[patch] Fix pr24486
Rafael Espíndola via llvm-commits
llvm-commits at lists.llvm.org
Sat Oct 3 11:50:51 PDT 2015
> Thank you for your patch.
>
> I've performed some investigation for failures occurred and found two
> issues:
>
> - We should assign a dummy fragment in current section in EmitLabel
> function.
> - In MCObjectStreamer::getCurrentFragment(), we should skip dummy fragments
> (or perhaps just not push them into appropriate section's fragments list at
> all). If we don't do this, MCExpr::evaluateAsAbsolute() will fail to
> evaluate .La - .Lb expressions.
Thanks for all the work on this.
There were still some things that needed improvement:
* There should really only be one dummy fragment per section.
* Ideally they would only be used by the asm streamer and not show up
in during relaxation.
The attached patch is an extension of yours.The only exception to
second goal is that the dummy fragment is still used as a placeholder
in the pending labels optimization. The entire area of bundles is a
bit fuzzy to me. In any case, it is a local enough issue that it is
probably not worth making this patch bigger to clean it up.
So, the summary is that the attached patch fixes the bug and LGTM.
Does it work for you? Do you have commit access?
Cheers,
Rafael
-------------- next part --------------
diff --git a/include/llvm/MC/MCAssembler.h b/include/llvm/MC/MCAssembler.h
index 6becda8..d69472b 100644
--- a/include/llvm/MC/MCAssembler.h
+++ b/include/llvm/MC/MCAssembler.h
@@ -52,7 +52,8 @@ public:
FT_Dwarf,
FT_DwarfFrame,
FT_LEB,
- FT_SafeSEH
+ FT_SafeSEH,
+ FT_Dummy
};
private:
@@ -136,9 +137,19 @@ public:
/// and only some fragments have a meaningful implementation.
void setBundlePadding(uint8_t N) { BundlePadding = N; }
+ /// \brief Return true if given frgment has FT_Dummy type.
+ bool isDummy() const { return Kind == FT_Dummy; }
+
void dump();
};
+class MCDummyFragment : public MCFragment {
+public:
+ explicit MCDummyFragment(MCSection *Sec)
+ : MCFragment(FT_Dummy, false, 0, Sec){};
+ static bool classof(const MCFragment *F) { return F->getKind() == FT_Dummy; }
+};
+
/// Interface implemented by fragments that contain encoded instructions and/or
/// data.
///
diff --git a/include/llvm/MC/MCExpr.h b/include/llvm/MC/MCExpr.h
index b3a6073..76da86c 100644
--- a/include/llvm/MC/MCExpr.h
+++ b/include/llvm/MC/MCExpr.h
@@ -20,6 +20,7 @@ class MCAsmLayout;
class MCAssembler;
class MCContext;
class MCFixup;
+class MCFragment;
class MCSection;
class MCStreamer;
class MCSymbol;
@@ -115,7 +116,7 @@ public:
/// currently defined as the absolute section for constants, or
/// otherwise the section associated with the first defined symbol in the
/// expression.
- MCSection *findAssociatedSection() const;
+ MCFragment *findAssociatedFragment() const;
/// @}
};
@@ -556,7 +557,7 @@ public:
const MCAsmLayout *Layout,
const MCFixup *Fixup) const = 0;
virtual void visitUsedExpr(MCStreamer& Streamer) const = 0;
- virtual MCSection *findAssociatedSection() const = 0;
+ virtual MCFragment *findAssociatedFragment() const = 0;
virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
diff --git a/include/llvm/MC/MCMachObjectWriter.h b/include/llvm/MC/MCMachObjectWriter.h
index 7eccd562..fe1227f 100644
--- a/include/llvm/MC/MCMachObjectWriter.h
+++ b/include/llvm/MC/MCMachObjectWriter.h
@@ -248,6 +248,11 @@ public:
const MCAsmLayout &Layout) override;
bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+ const MCSymbol &A,
+ const MCSymbol &B,
+ bool InSet) const override;
+
+ bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
const MCSymbol &SymA,
const MCFragment &FB, bool InSet,
bool IsPCRel) const override;
diff --git a/include/llvm/MC/MCObjectWriter.h b/include/llvm/MC/MCObjectWriter.h
index 406831a..ed1f493 100644
--- a/include/llvm/MC/MCObjectWriter.h
+++ b/include/llvm/MC/MCObjectWriter.h
@@ -93,6 +93,11 @@ public:
bool InSet) const;
virtual bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+ const MCSymbol &A,
+ const MCSymbol &B,
+ bool InSet) const;
+
+ virtual bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
const MCSymbol &SymA,
const MCFragment &FB,
bool InSet,
diff --git a/include/llvm/MC/MCSection.h b/include/llvm/MC/MCSection.h
index 2d0d4df..f5490fc 100644
--- a/include/llvm/MC/MCSection.h
+++ b/include/llvm/MC/MCSection.h
@@ -18,6 +18,7 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/ilist.h"
