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-rw-r--r--COFF/InputFiles.cpp394
1 files changed, 244 insertions, 150 deletions
diff --git a/COFF/InputFiles.cpp b/COFF/InputFiles.cpp
index 7d41caebb4b9..a8f52e0391f7 100644
--- a/COFF/InputFiles.cpp
+++ b/COFF/InputFiles.cpp
@@ -11,10 +11,10 @@
#include "Chunks.h"
#include "Config.h"
#include "Driver.h"
-#include "Error.h"
-#include "Memory.h"
#include "SymbolTable.h"
#include "Symbols.h"
+#include "lld/Common/ErrorHandler.h"
+#include "lld/Common/Memory.h"
#include "llvm-c/lto.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Triple.h"
@@ -43,14 +43,18 @@ using llvm::support::ulittle32_t;
namespace lld {
namespace coff {
+std::vector<ObjFile *> ObjFile::Instances;
+std::vector<ImportFile *> ImportFile::Instances;
+std::vector<BitcodeFile *> BitcodeFile::Instances;
+
/// Checks that Source is compatible with being a weak alias to Target.
/// If Source is Undefined and has no weak alias set, makes it a weak
/// alias to Target.
static void checkAndSetWeakAlias(SymbolTable *Symtab, InputFile *F,
- SymbolBody *Source, SymbolBody *Target) {
+ Symbol *Source, Symbol *Target) {
if (auto *U = dyn_cast<Undefined>(Source)) {
if (U->WeakAlias && U->WeakAlias != Target)
- Symtab->reportDuplicate(Source->symbol(), F);
+ Symtab->reportDuplicate(Source, F);
U->WeakAlias = Target;
}
}
@@ -59,7 +63,7 @@ ArchiveFile::ArchiveFile(MemoryBufferRef M) : InputFile(ArchiveKind, M) {}
void ArchiveFile::parse() {
// Parse a MemoryBufferRef as an archive file.
- File = check(Archive::create(MB), toString(this));
+ File = CHECK(Archive::create(MB), this);
// Read the symbol table to construct Lazy objects.
for (const Archive::Symbol &Sym : File->symbols())
@@ -69,7 +73,7 @@ void ArchiveFile::parse() {
// Returns a buffer pointing to a member file containing a given symbol.
void ArchiveFile::addMember(const Archive::Symbol *Sym) {
const Archive::Child &C =
- check(Sym->getMember(),
+ CHECK(Sym->getMember(),
"could not get the member for symbol " + Sym->getName());
// Return an empty buffer if we have already returned the same buffer.
@@ -79,9 +83,28 @@ void ArchiveFile::addMember(const Archive::Symbol *Sym) {
Driver->enqueueArchiveMember(C, Sym->getName(), getName());
}
-void ObjectFile::parse() {
+std::vector<MemoryBufferRef> getArchiveMembers(Archive *File) {
+ std::vector<MemoryBufferRef> V;
+ Error Err = Error::success();
+ for (const ErrorOr<Archive::Child> &COrErr : File->children(Err)) {
+ Archive::Child C =
+ CHECK(COrErr,
+ File->getFileName() + ": could not get the child of the archive");
+ MemoryBufferRef MBRef =
+ CHECK(C.getMemoryBufferRef(),
+ File->getFileName() +
+ ": could not get the buffer for a child of the archive");
+ V.push_back(MBRef);
+ }
+ if (Err)
+ fatal(File->getFileName() +
+ ": Archive::children failed: " + toString(std::move(Err)));
+ return V;
+}
+
+void ObjFile::parse() {
// Parse a memory buffer as a COFF file.
- std::unique_ptr<Binary> Bin = check(createBinary(MB), toString(this));
+ std::unique_ptr<Binary> Bin = CHECK(createBinary(MB), this);
if (auto *Obj = dyn_cast<COFFObjectFile>(Bin.get())) {
Bin.release();
@@ -93,114 +116,184 @@ void ObjectFile::parse() {
// Read section and symbol tables.
initializeChunks();
initializeSymbols();
- initializeSEH();
}
-void ObjectFile::initializeChunks() {
+// We set SectionChunk pointers in the SparseChunks vector to this value
+// temporarily to mark comdat sections as having an unknown resolution. As we
+// walk the object file's symbol table, once we visit either a leader symbol or
+// an associative section definition together with the parent comdat's leader,
+// we set the pointer to either nullptr (to mark the section as discarded) or a
+// valid SectionChunk for that section.
