[lld] r263386 - ELF: Redefine canBeDefined as a member function of SymbolBody.
Rui Ueyama via llvm-commits
llvm-commits at lists.llvm.org
Sun Mar 13 12:48:19 PDT 2016
Author: ruiu
Date: Sun Mar 13 14:48:18 2016
New Revision: 263386
URL: http://llvm.org/viewvc/llvm-project?rev=263386&view=rev
Log:
ELF: Redefine canBeDefined as a member function of SymbolBody.
We want to make SymbolBody the central place to query symbol information.
This patch also renames canBePreempted to isPreemptible because I feel that
the latter is slightly better (the former is three words and the latter
is two words.)
Modified:
lld/trunk/ELF/InputSection.cpp
lld/trunk/ELF/OutputSections.cpp
lld/trunk/ELF/OutputSections.h
lld/trunk/ELF/Symbols.cpp
lld/trunk/ELF/Symbols.h
lld/trunk/ELF/Target.cpp
lld/trunk/ELF/Writer.cpp
Modified: lld/trunk/ELF/InputSection.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputSection.cpp?rev=263386&r1=263385&r2=263386&view=diff
==============================================================================
--- lld/trunk/ELF/InputSection.cpp (original)
+++ lld/trunk/ELF/InputSection.cpp Sun Mar 13 14:48:18 2016
@@ -209,7 +209,7 @@ static uintX_t getMipsGotVA(const Symbol
AHL += SignExtend64<16>(read32<E>(PairedLoc));
return Out<ELFT>::Got->getMipsLocalPageAddr(SymVA + AHL);
}
- if (!canBePreempted(Body))
+ if (!Body.isPreemptible())
// For non-local symbols GOT entries should contain their full
// addresses. But if such symbol cannot be preempted, we do not
// have to put them into the "global" part of GOT and use dynamic
@@ -274,7 +274,6 @@ void InputSectionBase<ELFT>::relocate(ui
}
uintX_t SymVA = Body.getVA<ELFT>(A);
- bool CBP = canBePreempted(Body);
uint8_t *PairedLoc = nullptr;
if (Config->EMachine == EM_MIPS)
PairedLoc = findMipsPairedReloc(Buf, &RI, Rels.end());
@@ -288,7 +287,7 @@ void InputSectionBase<ELFT>::relocate(ui
SymVA = Body.getGotVA<ELFT>() + A;
if (Body.IsTls)
Type = Target->getTlsGotRel(Type);
- } else if (Target->isSizeRel(Type) && CBP) {
+ } else if (Target->isSizeRel(Type) && Body.isPreemptible()) {
// A SIZE relocation is supposed to set a symbol size, but if a symbol
// can be preempted, the size at runtime may be different than link time.
// If that's the case, we leave the field alone rather than filling it
@@ -296,7 +295,8 @@ void InputSectionBase<ELFT>::relocate(ui
continue;
} else if (Config->EMachine == EM_MIPS) {
SymVA = adjustMipsSymVA<ELFT>(Type, *File, Body, AddrLoc, SymVA) + A;
- } else if (!Target->needsCopyRel<ELFT>(Type, Body) && CBP) {
+ } else if (!Target->needsCopyRel<ELFT>(Type, Body) &&
+ Body.isPreemptible()) {
continue;
}
uintX_t Size = Body.getSize<ELFT>();
Modified: lld/trunk/ELF/OutputSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.cpp?rev=263386&r1=263385&r2=263386&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.cpp (original)
+++ lld/trunk/ELF/OutputSections.cpp Sun Mar 13 14:48:18 2016
@@ -182,7 +182,7 @@ template <class ELFT> void GotSection<EL
// for detailed description:
// ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
// As the first approach, we can just store addresses for all symbols.
- if (Config->EMachine != EM_MIPS && canBePreempted(*B))
+ if (Config->EMachine != EM_MIPS && B->isPreemptible())
continue; // The dynamic linker will take care of it.
uintX_t VA = B->getVA<ELFT>();
write<uintX_t, ELFT::TargetEndianness, sizeof(uintX_t)>(Entry, VA);
@@ -882,37 +882,6 @@ template <class ELFT> void OutputSection
reassignOffsets();
}
-// 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 elf::canBePreempted(const SymbolBody &Body) {
- if (Body.isLocal())
- return false;
-
- if (Body.isShared())
- return true;
-
- if (Body.isUndefined()) {
- if (!Body.isWeak())
- return true;
-
- // Ideally the static linker should see a definition for every symbol, but
- // shared object are normally allowed to have undefined references that the
- // static linker never sees a definition for.
- if (Config->Shared)
- return true;
-
- // Otherwise, just resolve to 0.
