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-rw-r--r--ELF/OutputSections.cpp174
1 files changed, 100 insertions, 74 deletions
diff --git a/ELF/OutputSections.cpp b/ELF/OutputSections.cpp
index 30ec83f4d3b1f..2aa814524d6be 100644
--- a/ELF/OutputSections.cpp
+++ b/ELF/OutputSections.cpp
@@ -21,21 +21,20 @@ using namespace llvm::ELF;
using namespace lld;
using namespace lld::elf2;
-bool lld::elf2::HasGotOffRel = false;
+bool elf2::HasGotOffRel = false;
template <class ELFT>
-OutputSectionBase<ELFT>::OutputSectionBase(StringRef Name, uint32_t sh_type,
- uintX_t sh_flags)
+OutputSectionBase<ELFT>::OutputSectionBase(StringRef Name, uint32_t Type,
+ uintX_t Flags)
: Name(Name) {
memset(&Header, 0, sizeof(Elf_Shdr));
- Header.sh_type = sh_type;
- Header.sh_flags = sh_flags;
+ Header.sh_type = Type;
+ Header.sh_flags = Flags;
}
template <class ELFT>
GotPltSection<ELFT>::GotPltSection()
- : OutputSectionBase<ELFT>(".got.plt", llvm::ELF::SHT_PROGBITS,
- llvm::ELF::SHF_ALLOC | llvm::ELF::SHF_WRITE) {
+ : OutputSectionBase<ELFT>(".got.plt", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE) {
this->Header.sh_addralign = sizeof(uintX_t);
}
@@ -70,10 +69,9 @@ template <class ELFT> void GotPltSection<ELFT>::writeTo(uint8_t *Buf) {
template <class ELFT>
GotSection<ELFT>::GotSection()
- : OutputSectionBase<ELFT>(".got", llvm::ELF::SHT_PROGBITS,
- llvm::ELF::SHF_ALLOC | llvm::ELF::SHF_WRITE) {
+ : OutputSectionBase<ELFT>(".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE) {
if (Config->EMachine == EM_MIPS)
- this->Header.sh_flags |= llvm::ELF::SHF_MIPS_GPREL;
+ this->Header.sh_flags |= SHF_MIPS_GPREL;
this->Header.sh_addralign = sizeof(uintX_t);
}
@@ -120,7 +118,7 @@ const SymbolBody *GotSection<ELFT>::getMipsFirstGlobalEntry() const {
template <class ELFT>
unsigned GotSection<ELFT>::getMipsLocalEntriesNum() const {
- // TODO: Update when the suppoort of GOT entries for local symbols is added.
+ // TODO: Update when the support of GOT entries for local symbols is added.
return Target->getGotHeaderEntriesNum();
}
@@ -151,8 +149,7 @@ template <class ELFT> void GotSection<ELFT>::writeTo(uint8_t *Buf) {
template <class ELFT>
PltSection<ELFT>::PltSection()
- : OutputSectionBase<ELFT>(".plt", llvm::ELF::SHT_PROGBITS,
- llvm::ELF::SHF_ALLOC | llvm::ELF::SHF_EXECINSTR) {
+ : OutputSectionBase<ELFT>(".plt", SHT_PROGBITS, SHF_ALLOC | SHF_EXECINSTR) {
this->Header.sh_addralign = 16;
}
@@ -199,9 +196,7 @@ template <class ELFT> void PltSection<ELFT>::finalize() {
template <class ELFT>
RelocationSection<ELFT>::RelocationSection(StringRef Name, bool IsRela)
- : OutputSectionBase<ELFT>(Name,
- IsRela ? llvm::ELF::SHT_RELA : llvm::ELF::SHT_REL,
- llvm::ELF::SHF_ALLOC),
+ : OutputSectionBase<ELFT>(Name, IsRela ? SHT_RELA : SHT_REL, SHF_ALLOC),
IsRela(IsRela) {
this->Header.sh_entsize = IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel);
