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authorDimitry Andric <dim@FreeBSD.org>2017-04-16 16:03:39 +0000
committerDimitry Andric <dim@FreeBSD.org>2017-04-16 16:03:39 +0000
commitd2d3ebb81992e107edf95c1c136d7a342d9b1418 (patch)
treebb1af8fff2b1400cf240e3b2532a1e5d22a121da /ELF/LinkerScript.cpp
parent16787c9ce0b96aaa669d7fab3a495916b35ce758 (diff)
downloadsrc-d2d3ebb81992e107edf95c1c136d7a342d9b1418.tar.gz
src-d2d3ebb81992e107edf95c1c136d7a342d9b1418.zip
Vendor import of lld trunk r300422:vendor/lld/lld-trunk-r300422
Notes
Notes: svn path=/vendor/lld/dist/; revision=317025 svn path=/vendor/lld/lld-trunk-r300422/; revision=317026; tag=vendor/lld/lld-trunk-r300422
Diffstat (limited to 'ELF/LinkerScript.cpp')
-rw-r--r--ELF/LinkerScript.cpp1919
1 files changed, 466 insertions, 1453 deletions
diff --git a/ELF/LinkerScript.cpp b/ELF/LinkerScript.cpp
index 3cc235386b88..ab2ca22e9e17 100644
--- a/ELF/LinkerScript.cpp
+++ b/ELF/LinkerScript.cpp
@@ -13,27 +13,21 @@
#include "LinkerScript.h"
#include "Config.h"
-#include "Driver.h"
#include "InputSection.h"
#include "Memory.h"
#include "OutputSections.h"
-#include "ScriptParser.h"
#include "Strings.h"
#include "SymbolTable.h"
#include "Symbols.h"
#include "SyntheticSections.h"
-#include "Target.h"
#include "Writer.h"
#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringRef.h"
-#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
-#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Path.h"
#include <algorithm>
#include <cassert>
@@ -41,9 +35,7 @@
#include <cstdint>
#include <iterator>
#include <limits>
-#include <memory>
#include <string>
-#include <tuple>
#include <vector>
using namespace llvm;
@@ -53,77 +45,145 @@ using namespace llvm::support::endian;
using namespace lld;
using namespace lld::elf;
-LinkerScriptBase *elf::ScriptBase;
-ScriptConfiguration *elf::ScriptConfig;
+LinkerScript *elf::Script;
+
+uint64_t ExprValue::getValue() const {
+ if (Sec)
+ return Sec->getOffset(Val) + Sec->getOutputSection()->Addr;
+ return Val;
+}
+
+uint64_t ExprValue::getSecAddr() const {
+ if (Sec)
+ return Sec->getOffset(0) + Sec->getOutputSection()->Addr;
+ return 0;
+}
template <class ELFT> static SymbolBody *addRegular(SymbolAssignment *Cmd) {
+ Symbol *Sym;
uint8_t Visibility = Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT;
- Symbol *Sym = Symtab<ELFT>::X->addUndefined(
- Cmd->Name, /*IsLocal=*/false, STB_GLOBAL, Visibility,
- /*Type*/ 0,
- /*CanOmitFromDynSym*/ false, /*File*/ nullptr);
-
- replaceBody<DefinedRegular<ELFT>>(Sym, Cmd->Name, /*IsLocal=*/false,
- Visibility, STT_NOTYPE, 0, 0, nullptr,
- nullptr);
+ std::tie(Sym, std::ignore) = Symtab<ELFT>::X->insert(
+ Cmd->Name, /*Type*/ 0, Visibility, /*CanOmitFromDynSym*/ false,
+ /*File*/ nullptr);
+ Sym->Binding = STB_GLOBAL;
+ ExprValue Value = Cmd->Expression();
+ SectionBase *Sec = Value.isAbsolute() ? nullptr : Value.Sec;
+
+ // We want to set symbol values early if we can. This allows us to use symbols
+ // as variables in linker scripts. Doing so allows us to write expressions
+ // like this: `alignment = 16; . = ALIGN(., alignment)`
+ uint64_t SymValue = Value.isAbsolute() ? Value.getValue() : 0;
+ replaceBody<DefinedRegular>(Sym, Cmd->Name, /*IsLocal=*/false, Visibility,
+ STT_NOTYPE, SymValue, 0, Sec, nullptr);
return Sym->body();
}
-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->addUndefined(
- Cmd->Name, /*IsLocal=*/false, STB_GLOBAL, Visibility,
- /*Type*/ 0,
- /*CanOmitFromDynSym*/ false, /*File*/ nullptr);
-
- replaceBody<DefinedSynthetic>(Sym, Cmd->Name, 0, Sec);
- return Sym->body();
+OutputSection *LinkerScript::getOutputSection(const Twine &Loc,
+ StringRef Name) {
+ for (OutputSection *Sec : *OutputSections)
+ if (Sec->Name == Name)
+ return Sec;
+
+ static OutputSection Dummy("", 0, 0);
+ if (ErrorOnMissingSection)
+ error(Loc + ": undefined section " + Name);
+ return &Dummy;
}
-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;
+// This function is essentially the same as getOutputSection(Name)->Size,
+// but it won't print out an error message if a given section is not found.
+//
+// Linker script does not create an output section if its content is empty.
+// We want to allow SIZEOF(.foo) where .foo is a section which happened to
+// be empty. That is why this function is different from getOutputSection().
+uint64_t LinkerScript::getOutputSectionSize(StringRef Name) {
+ for (OutputSection *Sec : *OutputSections)
+ if (Sec->Name == Name)
+ return Sec->Size;
+ return 0;
+}
+
+void LinkerScript::setDot(Expr E, const Twine &Loc, bool InSec) {
+ uint64_t Val = E().getValue();
+ if (Val < Dot) {
+ if (InSec)
+ error(Loc + ": unable to move location counter backward for: " +
+ CurOutSec->Name);
+ else
+ error(Loc + ": unable to move location counter backward");
+ }
+ Dot = Val;
+ // Update to location counter means update to section size.
+ if (InSec)
+ CurOutSec->Size = Dot - CurOutSec->Addr;
}
-template <class ELFT> static void assignSymbol(SymbolAssignment *Cmd) {
- // If there are sections, then let the value be assigned later in
- // `assignAddresses`.
- if (ScriptConfig->HasSections)
+// Sets value of a 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.
+void LinkerScript::assignSymbol(SymbolAssignment *Cmd, bool InSec) {
+ if (Cmd->Name == ".") {
+ setDot(Cmd->Expression, Cmd->Location, InSec);
+ return;
+ }
+
+ if (!Cmd->Sym)
return;
- uint64_t Value = Cmd->Expression(0);
- if (Cmd->Expression.IsAbsolute()) {
- cast<DefinedRegular<ELFT>>(Cmd->Sym)->Value = Value;
+ auto *Sym = cast<DefinedRegular>(Cmd->Sym);
+ ExprValue V = Cmd->Expression();
+ if (V.isAbsolute()) {
+ Sym->Value = V.getValue();
} else {
- const OutputSectionBase *Sec = Cmd->Expression.Section();
- if (Sec)
- cast<DefinedSynthetic>(Cmd->Sym)->Value = Value - Sec->Addr;
+ Sym->Section = V.Sec;
+ if (Sym->Section->Flags & SHF_ALLOC)
+ Sym->Value = V.Val;
+ else
+ Sym->Value = V.getValue();
+ }
+}
+
+static SymbolBody *findSymbol(StringRef S) {
+ switch (Config->EKind) {
+ case ELF32LEKind:
+ return Symtab<ELF32LE>::X->find(S);
+ case ELF32BEKind:
+ return Symtab<ELF32BE>::X->find(S);
+ case ELF64LEKind:
+ return Symtab<ELF64LE>::X->find(S);
+ case ELF64BEKind:
+ return Symtab<ELF64BE>::X->find(S);
+ default:
+ llvm_unreachable("unknown Config->EKind");
}
}
-template <class ELFT> static void addSymbol(SymbolAssignment *Cmd) {
+static SymbolBody *addRegularSymbol(SymbolAssignment *Cmd) {
+ switch (Config->EKind) {
+ case ELF32LEKind:
+ return addRegular<ELF32LE>(Cmd);
+ case ELF32BEKind:
+ return addRegular<ELF32BE>(Cmd);
+ case ELF64LEKind:
+ return addRegular<ELF64LE>(Cmd);
+ case ELF64BEKind:
+ return addRegular<ELF64BE>(Cmd);
+ default:
+ llvm_unreachable("unknown Config->EKind");
+ }
+}
+
+void LinkerScript::addSymbol(SymbolAssignment *Cmd) {
if (Cmd->Name == ".")
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);
+ SymbolBody *B = findSymbol(Cmd->Name);
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);
+ Cmd->Sym = addRegularSymbol(Cmd);
}
bool SymbolAssignment::classof(const BaseCommand *C) {
@@ -146,17 +206,13 @@ bool BytesDataCommand::classof(const BaseCommand *C) {
return C->Kind == BytesDataKind;
}
-template <class ELFT> LinkerScript<ELFT>::LinkerScript() = default;
-template <class ELFT> LinkerScript<ELFT>::~LinkerScript() = default;
-
-template <class ELFT> static StringRef basename(InputSectionBase<ELFT> *S) {
- if (S->getFile())
- return sys::path::filename(S->getFile()->getName());
+static StringRef basename(InputSectionBase *S) {
+ if (S->File)
+ return sys::path::filename(S->File->getName());
return "";
}
-template <class ELFT>
-bool LinkerScript<ELFT>::shouldKeep(InputSectionBase<ELFT> *S) {
+bool LinkerScript::shouldKeep(InputSectionBase *S) {
for (InputSectionDescription *ID : Opt.KeptSections)
if (ID->FilePat.match(basename(S)))
for (SectionPattern &P : ID->SectionPatterns)
@@ -165,73 +221,77 @@ bool LinkerScript<ELFT>::shouldKeep(InputSectionBase<ELFT> *S) {
return false;
}
-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 *)>
+// A helper function for the SORT() command.
