llvm-project/lld/ELF/LinkerScript.cpp

1512 lines
44 KiB
C++
Raw Normal View History

//===- LinkerScript.cpp ---------------------------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the parser/evaluator of the linker script.
2016-07-22 03:45:22 +08:00
// It parses a linker script and write the result to Config or ScriptConfig
// objects.
//
// If SECTIONS command is used, a ScriptConfig contains an AST
// of the command which will later be consumed by createSections() and
// assignAddresses().
//
//===----------------------------------------------------------------------===//
#include "LinkerScript.h"
#include "Config.h"
#include "Driver.h"
#include "InputSection.h"
#include "OutputSections.h"
#include "ScriptParser.h"
#include "Strings.h"
#include "Symbols.h"
#include "SymbolTable.h"
#include "Target.h"
#include "Writer.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/StringSaver.h"
using namespace llvm;
using namespace llvm::ELF;
using namespace llvm::object;
using namespace lld;
2016-02-28 08:25:54 +08:00
using namespace lld::elf;
LinkerScriptBase *elf::ScriptBase;
ScriptConfiguration *elf::ScriptConfig;
template <class ELFT> static void addRegular(SymbolAssignment *Cmd) {
Symbol *Sym = Symtab<ELFT>::X->addRegular(Cmd->Name, STB_GLOBAL, STV_DEFAULT);
Sym->Visibility = Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT;
Cmd->Sym = Sym->body();
}
template <class ELFT> static void addSynthetic(SymbolAssignment *Cmd) {
Symbol *Sym = Symtab<ELFT>::X->addSynthetic(
Cmd->Name, nullptr, 0, Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT);
Cmd->Sym = Sym->body();
}
template <class ELFT> static void addSymbol(SymbolAssignment *Cmd) {
if (Cmd->IsAbsolute)
addRegular<ELFT>(Cmd);
else
addSynthetic<ELFT>(Cmd);
}
// 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) {
if (Cmd->Name == ".")
return false;
if (!Cmd->Provide)
return true;
SymbolBody *B = Symtab<ELFT>::X->find(Cmd->Name);
return B && B->isUndefined();
}
bool SymbolAssignment::classof(const BaseCommand *C) {
return C->Kind == AssignmentKind;
}
bool OutputSectionCommand::classof(const BaseCommand *C) {
return C->Kind == OutputSectionKind;
}
bool InputSectionDescription::classof(const BaseCommand *C) {
return C->Kind == InputSectionKind;
}
bool AssertCommand::classof(const BaseCommand *C) {
return C->Kind == AssertKind;
}
template <class ELFT> static bool isDiscarded(InputSectionBase<ELFT> *S) {
return !S || !S->Live;
}
template <class ELFT> LinkerScript<ELFT>::LinkerScript() {}
template <class ELFT> LinkerScript<ELFT>::~LinkerScript() {}
template <class ELFT>
bool LinkerScript<ELFT>::shouldKeep(InputSectionBase<ELFT> *S) {
for (Regex *Re : Opt.KeptSections)
if (Re->match(S->Name))
return true;
return false;
}
static bool fileMatches(const InputSectionDescription *Desc,
StringRef Filename) {
return const_cast<Regex &>(Desc->FileRe).match(Filename) &&
!const_cast<Regex &>(Desc->ExcludedFileRe).match(Filename);
}
static bool comparePriority(InputSectionData *A, InputSectionData *B) {
return getPriority(A->Name) < getPriority(B->Name);
}
static bool compareName(InputSectionData *A, InputSectionData *B) {
return A->Name < B->Name;
}
static bool compareAlignment(InputSectionData *A, InputSectionData *B) {
// ">" is not a mistake. Larger alignments are placed before smaller
// alignments in order to reduce the amount of padding necessary.
// This is compatible with GNU.
return A->Alignment > B->Alignment;
}
static std::function<bool(InputSectionData *, InputSectionData *)>
getComparator(SortKind K) {
if (K == SortByPriority)
return comparePriority;
if (K == SortByName)
return compareName;
return compareAlignment;
}
static bool checkConstraint(uint64_t Flags, ConstraintKind Kind) {
bool RO = (Kind == ConstraintKind::ReadOnly);
bool RW = (Kind == ConstraintKind::ReadWrite);
bool Writable = Flags & SHF_WRITE;
return !(RO && Writable) && !(RW && !Writable);
}
template <class ELFT>
static bool matchConstraints(ArrayRef<InputSectionBase<ELFT> *> Sections,
ConstraintKind Kind) {
if (Kind == ConstraintKind::NoConstraint)
return true;
return llvm::all_of(Sections, [=](InputSectionBase<ELFT> *Sec) {
return checkConstraint(Sec->getSectionHdr()->sh_flags, Kind);
});
}
// Returns input sections filtered by given glob patterns.
template <class ELFT>
std::vector<InputSectionBase<ELFT> *>
LinkerScript<ELFT>::getInputSections(const InputSectionDescription *I) {
const Regex &Re = I->SectionRe;
std::vector<InputSectionBase<ELFT> *> Ret;
for (ObjectFile<ELFT> *F : Symtab<ELFT>::X->getObjectFiles())
if (fileMatches(I, sys::path::filename(F->getName())))
for (InputSectionBase<ELFT> *S : F->getSections())
if (!isDiscarded(S) && !S->OutSec &&
const_cast<Regex &>(Re).match(S->Name))
Ret.push_back(S);
if (const_cast<Regex &>(Re).match("COMMON"))
Ret.push_back(CommonInputSection<ELFT>::X);
return Ret;
}
template <class ELFT>
void LinkerScript<ELFT>::discard(ArrayRef<InputSectionBase<ELFT> *> V) {
for (InputSectionBase<ELFT> *S : V) {
S->Live = false;
reportDiscarded(S);
}
}
template <class ELFT>
std::vector<InputSectionBase<ELFT> *>
LinkerScript<ELFT>::createInputSectionList(OutputSectionCommand &OutCmd) {
std::vector<InputSectionBase<ELFT> *> Ret;
DenseSet<InputSectionBase<ELFT> *> SectionIndex;
for (const std::unique_ptr<BaseCommand> &Base : OutCmd.Commands) {
if (auto *OutCmd = dyn_cast<SymbolAssignment>(Base.get())) {
if (shouldDefine<ELFT>(OutCmd))
addSymbol<ELFT>(OutCmd);
OutCmd->GoesAfter = Ret.empty() ? nullptr : Ret.back();
continue;
}
auto *Cmd = cast<InputSectionDescription>(Base.get());
std::vector<InputSectionBase<ELFT> *> V = getInputSections(Cmd);
if (!matchConstraints<ELFT>(V, OutCmd.Constraint))
continue;
if (Cmd->SortInner)
std::stable_sort(V.begin(), V.end(), getComparator(Cmd->SortInner));
if (Cmd->SortOuter)
std::stable_sort(V.begin(), V.end(), getComparator(Cmd->SortOuter));
// Add all input sections corresponding to rule 'Cmd' to
// resulting vector. We do not add duplicate input sections.