this->Header.sh_addralign = ELFT::Is64Bits ? 8 : 4;
@@ -328,15 +323,14 @@ template <class ELFT> void RelocationSection<ELFT>::finalize() {
template <class ELFT>
InterpSection<ELFT>::InterpSection()
- : OutputSectionBase<ELFT>(".interp", llvm::ELF::SHT_PROGBITS,
- llvm::ELF::SHF_ALLOC) {
+ : OutputSectionBase<ELFT>(".interp", SHT_PROGBITS, SHF_ALLOC) {
this->Header.sh_size = Config->DynamicLinker.size() + 1;
this->Header.sh_addralign = 1;
}
template <class ELFT>
void OutputSectionBase<ELFT>::writeHeaderTo(Elf_Shdr *SHdr) {
- Header.sh_name = Out<ELFT>::ShStrTab->getOffset(Name);
+ Header.sh_name = Out<ELFT>::ShStrTab->addString(Name);
*SHdr = Header;
}
@@ -346,8 +340,7 @@ template <class ELFT> void InterpSection<ELFT>::writeTo(uint8_t *Buf) {
template <class ELFT>
HashTableSection<ELFT>::HashTableSection()
- : OutputSectionBase<ELFT>(".hash", llvm::ELF::SHT_HASH,
- llvm::ELF::SHF_ALLOC) {
+ : OutputSectionBase<ELFT>(".hash", SHT_HASH, SHF_ALLOC) {
this->Header.sh_entsize = sizeof(Elf_Word);
this->Header.sh_addralign = sizeof(Elf_Word);
}
@@ -404,8 +397,7 @@ static uint32_t hashGnu(StringRef Name) {
template <class ELFT>
GnuHashTableSection<ELFT>::GnuHashTableSection()
- : OutputSectionBase<ELFT>(".gnu.hash", llvm::ELF::SHT_GNU_HASH,
- llvm::ELF::SHF_ALLOC) {
+ : OutputSectionBase<ELFT>(".gnu.hash", SHT_GNU_HASH, SHF_ALLOC) {
this->Header.sh_entsize = ELFT::Is64Bits ? 0 : 4;
this->Header.sh_addralign = ELFT::Is64Bits ? 8 : 4;
}
@@ -545,8 +537,7 @@ void GnuHashTableSection<ELFT>::addSymbols(std::vector<SymbolBody *> &Symbols) {
template <class ELFT>
DynamicSection<ELFT>::DynamicSection(SymbolTable<ELFT> &SymTab)
- : OutputSectionBase<ELFT>(".dynamic", llvm::ELF::SHT_DYNAMIC,
- llvm::ELF::SHF_ALLOC | llvm::ELF::SHF_WRITE),
+ : OutputSectionBase<ELFT>(".dynamic", SHT_DYNAMIC, SHF_ALLOC | SHF_WRITE),
SymTab(SymTab) {
Elf_Shdr &Header = this->Header;
Header.sh_addralign = ELFT::Is64Bits ? 8 : 4;
@@ -556,7 +547,7 @@ DynamicSection<ELFT>::DynamicSection(SymbolTable<ELFT> &SymTab)
// See "Special Section" in Chapter 4 in the following document:
// ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
if (Config->EMachine == EM_MIPS)
- Header.sh_flags = llvm::ELF::SHF_ALLOC;
+ Header.sh_flags = SHF_ALLOC;
}
template <class ELFT> void DynamicSection<ELFT>::finalize() {
@@ -590,12 +581,12 @@ template <class ELFT> void DynamicSection<ELFT>::finalize() {
if (!Config->RPath.empty()) {
++NumEntries; // DT_RUNPATH / DT_RPATH
- Out<ELFT>::DynStrTab->add(Config->RPath);
+ Out<ELFT>::DynStrTab->reserve(Config->RPath);
}
if (!Config->SoName.empty()) {
++NumEntries; // DT_SONAME
- Out<ELFT>::DynStrTab->add(Config->SoName);
+ Out<ELFT>::DynStrTab->reserve(Config->SoName);
}
if (PreInitArraySec)
@@ -608,7 +599,7 @@ template <class ELFT> void DynamicSection<ELFT>::finalize() {
for (const std::unique_ptr<SharedFile<ELFT>> &F : SymTab.getSharedFiles()) {
if (!F->isNeeded())
