delete m_pObjectReader;
+ delete m_pDynObjReader;
+ delete m_pArchiveReader;
+ delete m_pObjectWriter;
+ delete m_pDynObjWriter;
+ delete m_pExecWriter;
+ delete m_pGroupReader;
+}
+
+/// initFragmentLinker - initialize FragmentLinker
+/// Connect all components with FragmentLinker
+bool ObjectLinker::initFragmentLinker()
+{
+ if (NULL == m_pLinker) {
+ m_pLinker = new FragmentLinker(m_Config,
+ m_Module,
+ m_LDBackend);
+ }
+
+ // initialize the readers and writers
+ // Because constructor can not be failed, we initalize all readers and
+ // writers outside the FragmentLinker constructors.
+ m_pObjectReader = m_LDBackend.createObjectReader(*m_pLinker);
+ m_pArchiveReader = m_LDBackend.createArchiveReader(m_Module);
+ m_pDynObjReader = m_LDBackend.createDynObjReader(*m_pLinker);
+ m_pObjectWriter = m_LDBackend.createObjectWriter(*m_pLinker);
+ m_pDynObjWriter = m_LDBackend.createDynObjWriter(*m_pLinker);
+ m_pExecWriter = m_LDBackend.createExecWriter(*m_pLinker);
+ m_pGroupReader = new GroupReader(m_Module, *m_pObjectReader,
+ *m_pDynObjReader, *m_pArchiveReader);
+
+ // initialize RelocationFactory
+ m_LDBackend.initRelocFactory(*m_pLinker);
+
+ // initialize BranchIslandFactory
+ m_LDBackend.initBRIslandFactory();
+
+ // initialize StubFactory
+ m_LDBackend.initStubFactory();
+
+ // initialize target stubs
+ m_LDBackend.initTargetStubs(*m_pLinker);
+ return true;
+}
+
+/// initStdSections - initialize standard sections
+bool ObjectLinker::initStdSections()
+{
+ ObjectBuilder builder(m_Config, m_Module);
+
+ // initialize standard sections
+ if (!m_LDBackend.initStdSections(builder))
+ return false;
+
+ // initialize target-dependent sections
+ m_LDBackend.initTargetSections(m_Module, builder);
+
+ return true;
+}
+
+void ObjectLinker::normalize()
+{
+ // ----- set up inputs ----- //
+ Module::input_iterator input, inEnd = m_Module.input_end();
+ for (input = m_Module.input_begin(); input!=inEnd; ++input) {
+ // is a group node
+ if (isGroup(input)) {
+ getGroupReader()->readGroup(input, m_InputBuilder, m_Config);
+ continue;
+ }
+
+ // already got type - for example, bitcode or external OIR (object
+ // intermediate representation)
+ if ((*input)->type() == Input::Script ||
+ (*input)->type() == Input::Archive ||
+ (*input)->type() == Input::External)
+ continue;
+
+ if (Input::Object == (*input)->type()) {
+ m_Module.getObjectList().push_back(*input);
+ continue;
+ }
+
+ if (Input::DynObj == (*input)->type()) {
+ m_Module.getLibraryList().push_back(*input);
+ continue;
+ }
+
+ // is a relocatable object file
+ if (getObjectReader()->isMyFormat(**input)) {
+ (*input)->setType(Input::Object);
+ getObjectReader()->readHeader(**input);
+ getObjectReader()->readSections(**input);
+ getObjectReader()->readSymbols(**input);
+ m_Module.getObjectList().push_back(*input);
+ }
+ // is a shared object file
+ else if (getDynObjReader()->isMyFormat(**input)) {
+ (*input)->setType(Input::DynObj);
+ getDynObjReader()->readHeader(**input);
+ getDynObjReader()->readSymbols(**input);
+ m_Module.getLibraryList().push_back(*input);
+ }
+ // is an archive
+ else if (getArchiveReader()->isMyFormat(**input)) {
+ (*input)->setType(Input::Archive);
+ Archive archive(**input, m_InputBuilder);
+ getArchiveReader()->readArchive(archive);
+ if(archive.numOfObjectMember() > 0) {
+ m_Module.getInputTree().merge<InputTree::Inclusive>(input,
+ archive.inputs());
+ }
+ }
+ else {
+ fatal(diag::err_unrecognized_input_file) << (*input)->path()
+ << m_Config.triple().str();
+ }
+ } // end of for
+}
+
+bool ObjectLinker::linkable() const
+{
+ // check we have input and output files
+ if (m_Module.getInputTree().empty()) {
+ error(diag::err_no_inputs);
+ return false;
+ }
+
+ // can not mix -static with shared objects
+ Module::const_lib_iterator lib, libEnd = m_Module.lib_end();
+ for (lib = m_Module.lib_begin(); lib != libEnd; ++lib) {
+ if((*lib)->attribute()->isStatic()) {
+ error(diag::err_mixed_shared_static_objects)
+ << (*lib)->name() << (*lib)->path();
+ return false;
+ }
+ }
+
+ // can not mix -r with shared objects
+ return true;
+}
+
+/// readRelocations - read all relocation entries
+///
+/// All symbols should be read and resolved before this function.