+static SectionChunk *const PendingComdat = reinterpret_cast<SectionChunk *>(1);
+
+void ObjFile::initializeChunks() {
uint32_t NumSections = COFFObj->getNumberOfSections();
Chunks.reserve(NumSections);
SparseChunks.resize(NumSections + 1);
for (uint32_t I = 1; I < NumSections + 1; ++I) {
const coff_section *Sec;
- StringRef Name;
if (auto EC = COFFObj->getSection(I, Sec))
- fatal(EC, "getSection failed: #" + Twine(I));
- if (auto EC = COFFObj->getSectionName(Sec, Name))
- fatal(EC, "getSectionName failed: #" + Twine(I));
- if (Name == ".sxdata") {
- SXData = Sec;
- continue;
- }
- if (Name == ".drectve") {
- ArrayRef<uint8_t> Data;
- COFFObj->getSectionContents(Sec, Data);
- Directives = std::string((const char *)Data.data(), Data.size());
- continue;
- }
+ fatal("getSection failed: #" + Twine(I) + ": " + EC.message());
- // Object files may have DWARF debug info or MS CodeView debug info
- // (or both).
- //
- // DWARF sections don't need any special handling from the perspective
- // of the linker; they are just a data section containing relocations.
- // We can just link them to complete debug info.
- //
- // CodeView needs a linker support. We need to interpret and debug
- // info, and then write it to a separate .pdb file.
-
- // Ignore debug info unless /debug is given.
- if (!Config->Debug && Name.startswith(".debug"))
- continue;
-
- if (Sec->Characteristics & llvm::COFF::IMAGE_SCN_LNK_REMOVE)
- continue;
- auto *C = make<SectionChunk>(this, Sec);
-
- // CodeView sections are stored to a different vector because they are not
- // linked in the regular manner.
- if (C->isCodeView())
- DebugChunks.push_back(C);
+ if (Sec->Characteristics & IMAGE_SCN_LNK_COMDAT)
+ SparseChunks[I] = PendingComdat;
else
- Chunks.push_back(C);
+ SparseChunks[I] = readSection(I, nullptr);
+ }
+}
- SparseChunks[I] = C;
+SectionChunk *ObjFile::readSection(uint32_t SectionNumber,
+ const coff_aux_section_definition *Def) {
+ const coff_section *Sec;
+ StringRef Name;
+ if (auto EC = COFFObj->getSection(SectionNumber, Sec))
+ fatal("getSection failed: #" + Twine(SectionNumber) + ": " + EC.message());
+ if (auto EC = COFFObj->getSectionName(Sec, Name))
+ fatal("getSectionName failed: #" + Twine(SectionNumber) + ": " +
+ EC.message());
+ if (Name == ".sxdata") {
+ ArrayRef<uint8_t> Data;
+ COFFObj->getSectionContents(Sec, Data);
+ if (Data.size() % 4 != 0)
+ fatal(".sxdata must be an array of symbol table indices");
+ SXData = {reinterpret_cast<const ulittle32_t *>(Data.data()),
+ Data.size() / 4};
+ return nullptr;
+ }
+ if (Name == ".drectve") {
+ ArrayRef<uint8_t> Data;
+ COFFObj->getSectionContents(Sec, Data);
+ Directives = std::string((const char *)Data.data(), Data.size());
+ return nullptr;
}
+
+ // Object files may have DWARF debug info or MS CodeView debug info
+ // (or both).
+ //
+ // DWARF sections don't need any special handling from the perspective
+ // of the linker; they are just a data section containing relocations.
+ // We can just link them to complete debug info.
+ //
+ // CodeView needs a linker support. We need to interpret and debug
+ // info, and then write it to a separate .pdb file.
