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authorDimitry Andric <dim@FreeBSD.org>2017-01-09 21:23:48 +0000
committerDimitry Andric <dim@FreeBSD.org>2017-01-09 21:23:48 +0000
commitb047fead11133644be3dbae34b85be39ce2819e9 (patch)
tree3e7f6a4c9e5ffd7af6044225e9be2962e4d8eabf /ELF
parentc09ce7fd2d62d85dcdf370f4bef732380fca4f1b (diff)
downloadsrc-b047fead11133644be3dbae34b85be39ce2819e9.tar.gz
src-b047fead11133644be3dbae34b85be39ce2819e9.zip
Vendor import of lld trunk r291476:vendor/lld/lld-trunk-r291476
Notes
Notes: svn path=/vendor/lld/dist/; revision=311826 svn path=/vendor/lld/lld-trunk-r291476/; revision=311827; tag=vendor/lld/lld-trunk-r291476
Diffstat (limited to 'ELF')
-rw-r--r--ELF/Driver.cpp24
-rw-r--r--ELF/Driver.h3
-rw-r--r--ELF/InputFiles.cpp57
-rw-r--r--ELF/InputFiles.h8
-rw-r--r--ELF/LinkerScript.cpp100
-rw-r--r--ELF/Symbols.cpp4
6 files changed, 122 insertions, 74 deletions
diff --git a/ELF/Driver.cpp b/ELF/Driver.cpp
index 6afbe62e5ec7..c8ea821ec522 100644
--- a/ELF/Driver.cpp
+++ b/ELF/Driver.cpp
@@ -26,6 +26,7 @@
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Path.h"
+#include "llvm/Support/TarWriter.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdlib>
@@ -51,6 +52,7 @@ bool elf::link(ArrayRef<const char *> Args, bool CanExitEarly,
ErrorCount = 0;
ErrorOS = &Error;
Argv0 = Args[0];
+ Tar = nullptr;
Config = make<Configuration>();
Driver = make<LinkerDriver>();
@@ -170,25 +172,6 @@ void LinkerDriver::addFile(StringRef Path) {
}
}
-Optional<MemoryBufferRef> LinkerDriver::readFile(StringRef Path) {
- if (Config->Verbose)
- outs() << Path << "\n";
-
- auto MBOrErr = MemoryBuffer::getFile(Path);
- if (auto EC = MBOrErr.getError()) {
- error(EC, "cannot open " + Path);
- return None;
- }
- std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
- MemoryBufferRef MBRef = MB->getMemBufferRef();
- make<std::unique_ptr<MemoryBuffer>>(std::move(MB)); // take MB ownership
-
- if (Tar)
- Tar->append(relativeToRoot(Path), MBRef.getBuffer());
-
- return MBRef;
-}
-
// Add a given library by searching it from input search paths.
void LinkerDriver::addLibrary(StringRef Name) {
if (Optional<std::string> Path = searchLibrary(Name))
@@ -313,9 +296,10 @@ void LinkerDriver::main(ArrayRef<const char *> ArgsArr, bool CanExitEarly) {
Expected<std::unique_ptr<TarWriter>> ErrOrWriter =
TarWriter::create(Path, path::stem(Path));
if (ErrOrWriter) {
- Tar = std::move(*ErrOrWriter);
+ Tar = ErrOrWriter->get();
Tar->append("response.txt", createResponseFile(Args));
Tar->append("version.txt", getLLDVersion() + "\n");
+ make<std::unique_ptr<TarWriter>>(std::move(*ErrOrWriter));
} else {
error(Twine("--reproduce: failed to open ") + Path + ": " +
toString(ErrOrWriter.takeError()));
diff --git a/ELF/Driver.h b/ELF/Driver.h
index dadee5eef355..8bb2093e86ca 100644
--- a/ELF/Driver.h
+++ b/ELF/Driver.h
@@ -17,7 +17,6 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Option/ArgList.h"
-#include "llvm/Support/TarWriter.h"
#include "llvm/Support/raw_ostream.h"
namespace lld {
@@ -30,11 +29,9 @@ public:
void main(ArrayRef<const char *> Args, bool CanExitEarly);
void addFile(StringRef Path);
void addLibrary(StringRef Name);
- std::unique_ptr<llvm::TarWriter> Tar; // for reproduce
private:
std::vector<MemoryBufferRef> getArchiveMembers(MemoryBufferRef MB);
- llvm::Optional<MemoryBufferRef> readFile(StringRef Path);
void readConfigs(llvm::opt::InputArgList &Args);
void createFiles(llvm::opt::InputArgList &Args);
void inferMachineType();
diff --git a/ELF/InputFiles.cpp b/ELF/InputFiles.cpp
index bd9f25873c87..1fddf40f5b22 100644
--- a/ELF/InputFiles.cpp
+++ b/ELF/InputFiles.cpp
