Revert r360194 "[JITLink] Add support for MachO .alt_entry atoms."

The testcase is asserting on some bots - reverting while I investigate.

llvm-svn: 360200
This commit is contained in:
Lang Hames 2019-05-07 22:19:29 +00:00
parent 8a3d3a9af6
commit 1a10101e21
4 changed files with 12 additions and 173 deletions

View File

@ -44,33 +44,6 @@ void MachOAtomGraphBuilder::addCustomAtomizer(StringRef SectionName,
CustomAtomizeFunctions[SectionName] = std::move(Atomizer);
}
bool MachOAtomGraphBuilder::areLayoutLocked(const Atom &A, const Atom &B) {
// If these atoms are the same then they're trivially "locked".
if (&A == &B)
return true;
// If A and B are different, check whether either is undefined. (in which
// case they are not locked).
if (!A.isDefined() || !B.isDefined())
return false;
// A and B are different, but they're both defined atoms. We need to check
// whether they're part of the same alt_entry chain.
auto &DA = static_cast<const DefinedAtom &>(A);
auto &DB = static_cast<const DefinedAtom &>(B);
auto AStartItr = AltEntryStarts.find(&DA);
if (AStartItr == AltEntryStarts.end()) // If A is not in a chain bail out.
return false;
auto BStartItr = AltEntryStarts.find(&DB);
if (BStartItr == AltEntryStarts.end()) // If B is not in a chain bail out.
return false;
// A and B are layout locked if they're in the same chain.
return AStartItr->second == BStartItr->second;
}
unsigned
MachOAtomGraphBuilder::getPointerSize(const object::MachOObjectFile &Obj) {
return Obj.is64Bit() ? 8 : 4;
@ -153,9 +126,6 @@ Error MachOAtomGraphBuilder::addNonCustomAtoms() {
DenseMap<MachOSection *, AddrToAtomMap> SecToAtoms;
DenseMap<MachOSection *, unsigned> FirstOrdinal;
std::vector<DefinedAtom *> AltEntryAtoms;
DenseSet<StringRef> ProcessedSymbols; // Used to check for duplicate defs.
for (auto SymI = Obj.symbol_begin(), SymE = Obj.symbol_end(); SymI != SymE;
++SymI) {
@ -165,14 +135,6 @@ Error MachOAtomGraphBuilder::addNonCustomAtoms() {
if (!Name)
return Name.takeError();
// Bail out on duplicate definitions: There should never be more than one
// definition for a symbol in a given object file.
if (ProcessedSymbols.count(*Name))
return make_error<JITLinkError>("Duplicate definition within object: " +
*Name);
else
ProcessedSymbols.insert(*Name);
auto Addr = Sym.getAddress();
if (!Addr)
return Addr.takeError();
@ -227,35 +189,24 @@ Error MachOAtomGraphBuilder::addNonCustomAtoms() {
auto &Sec = SecByIndexItr->second;
auto &DA = G->addDefinedAtom(Sec.getGenericSection(), *Name, *Addr,
std::max(Sym.getAlignment(), 1U));
auto &A = G->addDefinedAtom(Sec.getGenericSection(), *Name, *Addr,
std::max(Sym.getAlignment(), 1U));
DA.setGlobal(Flags & object::SymbolRef::SF_Global);
DA.setExported(Flags & object::SymbolRef::SF_Exported);
DA.setWeak(Flags & object::SymbolRef::SF_Weak);
A.setGlobal(Flags & object::SymbolRef::SF_Global);
A.setExported(Flags & object::SymbolRef::SF_Exported);
A.setWeak(Flags & object::SymbolRef::SF_Weak);
DA.setCallable(*SymType & object::SymbolRef::ST_Function);
// Check alt-entry.
{
uint16_t NDesc = 0;
if (Obj.is64Bit())
NDesc = Obj.getSymbolTableEntry(SymI->getRawDataRefImpl()).n_desc;
else
NDesc = Obj.getSymbolTableEntry(SymI->getRawDataRefImpl()).n_desc;
if (NDesc & MachO::N_ALT_ENTRY)
AltEntryAtoms.push_back(&DA);
}
A.setCallable(*SymType & object::SymbolRef::ST_Function);
LLVM_DEBUG({
dbgs() << " Added " << *Name
<< " addr: " << format("0x%016" PRIx64, *Addr)
<< ", align: " << DA.getAlignment()
<< ", align: " << A.getAlignment()
<< ", section: " << Sec.getGenericSection().getName() << "\n";
});
auto &SecAtoms = SecToAtoms[&Sec];
SecAtoms[DA.getAddress() - Sec.getAddress()] = &DA;
SecAtoms[A.getAddress() - Sec.getAddress()] = &A;
}
// Add anonymous atoms.
@ -312,50 +263,6 @@ Error MachOAtomGraphBuilder::addNonCustomAtoms() {
}
}
LLVM_DEBUG(dbgs() << "Adding alt-entry starts\n");
// Sort alt-entry atoms by address in ascending order.
llvm::sort(AltEntryAtoms.begin(), AltEntryAtoms.end(),
[](const DefinedAtom *LHS, const DefinedAtom *RHS) {
return LHS->getAddress() < RHS->getAddress();
});
// Process alt-entry atoms in address order to build the table of alt-entry
// atoms to alt-entry chain starts.
for (auto *DA : AltEntryAtoms) {
assert(!AltEntryStarts.count(DA) && "Duplicate entry in AltEntryStarts");
// DA is an alt-entry atom. Look for the predecessor atom that it is locked
// to, bailing out if we do not find one.
auto AltEntryPred = G->findAtomByAddress(DA->getAddress() - 1);
if (!AltEntryPred)
return AltEntryPred.takeError();
// Add a LayoutNext edge from the predecessor to this atom.
AltEntryPred->addEdge(Edge::LayoutNext, 0, *DA, 0);
// Check to see whether the predecessor itself is an alt-entry atom.
auto AltEntryStartItr = AltEntryStarts.find(&*AltEntryPred);
if (AltEntryStartItr != AltEntryStarts.end()) {
// If the predecessor was an alt-entry atom then re-use its value.
AltEntryStarts[DA] = AltEntryStartItr->second;
LLVM_DEBUG({
dbgs() << " " << *DA << " -> " << *AltEntryStartItr->second
<< " (based on existing entry for " << *AltEntryPred << ")\n";
});
} else {
// If the predecessor does not have an entry then add an entry for this
// atom (i.e. the alt_entry atom) and a self-reference entry for the
/// predecessory atom that is the start of this chain.
AltEntryStarts[&*AltEntryPred] = &*AltEntryPred;
AltEntryStarts[DA] = &*AltEntryPred;
LLVM_DEBUG({
dbgs() << " " << *AltEntryPred << " -> " << *AltEntryPred << "\n"
<< " " << *DA << " -> " << *AltEntryPred << "\n";
});
}
}
return Error::success();
}