+static std::function<bool(InputSectionBase *, InputSectionBase *)>
getComparator(SortSectionPolicy K) {
switch (K) {
case SortSectionPolicy::Alignment:
- return compareAlignment;
+ return [](InputSectionBase *A, InputSectionBase *B) {
+ // ">" is not a mistake. Sections with larger alignments are placed
+ // before sections with smaller alignments in order to reduce the
+ // amount of padding necessary. This is compatible with GNU.
+ return A->Alignment > B->Alignment;
+ };
case SortSectionPolicy::Name:
- return compareName;
+ return [](InputSectionBase *A, InputSectionBase *B) {
+ return A->Name < B->Name;
+ };
case SortSectionPolicy::Priority:
- return comparePriority;
+ return [](InputSectionBase *A, InputSectionBase *B) {
+ return getPriority(A->Name) < getPriority(B->Name);
+ };
default:
llvm_unreachable("unknown sort policy");
}
}
-template <class ELFT>
-static bool matchConstraints(ArrayRef<InputSectionBase<ELFT> *> Sections,
+// A helper function for the SORT() command.
+static bool matchConstraints(ArrayRef<InputSectionBase *> Sections,
ConstraintKind Kind) {
if (Kind == ConstraintKind::NoConstraint)
return true;
- bool IsRW = llvm::any_of(Sections, [=](InputSectionData *Sec2) {
- auto *Sec = static_cast<InputSectionBase<ELFT> *>(Sec2);
- return Sec->Flags & SHF_WRITE;
+
+ bool IsRW = llvm::any_of(Sections, [](InputSectionBase *Sec) {
+ return static_cast<InputSectionBase *>(Sec)->Flags & SHF_WRITE;
});
+
return (IsRW && Kind == ConstraintKind::ReadWrite) ||
(!IsRW && Kind == ConstraintKind::ReadOnly);
}
-static void sortSections(InputSectionData **Begin, InputSectionData **End,
+static void sortSections(InputSectionBase **Begin, InputSectionBase **End,
SortSectionPolicy K) {
if (K != SortSectionPolicy::Default && K != SortSectionPolicy::None)
std::stable_sort(Begin, End, getComparator(K));
}
// Compute and remember which sections the InputSectionDescription matches.
-template <class ELFT>
-void LinkerScript<ELFT>::computeInputSections(InputSectionDescription *I) {
- // Collects all sections that satisfy constraints of I
- // and attach them to I.
- for (SectionPattern &Pat : I->SectionPatterns) {
- size_t SizeBefore = I->Sections.size();
-
- for (InputSectionBase<ELFT> *S : Symtab<ELFT>::X->Sections) {
- if (!S->Live || S->Assigned)
+std::vector<InputSectionBase *>
+LinkerScript::computeInputSections(const InputSectionDescription *Cmd) {
+ std::vector<InputSectionBase *> Ret;
+
+ // Collects all sections that satisfy constraints of Cmd.
+ for (const SectionPattern &Pat : Cmd->SectionPatterns) {
+ size_t SizeBefore = Ret.size();
+
+ for (InputSectionBase *Sec : InputSections) {
+ if (Sec->Assigned)
continue;
- StringRef Filename = basename(S);
- if (!I->FilePat.match(Filename) || Pat.ExcludedFilePat.match(Filename))
+ // For -emit-relocs we have to ignore entries like
+ // .rela.dyn : { *(.rela.data) }
+ // which are common because they are in the default bfd script.
+ if (Sec->Type == SHT_REL || Sec->Type == SHT_RELA)
continue;
- if (!Pat.SectionPat.match(S->Name))
+
+ StringRef Filename = basename(Sec);
+ if (!Cmd->FilePat.match(Filename) ||
+ Pat.ExcludedFilePat.match(Filename) ||
+ !Pat.SectionPat.match(Sec->Name))
continue;
- I->Sections.push_back(S);
- S->Assigned = true;
+
+ Ret.push_back(Sec);
+ Sec->Assigned = true;
}
// Sort sections as instructed by SORT-family commands and --sort-section
@@ -245,8 +305,8 @@ void LinkerScript<ELFT>::computeInputSections(InputSectionDescription *I) {
// --sort-section is handled as an inner SORT command.
// 3. If one SORT command is given, and if it is SORT_NONE, don't sort.
// 4. If no SORT command is given, sort according to --sort-section.
- InputSectionData **Begin = I->Sections.data() + SizeBefore;
- InputSectionData **End = I->Sections.data() + I->Sections.size();
+ InputSectionBase **Begin = Ret.data() + SizeBefore;
+ InputSectionBase **End = Ret.data() + Ret.size();
if (Pat.SortOuter != SortSectionPolicy::None) {
if (Pat.SortInner == SortSectionPolicy::Default)
sortSections(Begin, End, Config->SortSection);
@@ -255,68 +315,58 @@ void LinkerScript<ELFT>::computeInputSections(InputSectionDescription *I) {
sortSections(Begin, End, Pat.SortOuter);
}
}
+ return Ret;
}
-template <class ELFT>
-void LinkerScript<ELFT>::discard(ArrayRef<InputSectionBase<ELFT> *> V) {
- for (InputSectionBase<ELFT> *S : V) {
+void LinkerScript::discard(ArrayRef<InputSectionBase *> V) {
+ for (InputSectionBase *S : V) {
S->Live = false;
- reportDiscarded(S);
+ if (S == InX::ShStrTab)
+ error("discarding .shstrtab section is not allowed");
+ discard(S->DependentSections);
}
}
-template <class ELFT>
-std::vector<InputSectionBase<ELFT> *>
-LinkerScript<ELFT>::createInputSectionList(OutputSectionCommand &OutCmd) {
- std::vector<InputSectionBase<ELFT> *> Ret;
+std::vector<InputSectionBase *>
+LinkerScript::createInputSectionList(OutputSectionCommand &OutCmd) {
+ std::vector<InputSectionBase *> Ret;
- for (const std::unique_ptr<BaseCommand> &Base : OutCmd.Commands) {
- auto *Cmd = dyn_cast<InputSectionDescription>(Base.get());
+ for (BaseCommand *Base : OutCmd.Commands) {
+ auto *Cmd = dyn_cast<InputSectionDescription>(Base);
if (!Cmd)
continue;
- computeInputSections(Cmd);
- for (InputSectionData *S : Cmd->Sections)
- Ret.push_back(static_cast<InputSectionBase<ELFT> *>(S));
+
+ Cmd->Sections = computeInputSections(Cmd);
+ Ret.insert(Ret.end(), Cmd->Sections.begin(), Cmd->Sections.end());
}
return Ret;
}
-template <class ELFT>
-void LinkerScript<ELFT>::addSection(OutputSectionFactory<ELFT> &Factory,
- InputSectionBase<ELFT> *Sec,
- StringRef Name) {
- OutputSectionBase *OutSec;
- bool IsNew;
- std::tie(OutSec, IsNew) = Factory.create(Sec, Name);
- if (IsNew)
- OutputSections->push_back(OutSec);
- OutSec->addSection(Sec);
-}
-
-template <class ELFT>
-void LinkerScript<ELFT>::processCommands(OutputSectionFactory<ELFT> &Factory) {
- for (unsigned I = 0; I < Opt.Commands.size(); ++I) {
- auto Iter = Opt.Commands.begin() + I;
- const std::unique_ptr<BaseCommand> &Base1 = *Iter;
+void LinkerScript::processCommands(OutputSectionFactory &Factory) {
+ // A symbol can be assigned before any section is mentioned in the linker
+ // script. In an DSO, the symbol values are addresses, so the only important
+ // section values are:
+ // * SHN_UNDEF
+ // * SHN_ABS
+ // * Any value meaning a regular section.
+ // To handle that, create a dummy aether section that fills the void before
+ // the linker scripts switches to another section. It has an index of one
+ // which will map to whatever the first actual section is.
+ Aether = make<OutputSection>("", 0, SHF_ALLOC);
+ Aether->SectionIndex = 1;
+ CurOutSec = Aether;
+ Dot = 0;
+ for (size_t I = 0; I < Opt.Commands.size(); ++I) {
// Handle symbol assignments outside of any output section.
- if (auto *Cmd = dyn_cast<SymbolAssignment>(Base1.get())) {
- addSymbol<ELFT>(Cmd);
+ if (auto *Cmd = dyn_cast<SymbolAssignment>(Opt.Commands[I])) {
+ addSymbol(Cmd);
continue;
}
- if (auto *Cmd = dyn_cast<AssertCommand>(Base1.get())) {
- // If we don't have SECTIONS then output sections have already been
- // created by Writer<ELFT>. The LinkerScript<ELFT>::assignAddresses
- // will not be called, so ASSERT should be evaluated now.