- return false;
- }
- if (!Config->Shared)
- return false;
- if (Body.getVisibility() != STV_DEFAULT)
- return false;
- if (Config->Bsymbolic || (Config->BsymbolicFunctions && Body.IsFunc))
- return false;
- return true;
-}
-
static void fill(uint8_t *Buf, size_t Size, ArrayRef<uint8_t> A) {
size_t I = 0;
for (; I + A.size() < Size; I += A.size())
Modified: lld/trunk/ELF/OutputSections.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.h?rev=263386&r1=263385&r2=263386&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.h (original)
+++ lld/trunk/ELF/OutputSections.h Sun Mar 13 14:48:18 2016
@@ -47,8 +47,6 @@ getAddend(const typename llvm::object::E
return Rel.r_addend;
}
-bool canBePreempted(const SymbolBody &Body);
-
bool isValidCIdentifier(StringRef S);
// This represents a section in an output file.
Modified: lld/trunk/ELF/Symbols.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Symbols.cpp?rev=263386&r1=263385&r2=263386&view=diff
==============================================================================
--- lld/trunk/ELF/Symbols.cpp (original)
+++ lld/trunk/ELF/Symbols.cpp Sun Mar 13 14:48:18 2016
@@ -81,6 +81,38 @@ getSymVA(const SymbolBody &Body, typenam
llvm_unreachable("invalid symbol kind");
}
+// 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 SymbolBody::isPreemptible() const {
+ if (isLocal())
+ return false;
+
+ if (isShared())
+ return true;
+
+ if (isUndefined()) {
+ if (!isWeak())
+ return true;
+
+ // Ideally the static linker should see a definition for every symbol, but
+ // shared object are normally allowed to have undefined references that the
+ // static linker never sees a definition for.
+ if (Config->Shared)
+ return true;
+
+ // Otherwise, just resolve to 0.
+ return false;
+ }
+
+ if (!Config->Shared)
+ return false;
+ if (getVisibility() != STV_DEFAULT)
+ return false;
+ if (Config->Bsymbolic || (Config->BsymbolicFunctions && IsFunc))
+ return false;
+ return true;
+}
+
template <class ELFT> bool SymbolBody::isGnuIfunc() const {
if (auto *D = dyn_cast<DefinedElf<ELFT>>(this))
return D->Sym.getType() == STT_GNU_IFUNC;
Modified: lld/trunk/ELF/Symbols.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Symbols.h?rev=263386&r1=263385&r2=263386&view=diff
==============================================================================
--- lld/trunk/ELF/Symbols.h (original)
+++ lld/trunk/ELF/Symbols.h Sun Mar 13 14:48:18 2016
@@ -75,7 +75,7 @@ public:
bool isShared() const { return SymbolKind == SharedKind; }
bool isLocal() const { return IsLocal; }
bool isUsedInRegularObj() const { return IsUsedInRegularObj; }
-
+ bool isPreemptible() const;
template <class ELFT> bool isGnuIfunc() const;
// Returns the symbol name.
Modified: lld/trunk/ELF/Target.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.cpp?rev=263386&r1=263385&r2=263386&view=diff
==============================================================================
--- lld/trunk/ELF/Target.cpp (original)
+++ lld/trunk/ELF/Target.cpp Sun Mar 13 14:48:18 2016
@@ -272,7 +272,7 @@ bool TargetInfo::canRelaxTls(uint32_t Ty
// Initial-Exec relocs can be relaxed to Local-Exec if the symbol is locally
// defined.
if (isTlsInitialExecRel(Type))
- return !canBePreempted(*S);
+ return !S->isPreemptible();
return false;
}
@@ -311,7 +311,7 @@ TargetInfo::PltNeed TargetInfo::needsPlt
const SymbolBody &S) const {
if (S.isGnuIfunc<ELFT>())
return Plt_Explicit;
- if (canBePreempted(S) && needsPltImpl(Type))
+ if (S.isPreemptible() && needsPltImpl(Type))
return Plt_Explicit;
// This handles a non PIC program call to function in a shared library.