continue;
- Out<ELFT>::DynStrTab->add(F->getSoName());
+ Out<ELFT>::DynStrTab->reserve(F->getSoName());
++NumEntries;
}
@@ -696,7 +687,7 @@ template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t *Buf) {
WritePtr(DT_SYMTAB, Out<ELFT>::DynSymTab->getVA());
WritePtr(DT_SYMENT, sizeof(Elf_Sym));
WritePtr(DT_STRTAB, Out<ELFT>::DynStrTab->getVA());
- WriteVal(DT_STRSZ, Out<ELFT>::DynStrTab->data().size());
+ WriteVal(DT_STRSZ, Out<ELFT>::DynStrTab->getSize());
if (Out<ELFT>::GnuHashTab)
WritePtr(DT_GNU_HASH, Out<ELFT>::GnuHashTab->getVA());
if (Out<ELFT>::HashTab)
@@ -712,10 +703,10 @@ template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t *Buf) {
// DT_RPATH is used for indirect dependencies as well.
if (!Config->RPath.empty())
WriteVal(Config->EnableNewDtags ? DT_RUNPATH : DT_RPATH,
- Out<ELFT>::DynStrTab->getOffset(Config->RPath));
+ Out<ELFT>::DynStrTab->addString(Config->RPath));
if (!Config->SoName.empty())
- WriteVal(DT_SONAME, Out<ELFT>::DynStrTab->getOffset(Config->SoName));
+ WriteVal(DT_SONAME, Out<ELFT>::DynStrTab->addString(Config->SoName));
auto WriteArray = [&](int32_t T1, int32_t T2,
const OutputSectionBase<ELFT> *Sec) {
@@ -730,7 +721,7 @@ template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t *Buf) {
for (const std::unique_ptr<SharedFile<ELFT>> &F : SymTab.getSharedFiles())
if (F->isNeeded())
- WriteVal(DT_NEEDED, Out<ELFT>::DynStrTab->getOffset(F->getSoName()));
+ WriteVal(DT_NEEDED, Out<ELFT>::DynStrTab->addString(F->getSoName()));
if (InitSym)
WritePtr(DT_INIT, getSymVA<ELFT>(*InitSym));
@@ -765,9 +756,9 @@ template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t *Buf) {
}
template <class ELFT>
-OutputSection<ELFT>::OutputSection(StringRef Name, uint32_t sh_type,
- uintX_t sh_flags)
- : OutputSectionBase<ELFT>(Name, sh_type, sh_flags) {}
+OutputSection<ELFT>::OutputSection(StringRef Name, uint32_t Type,
+ uintX_t Flags)
+ : OutputSectionBase<ELFT>(Name, Type, Flags) {}
template <class ELFT>
void OutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
@@ -779,14 +770,14 @@ void OutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
this->Header.sh_addralign = Align;
uintX_t Off = this->Header.sh_size;
- Off = RoundUpToAlignment(Off, Align);
+ Off = align(Off, Align);
S->OutSecOff = Off;
Off += S->getSize();
this->Header.sh_size = Off;
}
template <class ELFT>
-typename ELFFile<ELFT>::uintX_t lld::elf2::getSymVA(const SymbolBody &S) {
+typename ELFFile<ELFT>::uintX_t elf2::getSymVA(const SymbolBody &S) {
switch (S.kind()) {
case SymbolBody::DefinedSyntheticKind: {
auto &D = cast<DefinedSynthetic<ELFT>>(S);
@@ -797,6 +788,11 @@ typename ELFFile<ELFT>::uintX_t lld::elf2::getSymVA(const SymbolBody &S) {
InputSectionBase<ELFT> *SC = DR.Section;
if (!SC)
return DR.Sym.st_value;
+
+ // Symbol offsets for AMDGPU need to be the offset in bytes of the symbol
+ // from the beginning of the section.