+bool ObjectLinker::readRelocations()
+{
+ // Bitcode is read by the other path. This function reads relocation sections
+ // in object files.
+ mcld::InputTree::bfs_iterator input, inEnd = m_Module.getInputTree().bfs_end();
+ for (input=m_Module.getInputTree().bfs_begin(); input!=inEnd; ++input) {
+ if ((*input)->type() == Input::Object && (*input)->hasMemArea()) {
+ if (!getObjectReader()->readRelocations(**input))
+ return false;
+ }
+ // ignore the other kinds of files.
+ }
+ return true;
+}
+
+/// mergeSections - put allinput sections into output sections
+bool ObjectLinker::mergeSections()
+{
+ ObjectBuilder builder(m_Config, m_Module);
+ Module::obj_iterator obj, objEnd = m_Module.obj_end();
+ for (obj = m_Module.obj_begin(); obj != objEnd; ++obj) {
+ LDContext::sect_iterator sect, sectEnd = (*obj)->context()->sectEnd();
+ for (sect = (*obj)->context()->sectBegin(); sect != sectEnd; ++sect) {
+ switch ((*sect)->kind()) {
+ // Some *INPUT sections should not be merged.
+ case LDFileFormat::Ignore:
+ case LDFileFormat::Null:
+ case LDFileFormat::Relocation:
+ case LDFileFormat::NamePool:
+ case LDFileFormat::Group:
+ case LDFileFormat::StackNote:
+ // skip
+ continue;
+ case LDFileFormat::Target:
+ if (!m_LDBackend.mergeSection(m_Module, **sect)) {
+ error(diag::err_cannot_merge_section) << (*sect)->name()
+ << (*obj)->name();
+ return false;
+ }
+ break;
+ case LDFileFormat::EhFrame: {
+ if (!(*sect)->hasEhFrame())
+ continue; // skip
+
+ if (!builder.MergeSection(**sect)) {
+ error(diag::err_cannot_merge_section) << (*sect)->name()
+ << (*obj)->name();
+ return false;
+ }
+ break;
+ }
+ default: {
+ if (!(*sect)->hasSectionData())
+ continue; // skip
+
+ if (!builder.MergeSection(**sect)) {
+ error(diag::err_cannot_merge_section) << (*sect)->name()
+ << (*obj)->name();
+ return false;
+ }
+ break;
+ }
+ } // end of switch
+ } // for each section
+ } // for each obj
+ return true;
+}
+
+/// addStandardSymbols - shared object and executable files need some
+/// standard symbols
+/// @return if there are some input symbols with the same name to the
+/// standard symbols, return false
+bool ObjectLinker::addStandardSymbols()
+{
+ // create and add section symbols for each output section
+ Module::iterator iter, iterEnd = m_Module.end();
+ for (iter = m_Module.begin(); iter != iterEnd; ++iter) {
+ m_Module.getSectionSymbolSet().add(**iter, m_Module.getNamePool());
+ }
+
+ return m_LDBackend.initStandardSymbols(*m_pLinker, m_Module);
+}
+
+/// addTargetSymbols - some targets, such as MIPS and ARM, need some
+/// target-dependent symbols
+/// @return if there are some input symbols with the same name to the
+/// target symbols, return false
+bool ObjectLinker::addTargetSymbols()
+{
+ m_LDBackend.initTargetSymbols(*m_pLinker);
+ return true;
+}
+
+bool ObjectLinker::scanRelocations()
+{
+ // apply all relocations of all inputs
+ Module::obj_iterator input, inEnd = m_Module.obj_end();
+ for (input = m_Module.obj_begin(); input != inEnd; ++input) {
+ LDContext::sect_iterator rs, rsEnd = (*input)->context()->relocSectEnd();
+ for (rs = (*input)->context()->relocSectBegin(); rs != rsEnd; ++rs) {
+ // bypass the reloc section if
+ // 1. its section kind is changed to Ignore. (The target section is a
+ // discarded group section.)