@@ -464,7 +464,7 @@ bool X86TargetInfo::needsCopyRelImpl(uin
bool X86TargetInfo::needsGot(uint32_t Type, SymbolBody &S) const {
if (S.IsTls && Type == R_386_TLS_GD)
- return Target->canRelaxTls(Type, &S) && canBePreempted(S);
+ return Target->canRelaxTls(Type, &S) && S.isPreemptible();
if (Type == R_386_TLS_GOTIE || Type == R_386_TLS_IE)
return !canRelaxTls(Type, &S);
return Type == R_386_GOT32 || needsPlt<ELF32LE>(Type, S);
@@ -542,7 +542,7 @@ size_t X86TargetInfo::relaxTls(uint8_t *
const SymbolBody &S) const {
switch (Type) {
case R_386_TLS_GD:
- if (canBePreempted(S))
+ if (S.isPreemptible())
relocateTlsGdToIe(Loc, BufEnd, P, SA);
else
relocateTlsGdToLe(Loc, BufEnd, P, SA);
@@ -726,7 +726,7 @@ bool X86_64TargetInfo::refersToGotEntry(
bool X86_64TargetInfo::needsGot(uint32_t Type, SymbolBody &S) const {
if (Type == R_X86_64_TLSGD)
- return Target->canRelaxTls(Type, &S) && canBePreempted(S);
+ return Target->canRelaxTls(Type, &S) && S.isPreemptible();
if (Type == R_X86_64_GOTTPOFF)
return !canRelaxTls(Type, &S);
return refersToGotEntry(Type) || needsPlt<ELF64LE>(Type, S);
@@ -896,7 +896,7 @@ size_t X86_64TargetInfo::relaxTls(uint8_
relocateTlsIeToLe(Loc, BufEnd, P, SA);
return 0;
case R_X86_64_TLSGD: {
- if (canBePreempted(S))
+ if (S.isPreemptible())
relocateTlsGdToIe(Loc, BufEnd, P, SA);
else
relocateTlsGdToLe(Loc, BufEnd, P, SA);
@@ -1463,7 +1463,7 @@ size_t AArch64TargetInfo::relaxTls(uint8
case R_AARCH64_TLSDESC_LD64_LO12_NC:
case R_AARCH64_TLSDESC_ADD_LO12_NC:
case R_AARCH64_TLSDESC_CALL: {
- if (canBePreempted(S))
+ if (S.isPreemptible())
fatal("unsupported TLS optimization");
uint64_t X = S.getVA<ELF64LE>();
relocateTlsGdToLe(Type, Loc, BufEnd, P, X);
Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=263386&r1=263385&r2=263386&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Sun Mar 13 14:48:18 2016
@@ -290,7 +290,7 @@ static bool handleTlsRelocation(uint32_t
}
return true;
}
- if (!canBePreempted(Body))
+ if (!Body.isPreemptible())
return true;
}
return false;
@@ -332,7 +332,7 @@ void Writer<ELFT>::scanRelocs(InputSecti
if (auto *S = dyn_cast<SharedSymbol<ELFT>>(&Body))
S->File->IsUsed = true;
- bool CBP = canBePreempted(Body);
+ bool Preemptible = Body.isPreemptible();
if (handleTlsRelocation<ELFT>(Type, Body, C, RI))
continue;
@@ -341,7 +341,7 @@ void Writer<ELFT>::scanRelocs(InputSecti
&Body, getAddend<ELFT>(RI)});
// MIPS has a special rule to create GOTs for local symbols.
- if (Config->EMachine == EM_MIPS && !CBP &&
+ if (Config->EMachine == EM_MIPS && !Preemptible &&
(Type == R_MIPS_GOT16 || Type == R_MIPS_CALL16)) {
// FIXME (simon): Do not add so many redundant entries.
Out<ELFT>::Got->addMipsLocalEntry();
@@ -371,13 +371,13 @@ void Writer<ELFT>::scanRelocs(InputSecti
if (Target->UseLazyBinding) {
Out<ELFT>::GotPlt->addEntry(Body);
Out<ELFT>::RelaPlt->addReloc(
- {CBP ? Target->PltRel : Target->IRelativeRel,
- DynamicReloc<ELFT>::Off_GotPlt, !CBP, &Body});
+ {Preemptible ? Target->PltRel : Target->IRelativeRel,
+ DynamicReloc<ELFT>::Off_GotPlt, !Preemptible, &Body});
} else {
Out<ELFT>::Got->addEntry(Body);
Out<ELFT>::RelaDyn->addReloc(
- {CBP ? Target->PltRel : Target->IRelativeRel,
- DynamicReloc<ELFT>::Off_Got, !CBP, &Body});
+ {Preemptible ? Target->PltRel : Target->IRelativeRel,
+ DynamicReloc<ELFT>::Off_Got, !Preemptible, &Body});
}
continue;
}
@@ -424,16 +424,16 @@ void Writer<ELFT>::scanRelocs(InputSecti
bool Dynrel = Config->Shared && !Target->isRelRelative(Type) &&
!Target->isSizeRel(Type);
- if (CBP || Dynrel) {
+ if (Preemptible || Dynrel) {
uint32_t DynType;
if (Body.IsTls)
DynType = Target->TlsGotRel;
- else if (CBP)
+ else if (Preemptible)
DynType = Target->GotRel;
else
DynType = Target->RelativeRel;
Out<ELFT>::RelaDyn->addReloc(
- {DynType, DynamicReloc<ELFT>::Off_Got, !CBP, &Body});
+ {DynType, DynamicReloc<ELFT>::Off_Got, !Preemptible, &Body});
}
continue;
}
@@ -456,7 +456,7 @@ void Writer<ELFT>::scanRelocs(InputSecti
continue;
}
- if (CBP) {
+ if (Preemptible) {
// We don't know anything about the finaly symbol. Just ask the dynamic
// linker to handle the relocation for us.
Out<ELFT>::RelaDyn->addReloc({Target->getDynRel(Type), &C, RI.r_offset,
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