+ if (Config->EMachine == EM_AMDGPU)
+ return SC->getOffset(DR.Sym);
if (DR.Sym.getType() == STT_TLS)
return SC->OutSec->getVA() + SC->getOffset(DR.Sym) -
Out<ELFT>::TlsPhdr->p_vaddr;
@@ -824,9 +820,9 @@ typename ELFFile<ELFT>::uintX_t lld::elf2::getSymVA(const SymbolBody &S) {
// For non-local symbols, use getSymVA instead.
template <class ELFT, bool IsRela>
typename ELFFile<ELFT>::uintX_t
-lld::elf2::getLocalRelTarget(const ObjectFile<ELFT> &File,
- const Elf_Rel_Impl<ELFT, IsRela> &RI,
- typename ELFFile<ELFT>::uintX_t Addend) {
+elf2::getLocalRelTarget(const ObjectFile<ELFT> &File,
+ const Elf_Rel_Impl<ELFT, IsRela> &RI,
+ typename ELFFile<ELFT>::uintX_t Addend) {
typedef typename ELFFile<ELFT>::Elf_Sym Elf_Sym;
typedef typename ELFFile<ELFT>::uintX_t uintX_t;
@@ -868,7 +864,7 @@ lld::elf2::getLocalRelTarget(const ObjectFile<ELFT> &File,
// Returns true if a symbol can be replaced at load-time by a symbol
// with the same name defined in other ELF executable or DSO.
-bool lld::elf2::canBePreempted(const SymbolBody *Body, bool NeedsGot) {
+bool elf2::canBePreempted(const SymbolBody *Body, bool NeedsGot) {
if (!Body)
return false; // Body is a local symbol.
if (Body->isShared())
@@ -910,9 +906,9 @@ template <class ELFT> void OutputSection<ELFT>::writeTo(uint8_t *Buf) {
}
template <class ELFT>
-EHOutputSection<ELFT>::EHOutputSection(StringRef Name, uint32_t sh_type,
- uintX_t sh_flags)
- : OutputSectionBase<ELFT>(Name, sh_type, sh_flags) {}
+EHOutputSection<ELFT>::EHOutputSection(StringRef Name, uint32_t Type,
+ uintX_t Flags)
+ : OutputSectionBase<ELFT>(Name, Type, Flags) {}
template <class ELFT>
EHRegion<ELFT>::EHRegion(EHInputSection<ELFT> *S, unsigned Index)
@@ -980,7 +976,7 @@ void EHOutputSection<ELFT>::addSectionAux(
auto P = CieMap.insert(std::make_pair(CieInfo, Cies.size()));
if (P.second) {
Cies.push_back(C);
- this->Header.sh_size += RoundUpToAlignment(Length, sizeof(uintX_t));
+ this->Header.sh_size += align(Length, sizeof(uintX_t));
}
OffsetToIndex[Offset] = P.first->second;
} else {
@@ -993,7 +989,7 @@ void EHOutputSection<ELFT>::addSectionAux(
if (I == OffsetToIndex.end())
error("Invalid CIE reference");
Cies[I->second].Fdes.push_back(EHRegion<ELFT>(S, Index));
- this->Header.sh_size += RoundUpToAlignment(Length, sizeof(uintX_t));
+ this->Header.sh_size += align(Length, sizeof(uintX_t));
}
}
@@ -1046,7 +1042,7 @@ static typename ELFFile<ELFT>::uintX_t writeAlignedCieOrFde(StringRef Data,
uint8_t *Buf) {
typedef typename ELFFile<ELFT>::uintX_t uintX_t;
const endianness E = ELFT::TargetEndianness;