@@ -8,7 +8,6 @@
//===----------------------------------------------------------------------===//
#include "InputFiles.h"
-#include "Driver.h"
#include "Error.h"
#include "InputSection.h"
#include "LinkerScript.h"
@@ -26,6 +25,7 @@
#include "llvm/MC/StringTableBuilder.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Support/Path.h"
+#include "llvm/Support/TarWriter.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
@@ -36,6 +36,8 @@ using namespace llvm::sys::fs;
using namespace lld;
using namespace lld::elf;
+TarWriter *elf::Tar;
+
namespace {
// In ELF object file all section addresses are zero. If we have multiple
// .text sections (when using -ffunction-section or comdat group) then
@@ -53,6 +55,24 @@ public:
};
}
+Optional<MemoryBufferRef> elf::readFile(StringRef Path) {
+ if (Config->Verbose)
+ outs() << Path << "\n";
+
+ auto MBOrErr = MemoryBuffer::getFile(Path);
+ if (auto EC = MBOrErr.getError()) {
+ error(EC, "cannot open " + Path);
+ return None;
+ }
+ std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
+ MemoryBufferRef MBRef = MB->getMemBufferRef();
+ make<std::unique_ptr<MemoryBuffer>>(std::move(MB)); // take MB ownership
+
+ if (Tar)
+ Tar->append(relativeToRoot(Path), MBRef.getBuffer());
+ return MBRef;
+}
+
template <class ELFT> void elf::ObjectFile<ELFT>::initializeDwarfLine() {
std::unique_ptr<object::ObjectFile> Obj =
check(object::ObjectFile::createObjectFile(this->MB),
@@ -398,6 +418,14 @@ elf::ObjectFile<ELFT>::createInputSection(const Elf_Shdr &Sec,
if (Config->Strip != StripPolicy::None && Name.startswith(".debug"))
return &InputSection<ELFT>::Discarded;
+ // The linkonce feature is a sort of proto-comdat. Some glibc i386 object
+ // files contain definitions of symbol "__x86.get_pc_thunk.bx" in linkonce
+ // sections. Drop those sections to avoid duplicate symbol errors.
+ // FIXME: This is glibc PR20543, we should remove this hack once that has been
+ // fixed for a while.
+ if (Name.startswith(".gnu.linkonce."))
+ return &InputSection<ELFT>::Discarded;
+
// The linker merges EH (exception handling) frames and creates a
// .eh_frame_hdr section for runtime. So we handle them with a special
// class. For relocatable outputs, they are just passed through.
@@ -524,9 +552,8 @@ ArchiveFile::getMember(const Archive::Symbol *Sym) {
"could not get the buffer for the member defining symbol " +
Sym->getName());
- if (C.getParent()->isThin() && Driver->Tar)
- Driver->Tar->append(relativeToRoot(check(C.getFullName())),
- Ret.getBuffer());
+ if (C.getParent()->isThin() && Tar)
+ Tar->append(relativeToRoot(check(C.getFullName())), Ret.getBuffer());
if (C.getParent()->isThin())
return {Ret, 0};
return {Ret, C.getChildOffset()};
@@ -651,6 +678,8 @@ template <class ELFT> void SharedFile<ELFT>::parseRest() {
VersymIndex = Versym->vs_index;
++Versym;
}
+ bool Hidden = VersymIndex & VERSYM_HIDDEN;
+ VersymIndex = VersymIndex & ~VERSYM_HIDDEN;
StringRef Name = check(Sym.getName(this->StringTable));
if (Sym.isUndefined()) {
@@ -658,15 +687,23 @@ template <class ELFT> void SharedFile<ELFT>::parseRest() {
continue;
}
- if (Versym) {
- // Ignore local symbols and non-default versions.
- if (VersymIndex == VER_NDX_LOCAL || (VersymIndex & VERSYM_HIDDEN))
- continue;
- }
+ // Ignore local symbols.
+ if (Versym && VersymIndex == VER_NDX_LOCAL)
+ continue;
const Elf_Verdef *V =
VersymIndex == VER_NDX_GLOBAL ? nullptr : Verdefs[VersymIndex];
- elf::Symtab<ELFT>::X->addShared(this, Name, Sym, V);
+
+ if (!Hidden)
+ elf::Symtab<ELFT>::X->addShared(this, Name, Sym, V);
+
+ // Also add the symbol with the versioned name to handle undefined symbols
+ // with explicit versions.