for (InputSectionBase<ELFT> *S : V)
if (SectionIndex.insert(S).second)
Ret.push_back(S);
}
return Ret;
}
template <class ELFT> void LinkerScript<ELFT>::createAssignments() {
for (const std::unique_ptr<SymbolAssignment> &Cmd : Opt.Assignments) {
if (shouldDefine<ELFT>(Cmd.get()))
addRegular<ELFT>(Cmd.get());
if (Cmd->Sym)
cast<DefinedRegular<ELFT>>(Cmd->Sym)->Value = Cmd->Expression(0);
}
}
template <class ELFT>
static SectionKey<ELFT::Is64Bits> createKey(InputSectionBase<ELFT> *C,
StringRef OutsecName) {
// When using linker script the merge rules are different.
// Unfortunately, linker scripts are name based. This means that expressions
// like *(.foo*) can refer to multiple input sections that would normally be
// placed in different output sections. We cannot put them in different
// output sections or we would produce wrong results for
// start = .; *(.foo.*) end = .; *(.bar)
// and a mapping of .foo1 and .bar1 to one section and .foo2 and .bar2 to
// another. The problem is that there is no way to layout those output
// sections such that the .foo sections are the only thing between the
// start and end symbols.
// An extra annoyance is that we cannot simply disable merging of the contents
// of SHF_MERGE sections, but our implementation requires one output section
// per "kind" (string or not, which size/aligment).
// Fortunately, creating symbols in the middle of a merge section is not
// supported by bfd or gold, so we can just create multiple section in that
// case.
const typename ELFT::Shdr *H = C->getSectionHdr();
typedef typename ELFT::uint uintX_t;
uintX_t Flags = H->sh_flags & (SHF_MERGE | SHF_STRINGS);
uintX_t Alignment = 0;
if (isa<MergeInputSection<ELFT>>(C))
Alignment = std::max(H->sh_addralign, H->sh_entsize);
return SectionKey<ELFT::Is64Bits>{OutsecName, /*Type*/ 0, Flags, Alignment};
}
template <class ELFT>
void LinkerScript<ELFT>::createSections(OutputSectionFactory<ELFT> &Factory) {
auto AddSec = [&](InputSectionBase<ELFT> *Sec, StringRef Name) {
OutputSectionBase<ELFT> *OutSec;
bool IsNew;
std::tie(OutSec, IsNew) = Factory.create(createKey(Sec, Name), Sec);
if (IsNew)
OutputSections->push_back(OutSec);
return OutSec;
};
for (const std::unique_ptr<BaseCommand> &Base1 : Opt.Commands) {
2016-08-12 11:33:04 +08:00
if (auto *Cmd = dyn_cast<SymbolAssignment>(Base1.get())) {
if (shouldDefine<ELFT>(Cmd))
addRegular<ELFT>(Cmd);
continue;
}
if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base1.get())) {
std::vector<InputSectionBase<ELFT> *> V = createInputSectionList(*Cmd);
if (Cmd->Name == "/DISCARD/") {
discard(V);
continue;
}
if (V.empty())
continue;
for (InputSectionBase<ELFT> *Sec : V) {
OutputSectionBase<ELFT> *OutSec = AddSec(Sec, Cmd->Name);
uint32_t Subalign = Cmd->SubalignExpr ? Cmd->SubalignExpr(0) : 0;
if (Subalign)
Sec->Alignment = Subalign;
OutSec->addSection(Sec);
}
}
}
// Add orphan sections.
for (ObjectFile<ELFT> *F : Symtab<ELFT>::X->getObjectFiles()) {
for (InputSectionBase<ELFT> *S : F->getSections()) {
2016-08-12 11:33:04 +08:00
if (isDiscarded(S) || S->OutSec)
continue;
OutputSectionBase<ELFT> *OutSec = AddSec(S, getOutputSectionName(S));
2016-08-12 11:33:04 +08:00
OutSec->addSection(S);
}
}
}
// Sets value of a section-defined symbol. Two kinds of
// symbols are processed: synthetic symbols, whose value
// is an offset from beginning of section and regular
// symbols whose value is absolute.
template <class ELFT>
static void assignSectionSymbol(SymbolAssignment *Cmd,
OutputSectionBase<ELFT> *Sec,
typename ELFT::uint Off) {
if (!Cmd->Sym)
return;
if (auto *Body = dyn_cast<DefinedSynthetic<ELFT>>(Cmd->Sym)) {
Body->Section = Sec;
Body->Value = Cmd->Expression(Sec->getVA() + Off) - Sec->getVA();
return;
}
auto *Body = cast<DefinedRegular<ELFT>>(Cmd->Sym);
Body->Value = Cmd->Expression(Sec->getVA() + Off);
}
// Linker script may define start and end symbols for special section types,
// like .got, .eh_frame_hdr, .eh_frame and others. Those sections are not a list
// of regular input input sections, therefore our way of defining symbols for
// regular sections will not work. The approach we use for special section types
// is not perfect - it handles only start and end symbols.
template <class ELFT>
void addStartEndSymbols(OutputSectionCommand *Cmd,
OutputSectionBase<ELFT> *Sec) {
bool Start = true;
BaseCommand *PrevCmd = nullptr;
for (std::unique_ptr<BaseCommand> &Base : Cmd->Commands) {
if (auto *AssignCmd = dyn_cast<SymbolAssignment>(Base.get())) {
assignSectionSymbol<ELFT>(AssignCmd, Sec, Start ? 0 : Sec->getSize());
} else {
if (!Start && isa<SymbolAssignment>(PrevCmd))
error("section '" + Sec->getName() +
"' supports only start and end symbols");
Start = false;
}
PrevCmd = Base.get();
}
}
template <class ELFT>
void assignOffsets(OutputSectionCommand *Cmd, OutputSectionBase<ELFT> *Sec) {
auto *OutSec = dyn_cast<OutputSection<ELFT>>(Sec);
if (!OutSec) {
Sec->assignOffsets();
// This section is not regular output section. However linker script may
// have defined start/end symbols for it. This case is handled below.
addStartEndSymbols(Cmd, Sec);
return;
}
typedef typename ELFT::uint uintX_t;
uintX_t Off = 0;
auto ItCmd = Cmd->Commands.begin();
// Assigns values to all symbols following the given
// input section 'D' in output section 'Sec'. When symbols
// are in the beginning of output section the value of 'D'
// is nullptr.
auto AssignSuccessors = [&](InputSectionData *D) {
for (; ItCmd != Cmd->Commands.end(); ++ItCmd) {
auto *AssignCmd = dyn_cast<SymbolAssignment>(ItCmd->get());
if (!AssignCmd)
continue;
if (D != AssignCmd->GoesAfter)
break;
if (AssignCmd->Name == ".") {
// Update to location counter means update to section size.