- uint64_t Len = RoundUpToAlignment(Data.size(), sizeof(uintX_t));
+ uint64_t Len = align(Data.size(), sizeof(uintX_t));
write32<E>(Buf, Len - 4);
memcpy(Buf + 4, Data.data() + 4, Data.size() - 4);
return Len;
@@ -1083,9 +1079,9 @@ template <class ELFT> void EHOutputSection<ELFT>::writeTo(uint8_t *Buf) {
}
template <class ELFT>
-MergeOutputSection<ELFT>::MergeOutputSection(StringRef Name, uint32_t sh_type,
- uintX_t sh_flags)
- : OutputSectionBase<ELFT>(Name, sh_type, sh_flags) {}
+MergeOutputSection<ELFT>::MergeOutputSection(StringRef Name, uint32_t Type,
+ uintX_t Flags)
+ : OutputSectionBase<ELFT>(Name, Type, Flags) {}
template <class ELFT> void MergeOutputSection<ELFT>::writeTo(uint8_t *Buf) {
if (shouldTailMerge()) {
@@ -1165,21 +1161,50 @@ template <class ELFT> void MergeOutputSection<ELFT>::finalize() {
template <class ELFT>
StringTableSection<ELFT>::StringTableSection(StringRef Name, bool Dynamic)
- : OutputSectionBase<ELFT>(Name, llvm::ELF::SHT_STRTAB,
- Dynamic ? (uintX_t)llvm::ELF::SHF_ALLOC : 0),
+ : OutputSectionBase<ELFT>(Name, SHT_STRTAB,
+ Dynamic ? (uintX_t)SHF_ALLOC : 0),
Dynamic(Dynamic) {
this->Header.sh_addralign = 1;
}
+// String tables are created in two phases. First you call reserve()
+// to reserve room in the string table, and then call addString() to actually
+// add that string.
+//
+// Why two phases? We want to know the size of the string table as early as
+// possible to fix file layout. So we have separated finalize(), which
+// determines the size of the section, from writeTo(), which writes the section
+// contents to the output buffer. If we merge reserve() with addString(),
+// we need a plumbing work for finalize() and writeTo() so that offsets
+// we obtained in the former function can be written in the latter.
+// This design eliminated that need.
+template <class ELFT> void StringTableSection<ELFT>::reserve(StringRef S) {
+ Reserved += S.size() + 1; // +1 for NUL
+}
+
+// Adds a string to the string table. You must call reserve() with the
+// same string before calling addString().
+template <class ELFT> size_t StringTableSection<ELFT>::addString(StringRef S) {
+ size_t Pos = Used;
+ Strings.push_back(S);
+ Used += S.size() + 1;
+ Reserved -= S.size() + 1;
+ assert((int64_t)Reserved >= 0);
+ return Pos;
+}
+
template <class ELFT> void StringTableSection<ELFT>::writeTo(uint8_t *Buf) {
- StringRef Data = StrTabBuilder.data();
- memcpy(Buf, Data.data(), Data.size());
+ // ELF string tables start with NUL byte, so advance the pointer by one.