#include "llvm/ADT/ilist_node.h"
+#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/SectionKind.h"
#include "llvm/Support/Compiler.h"
@@ -92,6 +93,8 @@ private:
unsigned IsRegistered : 1;
+ MCDummyFragment DummyFragment;
+
FragmentListType Fragments;
/// Mapping from subsection number to insertion point for subsection numbers
@@ -152,6 +155,9 @@ public:
return const_cast<MCSection *>(this)->getFragmentList();
}
+ const MCDummyFragment &getDummyFragment() const { return DummyFragment; }
+ MCDummyFragment &getDummyFragment() { return DummyFragment; }
+
MCSection::iterator begin();
MCSection::const_iterator begin() const {
return const_cast<MCSection *>(this)->begin();
diff --git a/include/llvm/MC/MCStreamer.h b/include/llvm/MC/MCStreamer.h
index 6beeaa9..209bfe5 100644
--- a/include/llvm/MC/MCStreamer.h
+++ b/include/llvm/MC/MCStreamer.h
@@ -358,7 +358,7 @@ public:
///
/// Each emitted symbol will be tracked in the ordering table,
/// so we can sort on them later.
- void AssignSection(MCSymbol *Symbol, MCSection *Section);
+ void AssignFragment(MCSymbol *Symbol, MCFragment *Fragment);
/// \brief Emit a label for \p Symbol into the current section.
///
diff --git a/include/llvm/MC/MCSymbol.h b/include/llvm/MC/MCSymbol.h
index 563fa80..c51ecfc 100644
--- a/include/llvm/MC/MCSymbol.h
+++ b/include/llvm/MC/MCSymbol.h
@@ -56,19 +56,17 @@ protected:
SymContentsCommon,
};
- // Special sentinal value for the absolute pseudo section.
- //
- // FIXME: Use a PointerInt wrapper for this?
- static MCSection *AbsolutePseudoSection;
+ // Special sentinal value for the absolute pseudo fragment.
+ static MCFragment *AbsolutePseudoFragment;
/// If a symbol has a Fragment, the section is implied, so we only need
/// one pointer.
+ /// The special AbsolutePseudoFragment value is for absolute symbols.
+ /// If this is a variable symbol, this caches the variable value's fragment.
/// FIXME: We might be able to simplify this by having the asm streamer create
/// dummy fragments.
/// If this is a section, then it gives the symbol is defined in. This is null
- /// for undefined symbols, and the special AbsolutePseudoSection value for
- /// absolute symbols. If this is a variable symbol, this caches the variable
- /// value's section.
+ /// for undefined symbols.
///
/// If this is a fragment, then it gives the fragment this symbol's value is
/// relative to, if any.
@@ -76,8 +74,7 @@ protected:
/// For the 'HasName' integer, this is true if this symbol is named.
/// A named symbol will have a pointer to the name allocated in the bytes
/// immediately prior to the MCSymbol.
- mutable PointerIntPair<PointerUnion<MCSection *, MCFragment *>, 1>
- SectionOrFragmentAndHasName;
+ mutable PointerIntPair<MCFragment *, 1> FragmentAndHasName;
/// IsTemporary - True if this is an assembler temporary label, which
/// typically does not survive in the .o file's symbol table. Usually
@@ -155,7 +152,7 @@ protected: // MCContext creates and uniques these.
Kind(Kind), IsUsedInReloc(false), SymbolContents(SymContentsUnset),
CommonAlignLog2(0), Flags(0) {
Offset = 0;
- SectionOrFragmentAndHasName.setInt(!!Name);
+ FragmentAndHasName.setInt(!!Name);
if (Name)
getNameEntryPtr() = Name;
}
@@ -180,19 +177,16 @@ private:
MCSymbol(const MCSymbol &) = delete;
void operator=(const MCSymbol &) = delete;
MCSection *getSectionPtr(bool SetUsed = true) const {
- if (MCFragment *F = getFragment())
+ if (MCFragment *F = getFragment(SetUsed)) {
+ assert(F != AbsolutePseudoFragment);
return F->getParent();
- const auto &SectionOrFragment = SectionOrFragmentAndHasName.getPointer();
- assert(!SectionOrFragment.is<MCFragment *>() && "Section or null expected");
- MCSection *Section = SectionOrFragment.dyn_cast<MCSection *>();
- if (Section || !isVariable())
- return Section;
- return Section = getVariableValue(SetUsed)->findAssociatedSection();
+ }
+ return nullptr;
}
/// \brief Get a reference to the name field. Requires that we have a name
const StringMapEntry<bool> *&getNameEntryPtr() {
- assert(SectionOrFragmentAndHasName.getInt() && "Name is required");
+ assert(FragmentAndHasName.getInt() && "Name is required");
NameEntryStorageTy *Name = reinterpret_cast<NameEntryStorageTy *>(this);
return (*(Name - 1)).NameEntry;
}
@@ -203,7 +197,7 @@ private:
public:
/// getName - Get the symbol name.