- if (!Opt.HasSections)
- Cmd->Expression(0);
- continue;
- }
-
- if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base1.get())) {
- std::vector<InputSectionBase<ELFT> *> V = createInputSectionList(*Cmd);
+ if (auto *Cmd = dyn_cast<OutputSectionCommand>(Opt.Commands[I])) {
+ std::vector<InputSectionBase *> V = createInputSectionList(*Cmd);
// The output section name `/DISCARD/' is special.
// Any input section assigned to it is discarded.
@@ -332,74 +382,54 @@ void LinkerScript<ELFT>::processCommands(OutputSectionFactory<ELFT> &Factory) {
//
// Because we'll iterate over Commands many more times, the easiest
// way to "make it as if it wasn't present" is to just remove it.
- if (!matchConstraints<ELFT>(V, Cmd->Constraint)) {
- for (InputSectionBase<ELFT> *S : V)
+ if (!matchConstraints(V, Cmd->Constraint)) {
+ for (InputSectionBase *S : V)
S->Assigned = false;
- Opt.Commands.erase(Iter);
+ Opt.Commands.erase(Opt.Commands.begin() + I);
--I;
continue;
}
// A directive may contain symbol definitions like this:
// ".foo : { ...; bar = .; }". Handle them.
- for (const std::unique_ptr<BaseCommand> &Base : Cmd->Commands)
- if (auto *OutCmd = dyn_cast<SymbolAssignment>(Base.get()))
- addSymbol<ELFT>(OutCmd);
+ for (BaseCommand *Base : Cmd->Commands)
+ if (auto *OutCmd = dyn_cast<SymbolAssignment>(Base))
+ addSymbol(OutCmd);
// Handle subalign (e.g. ".foo : SUBALIGN(32) { ... }"). If subalign
// is given, input sections are aligned to that value, whether the
// given value is larger or smaller than the original section alignment.
if (Cmd->SubalignExpr) {
- uint32_t Subalign = Cmd->SubalignExpr(0);
- for (InputSectionBase<ELFT> *S : V)
+ uint32_t Subalign = Cmd->SubalignExpr().getValue();
+ for (InputSectionBase *S : V)
S->Alignment = Subalign;
}
// Add input sections to an output section.
- for (InputSectionBase<ELFT> *S : V)
- addSection(Factory, S, Cmd->Name);
+ for (InputSectionBase *S : V)
+ Factory.addInputSec(S, Cmd->Name);
}
}
+ CurOutSec = nullptr;
}
// Add sections that didn't match any sections command.
-template <class ELFT>
-void LinkerScript<ELFT>::addOrphanSections(
- OutputSectionFactory<ELFT> &Factory) {
- for (InputSectionBase<ELFT> *S : Symtab<ELFT>::X->Sections)
+void LinkerScript::addOrphanSections(OutputSectionFactory &Factory) {
+ for (InputSectionBase *S : InputSections)
if (S->Live && !S->OutSec)
- addSection(Factory, S, getOutputSectionName(S->Name));
+ Factory.addInputSec(S, getOutputSectionName(S->Name));
}
-// 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,
- typename ELFT::uint Value) {
- if (!Cmd->Sym)
- return;
-
- if (auto *Body = dyn_cast<DefinedSynthetic>(Cmd->Sym)) {
- Body->Section = Cmd->Expression.Section();
- Body->Value = Cmd->Expression(Value) - Body->Section->Addr;
- return;
- }
- auto *Body = cast<DefinedRegular<ELFT>>(Cmd->Sym);
- Body->Value = Cmd->Expression(Value);
-}
-
-template <class ELFT> static bool isTbss(OutputSectionBase *Sec) {
+static bool isTbss(OutputSection *Sec) {
return (Sec->Flags & SHF_TLS) && Sec->Type == SHT_NOBITS;
}
-template <class ELFT> void LinkerScript<ELFT>::output(InputSection<ELFT> *S) {
+void LinkerScript::output(InputSection *S) {
if (!AlreadyOutputIS.insert(S).second)
return;
- bool IsTbss = isTbss<ELFT>(CurOutSec);
+ bool IsTbss = isTbss(CurOutSec);
- uintX_t Pos = IsTbss ? Dot + ThreadBssOffset : Dot;
+ uint64_t Pos = IsTbss ? Dot + ThreadBssOffset : Dot;
Pos = alignTo(Pos, S->Alignment);
S->OutSecOff = Pos - CurOutSec->Addr;
Pos += S->getSize();
@@ -409,134 +439,171 @@ template <class ELFT> void LinkerScript<ELFT>::output(InputSection<ELFT> *S) {
// .foo { *(.aaa) a = SIZEOF(.foo); *(.bbb) }
CurOutSec->Size = Pos - CurOutSec->Addr;
+ // If there is a memory region associated with this input section, then
+ // place the section in that region and update the region index.
+ if (CurMemRegion) {
+ CurMemRegion->Offset += CurOutSec->Size;
+ uint64_t CurSize = CurMemRegion->Offset - CurMemRegion->Origin;
+ if (CurSize > CurMemRegion->Length) {
+ uint64_t OverflowAmt = CurSize - CurMemRegion->Length;
+ error("section '" + CurOutSec->Name + "' will not fit in region '" +
+ CurMemRegion->Name + "': overflowed by " + Twine(OverflowAmt) +
+ " bytes");
+ }
+ }
+
if (IsTbss)
ThreadBssOffset = Pos - Dot;
else
Dot = Pos;
}
-template <class ELFT> void LinkerScript<ELFT>::flush() {
- if (!CurOutSec || !AlreadyOutputOS.insert(CurOutSec).second)
+void LinkerScript::flush() {
+ assert(CurOutSec);
+ if (!AlreadyOutputOS.insert(CurOutSec).second)
return;
- if (auto *OutSec = dyn_cast<OutputSection<ELFT>>(CurOutSec)) {
- for (InputSection<ELFT> *I : OutSec->Sections)
- output(I);
- } else {
- Dot += CurOutSec->Size;
- }
+ for (InputSection *I : CurOutSec->Sections)
+ output(I);
}
-template <class ELFT>
-void LinkerScript<ELFT>::switchTo(OutputSectionBase *Sec) {
+void LinkerScript::switchTo(OutputSection *Sec) {
if (CurOutSec == Sec)
return;
if (AlreadyOutputOS.count(Sec))
return;
- flush();
CurOutSec = Sec;
- Dot = alignTo(Dot, CurOutSec->Addralign);
- CurOutSec->Addr = isTbss<ELFT>(CurOutSec) ? Dot + ThreadBssOffset : Dot;
+ Dot = alignTo(Dot, CurOutSec->Alignment);
+ CurOutSec->Addr = isTbss(CurOutSec) ? Dot + ThreadBssOffset : Dot;
// If neither AT nor AT> is specified for an allocatable section, the linker
// will set the LMA such that the difference between VMA and LMA for the
// section is the same as the preceding output section in the same region
// https://sourceware.org/binutils/docs-2.20/ld/Output-Section-LMA.html
- CurOutSec->setLMAOffset(LMAOffset);
+ if (LMAOffset)
+ CurOutSec->LMAOffset = LMAOffset();
}
-template <class ELFT> void LinkerScript<ELFT>::process(BaseCommand &Base) {
- // This handles the assignments to symbol or to a location counter (.)
- if (auto *AssignCmd = dyn_cast<SymbolAssignment>(&Base)) {
- if (AssignCmd->Name == ".") {
- // Update to location counter means update to section size.
- uintX_t Val = AssignCmd->Expression(Dot);
- if (Val < Dot)
- error("unable to move location counter backward for: " +
- CurOutSec->Name);
- Dot = Val;
- CurOutSec->Size = Dot - CurOutSec->Addr;
- return;
- }
- assignSectionSymbol<ELFT>(AssignCmd, Dot);
+void LinkerScript::process(BaseCommand &Base) {
+ // This handles the assignments to symbol or to the dot.
+ if (auto *Cmd = dyn_cast<SymbolAssignment>(&Base)) {
+ assignSymbol(Cmd, true);
return;
}
// Handle BYTE(), SHORT(), LONG(), or QUAD().
- if (auto *DataCmd = dyn_cast<BytesDataCommand>(&Base)) {
- DataCmd->Offset = Dot - CurOutSec->Addr;
- Dot += DataCmd->Size;
+ if (auto *Cmd = dyn_cast<BytesDataCommand>(&Base)) {
+ Cmd->Offset = Dot - CurOutSec->Addr;
+ Dot += Cmd->Size;
CurOutSec->Size = Dot - CurOutSec->Addr;
return;
}
- if (auto *AssertCmd = dyn_cast<AssertCommand>(&Base)) {
- AssertCmd->Expression(Dot);
+ // Handle ASSERT().
+ if (auto *Cmd = dyn_cast<AssertCommand>(&Base)) {
+ Cmd->Expression();
return;
}
- // It handles single input section description command,
- // calculates and assigns the offsets for each section and also
+ // Handle a single input section description command.
+ // It calculates and assigns the offsets for each section and also
// updates the output section size.
- auto &ICmd = cast<InputSectionDescription>(Base);
- for (InputSectionData *ID : ICmd.Sections) {
+ auto &Cmd = cast<InputSectionDescription>(Base);
+ for (InputSectionBase *Sec : Cmd.Sections) {
// We tentatively added all synthetic sections at the beginning and removed
// empty ones afterwards (because there is no way to know whether they were
// going be empty or not other than actually running linker scripts.)
// We need to ignore remains of empty sections.