+ if (V) {
+ StringRef VerName = this->StringTable.data() + V->getAux()->vda_name;
+ Name = Saver.save(Twine(Name) + "@" + VerName);
+ elf::Symtab<ELFT>::X->addShared(this, Name, Sym, V);
+ }
}
}
diff --git a/ELF/InputFiles.h b/ELF/InputFiles.h
index 8b188348199f..73dda7b566b8 100644
--- a/ELF/InputFiles.h
+++ b/ELF/InputFiles.h
@@ -29,6 +29,7 @@
namespace llvm {
class DWARFDebugLine;
+class TarWriter;
namespace lto {
class InputFile;
}
@@ -49,6 +50,13 @@ using llvm::object::Archive;
class Lazy;
class SymbolBody;
+// If -reproduce option is given, all input files are written
+// to this tar archive.
+extern llvm::TarWriter *Tar;
+
+// Opens a given file.
+llvm::Optional<MemoryBufferRef> readFile(StringRef Path);
+
// The root class of input files.
class InputFile {
public:
diff --git a/ELF/LinkerScript.cpp b/ELF/LinkerScript.cpp
index ccc1059949db..59ef36c87de5 100644
--- a/ELF/LinkerScript.cpp
+++ b/ELF/LinkerScript.cpp
@@ -56,29 +56,30 @@ using namespace lld::elf;
LinkerScriptBase *elf::ScriptBase;
ScriptConfiguration *elf::ScriptConfig;
-template <class ELFT> static void addRegular(SymbolAssignment *Cmd) {
+template <class ELFT> static SymbolBody *addRegular(SymbolAssignment *Cmd) {
uint8_t Visibility = Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT;
- Symbol *Sym = Symtab<ELFT>::X->addRegular(Cmd->Name, Visibility, STT_NOTYPE,
- 0, 0, STB_GLOBAL, nullptr, nullptr);
- Cmd->Sym = Sym->body();
+ Symbol *Sym = Symtab<ELFT>::X->addUndefined(
+ Cmd->Name, /*IsLocal=*/false, STB_GLOBAL, Visibility,
+ /*Type*/ 0,
+ /*CanOmitFromDynSym*/ false, /*File*/ nullptr);
- // If we have no SECTIONS then we don't have '.' and don't call
- // assignAddresses(). We calculate symbol value immediately in this case.
- if (!ScriptConfig->HasSections)
- cast<DefinedRegular<ELFT>>(Cmd->Sym)->Value = Cmd->Expression(0);
+ replaceBody<DefinedRegular<ELFT>>(Sym, Cmd->Name, /*IsLocal=*/false,
+ Visibility, STT_NOTYPE, 0, 0, nullptr,
+ nullptr);
+ return Sym->body();
}
-template <class ELFT> static void addSynthetic(SymbolAssignment *Cmd) {
- // If we have SECTIONS block then output sections haven't been created yet.
+template <class ELFT> static SymbolBody *addSynthetic(SymbolAssignment *Cmd) {
+ uint8_t Visibility = Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT;
const OutputSectionBase *Sec =
ScriptConfig->HasSections ? nullptr : Cmd->Expression.Section();
- Symbol *Sym = Symtab<ELFT>::X->addSynthetic(
- Cmd->Name, Sec, 0, Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT);
- Cmd->Sym = Sym->body();
+ Symbol *Sym = Symtab<ELFT>::X->addUndefined(
+ Cmd->Name, /*IsLocal=*/false, STB_GLOBAL, Visibility,
+ /*Type*/ 0,
+ /*CanOmitFromDynSym*/ false, /*File*/ nullptr);
- // If we already know section then we can calculate symbol value immediately.
- if (Sec)
- cast<DefinedSynthetic>(Cmd->Sym)->Value = Cmd->Expression(0) - Sec->Addr;
+ replaceBody<DefinedSynthetic>(Sym, Cmd->Name, 0, Sec);
+ return Sym->body();
}
static bool isUnderSysroot(StringRef Path) {
@@ -90,21 +91,39 @@ static bool isUnderSysroot(StringRef Path) {
return false;
}
-template <class ELFT> static void addSymbol(SymbolAssignment *Cmd) {
- if (Cmd->Expression.IsAbsolute())
- addRegular<ELFT>(Cmd);
- else
- addSynthetic<ELFT>(Cmd);
+template <class ELFT> static void assignSymbol(SymbolAssignment *Cmd) {
+ // If there are sections, then let the value be assigned later in
+ // `assignAddresses`.