StringRef getName() const {
- if (!SectionOrFragmentAndHasName.getInt())
+ if (!FragmentAndHasName.getInt())
return StringRef();
return getNameEntryPtr()->first();
@@ -249,7 +243,7 @@ public:
///
/// Defined symbols are either absolute or in some section.
bool isDefined(bool SetUsed = true) const {
- return getSectionPtr(SetUsed) != nullptr;
+ return getFragment(SetUsed) != nullptr;
}
/// isInSection - Check if this symbol is defined in some section (i.e., it
@@ -263,7 +257,7 @@ public:
/// isAbsolute - Check if this is an absolute symbol.
bool isAbsolute(bool SetUsed = true) const {
- return getSectionPtr(SetUsed) == AbsolutePseudoSection;
+ return getFragment(SetUsed) == AbsolutePseudoFragment;
}
/// Get the section associated with a defined, non-absolute symbol.
@@ -272,19 +266,14 @@ public:
return *getSectionPtr(SetUsed);
}
- /// Mark the symbol as defined in the section \p S.
- void setSection(MCSection &S) {
- assert(!isVariable() && "Cannot set section of variable");
- assert(!SectionOrFragmentAndHasName.getPointer().is<MCFragment *>() &&
- "Section or null expected");
- SectionOrFragmentAndHasName.setPointer(&S);
+ /// Mark the symbol as defined in the fragment \p F.
+ void setFragment(MCFragment *F) const {
+ assert(!isVariable() && "Cannot set fragment of variable");
+ FragmentAndHasName.setPointer(F);
}
/// Mark the symbol as undefined.
- void setUndefined() {
- SectionOrFragmentAndHasName.setPointer(
- PointerUnion<MCSection *, MCFragment *>());
- }
+ void setUndefined() { FragmentAndHasName.setPointer(nullptr); }
bool isELF() const { return Kind == SymbolKindELF; }
@@ -385,11 +374,13 @@ public:
return SymbolContents == SymContentsCommon;
}
- MCFragment *getFragment() const {
- return SectionOrFragmentAndHasName.getPointer().dyn_cast<MCFragment *>();
- }
- void setFragment(MCFragment *Value) const {
- SectionOrFragmentAndHasName.setPointer(Value);
+ MCFragment *getFragment(bool SetUsed = true) const {
+ MCFragment *Fragment = FragmentAndHasName.getPointer();
+ if (Fragment || !isVariable())
+ return Fragment;
+ Fragment = getVariableValue(SetUsed)->findAssociatedFragment();
+ FragmentAndHasName.setPointer(Fragment);
+ return Fragment;
}
bool isExternal() const { return IsExternal; }
diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index 16f299c..f1acc1d 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -447,9 +447,6 @@ void ELFObjectWriter::writeSymbol(SymbolTableWriter &Writer,
uint32_t StringIndex, ELFSymbolData &MSD,
const MCAsmLayout &Layout) {
const auto &Symbol = cast<MCSymbolELF>(*MSD.Symbol);
- assert((!Symbol.getFragment() ||
- (Symbol.getFragment()->getParent() == &Symbol.getSection())) &&
- "The symbol's section doesn't match the fragment's symbol");
const MCSymbolELF *Base =
cast_or_null<MCSymbolELF>(Layout.getBaseSymbol(Symbol));
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 7a30075..f9dbd5a 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -575,7 +575,7 @@ void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
void MCAsmStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment) {
if (Symbol)
- AssignSection(Symbol, Section);
+ AssignFragment(Symbol, &Section->getDummyFragment());
// Note: a .zerofill directive does not switch sections.
OS << ".zerofill ";
@@ -599,7 +599,7 @@ void MCAsmStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
// e.g. _a.
void MCAsmStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment) {
- AssignSection(Symbol, Section);
+ AssignFragment(Symbol, &Section->getDummyFragment());
assert(Symbol && "Symbol shouldn't be NULL!");
// Instead of using the Section we'll just use the shortcut.