- if (auto *Sec = dyn_cast<SyntheticSection<ELFT>>(ID))
- if (Sec->empty())
+ if (auto *S = dyn_cast<SyntheticSection>(Sec))
+ if (S->empty())
continue;
- auto *IB = static_cast<InputSectionBase<ELFT> *>(ID);
- switchTo(IB->OutSec);
- if (auto *I = dyn_cast<InputSection<ELFT>>(IB))
- output(I);
- else
- flush();
+ if (!Sec->Live)
+ continue;
+ assert(CurOutSec == Sec->OutSec || AlreadyOutputOS.count(Sec->OutSec));
+ output(cast<InputSection>(Sec));
}
}
-template <class ELFT>
-static std::vector<OutputSectionBase *>
-findSections(StringRef Name, const std::vector<OutputSectionBase *> &Sections) {
- std::vector<OutputSectionBase *> Ret;
- for (OutputSectionBase *Sec : Sections)
- if (Sec->getName() == Name)
- Ret.push_back(Sec);
- return Ret;
+static OutputSection *
+findSection(StringRef Name, const std::vector<OutputSection *> &Sections) {
+ for (OutputSection *Sec : Sections)
+ if (Sec->Name == Name)
+ return Sec;
+ return nullptr;
+}
+
+// This function searches for a memory region to place the given output
+// section in. If found, a pointer to the appropriate memory region is
+// returned. Otherwise, a nullptr is returned.
+MemoryRegion *LinkerScript::findMemoryRegion(OutputSectionCommand *Cmd) {
+ // If a memory region name was specified in the output section command,
+ // then try to find that region first.
+ if (!Cmd->MemoryRegionName.empty()) {
+ auto It = Opt.MemoryRegions.find(Cmd->MemoryRegionName);
+ if (It != Opt.MemoryRegions.end())
+ return &It->second;
+ error("memory region '" + Cmd->MemoryRegionName + "' not declared");
+ return nullptr;
+ }
+
+ // If at least one memory region is defined, all sections must
+ // belong to some memory region. Otherwise, we don't need to do
+ // anything for memory regions.
+ if (Opt.MemoryRegions.empty())
+ return nullptr;
+
+ OutputSection *Sec = Cmd->Sec;
+ // See if a region can be found by matching section flags.
+ for (auto &Pair : Opt.MemoryRegions) {
+ MemoryRegion &M = Pair.second;
+ if ((M.Flags & Sec->Flags) && (M.NegFlags & Sec->Flags) == 0)
+ return &M;
+ }
+
+ // Otherwise, no suitable region was found.
+ if (Sec->Flags & SHF_ALLOC)
+ error("no memory region specified for section '" + Sec->Name + "'");
+ return nullptr;
}
// This function assigns offsets to input sections and an output section
// for a single sections command (e.g. ".text { *(.text); }").
-template <class ELFT>
-void LinkerScript<ELFT>::assignOffsets(OutputSectionCommand *Cmd) {
- if (Cmd->LMAExpr)
- LMAOffset = Cmd->LMAExpr(Dot) - Dot;
- std::vector<OutputSectionBase *> Sections =
- findSections<ELFT>(Cmd->Name, *OutputSections);
- if (Sections.empty())
+void LinkerScript::assignOffsets(OutputSectionCommand *Cmd) {
+ OutputSection *Sec = Cmd->Sec;
+ if (!Sec)
return;
- switchTo(Sections[0]);
-
- // Find the last section output location. We will output orphan sections
- // there so that end symbols point to the correct location.
- auto E = std::find_if(Cmd->Commands.rbegin(), Cmd->Commands.rend(),
- [](const std::unique_ptr<BaseCommand> &Cmd) {
- return !isa<SymbolAssignment>(*Cmd);
- })
- .base();
- for (auto I = Cmd->Commands.begin(); I != E; ++I)
+
+ if (Cmd->AddrExpr && (Sec->Flags & SHF_ALLOC))
+ setDot(Cmd->AddrExpr, Cmd->Location, false);
+
+ if (Cmd->LMAExpr) {
+ uint64_t D = Dot;
+ LMAOffset = [=] { return Cmd->LMAExpr().getValue() - D; };
+ }
+
+ CurMemRegion = Cmd->MemRegion;
+ if (CurMemRegion)
+ Dot = CurMemRegion->Offset;
+ switchTo(Sec);
+
+ // flush() may add orphan sections, so the order of flush() and
+ // symbol assignments is important. We want to call flush() first so
+ // that symbols pointing the end of the current section points to
+ // the location after orphan sections.
+ auto Mid =
+ std::find_if(Cmd->Commands.rbegin(), Cmd->Commands.rend(),
+ [](BaseCommand *Cmd) { return !isa<SymbolAssignment>(Cmd); })
+ .base();
+ for (auto I = Cmd->Commands.begin(); I != Mid; ++I)
process(**I);
- for (OutputSectionBase *Base : Sections)
- switchTo(Base);
flush();
- std::for_each(E, Cmd->Commands.end(),
- [this](std::unique_ptr<BaseCommand> &B) { process(*B.get()); });
+ for (auto I = Mid, E = Cmd->Commands.end(); I != E; ++I)
+ process(**I);
}
-template <class ELFT> void LinkerScript<ELFT>::removeEmptyCommands() {
+void LinkerScript::removeEmptyCommands() {
// It is common practice to use very generic linker scripts. So for any
// given run some of the output sections in the script will be empty.
// We could create corresponding empty output sections, but that would
@@ -544,52 +611,61 @@ template <class ELFT> void LinkerScript<ELFT>::removeEmptyCommands() {
// We instead remove trivially empty sections. The bfd linker seems even
// more aggressive at removing them.
auto Pos = std::remove_if(
- Opt.Commands.begin(), Opt.Commands.end(),
- [&](const std::unique_ptr<BaseCommand> &Base) {
- if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get()))
- return findSections<ELFT>(Cmd->Name, *OutputSections).empty();
+ Opt.Commands.begin(), Opt.Commands.end(), [&](BaseCommand *Base) {
+ if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base))
+ return !Cmd->Sec;
return false;
});
Opt.Commands.erase(Pos, Opt.Commands.end());
}
static bool isAllSectionDescription(const OutputSectionCommand &Cmd) {
- for (const std::unique_ptr<BaseCommand> &I : Cmd.Commands)
- if (!isa<InputSectionDescription>(*I))
+ for (BaseCommand *Base : Cmd.Commands)
+ if (!isa<InputSectionDescription>(*Base))
return false;
return true;
}
-template <class ELFT> void LinkerScript<ELFT>::adjustSectionsBeforeSorting() {
+void LinkerScript::adjustSectionsBeforeSorting() {
// If the output section contains only symbol assignments, create a
// corresponding output section. The bfd linker seems to only create them if
// '.' is assigned to, but creating these section should not have any bad
// consequeces and gives us a section to put the symbol in.
- uintX_t Flags = SHF_ALLOC;
- uint32_t Type = SHT_NOBITS;
- for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
- auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get());
+ uint64_t Flags = SHF_ALLOC;
+ uint32_t Type = SHT_PROGBITS;
+ for (BaseCommand *Base : Opt.Commands) {
+ auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
if (!Cmd)
continue;
- std::vector<OutputSectionBase *> Secs =
- findSections<ELFT>(Cmd->Name, *OutputSections);
- if (!Secs.empty()) {
- Flags = Secs[0]->Flags;
- Type = Secs[0]->Type;
+ if (OutputSection *Sec = findSection(Cmd->Name, *OutputSections)) {
+ Cmd->Sec = Sec;
+ Flags = Sec->Flags;
+ Type = Sec->Type;
continue;
}
if (isAllSectionDescription(*Cmd))
continue;
- auto *OutSec = make<OutputSection<ELFT>>(Cmd->Name, Type, Flags);
+ auto *OutSec = make<OutputSection>(Cmd->Name, Type, Flags);
OutputSections->push_back(OutSec);
+ Cmd->Sec = OutSec;
}
}
-template <class ELFT> void LinkerScript<ELFT>::adjustSectionsAfterSorting() {
+void LinkerScript::adjustSectionsAfterSorting() {
placeOrphanSections();
+ // Try and find an appropriate memory region to assign offsets in.
+ for (BaseCommand *Base : Opt.Commands) {
+ if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base)) {
+ Cmd->MemRegion = findMemoryRegion(Cmd);
+ // Handle align (e.g. ".foo : ALIGN(16) { ... }").
+ if (Cmd->AlignExpr)
+ Cmd->Sec->updateAlignment(Cmd->AlignExpr().getValue());
+ }
+ }
+
// If output section command doesn't specify any segments,
// and we haven't previously assigned any section to segment,
// then we simply assign section to the very first load segment.
@@ -605,10 +681,11 @@ template <class ELFT> void LinkerScript<ELFT>::adjustSectionsAfterSorting() {
// Walk the commands and propagate the program headers to commands that don't
// explicitly specify them.
- for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
- auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get());
+ for (BaseCommand *Base : Opt.Commands) {
+ auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
if (!Cmd)
continue;
+
if (Cmd->Phdrs.empty())
Cmd->Phdrs = DefPhdrs;
else
@@ -632,19 +709,37 @@ template <class ELFT> void LinkerScript<ELFT>::adjustSectionsAfterSorting() {
// /* The RW PT_LOAD starts here*/
// rw_sec : { *(rw_sec) }
// would mean that the RW PT_LOAD would become unaligned.