+
+ // Ignore debug info unless /debug is given.
+ if (!Config->Debug && Name.startswith(".debug"))
+ return nullptr;
+
+ if (Sec->Characteristics & llvm::COFF::IMAGE_SCN_LNK_REMOVE)
+ return nullptr;
+ auto *C = make<SectionChunk>(this, Sec);
+ if (Def)
+ C->Checksum = Def->CheckSum;
+
+ // CodeView sections are stored to a different vector because they are not
+ // linked in the regular manner.
+ if (C->isCodeView())
+ DebugChunks.push_back(C);
+ else
+ Chunks.push_back(C);
+
+ return C;
}
-void ObjectFile::initializeSymbols() {
+void ObjFile::readAssociativeDefinition(
+ COFFSymbolRef Sym, const coff_aux_section_definition *Def) {
+ SectionChunk *Parent = SparseChunks[Def->getNumber(Sym.isBigObj())];
+
+ // If the parent is pending, it probably means that its section definition
+ // appears after us in the symbol table. Leave the associated section as
+ // pending; we will handle it during the second pass in initializeSymbols().
+ if (Parent == PendingComdat)
+ return;
+
+ // Check whether the parent is prevailing. If it is, so are we, and we read
+ // the section; otherwise mark it as discarded.
+ int32_t SectionNumber = Sym.getSectionNumber();
+ if (Parent) {
+ SparseChunks[SectionNumber] = readSection(SectionNumber, Def);
+ if (SparseChunks[SectionNumber])
+ Parent->addAssociative(SparseChunks[SectionNumber]);
+ } else {
+ SparseChunks[SectionNumber] = nullptr;
+ }
+}
+
+Symbol *ObjFile::createRegular(COFFSymbolRef Sym) {
+ SectionChunk *SC = SparseChunks[Sym.getSectionNumber()];
+ if (Sym.isExternal()) {
+ StringRef Name;
+ COFFObj->getSymbolName(Sym, Name);
+ if (SC)
+ return Symtab->addRegular(this, Name, Sym.getGeneric(), SC);
+ return Symtab->addUndefined(Name, this, false);
+ }
+ if (SC)
+ return make<DefinedRegular>(this, /*Name*/ "", false,
+ /*IsExternal*/ false, Sym.getGeneric(), SC);
+ return nullptr;
+}
+
+void ObjFile::initializeSymbols() {
uint32_t NumSymbols = COFFObj->getNumberOfSymbols();
- SymbolBodies.reserve(NumSymbols);
- SparseSymbolBodies.resize(NumSymbols);
+ Symbols.resize(NumSymbols);
- SmallVector<std::pair<SymbolBody *, uint32_t>, 8> WeakAliases;
- int32_t LastSectionNumber = 0;
+ SmallVector<std::pair<Symbol *, uint32_t>, 8> WeakAliases;
+ std::vector<uint32_t> PendingIndexes;
+ PendingIndexes.reserve(NumSymbols);
+
+ std::vector<const coff_aux_section_definition *> ComdatDefs(
+ COFFObj->getNumberOfSections() + 1);
for (uint32_t I = 0; I < NumSymbols; ++I) {
- // Get a COFFSymbolRef object.