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index d93bf44..143d284 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -277,7 +277,7 @@ MCFragment::MCFragment(FragmentType Kind, bool HasInstructions,
: Kind(Kind), HasInstructions(HasInstructions), AlignToBundleEnd(false),
BundlePadding(BundlePadding), Parent(Parent), Atom(nullptr),
Offset(~UINT64_C(0)) {
- if (Parent)
+ if (Parent && !isDummy())
Parent->getFragmentList().push_back(this);
}
@@ -319,6 +319,9 @@ void MCFragment::destroy() {
case FT_SafeSEH:
delete cast<MCSafeSEHFragment>(this);
return;
+ case FT_Dummy:
+ delete cast<MCDummyFragment>(this);
+ return;
}
}
@@ -411,7 +414,7 @@ const MCSymbol *MCAssembler::getAtom(const MCSymbol &S) const {
return &S;
// Absolute and undefined symbols have no defining atom.
- if (!S.getFragment())
+ if (!S.isInSection())
return nullptr;
// Non-linker visible symbols in sections which can't be atomized have no
@@ -547,6 +550,8 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
return cast<MCDwarfLineAddrFragment>(F).getContents().size();
case MCFragment::FT_DwarfFrame:
return cast<MCDwarfCallFrameFragment>(F).getContents().size();
+ case MCFragment::FT_Dummy:
+ llvm_unreachable("Should not have been added");
}
llvm_unreachable("invalid fragment kind");
@@ -780,6 +785,8 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout,
OW->writeBytes(CF.getContents());
break;
}
+ case MCFragment::FT_Dummy:
+ llvm_unreachable("Should not have been added");
}
assert(OW->getStream().tell() - Start == FragmentSize &&
@@ -1147,6 +1154,9 @@ void MCFragment::dump() {
case MCFragment::FT_DwarfFrame: OS << "MCDwarfCallFrameFragment"; break;
case MCFragment::FT_LEB: OS << "MCLEBFragment"; break;
case MCFragment::FT_SafeSEH: OS << "MCSafeSEHFragment"; break;
+ case MCFragment::FT_Dummy:
+ OS << "MCDummyFragment";
+ break;
}
OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder
@@ -1245,6 +1255,8 @@ void MCFragment::dump() {
OS << " Sym:" << F->getSymbol();
break;
}
+ case MCFragment::FT_Dummy:
+ break;
}
OS << ">";
}
diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index f0b3ec6..fc4f8a6 100644
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -111,7 +111,7 @@ void MCELFStreamer::EmitLabel(MCSymbol *S) {
MCObjectStreamer::EmitLabel(Symbol);
const MCSectionELF &Section =
- static_cast<const MCSectionELF&>(Symbol->getSection());
+ static_cast<const MCSectionELF &>(*getCurrentSectionOnly());
if (Section.getFlags() & ELF::SHF_TLS)
Symbol->setType(ELF::STT_TLS);
}
@@ -311,11 +311,6 @@ void MCELFStreamer::EmitCommonSymbol(MCSymbol *S, uint64_t Size,
Symbol->setType(ELF::STT_OBJECT);
if (Symbol->getBinding() == ELF::STB_LOCAL) {
- MCSection *Section = getAssembler().getContext().getELFSection(
- ".bss", ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
-
- AssignSection(Symbol, Section);
-
struct LocalCommon L = {Symbol, Size, ByteAlignment};
LocalCommons.push_back(L);
} else {
@@ -630,7 +625,8 @@ void MCELFStreamer::Flush() {
const MCSymbol &Symbol = *i->Symbol;
uint64_t Size = i->Size;
unsigned ByteAlignment = i->ByteAlignment;
- MCSection &Section = Symbol.getSection();
+ MCSection &Section = *getAssembler().getContext().getELFSection(
+ ".bss", ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
getAssembler().registerSection(Section);
new MCAlignFragment(ByteAlignment, 0, 1, ByteAlignment, &Section);
diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index 042fd1c..916e505 100644
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -477,7 +477,8 @@ static void AttemptToFoldSymbolOffsetDifference(
if (!Asm->getWriter().isSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet))
return;
- if (SA.getFragment() == SB.getFragment()) {
+ if (SA.getFragment() == SB.getFragment() && !SA.isVariable() &&
+ !SB.isVariable()) {
Addend += (SA.getOffset() - SB.getOffset());
// Pointers to Thumb symbols need to have their low-bit set to allow
@@ -606,7 +607,7 @@ bool MCExpr::evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const {
true);
}
-static bool canExpand(const MCSymbol &Sym, const MCAssembler *Asm, bool InSet) {
+static bool canExpand(const MCSymbol &Sym, bool InSet) {
const MCExpr *Expr = Sym.getVariableValue();
const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr);
if (Inner) {
@@ -616,9 +617,7 @@ static bool canExpand(const MCSymbol &Sym, const MCAssembler *Asm, bool InSet) {
if (InSet)
return true;
- if (!Asm)
- return false;
- return !Asm->getWriter().isWeak(Sym);
+ return !Sym.isInSection();
}
bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
@@ -643,7 +642,7 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
// Evaluate recursively if this is a variable.