-static bool shouldSkip(const BaseCommand &Cmd) {
+static bool shouldSkip(BaseCommand *Cmd) {
if (isa<OutputSectionCommand>(Cmd))
return false;
- const auto *Assign = dyn_cast<SymbolAssignment>(&Cmd);
- if (!Assign)
- return true;
- return Assign->Name != ".";
+ if (auto *Assign = dyn_cast<SymbolAssignment>(Cmd))
+ return Assign->Name != ".";
+ return true;
}
-// Orphan sections are sections present in the input files which are not
-// explicitly placed into the output file by the linker script. This just
-// places them in the order already decided in OutputSections.
-template <class ELFT> void LinkerScript<ELFT>::placeOrphanSections() {
+// Orphan sections are sections present in the input files which are
+// not explicitly placed into the output file by the linker script.
+//
+// When the control reaches this function, Opt.Commands contains
+// output section commands for non-orphan sections only. This function
+// adds new elements for orphan sections so that all sections are
+// explicitly handled by Opt.Commands.
+//
+// Writer<ELFT>::sortSections has already sorted output sections.
+// What we need to do is to scan OutputSections vector and
+// Opt.Commands in parallel to find orphan sections. If there is an
+// output section that doesn't have a corresponding entry in
+// Opt.Commands, we will insert a new entry to Opt.Commands.
+//
+// There is some ambiguity as to where exactly a new entry should be
+// inserted, because Opt.Commands contains not only output section
+// commands but also other types of commands such as symbol assignment
+// expressions. There's no correct answer here due to the lack of the
+// formal specification of the linker script. We use heuristics to
+// determine whether a new output command should be added before or
+// after another commands. For the details, look at shouldSkip
+// function.
+void LinkerScript::placeOrphanSections() {
// The OutputSections are already in the correct order.
// This loops creates or moves commands as needed so that they are in the
// correct order.
@@ -656,40 +751,33 @@ template <class ELFT> void LinkerScript<ELFT>::placeOrphanSections() {
// after that.
auto FirstSectionOrDotAssignment =
std::find_if(Opt.Commands.begin(), Opt.Commands.end(),
- [](const std::unique_ptr<BaseCommand> &Cmd) {
- if (isa<OutputSectionCommand>(*Cmd))
- return true;
- const auto *Assign = dyn_cast<SymbolAssignment>(Cmd.get());
- if (!Assign)
- return false;
- return Assign->Name == ".";
- });
+ [](BaseCommand *Cmd) { return !shouldSkip(Cmd); });
if (FirstSectionOrDotAssignment != Opt.Commands.end()) {
CmdIndex = FirstSectionOrDotAssignment - Opt.Commands.begin();
if (isa<SymbolAssignment>(**FirstSectionOrDotAssignment))
++CmdIndex;
}
- for (OutputSectionBase *Sec : *OutputSections) {
- StringRef Name = Sec->getName();
+ for (OutputSection *Sec : *OutputSections) {
+ StringRef Name = Sec->Name;
// Find the last spot where we can insert a command and still get the
// correct result.
auto CmdIter = Opt.Commands.begin() + CmdIndex;
auto E = Opt.Commands.end();
- while (CmdIter != E && shouldSkip(**CmdIter)) {
+ while (CmdIter != E && shouldSkip(*CmdIter)) {
++CmdIter;
++CmdIndex;
}
- auto Pos =
- std::find_if(CmdIter, E, [&](const std::unique_ptr<BaseCommand> &Base) {
- auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get());
- return Cmd && Cmd->Name == Name;
- });
+ auto Pos = std::find_if(CmdIter, E, [&](BaseCommand *Base) {
+ auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
+ return Cmd && Cmd->Name == Name;
+ });
if (Pos == E) {
- Opt.Commands.insert(CmdIter,
- llvm::make_unique<OutputSectionCommand>(Name));
+ auto *Cmd = make<OutputSectionCommand>(Name);
+ Cmd->Sec = Sec;
+ Opt.Commands.insert(CmdIter, Cmd);
++CmdIndex;
continue;
}
@@ -699,55 +787,49 @@ template <class ELFT> void LinkerScript<ELFT>::placeOrphanSections() {
}
}
-template <class ELFT>
-void LinkerScript<ELFT>::assignAddresses(std::vector<PhdrEntry> &Phdrs) {
+void LinkerScript::processNonSectionCommands() {
+ for (BaseCommand *Base : Opt.Commands) {
+ if (auto *Cmd = dyn_cast<SymbolAssignment>(Base))
+ assignSymbol(Cmd, false);
+ else if (auto *Cmd = dyn_cast<AssertCommand>(Base))
+ Cmd->Expression();
+ }
+}
+
+void LinkerScript::assignAddresses(std::vector<PhdrEntry> &Phdrs) {
// Assign addresses as instructed by linker script SECTIONS sub-commands.
Dot = 0;
+ ErrorOnMissingSection = true;
+ switchTo(Aether);
- 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) {
- assignSectionSymbol<ELFT>(Cmd, Dot);
- }
+ for (BaseCommand *Base : Opt.Commands) {
+ if (auto *Cmd = dyn_cast<SymbolAssignment>(Base)) {
+ assignSymbol(Cmd, false);
continue;
}
- if (auto *Cmd = dyn_cast<AssertCommand>(Base.get())) {
- Cmd->Expression(Dot);
+ if (auto *Cmd = dyn_cast<AssertCommand>(Base)) {
+ Cmd->Expression();
continue;
}
- auto *Cmd = cast<OutputSectionCommand>(Base.get());
- if (Cmd->AddrExpr)
- Dot = Cmd->AddrExpr(Dot);
+ auto *Cmd = cast<OutputSectionCommand>(Base);
assignOffsets(Cmd);
}
- uintX_t MinVA = std::numeric_limits<uintX_t>::max();
- for (OutputSectionBase *Sec : *OutputSections) {
+ uint64_t MinVA = std::numeric_limits<uint64_t>::max();
+ for (OutputSection *Sec : *OutputSections) {
if (Sec->Flags & SHF_ALLOC)
MinVA = std::min<uint64_t>(MinVA, Sec->Addr);
else
Sec->Addr = 0;
}
- uintX_t HeaderSize = getHeaderSize();
- // If the linker script doesn't have PHDRS, add ElfHeader and ProgramHeaders
- // now that we know we have space.
- if (HeaderSize <= MinVA && !hasPhdrsCommands())
- allocateHeaders<ELFT>(Phdrs, *OutputSections);
-
- // ELF and Program headers need to be right before the first section in
- // memory. Set their addresses accordingly.
- MinVA = alignDown(MinVA - HeaderSize, Config->MaxPageSize);
- Out<ELFT>::ElfHeader->Addr = MinVA;
- Out<ELFT>::ProgramHeaders->Addr = Out<ELFT>::ElfHeader->Size + MinVA;
+ allocateHeaders(Phdrs, *OutputSections, MinVA);
}
// Creates program headers as instructed by PHDRS linker script command.
-template <class ELFT> std::vector<PhdrEntry> LinkerScript<ELFT>::createPhdrs() {
+std::vector<PhdrEntry> LinkerScript::createPhdrs() {
std::vector<PhdrEntry> Ret;
// Process PHDRS and FILEHDR keywords because they are not
@@ -757,23 +839,23 @@ template <class ELFT> std::vector<PhdrEntry> LinkerScript<ELFT>::createPhdrs() {
PhdrEntry &Phdr = Ret.back();
if (Cmd.HasFilehdr)
- Phdr.add(Out<ELFT>::ElfHeader);
+ Phdr.add(Out::ElfHeader);
if (Cmd.HasPhdrs)
- Phdr.add(Out<ELFT>::ProgramHeaders);
+ Phdr.add(Out::ProgramHeaders);
if (Cmd.LMAExpr) {
- Phdr.p_paddr = Cmd.LMAExpr(0);
+ Phdr.p_paddr = Cmd.LMAExpr().getValue();
Phdr.HasLMA = true;
}
}
// Add output sections to program headers.