Off = AssignCmd->Expression(Sec->getVA() + Off) - Sec->getVA();
Sec->setSize(Off);
continue;
}
assignSectionSymbol<ELFT>(AssignCmd, Sec, Off);
}
};
AssignSuccessors(nullptr);
for (InputSection<ELFT> *I : OutSec->Sections) {
Off = alignTo(Off, I->Alignment);
I->OutSecOff = Off;
Off += I->getSize();
// Update section size inside for-loop, so that SIZEOF
// works correctly in the case below:
// .foo { *(.aaa) a = SIZEOF(.foo); *(.bbb) }
Sec->setSize(Off);
// Add symbols following current input section.
AssignSuccessors(I);
}
}
template <class ELFT>
static std::vector<OutputSectionBase<ELFT> *>
findSections(OutputSectionCommand &Cmd,
ArrayRef<OutputSectionBase<ELFT> *> Sections) {
std::vector<OutputSectionBase<ELFT> *> Ret;
for (OutputSectionBase<ELFT> *Sec : Sections)
if (Sec->getName() == Cmd.Name &&
checkConstraint(Sec->getFlags(), Cmd.Constraint))
Ret.push_back(Sec);
return Ret;
}
template <class ELFT> void LinkerScript<ELFT>::assignAddresses() {
// Orphan sections are sections present in the input files which
// are not explicitly placed into the output file by the linker script.
// We place orphan sections at end of file.
// Other linkers places them using some heuristics as described in
// https://sourceware.org/binutils/docs/ld/Orphan-Sections.html#Orphan-Sections.
for (OutputSectionBase<ELFT> *Sec : *OutputSections) {
StringRef Name = Sec->getName();
if (getSectionIndex(Name) == INT_MAX)
Opt.Commands.push_back(llvm::make_unique<OutputSectionCommand>(Name));
}
// Assign addresses as instructed by linker script SECTIONS sub-commands.
Dot = getHeaderSize();
uintX_t MinVA = std::numeric_limits<uintX_t>::max();
uintX_t ThreadBssOffset = 0;
for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
if (auto *Cmd = dyn_cast<SymbolAssignment>(Base.get())) {
if (Cmd->Name == ".") {
Dot = Cmd->Expression(Dot);
} else if (Cmd->Sym) {
cast<DefinedRegular<ELFT>>(Cmd->Sym)->Value = Cmd->Expression(Dot);
}
continue;
}
if (auto *Cmd = dyn_cast<AssertCommand>(Base.get())) {
Cmd->Expression(Dot);
continue;
}
auto *Cmd = cast<OutputSectionCommand>(Base.get());
for (OutputSectionBase<ELFT> *Sec :
findSections<ELFT>(*Cmd, *OutputSections)) {
if (Cmd->AddrExpr)
Dot = Cmd->AddrExpr(Dot);
if ((Sec->getFlags() & SHF_TLS) && Sec->getType() == SHT_NOBITS) {
uintX_t TVA = Dot + ThreadBssOffset;
TVA = alignTo(TVA, Sec->getAlignment());
Sec->setVA(TVA);
assignOffsets(Cmd, Sec);
ThreadBssOffset = TVA - Dot + Sec->getSize();
continue;
}
if (!(Sec->getFlags() & SHF_ALLOC)) {
assignOffsets(Cmd, Sec);
continue;
}
Dot = alignTo(Dot, Sec->getAlignment());
Sec->setVA(Dot);
assignOffsets(Cmd, Sec);
MinVA = std::min(MinVA, Dot);
Dot += Sec->getSize();
}
}
2016-07-07 22:28:47 +08:00
// ELF and Program headers need to be right before the first section in
// memory. Set their addresses accordingly.
MinVA = alignDown(MinVA - Out<ELFT>::ElfHeader->getSize() -
Out<ELFT>::ProgramHeaders->getSize(),
Target->PageSize);
Out<ELFT>::ElfHeader->setVA(MinVA);
Out<ELFT>::ProgramHeaders->setVA(Out<ELFT>::ElfHeader->getSize() + MinVA);
}
// Creates program headers as instructed by PHDRS linker script command.
template <class ELFT>
std::vector<PhdrEntry<ELFT>> LinkerScript<ELFT>::createPhdrs() {
2016-07-25 07:47:31 +08:00
std::vector<PhdrEntry<ELFT>> Ret;
// Process PHDRS and FILEHDR keywords because they are not
// real output sections and cannot be added in the following loop.
for (const PhdrsCommand &Cmd : Opt.PhdrsCommands) {
2016-07-25 07:47:31 +08:00
Ret.emplace_back(Cmd.Type, Cmd.Flags == UINT_MAX ? PF_R : Cmd.Flags);
PhdrEntry<ELFT> &Phdr = Ret.back();
if (Cmd.HasFilehdr)
Phdr.add(Out<ELFT>::ElfHeader);
if (Cmd.HasPhdrs)
Phdr.add(Out<ELFT>::ProgramHeaders);
if (Cmd.LMAExpr) {
Phdr.H.p_paddr = Cmd.LMAExpr(0);
Phdr.HasLMA = true;
}
}
// Add output sections to program headers.