if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None &&
- canExpand(Sym, Asm, InSet)) {
+ canExpand(Sym, InSet)) {
bool IsMachO = SRE->hasSubsectionsViaSymbols();
if (Sym.getVariableValue()->evaluateAsRelocatableImpl(
Res, Asm, Layout, Fixup, Addrs, InSet || IsMachO)) {
@@ -775,45 +774,41 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
llvm_unreachable("Invalid assembly expression kind!");
}
-MCSection *MCExpr::findAssociatedSection() const {
+MCFragment *MCExpr::findAssociatedFragment() const {
switch (getKind()) {
case Target:
// We never look through target specific expressions.
- return cast<MCTargetExpr>(this)->findAssociatedSection();
+ return cast<MCTargetExpr>(this)->findAssociatedFragment();
case Constant:
- return MCSymbol::AbsolutePseudoSection;
+ return MCSymbol::AbsolutePseudoFragment;
case SymbolRef: {
const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
const MCSymbol &Sym = SRE->getSymbol();
-
- if (Sym.isDefined())
- return &Sym.getSection();
-
- return nullptr;
+ return Sym.getFragment();
}
case Unary:
- return cast<MCUnaryExpr>(this)->getSubExpr()->findAssociatedSection();
+ return cast<MCUnaryExpr>(this)->getSubExpr()->findAssociatedFragment();
case Binary: {
const MCBinaryExpr *BE = cast<MCBinaryExpr>(this);
- MCSection *LHS_S = BE->getLHS()->findAssociatedSection();
- MCSection *RHS_S = BE->getRHS()->findAssociatedSection();
+ MCFragment *LHS_F = BE->getLHS()->findAssociatedFragment();
+ MCFragment *RHS_F = BE->getRHS()->findAssociatedFragment();
- // If either section is absolute, return the other.
- if (LHS_S == MCSymbol::AbsolutePseudoSection)
- return RHS_S;
- if (RHS_S == MCSymbol::AbsolutePseudoSection)
- return LHS_S;
+ // If either is absolute, return the other.
+ if (LHS_F == MCSymbol::AbsolutePseudoFragment)
+ return RHS_F;
+ if (RHS_F == MCSymbol::AbsolutePseudoFragment)
+ return LHS_F;
// Not always correct, but probably the best we can do without more context.
if (BE->getOpcode() == MCBinaryExpr::Sub)
- return MCSymbol::AbsolutePseudoSection;
+ return MCSymbol::AbsolutePseudoFragment;
- // Otherwise, return the first non-null section.
- return LHS_S ? LHS_S : RHS_S;
+ // Otherwise, return the first non-null fragment.
+ return LHS_F ? LHS_F : RHS_F;
}
}
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index 0f65d51..50ee08f 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -180,8 +180,6 @@ void MCMachOStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
- // isSymbolLinkerVisible uses the section.
- AssignSection(Symbol, getCurrentSection().first);
// We have to create a new fragment if this is an atom defining symbol,
// fragments cannot span atoms.
if (getAssembler().isSymbolLinkerVisible(*Symbol))
@@ -415,8 +413,6 @@ void MCMachOStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
if (ByteAlignment != 1)
new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, Section);
- AssignSection(Symbol, Section);
-
MCFragment *F = new MCFillFragment(0, 0, Size, Section);
Symbol->setFragment(F);
@@ -460,7 +456,8 @@ void MCMachOStreamer::FinishImpl() {
// defining symbols.
DenseMap<const MCFragment *, const MCSymbol *> DefiningSymbolMap;
for (const MCSymbol &Symbol : getAssembler().symbols()) {
- if (getAssembler().isSymbolLinkerVisible(Symbol) && Symbol.getFragment()) {
+ if (getAssembler().isSymbolLinkerVisible(Symbol) && Symbol.isInSection() &&
+ !Symbol.isVariable()) {
// An atom defining symbol should never be internal to a fragment.
assert(Symbol.getOffset() == 0 &&
"Invalid offset in atom defining symbol!");
diff --git a/lib/MC/MCObjectStreamer.cpp b/lib/MC/MCObjectStreamer.cpp
index caee5da..992b2cf 100644
--- a/lib/MC/MCObjectStreamer.cpp
+++ b/lib/MC/MCObjectStreamer.cpp
@@ -58,7 +58,8 @@ void MCObjectStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi,
const MCSymbol *Lo,
unsigned Size) {
// If not assigned to the same (valid) fragment, fallback.