- ErrorOr<COFFSymbolRef> SymOrErr = COFFObj->getSymbol(I);
- if (!SymOrErr)
- fatal(SymOrErr.getError(), "broken object file: " + toString(this));
- COFFSymbolRef Sym = *SymOrErr;
-
- const void *AuxP = nullptr;
- if (Sym.getNumberOfAuxSymbols())
- AuxP = COFFObj->getSymbol(I + 1)->getRawPtr();
- bool IsFirst = (LastSectionNumber != Sym.getSectionNumber());
-
- SymbolBody *Body = nullptr;
- if (Sym.isUndefined()) {
- Body = createUndefined(Sym);
- } else if (Sym.isWeakExternal()) {
- Body = createUndefined(Sym);
- uint32_t TagIndex =
- static_cast<const coff_aux_weak_external *>(AuxP)->TagIndex;
- WeakAliases.emplace_back(Body, TagIndex);
+ COFFSymbolRef COFFSym = check(COFFObj->getSymbol(I));
+ if (COFFSym.isUndefined()) {
+ Symbols[I] = createUndefined(COFFSym);
+ } else if (COFFSym.isWeakExternal()) {
+ Symbols[I] = createUndefined(COFFSym);
+ uint32_t TagIndex = COFFSym.getAux<coff_aux_weak_external>()->TagIndex;
+ WeakAliases.emplace_back(Symbols[I], TagIndex);
+ } else if (Optional<Symbol *> OptSym = createDefined(COFFSym, ComdatDefs)) {
+ Symbols[I] = *OptSym;
} else {
- Body = createDefined(Sym, AuxP, IsFirst);
- }
- if (Body) {
- SymbolBodies.push_back(Body);
- SparseSymbolBodies[I] = Body;
+ // createDefined() returns None if a symbol belongs to a section that
+ // was pending at the point when the symbol was read. This can happen in
+ // two cases:
+ // 1) section definition symbol for a comdat leader;
+ // 2) symbol belongs to a comdat section associated with a section whose
+ // section definition symbol appears later in the symbol table.
+ // In both of these cases, we can expect the section to be resolved by
+ // the time we finish visiting the remaining symbols in the symbol
+ // table. So we postpone the handling of this symbol until that time.
+ PendingIndexes.push_back(I);
}
- I += Sym.getNumberOfAuxSymbols();
- LastSectionNumber = Sym.getSectionNumber();
+ I += COFFSym.getNumberOfAuxSymbols();
+ }
+
+ for (uint32_t I : PendingIndexes) {
+ COFFSymbolRef Sym = check(COFFObj->getSymbol(I));
+ if (auto *Def = Sym.getSectionDefinition())
+ if (Def->Selection == IMAGE_COMDAT_SELECT_ASSOCIATIVE)
+ readAssociativeDefinition(Sym, Def);
+ Symbols[I] = createRegular(Sym);
}
for (auto &KV : WeakAliases) {
- SymbolBody *Sym = KV.first;
+ Symbol *Sym = KV.first;
uint32_t Idx = KV.second;
- checkAndSetWeakAlias(Symtab, this, Sym, SparseSymbolBodies[Idx]);
+ checkAndSetWeakAlias(Symtab, this, Sym, Symbols[Idx]);
}
}
-SymbolBody *ObjectFile::createUndefined(COFFSymbolRef Sym) {
+Symbol *ObjFile::createUndefined(COFFSymbolRef Sym) {
StringRef Name;
COFFObj->getSymbolName(Sym, Name);
- return Symtab->addUndefined(Name, this, Sym.isWeakExternal())->body();
+ return Symtab->addUndefined(Name, this, Sym.isWeakExternal());
}
-SymbolBody *ObjectFile::createDefined(COFFSymbolRef Sym, const void *AuxP,
- bool IsFirst) {
+Optional<Symbol *> ObjFile::createDefined(
+ COFFSymbolRef Sym,
+ std::vector<const coff_aux_section_definition *> &ComdatDefs) {
StringRef Name;
if (Sym.isCommon()) {
auto *C = make<CommonChunk>(Sym);
@@ -208,7 +301,7 @@ SymbolBody *ObjectFile::createDefined(COFFSymbolRef Sym, const void *AuxP,
COFFObj->getSymbolName(Sym, Name);
Symbol *S =
Symtab->addCommon(this, Name, Sym.getValue(), Sym.getGeneric(), C);
- return S->body();
+ return S;
}
if (Sym.isAbsolute()) {
COFFObj->getSymbolName(Sym, Name);
@@ -222,7 +315,7 @@ SymbolBody *ObjectFile::createDefined(COFFSymbolRef Sym, const void *AuxP,
return nullptr;
}
if (Sym.isExternal())
- return Symtab->addAbsolute(Name, Sym)->body();
+ return Symtab->addAbsolute(Name, Sym);
else
return make<DefinedAbsolute>(Name, Sym);
}
@@ -239,54 +332,49 @@ SymbolBody *ObjectFile::createDefined(COFFSymbolRef Sym, const void *AuxP,
if ((uint32_t)SectionNumber >= SparseChunks.size())
fatal("broken object file: " + toString(this));
- // Nothing else to do without a section chunk.