- for (OutputSectionBase *Sec : *OutputSections) {
+ for (OutputSection *Sec : *OutputSections) {
if (!(Sec->Flags & SHF_ALLOC))
break;
// Assign headers specified by linker script
- for (size_t Id : getPhdrIndices(Sec->getName())) {
+ for (size_t Id : getPhdrIndices(Sec->Name)) {
Ret[Id].add(Sec);
if (Opt.PhdrsCommands[Id].Flags == UINT_MAX)
Ret[Id].p_flags |= Sec->getPhdrFlags();
@@ -782,60 +864,52 @@ template <class ELFT> std::vector<PhdrEntry> LinkerScript<ELFT>::createPhdrs() {
return Ret;
}
-template <class ELFT> bool LinkerScript<ELFT>::ignoreInterpSection() {
+bool LinkerScript::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();
+ if (Opt.PhdrsCommands.empty())
+ return false;
+ for (PhdrsCommand &Cmd : Opt.PhdrsCommands)
+ if (Cmd.Type == PT_INTERP)
+ return false;
+ return true;
}
-template <class ELFT> uint32_t LinkerScript<ELFT>::getFiller(StringRef Name) {
- for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands)
- if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get()))
+Optional<uint32_t> LinkerScript::getFiller(StringRef Name) {
+ for (BaseCommand *Base : Opt.Commands)
+ if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base))
if (Cmd->Name == Name)
return Cmd->Filler;
- return 0;
+ return None;
}
-template <class ELFT>
static void writeInt(uint8_t *Buf, uint64_t Data, uint64_t Size) {
- const endianness E = ELFT::TargetEndianness;
-
- switch (Size) {
- case 1:
- *Buf = (uint8_t)Data;
- break;
- case 2:
- write16<E>(Buf, Data);
- break;
- case 4:
- write32<E>(Buf, Data);
- break;
- case 8:
- write64<E>(Buf, Data);
- break;
- default:
+ if (Size == 1)
+ *Buf = Data;
+ else if (Size == 2)
+ write16(Buf, Data, Config->Endianness);
+ else if (Size == 4)
+ write32(Buf, Data, Config->Endianness);
+ else if (Size == 8)
+ write64(Buf, Data, Config->Endianness);
+ else
llvm_unreachable("unsupported Size argument");
- }
}
-template <class ELFT>
-void LinkerScript<ELFT>::writeDataBytes(StringRef Name, uint8_t *Buf) {
+void LinkerScript::writeDataBytes(StringRef Name, uint8_t *Buf) {
int I = getSectionIndex(Name);
if (I == INT_MAX)
return;
- auto *Cmd = dyn_cast<OutputSectionCommand>(Opt.Commands[I].get());
- for (const std::unique_ptr<BaseCommand> &Base : Cmd->Commands)
- if (auto *Data = dyn_cast<BytesDataCommand>(Base.get()))
- writeInt<ELFT>(Buf + Data->Offset, Data->Expression(0), Data->Size);
+ auto *Cmd = dyn_cast<OutputSectionCommand>(Opt.Commands[I]);
+ for (BaseCommand *Base : Cmd->Commands)
+ if (auto *Data = dyn_cast<BytesDataCommand>(Base))
+ writeInt(Buf + Data->Offset, Data->Expression().getValue(), Data->Size);
}
-template <class ELFT> bool LinkerScript<ELFT>::hasLMA(StringRef Name) {
- for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands)
- if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get()))
+bool LinkerScript::hasLMA(StringRef Name) {
+ for (BaseCommand *Base : Opt.Commands)
+ if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base))
if (Cmd->LMAExpr && Cmd->Name == Name)
return true;
return false;
@@ -845,89 +919,35 @@ template <class ELFT> bool LinkerScript<ELFT>::hasLMA(StringRef Name) {
// 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 LinkerScript::getSectionIndex(StringRef Name) {
for (int I = 0, E = Opt.Commands.size(); I != E; ++I)
- if (auto *Cmd = dyn_cast<OutputSectionCommand>(Opt.Commands[I].get()))
+ if (auto *Cmd = dyn_cast<OutputSectionCommand>(Opt.Commands[I]))
if (Cmd->Name == Name)
return I;
return INT_MAX;
}
-template <class ELFT> bool LinkerScript<ELFT>::hasPhdrsCommands() {
- return !Opt.PhdrsCommands.empty();
-}
-
-template <class ELFT>
-const OutputSectionBase *LinkerScript<ELFT>::getOutputSection(const Twine &Loc,
- StringRef Name) {
- static OutputSectionBase FakeSec("", 0, 0);
-
- for (OutputSectionBase *Sec : *OutputSections)
- if (Sec->getName() == Name)
- return Sec;
-
- error(Loc + ": undefined section " + Name);
- return &FakeSec;
-}
-
-// This function is essentially the same as getOutputSection(Name)->Size,
-// but it won't print out an error message if a given section is not found.
-//
-// Linker script does not create an output section if its content is empty.
-// We want to allow SIZEOF(.foo) where .foo is a section which happened to
-// be empty. That is why this function is different from getOutputSection().
-template <class ELFT>
-uint64_t LinkerScript<ELFT>::getOutputSectionSize(StringRef Name) {
- for (OutputSectionBase *Sec : *OutputSections)
- if (Sec->getName() == Name)
- return Sec->Size;
- return 0;
-}
-
-template <class ELFT> uint64_t LinkerScript<ELFT>::getHeaderSize() {
- return elf::getHeaderSize<ELFT>();
-}
-
-template <class ELFT>
-uint64_t LinkerScript<ELFT>::getSymbolValue(const Twine &Loc, StringRef S) {
- if (SymbolBody *B = Symtab<ELFT>::X->find(S))
- return B->getVA<ELFT>();
+ExprValue LinkerScript::getSymbolValue(const Twine &Loc, StringRef S) {
+ if (S == ".")
+ return {CurOutSec, Dot - CurOutSec->Addr};
+ if (SymbolBody *B = findSymbol(S)) {
+ if (auto *D = dyn_cast<DefinedRegular>(B))
+ return {D->Section, D->Value};
+ if (auto *C = dyn_cast<DefinedCommon>(B))
+ return {InX::Common, C->Offset};
+ }
error(Loc + ": symbol not found: " + S);
return 0;
}
-template <class ELFT> bool LinkerScript<ELFT>::isDefined(StringRef S) {
- return Symtab<ELFT>::X->find(S) != nullptr;
-}
-
-template <class ELFT> bool LinkerScript<ELFT>::isAbsolute(StringRef S) {
- SymbolBody *Sym = Symtab<ELFT>::X->find(S);
- auto *DR = dyn_cast_or_null<DefinedRegular<ELFT>>(Sym);
- return DR && !DR->Section;
-}
-
-// Gets section symbol belongs to. Symbol "." doesn't belong to any
-// specific section but isn't absolute at the same time, so we try
-// to find suitable section for it as well.
-template <class ELFT>
-const OutputSectionBase *LinkerScript<ELFT>::getSymbolSection(StringRef S) {
- SymbolBody *Sym = Symtab<ELFT>::X->find(S);
- if (!Sym) {
- if (OutputSections->empty())
- return nullptr;
- return CurOutSec ? CurOutSec : (*OutputSections)[0];
- }
-
- return SymbolTableSection<ELFT>::getOutputSection(Sym);
-}
+bool LinkerScript::isDefined(StringRef S) { return findSymbol(S) != nullptr; }
// 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>
-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());
+std::vector<size_t> LinkerScript::getPhdrIndices(StringRef SectionName) {
+ for (BaseCommand *Base : Opt.Commands) {
+ auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
if (!Cmd || Cmd->Name != SectionName)
continue;
@@ -939,8 +959,7 @@ std::vector<size_t> LinkerScript<ELFT>::getPhdrIndices(StringRef SectionName) {
return {};
}
-template <class ELFT>
-size_t LinkerScript<ELFT>::getPhdrIndex(const Twine &Loc, StringRef PhdrName) {
+size_t LinkerScript::getPhdrIndex(const Twine &Loc, StringRef PhdrName) {
size_t I = 0;
for (PhdrsCommand &Cmd : Opt.PhdrsCommands) {
if (Cmd.Name == PhdrName)
@@ -950,1009 +969,3 @@ size_t LinkerScript<ELFT>::getPhdrIndex(const Twine &Loc, StringRef PhdrName) {
error(Loc + ": section header '" + PhdrName + "' is not listed in PHDRS");
return 0;
}
-
-class elf::ScriptParser final : public ScriptParserBase {
- typedef void (ScriptParser::*Handler)();
-
-public:
- ScriptParser(MemoryBufferRef MB)
- : ScriptParserBase(MB),
- IsUnderSysroot(isUnderSysroot(MB.getBufferIdentifier())) {}
-
- void readLinkerScript();
- void readVersionScript();
- void readDynamicList();
-
-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);
- BytesDataCommand *readBytesDataCommand(StringRef Tok);
- uint32_t readFill();
- OutputSectionCommand *readOutputSectionDescription(StringRef OutSec);
- uint32_t readOutputSectionFiller(StringRef Tok);
- std::vector<StringRef> readOutputSectionPhdrs();
- InputSectionDescription *readInputSectionDescription(StringRef Tok);
- StringMatcher readFilePatterns();
- std::vector<SectionPattern> readInputSectionsList();
- InputSectionDescription *readInputSectionRules(StringRef FilePattern);
- unsigned readPhdrType();
- SortSectionPolicy readSortKind();
- SymbolAssignment *readProvideHidden(bool Provide, bool Hidden);
- SymbolAssignment *readProvideOrAssignment(StringRef Tok);
- void readSort();
- Expr readAssert();
-
- Expr readExpr();
- Expr readExpr1(Expr Lhs, int MinPrec);
- StringRef readParenLiteral();
- Expr readPrimary();
- Expr readTernary(Expr Cond);
- Expr readParenExpr();
-
- // For parsing version script.