- if (!Hi->getFragment() || Hi->getFragment() != Lo->getFragment()) {
+ if (!Hi->getFragment() || Hi->getFragment() != Lo->getFragment() ||
+ Hi->isVariable() || Lo->isVariable()) {
MCStreamer::emitAbsoluteSymbolDiff(Hi, Lo, Size);
return;
}
@@ -155,7 +156,6 @@ void MCObjectStreamer::EmitLabel(MCSymbol *Symbol) {
MCStreamer::EmitLabel(Symbol);
getAssembler().registerSymbol(*Symbol);
- assert(!Symbol->getFragment() && "Unexpected fragment on symbol data!");
// If there is a current fragment, mark the symbol as pointing into it.
// Otherwise queue the label and set its fragment pointer when we emit the
diff --git a/lib/MC/MCObjectWriter.cpp b/lib/MC/MCObjectWriter.cpp
index 3479034..e84f74a 100644
--- a/lib/MC/MCObjectWriter.cpp
+++ b/lib/MC/MCObjectWriter.cpp
@@ -33,8 +33,14 @@ bool MCObjectWriter::isSymbolRefDifferenceFullyResolved(
if (!SA.getFragment() || !SB.getFragment())
return false;
- return isSymbolRefDifferenceFullyResolvedImpl(Asm, SA, *SB.getFragment(),
- InSet, false);
+ return isSymbolRefDifferenceFullyResolvedImpl(Asm, SA, SB, InSet);
+}
+
+bool MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
+ const MCAssembler &Asm, const MCSymbol &A, const MCSymbol &B,
+ bool InSet) const {
+ return isSymbolRefDifferenceFullyResolvedImpl(Asm, A, *B.getFragment(), InSet,
+ false);
}
bool MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
diff --git a/lib/MC/MCSection.cpp b/lib/MC/MCSection.cpp
index 9152f2b..e0d29bb 100644
--- a/lib/MC/MCSection.cpp
+++ b/lib/MC/MCSection.cpp
@@ -21,7 +21,7 @@ using namespace llvm;
MCSection::MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
: Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
- IsRegistered(false), Variant(V), Kind(K) {}
+ IsRegistered(false), DummyFragment(this), Variant(V), Kind(K) {}
MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) {
if (!End)
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index d6b44a0..5d76851 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -188,9 +188,9 @@ void MCStreamer::InitSections(bool NoExecStack) {
SwitchSection(getContext().getObjectFileInfo()->getTextSection());
}
-void MCStreamer::AssignSection(MCSymbol *Symbol, MCSection *Section) {
- assert(Section);
- Symbol->setSection(*Section);
+void MCStreamer::AssignFragment(MCSymbol *Symbol, MCFragment *Fragment) {
+ assert(Fragment);
+ Symbol->setFragment(Fragment);
// As we emit symbols into a section, track the order so that they can
// be sorted upon later. Zero is reserved to mean 'unemitted'.
@@ -200,7 +200,8 @@ void MCStreamer::AssignSection(MCSymbol *Symbol, MCSection *Section) {
void MCStreamer::EmitLabel(MCSymbol *Symbol) {
assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
assert(getCurrentSection().first && "Cannot emit before setting section!");
- AssignSection(Symbol, getCurrentSection().first);
+ assert(!Symbol->getFragment() && "Unexpected fragment on symbol data!");
+ Symbol->setFragment(&getCurrentSectionOnly()->getDummyFragment());
MCTargetStreamer *TS = getTargetStreamer();
if (TS)
diff --git a/lib/MC/MCSymbol.cpp b/lib/MC/MCSymbol.cpp
index 125380a..c7d6213 100644
--- a/lib/MC/MCSymbol.cpp
+++ b/lib/MC/MCSymbol.cpp
@@ -16,8 +16,9 @@
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
-// Sentinel value for the absolute pseudo section.
-MCSection *MCSymbol::AbsolutePseudoSection = reinterpret_cast<MCSection *>(1);
+// Sentinel value for the absolute pseudo fragment.
+MCFragment *MCSymbol::AbsolutePseudoFragment =
+ reinterpret_cast<MCFragment *>(4);
void *MCSymbol::operator new(size_t s, const StringMapEntry<bool> *Name,
MCContext &Ctx) {
diff --git a/lib/MC/MachObjectWriter.cpp b/lib/MC/MachObjectWriter.cpp
index 94d71f1..d5184f1 100644
--- a/lib/MC/MachObjectWriter.cpp
+++ b/lib/MC/MachObjectWriter.cpp
@@ -626,6 +626,18 @@ void MachObjectWriter::executePostLayoutBinding(MCAssembler &Asm,
}
bool MachObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
+ const MCAssembler &Asm, const MCSymbol &A, const MCSymbol &B,
+ bool InSet) const {
+ // FIXME: We don't handle things like
+ // foo = .