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@ -96,10 +96,6 @@ protected:
virtual Error addRelocations() = 0;
/// Returns true if Atom A and Atom B are at a fixed offset from one another
/// (i.e. if they're part of the same alt-entry chain).
bool areLayoutLocked(const Atom &A, const Atom &B);
private:
static unsigned getPointerSize(const object::MachOObjectFile &Obj);
static support::endianness getEndianness(const object::MachOObjectFile &Obj);
@ -112,7 +108,6 @@ private:
const object::MachOObjectFile &Obj;
std::unique_ptr<AtomGraph> G;
DenseMap<const DefinedAtom *, const DefinedAtom *> AltEntryStarts;
DenseMap<unsigned, MachOSection> Sections;
StringMap<CustomAtomizeFunction> CustomAtomizeFunctions;
Optional<MachOSection> CommonSymbolsSection;

View File

@ -181,20 +181,19 @@ private:
MachOX86RelocationKind DeltaKind;
Atom *TargetAtom;
uint64_t Addend;
if (areLayoutLocked(AtomToFix, *FromAtom)) {
if (&AtomToFix == &*FromAtom) {
TargetAtom = ToAtom;
DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32;
Addend = FixupValue + (FixupAddress - FromAtom->getAddress());
// FIXME: handle extern 'from'.
} else if (areLayoutLocked(AtomToFix, *ToAtom)) {
} else if (&AtomToFix == ToAtom) {
TargetAtom = &*FromAtom;
DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32;
Addend = FixupValue - (FixupAddress - ToAtom->getAddress());
} else {
// AtomToFix was neither FromAtom nor ToAtom.
return make_error<JITLinkError>("SUBTRACTOR relocation must fix up "
"either 'A' or 'B' (or an atom in one "
"of their alt-entry groups)");
"either 'A' or 'B'");
}
return PairRelocInfo(DeltaKind, TargetAtom, Addend);