- auto *SC = cast_or_null<SectionChunk>(SparseChunks[SectionNumber]);
- if (!SC)
- return nullptr;
-
- // Handle section definitions
- if (IsFirst && AuxP) {
- auto *Aux = reinterpret_cast<const coff_aux_section_definition *>(AuxP);
- if (Aux->Selection == IMAGE_COMDAT_SELECT_ASSOCIATIVE)
- if (auto *ParentSC = cast_or_null<SectionChunk>(
- SparseChunks[Aux->getNumber(Sym.isBigObj())])) {
- ParentSC->addAssociative(SC);
- // If we already discarded the parent, discard the child.
- if (ParentSC->isDiscarded())
- SC->markDiscarded();
- }
- SC->Checksum = Aux->CheckSum;
+ // Handle comdat leader symbols.
+ if (const coff_aux_section_definition *Def = ComdatDefs[SectionNumber]) {
+ ComdatDefs[SectionNumber] = nullptr;
+ Symbol *Leader;
+ bool Prevailing;
+ if (Sym.isExternal()) {
+ COFFObj->getSymbolName(Sym, Name);
+ std::tie(Leader, Prevailing) =
+ Symtab->addComdat(this, Name, Sym.getGeneric());
+ } else {
+ Leader = make<DefinedRegular>(this, /*Name*/ "", false,
+ /*IsExternal*/ false, Sym.getGeneric());
+ Prevailing = true;
+ }
+ if (Prevailing) {
+ SectionChunk *C = readSection(SectionNumber, Def);
+ SparseChunks[SectionNumber] = C;
+ C->Sym = cast<DefinedRegular>(Leader);
+ cast<DefinedRegular>(Leader)->Data = &C->Repl;
+ } else {
+ SparseChunks[SectionNumber] = nullptr;
+ }
+ return Leader;
}
- DefinedRegular *B;
- if (Sym.isExternal()) {
- COFFObj->getSymbolName(Sym, Name);
- Symbol *S =
- Symtab->addRegular(this, Name, SC->isCOMDAT(), Sym.getGeneric(), SC);
- B = cast<DefinedRegular>(S->body());
- } else
- B = make<DefinedRegular>(this, /*Name*/ "", SC->isCOMDAT(),
- /*IsExternal*/ false, Sym.getGeneric(), SC);
- if (SC->isCOMDAT() && Sym.getValue() == 0 && !AuxP)
- SC->setSymbol(B);
-
- return B;
-}
+ // Read associative section definitions and prepare to handle the comdat
+ // leader symbol by setting the section's ComdatDefs pointer if we encounter a
+ // non-associative comdat.
+ if (SparseChunks[SectionNumber] == PendingComdat) {
+ if (auto *Def = Sym.getSectionDefinition()) {
+ if (Def->Selection == IMAGE_COMDAT_SELECT_ASSOCIATIVE)
+ readAssociativeDefinition(Sym, Def);
+ else
+ ComdatDefs[SectionNumber] = Def;
+ }
+ }
-void ObjectFile::initializeSEH() {
- if (!SEHCompat || !SXData)
- return;
- ArrayRef<uint8_t> A;
- COFFObj->getSectionContents(SXData, A);
- if (A.size() % 4 != 0)
- fatal(".sxdata must be an array of symbol table indices");
- auto *I = reinterpret_cast<const ulittle32_t *>(A.data());
- auto *E = reinterpret_cast<const ulittle32_t *>(A.data() + A.size());
- for (; I != E; ++I)
- SEHandlers.insert(SparseSymbolBodies[*I]);
+ if (SparseChunks[SectionNumber] == PendingComdat)
+ return None;
+ return createRegular(Sym);
}
-MachineTypes ObjectFile::getMachineType() {
+MachineTypes ObjFile::getMachineType() {
if (COFFObj)
return static_cast<MachineTypes>(COFFObj->getMachine());
return IMAGE_FILE_MACHINE_UNKNOWN;
@@ -332,26 +420,27 @@ void ImportFile::parse() {
this->Hdr = Hdr;
ExternalName = ExtName;
- ImpSym = cast<DefinedImportData>(
- Symtab->addImportData(ImpName, this)->body());
+ ImpSym = Symtab->addImportData(ImpName, this);
+
if (Hdr->getType() == llvm::COFF::IMPORT_CONST)
- ConstSym =
- cast<DefinedImportData>(Symtab->addImportData(Name, this)->body());
+ static_cast<void>(Symtab->addImportData(Name, this));
// If type is function, we need to create a thunk which jump to an
// address pointed by the __imp_ symbol. (This allows you to call
// DLL functions just like regular non-DLL functions.)