+ // creating atoms.
+ if (A.isVariable() || B.isVariable())
+ return false;
+ return MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(Asm, A, B,
+ InSet);
+}
+
+bool MachObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
const MCAssembler &Asm, const MCSymbol &SymA, const MCFragment &FB,
bool InSet, bool IsPCRel) const {
if (InSet)
diff --git a/lib/MC/WinCOFFStreamer.cpp b/lib/MC/WinCOFFStreamer.cpp
index 40c242c..02814fa 100644
--- a/lib/MC/WinCOFFStreamer.cpp
+++ b/lib/MC/WinCOFFStreamer.cpp
@@ -245,8 +245,6 @@ void MCWinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
getAssembler().registerSymbol(*Symbol);
Symbol->setExternal(false);
- AssignSection(Symbol, Section);
-
if (ByteAlignment != 1)
new MCAlignFragment(ByteAlignment, /*Value=*/0, /*ValueSize=*/0,
ByteAlignment, Section);
diff --git a/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp b/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp
index 29a903f..a540f498 100644
--- a/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp
+++ b/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp
@@ -85,7 +85,7 @@ void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const {
Streamer.visitUsedExpr(*getSubExpr());
}
-MCSection *AArch64MCExpr::findAssociatedSection() const {
+MCFragment *AArch64MCExpr::findAssociatedFragment() const {
llvm_unreachable("FIXME: what goes here?");
}
diff --git a/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h b/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h
index b111e7c..db36a65 100644
--- a/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h
+++ b/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h
@@ -149,7 +149,7 @@ public:
void visitUsedExpr(MCStreamer &Streamer) const override;
- MCSection *findAssociatedSection() const override;
+ MCFragment *findAssociatedFragment() const override;
bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
const MCFixup *Fixup) const override;
diff --git a/lib/Target/ARM/MCTargetDesc/ARMMCExpr.h b/lib/Target/ARM/MCTargetDesc/ARMMCExpr.h
index 9146d4d..75dde80 100644
--- a/lib/Target/ARM/MCTargetDesc/ARMMCExpr.h
+++ b/lib/Target/ARM/MCTargetDesc/ARMMCExpr.h
@@ -63,8 +63,8 @@ public:
return false;
}
void visitUsedExpr(MCStreamer &Streamer) const override;
- MCSection *findAssociatedSection() const override {
- return getSubExpr()->findAssociatedSection();
+ MCFragment *findAssociatedFragment() const override {
+ return getSubExpr()->findAssociatedFragment();
}
// There are no TLS ARMMCExprs at the moment.
diff --git a/lib/Target/Hexagon/MCTargetDesc/HexagonMCELFStreamer.cpp b/lib/Target/Hexagon/MCTargetDesc/HexagonMCELFStreamer.cpp
index bf51c35..1bec375 100644
--- a/lib/Target/Hexagon/MCTargetDesc/HexagonMCELFStreamer.cpp
+++ b/lib/Target/Hexagon/MCTargetDesc/HexagonMCELFStreamer.cpp
@@ -114,7 +114,7 @@ void HexagonMCELFStreamer::HexagonMCEmitCommonSymbol(MCSymbol *Symbol,
MCSection *Section = getAssembler().getContext().getELFSection(
SectionName, ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
SwitchSection(Section);
- AssignSection(Symbol, Section);
+ AssignFragment(Symbol, getCurrentFragment());
MCELFStreamer::EmitCommonSymbol(Symbol, Size, ByteAlignment);
SwitchSection(CrntSection);
diff --git a/lib/Target/Mips/MCTargetDesc/MipsMCExpr.h b/lib/Target/Mips/MCTargetDesc/MipsMCExpr.h
index fd2ed17..e889972 100644
--- a/lib/Target/Mips/MCTargetDesc/MipsMCExpr.h
+++ b/lib/Target/Mips/MCTargetDesc/MipsMCExpr.h
@@ -51,8 +51,8 @@ public:
const MCAsmLayout *Layout,
const MCFixup *Fixup) const override;
void visitUsedExpr(MCStreamer &Streamer) const override;
- MCSection *findAssociatedSection() const override {
- return getSubExpr()->findAssociatedSection();
+ MCFragment *findAssociatedFragment() const override {
+ return getSubExpr()->findAssociatedFragment();
}
// There are no TLS MipsMCExprs at the moment.