2016-07-25 07:47:31 +08:00
PhdrEntry<ELFT> *Load = nullptr;
uintX_t Flags = PF_R;
for (OutputSectionBase<ELFT> *Sec : *OutputSections) {
if (!(Sec->getFlags() & SHF_ALLOC))
break;
2016-07-25 07:47:31 +08:00
std::vector<size_t> PhdrIds = getPhdrIndices(Sec->getName());
if (!PhdrIds.empty()) {
// Assign headers specified by linker script
for (size_t Id : PhdrIds) {
2016-07-25 07:47:31 +08:00
Ret[Id].add(Sec);
if (Opt.PhdrsCommands[Id].Flags == UINT_MAX)
Ret[Id].H.p_flags |= Sec->getPhdrFlags();
}
} else {
// If we have no load segment or flags've changed then we want new load
// segment.
uintX_t NewFlags = Sec->getPhdrFlags();
if (Load == nullptr || Flags != NewFlags) {
2016-07-25 07:47:31 +08:00
Load = &*Ret.emplace(Ret.end(), PT_LOAD, NewFlags);
Flags = NewFlags;
}
Load->add(Sec);
}
}
2016-07-25 07:47:31 +08:00
return Ret;
}
template <class ELFT> bool LinkerScript<ELFT>::ignoreInterpSection() {
// Ignore .interp section in case we have PHDRS specification
// and PT_INTERP isn't listed.
return !Opt.PhdrsCommands.empty() &&
llvm::find_if(Opt.PhdrsCommands, [](const PhdrsCommand &Cmd) {
return Cmd.Type == PT_INTERP;
}) == Opt.PhdrsCommands.end();
}
template <class ELFT>
ArrayRef<uint8_t> LinkerScript<ELFT>::getFiller(StringRef Name) {
for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands)
if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get()))
if (Cmd->Name == Name)
return Cmd->Filler;
return {};
}
template <class ELFT> Expr LinkerScript<ELFT>::getLma(StringRef Name) {
for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands)
if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get()))
if (Cmd->LmaExpr && Cmd->Name == Name)
return Cmd->LmaExpr;
return {};
}
// Returns the index of the given section name in linker script
// SECTIONS commands. Sections are laid out as the same order as they
// were in the script. If a given name did not appear in the script,
// it returns INT_MAX, so that it will be laid out at end of file.
template <class ELFT> int LinkerScript<ELFT>::getSectionIndex(StringRef Name) {
int I = 0;
for (std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get()))
if (Cmd->Name == Name)
return I;
++I;
}
return INT_MAX;
}
// A compartor to sort output sections. Returns -1 or 1 if
// A or B are mentioned in linker script. Otherwise, returns 0.
template <class ELFT>
int LinkerScript<ELFT>::compareSections(StringRef A, StringRef B) {
int I = getSectionIndex(A);
int J = getSectionIndex(B);
if (I == INT_MAX && J == INT_MAX)
return 0;
return I < J ? -1 : 1;
}
template <class ELFT> bool LinkerScript<ELFT>::hasPhdrsCommands() {
return !Opt.PhdrsCommands.empty();
}
template <class ELFT>
uint64_t LinkerScript<ELFT>::getOutputSectionAddress(StringRef Name) {
for (OutputSectionBase<ELFT> *Sec : *OutputSections)
if (Sec->getName() == Name)
return Sec->getVA();
error("undefined section " + Name);
return 0;
}
template <class ELFT>
uint64_t LinkerScript<ELFT>::getOutputSectionSize(StringRef Name) {
for (OutputSectionBase<ELFT> *Sec : *OutputSections)
if (Sec->getName() == Name)
return Sec->getSize();
error("undefined section " + Name);
return 0;
}
template <class ELFT>
uint64_t LinkerScript<ELFT>::getOutputSectionAlign(StringRef Name) {
for (OutputSectionBase<ELFT> *Sec : *OutputSections)
if (Sec->getName() == Name)
return Sec->getAlignment();
error("undefined section " + Name);
return 0;
}
template <class ELFT> uint64_t LinkerScript<ELFT>::getHeaderSize() {
return Out<ELFT>::ElfHeader->getSize() + Out<ELFT>::ProgramHeaders->getSize();
}
template <class ELFT> uint64_t LinkerScript<ELFT>::getSymbolValue(StringRef S) {
if (SymbolBody *B = Symtab<ELFT>::X->find(S))
return B->getVA<ELFT>();
error("symbol not found: " + S);
return 0;
}
// Returns indices of ELF headers containing specific section, identified
// by Name. Each index is a zero based number of ELF header listed within
// PHDRS {} script block.
template <class ELFT>
2016-07-25 07:47:31 +08:00
std::vector<size_t> LinkerScript<ELFT>::getPhdrIndices(StringRef SectionName) {
for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get());
2016-07-25 07:47:31 +08:00
if (!Cmd || Cmd->Name != SectionName)
continue;
std::vector<size_t> Ret;
for (StringRef PhdrName : Cmd->Phdrs)
Ret.push_back(getPhdrIndex(PhdrName));
return Ret;
}
return {};
}
template <class ELFT>
size_t LinkerScript<ELFT>::getPhdrIndex(StringRef PhdrName) {
size_t I = 0;
for (PhdrsCommand &Cmd : Opt.PhdrsCommands) {
if (Cmd.Name == PhdrName)
return I;
++I;
}
error("section header '" + PhdrName + "' is not listed in PHDRS");
return 0;
}
class elf::ScriptParser : public ScriptParserBase {
typedef void (ScriptParser::*Handler)();
public:
ScriptParser(StringRef S, bool B) : ScriptParserBase(S), IsUnderSysroot(B) {}
void readLinkerScript();
void readVersionScript();
private:
void addFile(StringRef Path);
void readAsNeeded();
void readEntry();
void readExtern();
void readGroup();
void readInclude();
void readOutput();
void readOutputArch();
void readOutputFormat();
void readPhdrs();
void readSearchDir();
void readSections();
void readVersion();
void readVersionScriptCommand();
SymbolAssignment *readAssignment(StringRef Name);
std::vector<uint8_t> readFill();
OutputSectionCommand *readOutputSectionDescription(StringRef OutSec);
std::vector<uint8_t> readOutputSectionFiller(StringRef Tok);
std::vector<StringRef> readOutputSectionPhdrs();
InputSectionDescription *readInputSectionDescription(StringRef Tok);
Regex readFilePatterns();
InputSectionDescription *readInputSectionRules(StringRef FilePattern);
unsigned readPhdrType();
SortKind readSortKind();
SymbolAssignment *readProvideHidden(bool Provide, bool Hidden);
SymbolAssignment *readProvideOrAssignment(StringRef Tok, bool MakeAbsolute);
void readSort();
Expr readAssert();
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
Expr readExpr();
Expr readExpr1(Expr Lhs, int MinPrec);
Expr readPrimary();
Expr readTernary(Expr Cond);
Expr readParenExpr();
// For parsing version script.