+ // 2. it has no reloc data. (All symbols in the input relocs are in the
+ // discarded group sections)
+ if (LDFileFormat::Ignore == (*rs)->kind() || !(*rs)->hasRelocData())
+ continue;
+ RelocData::iterator reloc, rEnd = (*rs)->getRelocData()->end();
+ for (reloc = (*rs)->getRelocData()->begin(); reloc != rEnd; ++reloc) {
+ Relocation* relocation = llvm::cast<Relocation>(reloc);
+ // scan relocation
+ if (LinkerConfig::Object != m_Config.codeGenType()) {
+ m_LDBackend.scanRelocation(*relocation,
+ *m_pLinker,
+ m_Module,
+ *(*rs)->getLink());
+ }
+ else {
+ m_LDBackend.partialScanRelocation(*relocation,
+ *m_pLinker,
+ m_Module,
+ *(*rs)->getLink());
+ }
+ } // for all relocations
+ } // for all relocation section
+ } // for all inputs
+ return true;
+}
+
+/// prelayout - help backend to do some modification before layout
+bool ObjectLinker::prelayout()
+{
+ // finalize the section symbols, set their fragment reference and push them
+ // into output symbol table
+ Module::iterator iter, iterEnd = m_Module.end();
+ for (iter = m_Module.begin(); iter != iterEnd; ++iter) {
+ LDSection* section = *iter;
+ if (0x0 == section->size() || LDFileFormat::Relocation == section->kind())
+ continue;
+ m_Module.getSectionSymbolSet().finalize(
+ *section, m_Module.getSymbolTable());
+ }
+
+ m_LDBackend.preLayout(m_Module, *m_pLinker);
+
+ m_LDBackend.allocateCommonSymbols(m_Module);
+
+ /// check program interpreter - computer the name size of the runtime dyld
+ if (!m_pLinker->isStaticLink() &&
+ (LinkerConfig::Exec == m_Config.codeGenType() ||
+ m_Config.options().isPIE() ||
+ m_Config.options().hasDyld()))
+ m_LDBackend.sizeInterp();
+
+ /// measure NamePools - compute the size of name pool sections
+ /// In ELF, will compute the size of.symtab, .strtab, .dynsym, .dynstr,
+ /// .hash and .shstrtab sections.
+ ///
+ /// dump all symbols and strings from FragmentLinker and build the format-dependent
+ /// hash table.
+ m_LDBackend.sizeNamePools(m_Module, m_pLinker->isStaticLink());
+
+ return true;
+}
+
+/// layout - linearly layout all output sections and reserve some space
+/// for GOT/PLT
+/// Because we do not support instruction relaxing in this early version,
+/// if there is a branch can not jump to its target, we return false
+/// directly
+bool ObjectLinker::layout()
+{
+ Layout layout;
+ return layout.layout(m_Module, m_LDBackend, m_Config);
+}
+
+/// prelayout - help backend to do some modification after layout
+bool ObjectLinker::postlayout()
+{
+ m_LDBackend.postLayout(m_Module, *m_pLinker);
+ return true;
+}
+
+/// finalizeSymbolValue - finalize the resolved symbol value.
+/// Before relocate(), after layout(), FragmentLinker should correct value of all
+/// symbol.
+bool ObjectLinker::finalizeSymbolValue()
+{
+ return m_pLinker->finalizeSymbols();
+}
+
+/// relocate - applying relocation entries and create relocation
+/// section in the output files
+/// Create relocation section, asking TargetLDBackend to
+/// read the relocation information into RelocationEntry
+/// and push_back into the relocation section
+bool ObjectLinker::relocation()
+{
+ return m_pLinker->applyRelocations();
+}
+
+/// emitOutput - emit the output file.
+bool ObjectLinker::emitOutput(MemoryArea& pOutput)
+{
+ switch(m_Config.codeGenType()) {
+ case LinkerConfig::Object:
+ getObjectWriter()->writeObject(m_Module, pOutput);
+ return true;
+ case LinkerConfig::DynObj:
+ getDynObjWriter()->writeDynObj(m_Module, pOutput);
+ return true;
+ case LinkerConfig::Exec:
+ getExecWriter()->writeExecutable(m_Module, pOutput);
+ return true;
+ default:
+ fatal(diag::unrecognized_output_file) << m_Config.codeGenType();
+ }
+ return false;
+}
+
+/// postProcessing - do modification after all processes
+bool ObjectLinker::postProcessing(MemoryArea& pOutput)
+{
+ m_pLinker->syncRelocationResult(pOutput);
+
+ // emit .eh_frame_hdr
+ // eh_frame_hdr should be emitted after syncRelocation, because eh_frame_hdr
+ // needs FDE PC value, which will be corrected at syncRelocation
+ m_LDBackend.postProcessing(*m_pLinker, pOutput);
+ return true;
+}
+