+ ++Buf;
+ for (StringRef S : Strings) {
+ memcpy(Buf, S.data(), S.size());
+ Buf += S.size() + 1;
+ }
}
template <class ELFT>
-bool lld::elf2::shouldKeepInSymtab(const ObjectFile<ELFT> &File,
- StringRef SymName,
- const typename ELFFile<ELFT>::Elf_Sym &Sym) {
+bool elf2::shouldKeepInSymtab(const ObjectFile<ELFT> &File, StringRef SymName,
+ const typename ELFFile<ELFT>::Elf_Sym &Sym) {
if (Sym.getType() == STT_SECTION)
return false;
@@ -1208,16 +1233,12 @@ bool lld::elf2::shouldKeepInSymtab(const ObjectFile<ELFT> &File,
template <class ELFT>
SymbolTableSection<ELFT>::SymbolTableSection(
SymbolTable<ELFT> &Table, StringTableSection<ELFT> &StrTabSec)
- : OutputSectionBase<ELFT>(
- StrTabSec.isDynamic() ? ".dynsym" : ".symtab",
- StrTabSec.isDynamic() ? llvm::ELF::SHT_DYNSYM : llvm::ELF::SHT_SYMTAB,
- StrTabSec.isDynamic() ? (uintX_t)llvm::ELF::SHF_ALLOC : 0),
+ : OutputSectionBase<ELFT>(StrTabSec.isDynamic() ? ".dynsym" : ".symtab",
+ StrTabSec.isDynamic() ? SHT_DYNSYM : SHT_SYMTAB,
+ StrTabSec.isDynamic() ? (uintX_t)SHF_ALLOC : 0),
Table(Table), StrTabSec(StrTabSec) {
- typedef OutputSectionBase<ELFT> Base;
- typename Base::Elf_Shdr &Header = this->Header;
-
- Header.sh_entsize = sizeof(Elf_Sym);
- Header.sh_addralign = ELFT::Is64Bits ? 8 : 4;
+ this->Header.sh_entsize = sizeof(Elf_Sym);
+ this->Header.sh_addralign = ELFT::Is64Bits ? 8 : 4;
}
// Orders symbols according to their positions in the GOT,
@@ -1259,14 +1280,14 @@ template <class ELFT> void SymbolTableSection<ELFT>::finalize() {
template <class ELFT>
void SymbolTableSection<ELFT>::addLocalSymbol(StringRef Name) {
- StrTabSec.add(Name);
+ StrTabSec.reserve(Name);
++NumVisible;
++NumLocals;
}
template <class ELFT>
void SymbolTableSection<ELFT>::addSymbol(SymbolBody *Body) {
- StrTabSec.add(Body->getName());
+ StrTabSec.reserve(Body->getName());
Symbols.push_back(Body);
++NumVisible;
}
@@ -1306,9 +1327,13 @@ void SymbolTableSection<ELFT>::writeLocalSymbols(uint8_t *&Buf) {
continue;
const OutputSectionBase<ELFT> *OutSec = Section->OutSec;
ESym->st_shndx = OutSec->SectionIndex;
- VA += OutSec->getVA() + Section->getOffset(Sym);
+ VA = Section->getOffset(Sym);
+ // Symbol offsets for AMDGPU need to be the offset in bytes of the
+ // symbol from the beginning of the section.
+ if (Config->EMachine != EM_AMDGPU)
+ VA += OutSec->getVA();
}
- ESym->st_name = StrTabSec.getOffset(SymName);
+ ESym->st_name = StrTabSec.addString(SymName);
ESym->st_size = Sym.st_size;
ESym->setBindingAndType(Sym.getBinding(), Sym.getType());
ESym->st_value = VA;
@@ -1363,7 +1388,7 @@ void SymbolTableSection<ELFT>::writeGlobalSymbols(uint8_t *Buf) {
}
StringRef Name = Body->getName();
- ESym->st_name = StrTabSec.getOffset(Name);
+ ESym->st_name = StrTabSec.addString(Name);
unsigned char Type = STT_NOTYPE;
uintX_t Size = 0;
@@ -1413,13 +1438,14 @@ template <class ELFT>
void MipsReginfoOutputSection<ELFT>::writeTo(uint8_t *Buf) {
auto *R = reinterpret_cast<Elf_Mips_RegInfo *>(Buf);
R->ri_gp_value = getMipsGpAddr<ELFT>();
- R->ri_gprmask = GeneralMask;
+ R->ri_gprmask = GprMask;
}
template <class ELFT>
void MipsReginfoOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
+ // Copy input object file's .reginfo gprmask to output.
auto *S = cast<MipsReginfoInputSection<ELFT>>(C);
- GeneralMask |= S->getGeneralMask();
+ GprMask |= S->Reginfo->ri_gprmask;
}
namespace lld {
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-22 01:33:45 +0000