diff --git a/lib/Target/NVPTX/NVPTXMCExpr.h b/lib/Target/NVPTX/NVPTXMCExpr.h
index 46b4b33..81a606d 100644
--- a/lib/Target/NVPTX/NVPTXMCExpr.h
+++ b/lib/Target/NVPTX/NVPTXMCExpr.h
@@ -68,7 +68,7 @@ public:
return false;
}
void visitUsedExpr(MCStreamer &Streamer) const override {};
- MCSection *findAssociatedSection() const override { return nullptr; }
+ MCFragment *findAssociatedFragment() const override { return nullptr; }
// There are no TLS NVPTXMCExprs at the moment.
void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override {}
@@ -110,7 +110,7 @@ public:
return false;
}
void visitUsedExpr(MCStreamer &Streamer) const override {};
- MCSection *findAssociatedSection() const override { return nullptr; }
+ MCFragment *findAssociatedFragment() const override { return nullptr; }
// There are no TLS NVPTXMCExprs at the moment.
void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override {}
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.h b/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.h
index a641780..d42a111 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.h
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCExpr.h
@@ -82,8 +82,8 @@ public:
const MCAsmLayout *Layout,
const MCFixup *Fixup) const override;
void visitUsedExpr(MCStreamer &Streamer) const override;
- MCSection *findAssociatedSection() const override {
- return getSubExpr()->findAssociatedSection();
+ MCFragment *findAssociatedFragment() const override {
+ return getSubExpr()->findAssociatedFragment();
}
// There are no TLS PPCMCExprs at the moment.
diff --git a/lib/Target/Sparc/MCTargetDesc/SparcMCExpr.h b/lib/Target/Sparc/MCTargetDesc/SparcMCExpr.h
index d08ad86..13f0819 100644
--- a/lib/Target/Sparc/MCTargetDesc/SparcMCExpr.h
+++ b/lib/Target/Sparc/MCTargetDesc/SparcMCExpr.h
@@ -90,8 +90,8 @@ public:
const MCAsmLayout *Layout,
const MCFixup *Fixup) const override;
void visitUsedExpr(MCStreamer &Streamer) const override;
- MCSection *findAssociatedSection() const override {
- return getSubExpr()->findAssociatedSection();
+ MCFragment *findAssociatedFragment() const override {
+ return getSubExpr()->findAssociatedFragment();
}
void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override;
diff --git a/test/MC/COFF/alias.s b/test/MC/COFF/alias.s
index 2293d43..369bbe8 100644
--- a/test/MC/COFF/alias.s
+++ b/test/MC/COFF/alias.s
@@ -21,9 +21,9 @@ weak_aliased_to_external = external2
.long weak_aliased_to_external
// CHECK: Relocations [
-// CHECK: 0x0 IMAGE_REL_I386_DIR32 local1
+// CHECK: 0x0 IMAGE_REL_I386_DIR32 external_aliased_to_local
// CHECK: 0x4 IMAGE_REL_I386_DIR32 external1
-// CHECK: 0x8 IMAGE_REL_I386_DIR32 local2
+// CHECK: 0x8 IMAGE_REL_I386_DIR32 global_aliased_to_local
// CHECK: 0xC IMAGE_REL_I386_DIR32 external2
// CHECK: ]
// CHECK: Symbols [
diff --git a/test/MC/ELF/relocation.s b/test/MC/ELF/relocation.s
index 34f1a40..0fec767 100644
--- a/test/MC/ELF/relocation.s
+++ b/test/MC/ELF/relocation.s
@@ -55,6 +55,11 @@ bar:
.quad pr23272_2 - pr23272
.quad pr23272_3 - pr23272
+ .global pr24486
+pr24486:
+ pr24486_alias = pr24486
+ .long pr24486_alias
+
.code16
call pr23771
@@ -94,6 +99,7 @@ bar:
// CHECK-NEXT: 0xD4 R_X86_64_SIZE32 blah 0xFFFFFFFFFFFFFFE0
// CHECK-NEXT: 0xD8 R_X86_64_GOTPCREL foo 0x0
// CHECK-NEXT: 0xDC R_X86_64_PLT32 foo 0x0
-// CHECK-NEXT: 0xF1 R_X86_64_PC16 pr23771 0xFFFFFFFFFFFFFFFE
+// CHECK-NEXT: 0xF0 R_X86_64_32 .text 0xF0
+// CHECK-NEXT: 0xF5 R_X86_64_PC16 pr23771 0xFFFFFFFFFFFFFFFE
// CHECK-NEXT: ]
// CHECK-NEXT: }
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