- if (Hdr->getType() != llvm::COFF::IMPORT_CODE)
- return;
- ThunkSym = cast<DefinedImportThunk>(
- Symtab->addImportThunk(Name, ImpSym, Hdr->Machine)->body());
+ if (Hdr->getType() == llvm::COFF::IMPORT_CODE)
+ ThunkSym = Symtab->addImportThunk(Name, ImpSym, Hdr->Machine);
}
void BitcodeFile::parse() {
Obj = check(lto::InputFile::create(MemoryBufferRef(
MB.getBuffer(), Saver.save(ParentName + MB.getBufferIdentifier()))));
+ std::vector<std::pair<Symbol *, bool>> Comdat(Obj->getComdatTable().size());
+ for (size_t I = 0; I != Obj->getComdatTable().size(); ++I)
+ Comdat[I] = Symtab->addComdat(this, Saver.save(Obj->getComdatTable()[I]));
for (const lto::InputFile::Symbol &ObjSym : Obj->symbols()) {
StringRef SymName = Saver.save(ObjSym.getName());
+ int ComdatIndex = ObjSym.getComdatIndex();
Symbol *Sym;
if (ObjSym.isUndefined()) {
Sym = Symtab->addUndefined(SymName, this, false);
@@ -361,13 +450,19 @@ void BitcodeFile::parse() {
// Weak external.
Sym = Symtab->addUndefined(SymName, this, true);
std::string Fallback = ObjSym.getCOFFWeakExternalFallback();
- SymbolBody *Alias = Symtab->addUndefined(Saver.save(Fallback));
- checkAndSetWeakAlias(Symtab, this, Sym->body(), Alias);
+ Symbol *Alias = Symtab->addUndefined(Saver.save(Fallback));
+ checkAndSetWeakAlias(Symtab, this, Sym, Alias);
+ } else if (ComdatIndex != -1) {
+ if (SymName == Obj->getComdatTable()[ComdatIndex])
+ Sym = Comdat[ComdatIndex].first;
+ else if (Comdat[ComdatIndex].second)
+ Sym = Symtab->addRegular(this, SymName);
+ else
+ Sym = Symtab->addUndefined(SymName, this, false);
} else {
- bool IsCOMDAT = ObjSym.getComdatIndex() != -1;
- Sym = Symtab->addRegular(this, SymName, IsCOMDAT);
+ Sym = Symtab->addRegular(this, SymName);
}
- SymbolBodies.push_back(Sym->body());
+ SymbolBodies.push_back(Sym);
}
Directives = Obj->getCOFFLinkerOpts();
}
@@ -398,14 +493,13 @@ static StringRef getBasename(StringRef Path) {
}
// Returns a string in the format of "foo.obj" or "foo.obj(bar.lib)".
-std::string lld::toString(coff::InputFile *File) {
+std::string lld::toString(const coff::InputFile *File) {
if (!File)
- return "(internal)";
+ return "<internal>";
if (File->ParentName.empty())
- return File->getName().lower();
+ return File->getName();
- std::string Res =
- (getBasename(File->ParentName) + "(" + getBasename(File->getName()) + ")")
- .str();
- return StringRef(Res).lower();
+ return (getBasename(File->ParentName) + "(" + getBasename(File->getName()) +
+ ")")
+ .str();
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-27 10:16:12 +0000