void readExtern(std::vector<SymbolVersion> *Globals);
void readVersionDeclaration(StringRef VerStr);
void readGlobal(StringRef VerStr);
void readLocal();
ScriptConfiguration &Opt = *ScriptConfig;
StringSaver Saver = {ScriptConfig->Alloc};
bool IsUnderSysroot;
};
void ScriptParser::readVersionScript() {
readVersionScriptCommand();
if (!atEOF())
setError("EOF expected, but got " + next());
}
void ScriptParser::readVersionScriptCommand() {
if (skip("{")) {
readVersionDeclaration("");
return;
}
while (!atEOF() && !Error && peek() != "}") {
StringRef VerStr = next();
if (VerStr == "{") {
setError("anonymous version definition is used in "
"combination with other version definitions");
return;
}
expect("{");
readVersionDeclaration(VerStr);
}
}
void ScriptParser::readVersion() {
expect("{");
readVersionScriptCommand();
expect("}");
}
void ScriptParser::readLinkerScript() {
while (!atEOF()) {
StringRef Tok = next();
if (Tok == ";")
continue;
if (Tok == "ENTRY") {
readEntry();
} else if (Tok == "EXTERN") {
readExtern();
} else if (Tok == "GROUP" || Tok == "INPUT") {
readGroup();
} else if (Tok == "INCLUDE") {
readInclude();
} else if (Tok == "OUTPUT") {
readOutput();
} else if (Tok == "OUTPUT_ARCH") {
readOutputArch();
} else if (Tok == "OUTPUT_FORMAT") {
readOutputFormat();
} else if (Tok == "PHDRS") {
readPhdrs();
} else if (Tok == "SEARCH_DIR") {
readSearchDir();
} else if (Tok == "SECTIONS") {
readSections();
} else if (Tok == "VERSION") {
readVersion();
} else if (SymbolAssignment *Cmd = readProvideOrAssignment(Tok, true)) {
if (Opt.HasSections)
Opt.Commands.emplace_back(Cmd);
else
Opt.Assignments.emplace_back(Cmd);
} else {
setError("unknown directive: " + Tok);
}
}
}
void ScriptParser::addFile(StringRef S) {
if (IsUnderSysroot && S.startswith("/")) {
SmallString<128> Path;
(Config->Sysroot + S).toStringRef(Path);
if (sys::fs::exists(Path)) {
Driver->addFile(Saver.save(Path.str()));
return;
}
}
if (sys::path::is_absolute(S)) {
Driver->addFile(S);
} else if (S.startswith("=")) {
if (Config->Sysroot.empty())
Driver->addFile(S.substr(1));
else
Driver->addFile(Saver.save(Config->Sysroot + "/" + S.substr(1)));
} else if (S.startswith("-l")) {
Driver->addLibrary(S.substr(2));
} else if (sys::fs::exists(S)) {
Driver->addFile(S);
} else {
std::string Path = findFromSearchPaths(S);
if (Path.empty())
setError("unable to find " + S);
else
Driver->addFile(Saver.save(Path));
}
}
void ScriptParser::readAsNeeded() {
expect("(");
bool Orig = Config->AsNeeded;
Config->AsNeeded = true;
2016-08-05 09:25:45 +08:00
while (!Error && !skip(")"))
addFile(unquote(next()));
Config->AsNeeded = Orig;
}
void ScriptParser::readEntry() {
// -e <symbol> takes predecence over ENTRY(<symbol>).
expect("(");
StringRef Tok = next();
if (Config->Entry.empty())
Config->Entry = Tok;
expect(")");
}
void ScriptParser::readExtern() {
expect("(");
2016-08-05 09:25:45 +08:00
while (!Error && !skip(")"))
Config->Undefined.push_back(next());
}
void ScriptParser::readGroup() {
expect("(");
2016-08-05 09:25:45 +08:00
while (!Error && !skip(")")) {
StringRef Tok = next();
2016-08-05 09:25:45 +08:00
if (Tok == "AS_NEEDED")
readAsNeeded();
2016-08-05 09:25:45 +08:00
else
addFile(unquote(Tok));
}
}
void ScriptParser::readInclude() {
StringRef Tok = next();
auto MBOrErr = MemoryBuffer::getFile(unquote(Tok));
if (!MBOrErr) {
setError("cannot open " + Tok);
return;
}
std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
StringRef S = Saver.save(MB->getMemBufferRef().getBuffer());
std::vector<StringRef> V = tokenize(S);
Tokens.insert(Tokens.begin() + Pos, V.begin(), V.end());
}
void ScriptParser::readOutput() {
// -o <file> takes predecence over OUTPUT(<file>).
expect("(");
StringRef Tok = next();
if (Config->OutputFile.empty())
Config->OutputFile = unquote(Tok);
expect(")");
}
void ScriptParser::readOutputArch() {
// Error checking only for now.
expect("(");
next();
expect(")");
}
void ScriptParser::readOutputFormat() {
// Error checking only for now.
expect("(");
next();
StringRef Tok = next();
if (Tok == ")")
return;
if (Tok != ",") {
setError("unexpected token: " + Tok);
return;
}
next();
expect(",");
next();
expect(")");
}
void ScriptParser::readPhdrs() {
expect("{");
while (!Error && !skip("}")) {
StringRef Tok = next();
Opt.PhdrsCommands.push_back(
{Tok, PT_NULL, false, false, UINT_MAX, nullptr});
PhdrsCommand &PhdrCmd = Opt.PhdrsCommands.back();
PhdrCmd.Type = readPhdrType();
do {
Tok = next();
if (Tok == ";")
break;
if (Tok == "FILEHDR")
PhdrCmd.HasFilehdr = true;
else if (Tok == "PHDRS")
PhdrCmd.HasPhdrs = true;
else if (Tok == "AT")
PhdrCmd.LMAExpr = readParenExpr();
else if (Tok == "FLAGS") {
expect("(");
// Passing 0 for the value of dot is a bit of a hack. It means that
// we accept expressions like ".|1".