- std::vector<SymbolVersion> readVersionExtern();
- void readAnonymousDeclaration();
- void readVersionDeclaration(StringRef VerStr);
- std::vector<SymbolVersion> readSymbols();
- void readLocals();
-
- ScriptConfiguration &Opt = *ScriptConfig;
- bool IsUnderSysroot;
-};
-
-void ScriptParser::readDynamicList() {
- expect("{");
- readAnonymousDeclaration();
- if (!atEOF())
- setError("EOF expected, but got " + next());
-}
-
-void ScriptParser::readVersionScript() {
- readVersionScriptCommand();
- if (!atEOF())
- setError("EOF expected, but got " + next());
-}
-
-void ScriptParser::readVersionScriptCommand() {
- if (consume("{")) {
- readAnonymousDeclaration();
- 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 == "ASSERT") {
- Opt.Commands.emplace_back(new AssertCommand(readAssert()));
- } else 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)) {
- Opt.Commands.emplace_back(Cmd);
- } else {
- setError("unknown directive: " + Tok);
- }
- }
-}
-
-void ScriptParser::addFile(StringRef S) {
- if (IsUnderSysroot && S.startswith("/")) {
- SmallString<128> PathData;
- StringRef Path = (Config->Sysroot + S).toStringRef(PathData);
- if (sys::fs::exists(Path)) {
- Driver->addFile(Saver.save(Path));
- 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 {
- if (Optional<std::string> Path = findFromSearchPaths(S))
- Driver->addFile(Saver.save(*Path));
- else
- setError("unable to find " + S);
- }
-}
-
-void ScriptParser::readAsNeeded() {
- expect("(");
- bool Orig = Config->AsNeeded;
- Config->AsNeeded = true;
- while (!Error && !consume(")"))
- 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("(");
- while (!Error && !consume(")"))
- Config->Undefined.push_back(next());
-}
-
-void ScriptParser::readGroup() {
- expect("(");
- while (!Error && !consume(")")) {
- StringRef Tok = next();
- if (Tok == "AS_NEEDED")
- readAsNeeded();
- else
- addFile(unquote(Tok));
- }
-}
-
-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.
- 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;
- }
- setError("cannot open " + Tok);
-}
-
-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("(");
- skip();
- expect(")");
-}
-
-void ScriptParser::readOutputFormat() {
- // Error checking only for now.
- expect("(");
- skip();
- StringRef Tok = next();
- if (Tok == ")")
- return;
- if (Tok != ",") {
- setError("unexpected token: " + Tok);
- return;
- }
- skip();
- expect(",");
- skip();
- expect(")");
-}
-
-void ScriptParser::readPhdrs() {
- expect("{");
- while (!Error && !consume("}")) {
- 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();
- if (!Config->Nostdlib)
- Config->SearchPaths.push_back(unquote(Tok));
- expect(")");
-}
-
-void ScriptParser::readSections() {
- Opt.HasSections = true;
- // -no-rosegment is used to avoid placing read only non-executable sections in
- // their own segment. We do the same if SECTIONS command is present in linker
- // script. See comment for computeFlags().
- Config->SingleRoRx = true;
-
- expect("{");
- while (!Error && !consume("}")) {
- StringRef Tok = next();
- BaseCommand *Cmd = readProvideOrAssignment(Tok);
- if (!Cmd) {
- if (Tok == "ASSERT")
- Cmd = new AssertCommand(readAssert());
- else
- Cmd = readOutputSectionDescription(Tok);
- }
- Opt.Commands.emplace_back(Cmd);
- }
-}
-
-static int precedence(StringRef Op) {
- return StringSwitch<int>(Op)
- .Cases("*", "/", 5)
- .Cases("+", "-", 4)
- .Cases("<<", ">>", 3)
- .Cases("<", "<=", ">", ">=", "==", "!=", 2)
- .Cases("&", "|", 1)
- .Default(-1);
-}
-
-StringMatcher ScriptParser::readFilePatterns() {
- std::vector<StringRef> V;
- while (!Error && !consume(")"))
- V.push_back(next());
- return StringMatcher(V);
-}
-
-SortSectionPolicy ScriptParser::readSortKind() {
- if (consume("SORT") || consume("SORT_BY_NAME"))
- return SortSectionPolicy::Name;
- if (consume("SORT_BY_ALIGNMENT"))
- return SortSectionPolicy::Alignment;
- if (consume("SORT_BY_INIT_PRIORITY"))
- return SortSectionPolicy::Priority;
- if (consume("SORT_NONE"))
- return SortSectionPolicy::None;
- return SortSectionPolicy::Default;
-}
-
-// Method reads a list of sequence of excluded files and section globs given in
-// a following form: ((EXCLUDE_FILE(file_pattern+))? section_pattern+)+
-// Example: *(.foo.1 EXCLUDE_FILE (*a.o) .foo.2 EXCLUDE_FILE (*b.o) .foo.3)
-// The semantics of that is next:
-// * Include .foo.1 from every file.
-// * Include .foo.2 from every file but a.o
-// * Include .foo.3 from every file but b.o
-std::vector<SectionPattern> ScriptParser::readInputSectionsList() {
- std::vector<SectionPattern> Ret;
- while (!Error && peek() != ")") {
- StringMatcher ExcludeFilePat;
- if (consume("EXCLUDE_FILE")) {
- expect("(");
- ExcludeFilePat = readFilePatterns();
- }
-
- std::vector<StringRef> V;
- while (!Error && peek() != ")" && peek() != "EXCLUDE_FILE")
- V.push_back(next());
-
- if (!V.empty())
- Ret.push_back({std::move(ExcludeFilePat), StringMatcher(V)});
- else
- setError("section pattern is expected");
- }
- return Ret;
-}
-
-// Reads contents of "SECTIONS" directive. That directive contains a
-// list of glob patterns for input sections. The grammar is as follows.
-//
-// <patterns> ::= <section-list>
-// | <sort> "(" <section-list> ")"
-// | <sort> "(" <sort> "(" <section-list> ")" ")"
-//
-// <sort> ::= "SORT" | "SORT_BY_NAME" | "SORT_BY_ALIGNMENT"
-// | "SORT_BY_INIT_PRIORITY" | "SORT_NONE"
-//
-// <section-list> is parsed by readInputSectionsList().
-InputSectionDescription *
-ScriptParser::readInputSectionRules(StringRef FilePattern) {
- auto *Cmd = new InputSectionDescription(FilePattern);
- expect("(");
- while (!Error && !consume(")")) {
- SortSectionPolicy Outer = readSortKind();
- SortSectionPolicy Inner = SortSectionPolicy::Default;
- std::vector<SectionPattern> V;
- if (Outer != SortSectionPolicy::Default) {
- expect("(");
- Inner = readSortKind();
- if (Inner != SortSectionPolicy::Default) {
- expect("(");
- V = readInputSectionsList();
- expect(")");
- } else {
- V = readInputSectionsList();
- }
- expect(")");
- } else {
- V = readInputSectionsList();
- }
-
- for (SectionPattern &Pat : V) {
- Pat.SortInner = Inner;
- Pat.SortOuter = Outer;
- }
-
- std::move(V.begin(), V.end(), std::back_inserter(Cmd->SectionPatterns));
- }
- 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);
- 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;
- };
-}
-
-// 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
-uint32_t ScriptParser::readFill() {
- expect("(");
- uint32_t V = readOutputSectionFiller(next());
- expect(")");
- expect(";");
- return V;
-}
-
-OutputSectionCommand *
-ScriptParser::readOutputSectionDescription(StringRef OutSec) {
- OutputSectionCommand *Cmd = new OutputSectionCommand(OutSec);
- Cmd->Location = getCurrentLocation();
-
- // Read an address expression.
- // https://sourceware.org/binutils/docs/ld/Output-Section-Address.html#Output-Section-Address
- if (peek() != ":")
- Cmd->AddrExpr = readExpr();
-
- expect(":");
-
- if (consume("AT"))
- Cmd->LMAExpr = readParenExpr();
- if (consume("ALIGN"))
- Cmd->AlignExpr = readParenExpr();
- if (consume("SUBALIGN"))
- Cmd->SubalignExpr = readParenExpr();
-
- // Parse constraints.
- if (consume("ONLY_IF_RO"))
- Cmd->Constraint = ConstraintKind::ReadOnly;
- if (consume("ONLY_IF_RW"))
- Cmd->Constraint = ConstraintKind::ReadWrite;
- expect("{");
-
- while (!Error && !consume("}")) {
- StringRef Tok = next();
- if (SymbolAssignment *Assignment = readProvideOrAssignment(Tok)) {
- Cmd->Commands.emplace_back(Assignment);
- } else if (BytesDataCommand *Data = readBytesDataCommand(Tok)) {
- Cmd->Commands.emplace_back(Data);
- } else if (Tok == "ASSERT") {
- Cmd->Commands.emplace_back(new AssertCommand(readAssert()));
- expect(";");
- } 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 (consume("="))
- Cmd->Filler = readOutputSectionFiller(next());
- else 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.
-uint32_t ScriptParser::readOutputSectionFiller(StringRef Tok) {
- uint32_t V;
- if (!Tok.getAsInteger(0, V))
- return V;
- setError("invalid filler expression: " + Tok);
- return 0;
-}
-
-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) {
- 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);
- }
- return Cmd;
-}
-
-static uint64_t getSymbolValue(const Twine &Loc, StringRef S, uint64_t Dot) {
- if (S == ".")
- return Dot;
- return ScriptBase->getSymbolValue(Loc, S);
-}
-
-static bool isAbsolute(StringRef S) {
- if (S == ".")
- return false;
- return ScriptBase->isAbsolute(S);
-}
-
-SymbolAssignment *ScriptParser::readAssignment(StringRef Name) {
- StringRef Op = next();
- Expr E;
- assert(Op == "=" || Op == "+=");
- if (consume("ABSOLUTE")) {
- // The RHS may be something like "ABSOLUTE(.) & 0xff".
- // Call readExpr1 to read the whole expression.
- E = readExpr1(readParenExpr(), 0);
- E.IsAbsolute = [] { return true; };
- } else {
- E = readExpr();
- }
- if (Op == "+=") {
- std::string Loc = getCurrentLocation();
- E = [=](uint64_t Dot) {
- return getSymbolValue(Loc, Name, Dot) + E(Dot);
- };
- }
- return new SymbolAssignment(Name, E);
-}
-
-// 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); },
- [=] { return L.IsAbsolute() && R.IsAbsolute(); },
- [=] {
- const OutputSectionBase *S = L.Section();
- return S ? S : R.Section();
- }};
- 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); };
- if (Op == "|")
- return [=](uint64_t Dot) { return L(Dot) | R(Dot); };
- llvm_unreachable("invalid operator");
-}
-
-// 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.