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@ -129,19 +129,13 @@ Lanon_minuend_quad:
Lanon_minuend_long:
.long Lanon_minuend_long - named_data + 2
# Named quad storage target (first named atom in __data).
.globl named_data
.p2align 3
named_data:
.quad 0x2222222222222222
# An alt-entry point for named_data
.globl named_data_alt_entry
.p2align 3
.alt_entry named_data_alt_entry
named_data_alt_entry:
.quad 0
# Check X86_64_RELOC_UNSIGNED / extern handling by putting the address of a
# local named function in a pointer variable.
#
@ -207,60 +201,4 @@ minuend_quad3:
minuend_long3:
.long minuend_long3 - named_data + 2
# Check X86_64_RELOC_SUBTRACTOR handling for exprs of the form
# "A: .quad/long B - C + D", where 'B' or 'C' is at a fixed offset from 'A'
# (i.e. is part of an alt_entry chain that includes 'A').
#
# Check "A: .long B - C + D" where 'B' is an alt_entry for 'A'.
# jitlink-check: *{4}subtractor_with_alt_entry_minuend_long = (subtractor_with_alt_entry_minuend_long_B - named_data + 2)[31:0]
.globl subtractor_with_alt_entry_minuend_long
.p2align 2
subtractor_with_alt_entry_minuend_long:
.long subtractor_with_alt_entry_minuend_long_B - named_data + 2
.globl subtractor_with_alt_entry_minuend_long_B
.p2align 2
.alt_entry subtractor_with_alt_entry_minuend_long_B
subtractor_with_alt_entry_minuend_long_B:
.long 0
# Check "A: .quad B - C + D" where 'B' is an alt_entry for 'A'.
# jitlink-check: *{8}subtractor_with_alt_entry_minuend_quad = (subtractor_with_alt_entry_minuend_quad_B - named_data + 2)
.globl subtractor_with_alt_entry_minuend_quad
.p2align 3
subtractor_with_alt_entry_minuend_quad:
.quad subtractor_with_alt_entry_minuend_quad_B - named_data + 2
.globl subtractor_with_alt_entry_minuend_quad_B
.p2align 3
.alt_entry subtractor_with_alt_entry_minuend_quad_B
subtractor_with_alt_entry_minuend_quad_B:
.quad 0
# Check "A: .long B - C + D" where 'C' is an alt_entry for 'A'.
# jitlink-check: *{4}subtractor_with_alt_entry_subtrahend_long = (named_data - subtractor_with_alt_entry_subtrahend_long_B + 2)[31:0]
.globl subtractor_with_alt_entry_subtrahend_long
.p2align 2
subtractor_with_alt_entry_subtrahend_long:
.long named_data - subtractor_with_alt_entry_subtrahend_long_B + 2
.globl subtractor_with_alt_entry_subtrahend_long_B
.p2align 2
.alt_entry subtractor_with_alt_entry_subtrahend_long_B
subtractor_with_alt_entry_subtrahend_long_B:
.long 0
# Check "A: .quad B - C + D" where 'B' is an alt_entry for 'A'.
# jitlink-check: *{8}subtractor_with_alt_entry_subtrahend_quad = (named_data - subtractor_with_alt_entry_subtrahend_quad_B + 2)
.globl subtractor_with_alt_entry_subtrahend_quad
.p2align 3
subtractor_with_alt_entry_subtrahend_quad:
.quad named_data - subtractor_with_alt_entry_subtrahend_quad_B + 2
.globl subtractor_with_alt_entry_subtrahend_quad_B
.p2align 3
.alt_entry subtractor_with_alt_entry_subtrahend_quad_B
subtractor_with_alt_entry_subtrahend_quad_B:
.quad 0
.subsections_via_symbols