MC/Mach-O: Explicitly track atoms, as represented by their defining symbol, for each fragment (not yet used).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103438 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index 60b6c7c..ad6ce79 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -31,6 +31,9 @@
MCAssembler Assembler;
MCSectionData *CurSectionData;
+ /// Track the current atom for each section.
+ DenseMap<const MCSectionData*, MCSymbolData*> CurrentAtomMap;
+
private:
MCFragment *getCurrentFragment() const {
assert(CurSectionData && "No current section!");
@@ -46,10 +49,17 @@
MCDataFragment *getOrCreateDataFragment() const {
MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
if (!F)
- F = new MCDataFragment(CurSectionData);
+ F = createDataFragment();
return F;
}
+ /// Create a new data fragment in the current section.
+ MCDataFragment *createDataFragment() const {
+ MCDataFragment *DF = new MCDataFragment(CurSectionData);
+ DF->setAtom(CurrentAtomMap.lookup(CurSectionData));
+ return DF;
+ }
+
public:
MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
raw_ostream &_OS, MCCodeEmitter *_Emitter)
@@ -159,12 +169,23 @@
assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
assert(CurSection && "Cannot emit before setting section!");
+ MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+
+ // Update the current atom map, if necessary.
+ bool MustCreateFragment = false;
+ if (Assembler.isSymbolLinkerVisible(&SD)) {
+ CurrentAtomMap[CurSectionData] = &SD;
+
+ // We have to create a new fragment, fragments cannot span atoms.
+ MustCreateFragment = true;
+ }
+
// FIXME: This is wasteful, we don't necessarily need to create a data
// fragment. Instead, we should mark the symbol as pointing into the data
// fragment if it exists, otherwise we should just queue the label and set its
// fragment pointer when we emit the next fragment.
- MCDataFragment *F = getOrCreateDataFragment();
- MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+ MCDataFragment *F =
+ MustCreateFragment ? createDataFragment() : getOrCreateDataFragment();
assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
SD.setFragment(F);
SD.setOffset(F->getContents().size());
@@ -302,6 +323,8 @@
MCFragment *F = new MCZeroFillFragment(Size, ByteAlignment, &SectData);
SD.setFragment(F);
+ if (Assembler.isSymbolLinkerVisible(&SD))
+ F->setAtom(&SD);
Symbol->setSection(*Section);
@@ -336,8 +359,10 @@
unsigned MaxBytesToEmit) {
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
- new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
- false /* EmitNops */, CurSectionData);
+ MCFragment *F = new MCAlignFragment(ByteAlignment, Value, ValueSize,
+ MaxBytesToEmit, /*EmitNops=*/false,
+ CurSectionData);
+ F->setAtom(CurrentAtomMap.lookup(CurSectionData));
// Update the maximum alignment on the current section if necessary.
if (ByteAlignment > CurSectionData->getAlignment())
@@ -348,8 +373,9 @@
unsigned MaxBytesToEmit) {
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
- new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
- true /* EmitNops */, CurSectionData);
+ MCFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
+ /*EmitNops=*/true, CurSectionData);
+ F->setAtom(CurrentAtomMap.lookup(CurSectionData));
// Update the maximum alignment on the current section if necessary.
if (ByteAlignment > CurSectionData->getAlignment())
@@ -358,7 +384,8 @@
void MCMachOStreamer::EmitValueToOffset(const MCExpr *Offset,
unsigned char Value) {
- new MCOrgFragment(*Offset, Value, CurSectionData);
+ MCFragment *F = new MCOrgFragment(*Offset, Value, CurSectionData);
+ F->setAtom(CurrentAtomMap.lookup(CurSectionData));
}
void MCMachOStreamer::EmitInstruction(const MCInst &Inst) {
@@ -401,6 +428,7 @@
// are going to often know that we can never fully resolve a fixup.
if (Assembler.getBackend().MayNeedRelaxation(Inst, AsmFixups)) {
MCInstFragment *IF = new MCInstFragment(Inst, CurSectionData);
+ IF->setAtom(CurrentAtomMap.lookup(CurSectionData));
// Add the fixups and data.
//