+ if (ScriptConfig->HasSections)
+ return;
+
+ uint64_t Value = Cmd->Expression(0);
+ if (Cmd->Expression.IsAbsolute()) {
+ cast<DefinedRegular<ELFT>>(Cmd->Sym)->Value = Value;
+ } else {
+ const OutputSectionBase *Sec = Cmd->Expression.Section();
+ if (Sec)
+ cast<DefinedSynthetic>(Cmd->Sym)->Value = Value - Sec->Addr;
+ }
}
-// If a symbol was in PROVIDE(), we need to define it only when
-// it is an undefined symbol.
-template <class ELFT> static bool shouldDefine(SymbolAssignment *Cmd) {
+
+template <class ELFT> static void addSymbol(SymbolAssignment *Cmd) {
if (Cmd->Name == ".")
- return false;
- if (!Cmd->Provide)
- return true;
+ return;
+
+ // If a symbol was in PROVIDE(), we need to define it only when
+ // it is a referenced undefined symbol.
SymbolBody *B = Symtab<ELFT>::X->find(Cmd->Name);
- return B && B->isUndefined();
+ if (Cmd->Provide && (!B || B->isDefined()))
+ return;
+
+ // Otherwise, create a new symbol if one does not exist or an
+ // undefined one does exist.
+ if (Cmd->Expression.IsAbsolute())
+ Cmd->Sym = addRegular<ELFT>(Cmd);
+ else
+ Cmd->Sym = addSynthetic<ELFT>(Cmd);
+ assignSymbol<ELFT>(Cmd);
}
bool SymbolAssignment::classof(const BaseCommand *C) {
@@ -283,8 +302,7 @@ void LinkerScript<ELFT>::processCommands(OutputSectionFactory<ELFT> &Factory) {
// Handle symbol assignments outside of any output section.
if (auto *Cmd = dyn_cast<SymbolAssignment>(Base1.get())) {
- if (shouldDefine<ELFT>(Cmd))
- addSymbol<ELFT>(Cmd);
+ addSymbol<ELFT>(Cmd);
continue;
}
@@ -326,8 +344,7 @@ void LinkerScript<ELFT>::processCommands(OutputSectionFactory<ELFT> &Factory) {
// ".foo : { ...; bar = .; }". Handle them.
for (const std::unique_ptr<BaseCommand> &Base : Cmd->Commands)
if (auto *OutCmd = dyn_cast<SymbolAssignment>(Base.get()))
- if (shouldDefine<ELFT>(OutCmd))
- addSymbol<ELFT>(OutCmd);
+ addSymbol<ELFT>(OutCmd);
// Handle subalign (e.g. ".foo : SUBALIGN(32) { ... }"). If subalign
// is given, input sections are aligned to that value, whether the
@@ -1143,20 +1160,21 @@ void ScriptParser::readGroup() {
void ScriptParser::readInclude() {
StringRef Tok = unquote(next());
+
// https://sourceware.org/binutils/docs/ld/File-Commands.html:
// The file will be searched for in the current directory, and in any
// directory specified with the -L option.
- auto MBOrErr = MemoryBuffer::getFile(Tok);
- if (!MBOrErr)
- if (Optional<std::string> Path = findFromSearchPaths(Tok))
- MBOrErr = MemoryBuffer::getFile(*Path);
- if (!MBOrErr) {
- setError("cannot open " + Tok);
+ if (sys::fs::exists(Tok)) {
+ if (Optional<MemoryBufferRef> MB = readFile(Tok))
+ tokenize(*MB);
+ return;
+ }
+ if (Optional<std::string> Path = findFromSearchPaths(Tok)) {
+ if (Optional<MemoryBufferRef> MB = readFile(*Path))
+ tokenize(*MB);
return;
}
- MemoryBufferRef MBRef = (*MBOrErr)->getMemBufferRef();
- make<std::unique_ptr<MemoryBuffer>>(std::move(*MBOrErr)); // take MB ownership
- tokenize(MBRef);
+ setError("cannot open " + Tok);
}
void ScriptParser::readOutput() {
diff --git a/ELF/Symbols.cpp b/ELF/Symbols.cpp
index 72bcff4e0f4d..f3edafaf4b78 100644
--- a/ELF/Symbols.cpp
+++ b/ELF/Symbols.cpp
@@ -202,6 +202,10 @@ void SymbolBody::parseSymbolVersion() {
// Truncate the symbol name so that it doesn't include the version string.
Name = {S.data(), Pos};
+ // If this is an undefined or shared symbol it is not a definition.
+ if (isUndefined() || isShared())
+ return;
+
// '@@' in a symbol name means the default version.
// It is usually the most recent one.
bool IsDefault = (Verstr[0] == '@');