PhdrCmd.Flags = readExpr()(0);
expect(")");
} else
setError("unexpected header attribute: " + Tok);
} while (!Error);
}
}
void ScriptParser::readSearchDir() {
expect("(");
StringRef Tok = next();
2016-09-03 03:20:33 +08:00
if (!Config->Nostdlib)
Config->SearchPaths.push_back(unquote(Tok));
expect(")");
}
void ScriptParser::readSections() {
Opt.HasSections = true;
expect("{");
while (!Error && !skip("}")) {
StringRef Tok = next();
BaseCommand *Cmd = readProvideOrAssignment(Tok, true);
if (!Cmd) {
if (Tok == "ASSERT")
Cmd = new AssertCommand(readAssert());
else
Cmd = readOutputSectionDescription(Tok);
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
}
Opt.Commands.emplace_back(Cmd);
}
}
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
static int precedence(StringRef Op) {
return StringSwitch<int>(Op)
.Case("*", 4)
.Case("/", 4)
.Case("+", 3)
.Case("-", 3)
.Case("<", 2)
.Case(">", 2)
.Case(">=", 2)
.Case("<=", 2)
.Case("==", 2)
.Case("!=", 2)
.Case("&", 1)
.Case("|", 1)
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
.Default(-1);
}
Regex ScriptParser::readFilePatterns() {
std::vector<StringRef> V;
while (!Error && !skip(")"))
V.push_back(next());
return compileGlobPatterns(V);
}
SortKind ScriptParser::readSortKind() {
if (skip("SORT") || skip("SORT_BY_NAME"))
return SortByName;
if (skip("SORT_BY_ALIGNMENT"))
return SortByAlignment;
if (skip("SORT_BY_INIT_PRIORITY"))
return SortByPriority;
return SortNone;
}
InputSectionDescription *
ScriptParser::readInputSectionRules(StringRef FilePattern) {
auto *Cmd = new InputSectionDescription(FilePattern);
expect("(");
// Read EXCLUDE_FILE().
if (skip("EXCLUDE_FILE")) {
expect("(");
Cmd->ExcludedFileRe = readFilePatterns();
}
// Read SORT().
if (SortKind K1 = readSortKind()) {
Cmd->SortOuter = K1;
expect("(");
if (SortKind K2 = readSortKind()) {
Cmd->SortInner = K2;
expect("(");
Cmd->SectionRe = readFilePatterns();
expect(")");
} else {
Cmd->SectionRe = readFilePatterns();
}
expect(")");
return Cmd;
}
Cmd->SectionRe = readFilePatterns();
return Cmd;
}
InputSectionDescription *
ScriptParser::readInputSectionDescription(StringRef Tok) {
// Input section wildcard can be surrounded by KEEP.
// https://sourceware.org/binutils/docs/ld/Input-Section-Keep.html#Input-Section-Keep
if (Tok == "KEEP") {
expect("(");
StringRef FilePattern = next();
InputSectionDescription *Cmd = readInputSectionRules(FilePattern);
expect(")");
Opt.KeptSections.push_back(&Cmd->SectionRe);
return Cmd;
}
return readInputSectionRules(Tok);
}
void ScriptParser::readSort() {
expect("(");
expect("CONSTRUCTORS");
expect(")");
}
Expr ScriptParser::readAssert() {
expect("(");
Expr E = readExpr();
expect(",");
StringRef Msg = unquote(next());
expect(")");
return [=](uint64_t Dot) {
uint64_t V = E(Dot);
if (!V)
error(Msg);
return V;
};
}
2016-09-07 01:46:43 +08:00
// Reads a FILL(expr) command. We handle the FILL command as an
// alias for =fillexp section attribute, which is different from
// what GNU linkers do.
// https://sourceware.org/binutils/docs/ld/Output-Section-Data.html
std::vector<uint8_t> ScriptParser::readFill() {
expect("(");
std::vector<uint8_t> V = readOutputSectionFiller(next());
expect(")");
expect(";");
return V;
}
OutputSectionCommand *
ScriptParser::readOutputSectionDescription(StringRef OutSec) {
OutputSectionCommand *Cmd = new OutputSectionCommand(OutSec);
// Read an address expression.
// https://sourceware.org/binutils/docs/ld/Output-Section-Address.html#Output-Section-Address
if (peek() != ":")
Cmd->AddrExpr = readExpr();
expect(":");
if (skip("AT"))
Cmd->LmaExpr = readParenExpr();
if (skip("ALIGN"))
Cmd->AlignExpr = readParenExpr();
if (skip("SUBALIGN"))
Cmd->SubalignExpr = readParenExpr();
// Parse constraints.
if (skip("ONLY_IF_RO"))
Cmd->Constraint = ConstraintKind::ReadOnly;
if (skip("ONLY_IF_RW"))
Cmd->Constraint = ConstraintKind::ReadWrite;
expect("{");
while (!Error && !skip("}")) {
StringRef Tok = next();
if (SymbolAssignment *Assignment = readProvideOrAssignment(Tok, false))
Cmd->Commands.emplace_back(Assignment);
else if (Tok == "FILL")
Cmd->Filler = readFill();
else if (Tok == "SORT")
readSort();
else if (peek() == "(")
Cmd->Commands.emplace_back(readInputSectionDescription(Tok));
else
setError("unknown command " + Tok);
}
Cmd->Phdrs = readOutputSectionPhdrs();
if (peek().startswith("="))
Cmd->Filler = readOutputSectionFiller(next().drop_front());
return Cmd;
}
// Read "=<number>" where <number> is an octal/decimal/hexadecimal number.
// https://sourceware.org/binutils/docs/ld/Output-Section-Fill.html
//
// ld.gold is not fully compatible with ld.bfd. ld.bfd handles
// hexstrings as blobs of arbitrary sizes, while ld.gold handles them
// as 32-bit big-endian values. We will do the same as ld.gold does
// because it's simpler than what ld.bfd does.
std::vector<uint8_t> ScriptParser::readOutputSectionFiller(StringRef Tok) {
uint32_t V;
if (Tok.getAsInteger(0, V)) {
setError("invalid filler expression: " + Tok);
return {};
}
return {uint8_t(V >> 24), uint8_t(V >> 16), uint8_t(V >> 8), uint8_t(V)};
}
SymbolAssignment *ScriptParser::readProvideHidden(bool Provide, bool Hidden) {
expect("(");
SymbolAssignment *Cmd = readAssignment(next());
Cmd->Provide = Provide;
Cmd->Hidden = Hidden;
expect(")");
expect(";");
return Cmd;
}
SymbolAssignment *ScriptParser::readProvideOrAssignment(StringRef Tok,
bool MakeAbsolute) {
SymbolAssignment *Cmd = nullptr;
if (peek() == "=" || peek() == "+=") {
Cmd = readAssignment(Tok);
expect(";");
} else if (Tok == "PROVIDE") {
Cmd = readProvideHidden(true, false);
} else if (Tok == "HIDDEN") {
Cmd = readProvideHidden(false, true);
} else if (Tok == "PROVIDE_HIDDEN") {
Cmd = readProvideHidden(true, true);
}
if (Cmd && MakeAbsolute)
Cmd->IsAbsolute = true;
return Cmd;
}
static uint64_t getSymbolValue(StringRef S, uint64_t Dot) {
if (S == ".")
return Dot;
return ScriptBase->getSymbolValue(S);
}
SymbolAssignment *ScriptParser::readAssignment(StringRef Name) {
StringRef Op = next();
bool IsAbsolute = false;
Expr E;
assert(Op == "=" || Op == "+=");
if (skip("ABSOLUTE")) {
E = readParenExpr();
IsAbsolute = true;
} else {
E = readExpr();
}
if (Op == "+=")
E = [=](uint64_t Dot) { return getSymbolValue(Name, Dot) + E(Dot); };
return new SymbolAssignment(Name, E, IsAbsolute);
}
// This is an operator-precedence parser to parse a linker
// script expression.