- if (consume("?"))
- return readTernary(Lhs);
- StringRef Op1 = peek();
- if (precedence(Op1) < MinPrec)
- break;
- skip();
- 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;
- Rhs = readExpr1(Rhs, precedence(Op2));
- }
-
- Lhs = combine(Op1, Lhs, Rhs);
- }
- return Lhs;
-}
-
-uint64_t static getConstant(StringRef S) {
- if (S == "COMMONPAGESIZE")
- return Target->PageSize;
- if (S == "MAXPAGESIZE")
- return Config->MaxPageSize;
- error("unknown constant: " + S);
- return 0;
-}
-
-// 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) {
- // Negative number
- if (Tok.startswith("-")) {
- if (!readInteger(Tok.substr(1), Result))
- return false;
- Result = -Result;
- return true;
- }
-
- // Hexadecimal
- if (Tok.startswith_lower("0x"))
- return !Tok.substr(2).getAsInteger(16, Result);
- if (Tok.endswith_lower("H"))
- return !Tok.drop_back().getAsInteger(16, Result);
-
- // Decimal
- 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;
-}
-
-BytesDataCommand *ScriptParser::readBytesDataCommand(StringRef Tok) {
- int Size = StringSwitch<unsigned>(Tok)
- .Case("BYTE", 1)
- .Case("SHORT", 2)
- .Case("LONG", 4)
- .Case("QUAD", 8)
- .Default(-1);
- if (Size == -1)
- return nullptr;
-
- return new BytesDataCommand(readParenExpr(), Size);
-}
-
-StringRef ScriptParser::readParenLiteral() {
- expect("(");
- StringRef Tok = next();
- expect(")");
- return Tok;
-}
-
-Expr ScriptParser::readPrimary() {
- if (peek() == "(")
- return readParenExpr();
-
- StringRef Tok = next();
- std::string Location = getCurrentLocation();
-
- if (Tok == "~") {
- Expr E = readPrimary();
- return [=](uint64_t Dot) { return ~E(Dot); };
- }
- if (Tok == "-") {
- Expr E = readPrimary();
- return [=](uint64_t Dot) { return -E(Dot); };
- }
-
- // Built-in functions are parsed here.
- // https://sourceware.org/binutils/docs/ld/Builtin-Functions.html.
- if (Tok == "ADDR") {
- StringRef Name = readParenLiteral();
- return {[=](uint64_t Dot) {
- return ScriptBase->getOutputSection(Location, Name)->Addr;
- },
- [=] { return false; },
- [=] { return ScriptBase->getOutputSection(Location, Name); }};
- }
- if (Tok == "LOADADDR") {
- StringRef Name = readParenLiteral();
- return [=](uint64_t Dot) {
- return ScriptBase->getOutputSection(Location, Name)->getLMA();
- };
- }
- if (Tok == "ASSERT")
- return readAssert();
- if (Tok == "ALIGN") {
- expect("(");
- Expr E = readExpr();
- if (consume(",")) {
- Expr E2 = readExpr();
- expect(")");
- return [=](uint64_t Dot) { return alignTo(E(Dot), E2(Dot)); };
- }
- expect(")");
- return [=](uint64_t Dot) { return alignTo(Dot, E(Dot)); };
- }
- if (Tok == "CONSTANT") {
- StringRef Name = readParenLiteral();
- return [=](uint64_t Dot) { return getConstant(Name); };
- }
- if (Tok == "DEFINED") {
- StringRef Name = readParenLiteral();
- return [=](uint64_t Dot) { return ScriptBase->isDefined(Name) ? 1 : 0; };
- }
- if (Tok == "SEGMENT_START") {
- expect("(");
- skip();
- expect(",");
- Expr E = readExpr();
- expect(")");
- return [=](uint64_t Dot) { return E(Dot); };
- }
- if (Tok == "DATA_SEGMENT_ALIGN") {
- expect("(");
- Expr E = readExpr();
- expect(",");
- readExpr();
- expect(")");
- return [=](uint64_t Dot) { return alignTo(Dot, E(Dot)); };
- }
- 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") {
- StringRef Name = readParenLiteral();
- return [=](uint64_t Dot) { return ScriptBase->getOutputSectionSize(Name); };
- }
- if (Tok == "ALIGNOF") {
- StringRef Name = readParenLiteral();
- return [=](uint64_t Dot) {
- return ScriptBase->getOutputSection(Location, Name)->Addralign;
- };
- }
- if (Tok == "SIZEOF_HEADERS")
- return [=](uint64_t Dot) { return ScriptBase->getHeaderSize(); };
-
- // 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(Location, Tok, Dot); },
- [=] { return isAbsolute(Tok); },
- [=] { return ScriptBase->getSymbolSection(Tok); }};
-}
-
-Expr ScriptParser::readTernary(Expr Cond) {
- 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();
- Phdrs.push_back((Tok.size() == 1) ? next() : Tok.substr(1));
- }
- return Phdrs;
-}
-
-// Read a program header type name. The next token must be a
-// name of a program header type or a constant (e.g. "0x3").
-unsigned ScriptParser::readPhdrType() {
- StringRef Tok = next();
- uint64_t Val;
- if (readInteger(Tok, Val))
- return Val;
-
- 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)
- .Case("PT_OPENBSD_RANDOMIZE", PT_OPENBSD_RANDOMIZE)
- .Case("PT_OPENBSD_WXNEEDED", PT_OPENBSD_WXNEEDED)
- .Case("PT_OPENBSD_BOOTDATA", PT_OPENBSD_BOOTDATA)
- .Default(-1);
-
- if (Ret == (unsigned)-1) {
- setError("invalid program header type: " + Tok);
- return PT_NULL;
- }
- return Ret;
-}
-
-// Reads a list of symbols, e.g. "{ global: foo; bar; local: *; };".
-void ScriptParser::readAnonymousDeclaration() {
- // Read global symbols first. "global:" is default, so if there's
- // no label, we assume global symbols.
- if (consume("global:") || peek() != "local:")
- Config->VersionScriptGlobals = readSymbols();
-
- readLocals();
- expect("}");
- expect(";");
-}
-
-void ScriptParser::readLocals() {
- if (!consume("local:"))
- return;
- std::vector<SymbolVersion> Locals = readSymbols();
- for (SymbolVersion V : Locals) {
- if (V.Name == "*") {
- Config->DefaultSymbolVersion = VER_NDX_LOCAL;
- continue;
- }
- Config->VersionScriptLocals.push_back(V);
- }
-}
-
-// Reads a list of symbols, e.g. "VerStr { global: foo; bar; local: *; };".
-void ScriptParser::readVersionDeclaration(StringRef VerStr) {
- // Identifiers start at 2 because 0 and 1 are reserved
- // for VER_NDX_LOCAL and VER_NDX_GLOBAL constants.
- uint16_t VersionId = Config->VersionDefinitions.size() + 2;
- Config->VersionDefinitions.push_back({VerStr, VersionId});
-
- // Read global symbols.
- if (consume("global:") || peek() != "local:")
- Config->VersionDefinitions.back().Globals = readSymbols();
-
- readLocals();
- 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 hint; the runtime doesn't care about it
- // at all. In LLD, we simply ignore it.
- if (peek() != ";")
- skip();
- expect(";");
-}
-
-// Reads a list of symbols for a versions cript.
-std::vector<SymbolVersion> ScriptParser::readSymbols() {
- std::vector<SymbolVersion> Ret;
- for (;;) {
- if (consume("extern")) {
- for (SymbolVersion V : readVersionExtern())
- Ret.push_back(V);
- continue;
- }
-
- if (peek() == "}" || peek() == "local:" || Error)
- break;
- StringRef Tok = next();
- Ret.push_back({unquote(Tok), false, hasWildcard(Tok)});
- expect(";");
- }
- return Ret;
-}
-
-// Reads an "extern C++" directive, e.g.,
-// "extern "C++" { ns::*; "f(int, double)"; };"
-std::vector<SymbolVersion> ScriptParser::readVersionExtern() {
- StringRef Tok = next();
- bool IsCXX = Tok == "\"C++\"";
- if (!IsCXX && Tok != "\"C\"")
- setError("Unknown language");
- expect("{");
-
- std::vector<SymbolVersion> Ret;
- while (!Error && peek() != "}") {
- StringRef Tok = next();
- bool HasWildcard = !Tok.startswith("\"") && hasWildcard(Tok);
- Ret.push_back({unquote(Tok), IsCXX, HasWildcard});
- expect(";");
- }
-
- expect("}");
- expect(";");
- return Ret;
-}
-
-void elf::readLinkerScript(MemoryBufferRef MB) {
- ScriptParser(MB).readLinkerScript();
-}
-
-void elf::readVersionScript(MemoryBufferRef MB) {
- ScriptParser(MB).readVersionScript();
-}
-
-void elf::readDynamicList(MemoryBufferRef MB) {
- ScriptParser(MB).readDynamicList();
-}
-
-template class elf::LinkerScript<ELF32LE>;
-template class elf::LinkerScript<ELF32BE>;
-template class elf::LinkerScript<ELF64LE>;
-template class elf::LinkerScript<ELF64BE>;