Expr ScriptParser::readExpr() { return readExpr1(readPrimary(), 0); }
static Expr combine(StringRef Op, Expr L, Expr R) {
if (Op == "*")
return [=](uint64_t Dot) { return L(Dot) * R(Dot); };
if (Op == "/") {
return [=](uint64_t Dot) -> uint64_t {
uint64_t RHS = R(Dot);
if (RHS == 0) {
error("division by zero");
return 0;
}
return L(Dot) / RHS;
};
}
if (Op == "+")
return [=](uint64_t Dot) { return L(Dot) + R(Dot); };
if (Op == "-")
return [=](uint64_t Dot) { return L(Dot) - R(Dot); };
if (Op == "<")
return [=](uint64_t Dot) { return L(Dot) < R(Dot); };
if (Op == ">")
return [=](uint64_t Dot) { return L(Dot) > R(Dot); };
if (Op == ">=")
return [=](uint64_t Dot) { return L(Dot) >= R(Dot); };
if (Op == "<=")
return [=](uint64_t Dot) { return L(Dot) <= R(Dot); };
if (Op == "==")
return [=](uint64_t Dot) { return L(Dot) == R(Dot); };
if (Op == "!=")
return [=](uint64_t Dot) { return L(Dot) != R(Dot); };
if (Op == "&")
return [=](uint64_t Dot) { return L(Dot) & R(Dot); };
if (Op == "|")
return [=](uint64_t Dot) { return L(Dot) | R(Dot); };
llvm_unreachable("invalid operator");
}
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
// This is a part of the operator-precedence parser. This function
// assumes that the remaining token stream starts with an operator.
Expr ScriptParser::readExpr1(Expr Lhs, int MinPrec) {
while (!atEOF() && !Error) {
// Read an operator and an expression.
StringRef Op1 = peek();
if (Op1 == "?")
return readTernary(Lhs);
if (precedence(Op1) < MinPrec)
break;
next();
Expr Rhs = readPrimary();
// Evaluate the remaining part of the expression first if the
// next operator has greater precedence than the previous one.
// For example, if we have read "+" and "3", and if the next
// operator is "*", then we'll evaluate 3 * ... part first.
while (!atEOF()) {
StringRef Op2 = peek();
if (precedence(Op2) <= precedence(Op1))
break;
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
Rhs = readExpr1(Rhs, precedence(Op2));
}
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
Lhs = combine(Op1, Lhs, Rhs);
}
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
return Lhs;
}
uint64_t static getConstant(StringRef S) {
if (S == "COMMONPAGESIZE")
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
return Target->PageSize;
if (S == "MAXPAGESIZE")
return Target->MaxPageSize;
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
error("unknown constant: " + S);
return 0;
}
2016-09-03 02:19:00 +08:00
// Parses Tok as an integer. Returns true if successful.
// It recognizes hexadecimal (prefixed with "0x" or suffixed with "H")
// and decimal numbers. Decimal numbers may have "K" (kilo) or
// "M" (mega) prefixes.
static bool readInteger(StringRef Tok, uint64_t &Result) {
if (Tok.startswith("-")) {
if (!readInteger(Tok.substr(1), Result))
return false;
Result = -Result;
return true;
}
if (Tok.startswith_lower("0x"))
return !Tok.substr(2).getAsInteger(16, Result);
if (Tok.endswith_lower("H"))
return !Tok.drop_back().getAsInteger(16, Result);
int Suffix = 1;
if (Tok.endswith_lower("K")) {
Suffix = 1024;
Tok = Tok.drop_back();
} else if (Tok.endswith_lower("M")) {
Suffix = 1024 * 1024;
Tok = Tok.drop_back();
}
if (Tok.getAsInteger(10, Result))
return false;
Result *= Suffix;
return true;
}
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
Expr ScriptParser::readPrimary() {
if (peek() == "(")
return readParenExpr();
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
StringRef Tok = next();
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
if (Tok == "~") {
Expr E = readPrimary();
return [=](uint64_t Dot) { return ~E(Dot); };
}
if (Tok == "-") {
Expr E = readPrimary();
return [=](uint64_t Dot) { return -E(Dot); };
}
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
// Built-in functions are parsed here.
// https://sourceware.org/binutils/docs/ld/Builtin-Functions.html.
if (Tok == "ADDR") {
expect("(");
StringRef Name = next();
expect(")");
return
[=](uint64_t Dot) { return ScriptBase->getOutputSectionAddress(Name); };
}
if (Tok == "ASSERT")
return readAssert();
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
if (Tok == "ALIGN") {
Expr E = readParenExpr();
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
return [=](uint64_t Dot) { return alignTo(Dot, E(Dot)); };
}
if (Tok == "CONSTANT") {
expect("(");
StringRef Tok = next();
expect(")");
return [=](uint64_t Dot) { return getConstant(Tok); };
}
if (Tok == "SEGMENT_START") {
expect("(");
next();
expect(",");
uint64_t Val;
if (next().getAsInteger(0, Val))
setError("integer expected");
expect(")");
return [=](uint64_t Dot) { return Val; };
}
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
if (Tok == "DATA_SEGMENT_ALIGN") {
expect("(");
Expr E = readExpr();
expect(",");
readExpr();
expect(")");
return [=](uint64_t Dot) { return alignTo(Dot, E(Dot)); };
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
}
if (Tok == "DATA_SEGMENT_END") {
expect("(");
expect(".");
expect(")");
return [](uint64_t Dot) { return Dot; };
}
// GNU linkers implements more complicated logic to handle
// DATA_SEGMENT_RELRO_END. We instead ignore the arguments and just align to
// the next page boundary for simplicity.
if (Tok == "DATA_SEGMENT_RELRO_END") {
expect("(");
readExpr();
expect(",");
readExpr();
expect(")");
return [](uint64_t Dot) { return alignTo(Dot, Target->PageSize); };
}
if (Tok == "SIZEOF") {
expect("(");
StringRef Name = next();
expect(")");
return [=](uint64_t Dot) { return ScriptBase->getOutputSectionSize(Name); };
}
if (Tok == "ALIGNOF") {
expect("(");
StringRef Name = next();
expect(")");
return
[=](uint64_t Dot) { return ScriptBase->getOutputSectionAlign(Name); };
}
if (Tok == "SIZEOF_HEADERS")
return [=](uint64_t Dot) { return ScriptBase->getHeaderSize(); };
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
// Tok is a literal number.
uint64_t V;
if (readInteger(Tok, V))
return [=](uint64_t Dot) { return V; };
// Tok is a symbol name.
if (Tok != "." && !isValidCIdentifier(Tok))
setError("malformed number: " + Tok);
return [=](uint64_t Dot) { return getSymbolValue(Tok, Dot); };
Make readExpr return an Expr object instead of a vector of tokens. Previously, we handled an expression as a vector of tokens. In other words, an expression was a vector of uncooked raw StringRefs. When we need a value of an expression, we used ExprParser to run the expression. The separation was needed essentially because parse time is too early to evaluate an expression. In order to evaluate an expression, we need to finalize section sizes. Because linker script parsing is done at very early stage of the linking process, we can't evaluate expressions while parsing. The above mechanism worked fairly well, but there were a few drawbacks. One thing is that we sometimes have to parse the same expression more than once in order to find the end of the expression. In some contexts, linker script expressions have no clear end marker. So, we needed to recognize balanced expressions and ternary operators. The other is poor error reporting. Since expressions are parsed basically twice, and some information that is available at the first stage is lost in the second stage, it was hard to print out apprpriate error messages. This patch fixes the issues with a new approach. Now the expression parsing is integrated into ScriptParser. ExprParser class is removed. Expressions are represented as lambdas instead of vectors of tokens. Lambdas captures information they need to run themselves when they are created. In this way, ends of expressions are naturally detected, and errors are handled in the usual way. This patch also reduces the amount of code. Differential Revision: https://reviews.llvm.org/D22728 llvm-svn: 276574
2016-07-25 02:19:40 +08:00
}
Expr ScriptParser::readTernary(Expr Cond) {
next();
Expr L = readExpr();
expect(":");
Expr R = readExpr();
return [=](uint64_t Dot) { return Cond(Dot) ? L(Dot) : R(Dot); };
}
Expr ScriptParser::readParenExpr() {
expect("(");
Expr E = readExpr();
expect(")");
return E;
}
std::vector<StringRef> ScriptParser::readOutputSectionPhdrs() {
std::vector<StringRef> Phdrs;
while (!Error && peek().startswith(":")) {
StringRef Tok = next();
Tok = (Tok.size() == 1) ? next() : Tok.substr(1);
if (Tok.empty()) {
setError("section header name is empty");
break;
}
Phdrs.push_back(Tok);
}
return Phdrs;
}
unsigned ScriptParser::readPhdrType() {
StringRef Tok = next();
unsigned Ret = StringSwitch<unsigned>(Tok)
.Case("PT_NULL", PT_NULL)
.Case("PT_LOAD", PT_LOAD)
.Case("PT_DYNAMIC", PT_DYNAMIC)
.Case("PT_INTERP", PT_INTERP)
.Case("PT_NOTE", PT_NOTE)
.Case("PT_SHLIB", PT_SHLIB)
.Case("PT_PHDR", PT_PHDR)
.Case("PT_TLS", PT_TLS)
.Case("PT_GNU_EH_FRAME", PT_GNU_EH_FRAME)
.Case("PT_GNU_STACK", PT_GNU_STACK)
.Case("PT_GNU_RELRO", PT_GNU_RELRO)
.Default(-1);
if (Ret == (unsigned)-1) {
setError("invalid program header type: " + Tok);
return PT_NULL;
}
return Ret;
}
void ScriptParser::readVersionDeclaration(StringRef VerStr) {
// Identifiers start at 2 because 0 and 1 are reserved
// for VER_NDX_LOCAL and VER_NDX_GLOBAL constants.
size_t VersionId = Config->VersionDefinitions.size() + 2;
Config->VersionDefinitions.push_back({VerStr, VersionId});
if (skip("global:") || peek() != "local:")
readGlobal(VerStr);
if (skip("local:"))
readLocal();
expect("}");
// Each version may have a parent version. For example, "Ver2" defined as
// "Ver2 { global: foo; local: *; } Ver1;" has "Ver1" as a parent. This
// version hierarchy is, probably against your instinct, purely for human; the
// runtime doesn't care about them at all. In LLD, we simply skip the token.
if (!VerStr.empty() && peek() != ";")
next();
expect(";");
}
void ScriptParser::readLocal() {
Config->DefaultSymbolVersion = VER_NDX_LOCAL;
expect("*");
expect(";");
}
void ScriptParser::readExtern(std::vector<SymbolVersion> *Globals) {
expect("\"C++\"");
expect("{");
for (;;) {
if (peek() == "}" || Error)
break;
bool HasWildcard = !peek().startswith("\"") && hasWildcard(peek());
Globals->push_back({unquote(next()), true, HasWildcard});
expect(";");
}
expect("}");
expect(";");
}
void ScriptParser::readGlobal(StringRef VerStr) {
std::vector<SymbolVersion> *Globals;
if (VerStr.empty())
Globals = &Config->VersionScriptGlobals;
else
Globals = &Config->VersionDefinitions.back().Globals;
for (;;) {
if (skip("extern"))
readExtern(Globals);
StringRef Cur = peek();
if (Cur == "}" || Cur == "local:" || Error)
return;
next();
Globals->push_back({unquote(Cur), false, hasWildcard(Cur)});
expect(";");
}
}
static bool isUnderSysroot(StringRef Path) {
if (Config->Sysroot == "")
return false;
for (; !Path.empty(); Path = sys::path::parent_path(Path))
if (sys::fs::equivalent(Config->Sysroot, Path))
return true;
return false;
}
void elf::readLinkerScript(MemoryBufferRef MB) {
StringRef Path = MB.getBufferIdentifier();
ScriptParser(MB.getBuffer(), isUnderSysroot(Path)).readLinkerScript();
}
void elf::readVersionScript(MemoryBufferRef MB) {
ScriptParser(MB.getBuffer(), false).readVersionScript();
}
template class elf::LinkerScript<ELF32LE>;
template class elf::LinkerScript<ELF32BE>;
template class elf::LinkerScript<ELF64LE>;
template class elf::LinkerScript<ELF64BE>;