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Diffstat (limited to 'lib/MC/MachObjectWriter.cpp')
-rw-r--r--lib/MC/MachObjectWriter.cpp101
1 files changed, 85 insertions, 16 deletions
diff --git a/lib/MC/MachObjectWriter.cpp b/lib/MC/MachObjectWriter.cpp
index 1236dc1126..de96d64c27 100644
--- a/lib/MC/MachObjectWriter.cpp
+++ b/lib/MC/MachObjectWriter.cpp
@@ -197,6 +197,34 @@ class MachObjectWriter : public MCObjectWriter {
/// @}
+ SectionAddrMap SectionAddress;
+ uint64_t getSectionAddress(const MCSectionData* SD) const {
+ return SectionAddress.lookup(SD);
+ }
+ uint64_t getSymbolAddress(const MCSymbolData* SD,
+ const MCAsmLayout &Layout) const {
+ return getSectionAddress(SD->getFragment()->getParent()) +
+ Layout.getSymbolOffset(SD);
+ }
+ uint64_t getFragmentAddress(const MCFragment *Fragment,
+ const MCAsmLayout &Layout) const {
+ return getSectionAddress(Fragment->getParent()) +
+ Layout.getFragmentOffset(Fragment);
+ }
+
+ uint64_t getPaddingSize(const MCSectionData *SD,
+ const MCAsmLayout &Layout) const {
+ uint64_t EndAddr = getSectionAddress(SD) + Layout.getSectionAddressSize(SD);
+ unsigned Next = SD->getLayoutOrder() + 1;
+ if (Next >= Layout.getSectionOrder().size())
+ return 0;
+
+ const MCSectionData &NextSD = *Layout.getSectionOrder()[Next];
+ if (NextSD.getSection().isVirtualSection())
+ return 0;
+ return OffsetToAlignment(EndAddr, NextSD.getAlignment());
+ }
+
unsigned Is64Bit : 1;
uint32_t CPUType;
@@ -283,7 +311,7 @@ public:
void WriteSection(const MCAssembler &Asm, const MCAsmLayout &Layout,
const MCSectionData &SD, uint64_t FileOffset,
uint64_t RelocationsStart, unsigned NumRelocations) {
- uint64_t SectionSize = Layout.getSectionSize(&SD);
+ uint64_t SectionSize = Layout.getSectionAddressSize(&SD);
// The offset is unused for virtual sections.
if (SD.getSection().isVirtualSection()) {
@@ -301,10 +329,10 @@ public:
WriteBytes(Section.getSectionName(), 16);
WriteBytes(Section.getSegmentName(), 16);
if (Is64Bit) {
- Write64(Layout.getSectionAddress(&SD)); // address
+ Write64(getSectionAddress(&SD)); // address
Write64(SectionSize); // size
} else {
- Write32(Layout.getSectionAddress(&SD)); // address
+ Write32(getSectionAddress(&SD)); // address
Write32(SectionSize); // size
}
Write32(FileOffset);
@@ -413,7 +441,7 @@ public:
if (Symbol.isAbsolute()) {
Address = cast<MCConstantExpr>(Symbol.getVariableValue())->getValue();
} else {
- Address = Layout.getSymbolAddress(&Data);
+ Address = getSymbolAddress(&Data, Layout);
}
} else if (Data.isCommon()) {
// Common symbols are encoded with the size in the address
@@ -473,7 +501,7 @@ public:
uint32_t FixupOffset =
Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
uint32_t FixupAddress =
- Layout.getFragmentAddress(Fragment) + Fixup.getOffset();
+ getFragmentAddress(Fragment, Layout) + Fixup.getOffset();
int64_t Value = 0;
unsigned Index = 0;
unsigned IsExtern = 0;
@@ -603,10 +631,21 @@ public:
// The index is the section ordinal (1-based).
Index = SD.getFragment()->getParent()->getOrdinal() + 1;
IsExtern = 0;
- Value += Layout.getSymbolAddress(&SD);
+ Value += getSymbolAddress(&SD, Layout);
if (IsPCRel)
Value -= FixupAddress + (1 << Log2Size);
+ } else if (Symbol->isVariable()) {
+ const MCExpr *Value = Symbol->getVariableValue();
+ int64_t Res;
+ bool isAbs = Value->EvaluateAsAbsolute(Res, Layout, SectionAddress);
+ if (isAbs) {
+ FixedValue = Res;
+ return;
+ } else {
+ report_fatal_error("unsupported relocation of variable '" +
+ Symbol->getName() + "'");
+ }
} else {
report_fatal_error("unsupported relocation of undefined symbol '" +
Symbol->getName() + "'");
@@ -708,7 +747,9 @@ public:
report_fatal_error("symbol '" + A->getName() +
"' can not be undefined in a subtraction expression");
- uint32_t Value = Layout.getSymbolAddress(A_SD);
+ uint32_t Value = getSymbolAddress(A_SD, Layout);
+ uint64_t SecAddr = getSectionAddress(A_SD->getFragment()->getParent());
+ FixedValue += SecAddr;
uint32_t Value2 = 0;
if (const MCSymbolRefExpr *B = Target.getSymB()) {
@@ -725,7 +766,8 @@ public:
// for pedantic compatibility with 'as'.
Type = A_SD->isExternal() ? macho::RIT_Difference :
macho::RIT_LocalDifference;
- Value2 = Layout.getSymbolAddress(B_SD);
+ Value2 = getSymbolAddress(B_SD, Layout);
+ FixedValue -= getSectionAddress(B_SD->getFragment()->getParent());
}
// Relocations are written out in reverse order, so the PAIR comes first.
@@ -774,10 +816,10 @@ public:
if (Target.getSymB()) {
// If this is a subtraction then we're pcrel.
uint32_t FixupAddress =
- Layout.getFragmentAddress(Fragment) + Fixup.getOffset();
+ getFragmentAddress(Fragment, Layout) + Fixup.getOffset();
MCSymbolData *SD_B = &Asm.getSymbolData(Target.getSymB()->getSymbol());
IsPCRel = 1;
- FixedValue = (FixupAddress - Layout.getSymbolAddress(SD_B) +
+ FixedValue = (FixupAddress - getSymbolAddress(SD_B, Layout) +
Target.getConstant());
FixedValue += 1ULL << Log2Size;
} else {
@@ -855,10 +897,13 @@ public:
// compensate for the addend of the symbol address, if it was
// undefined. This occurs with weak definitions, for example.
if (!SD->Symbol->isUndefined())
- FixedValue -= Layout.getSymbolAddress(SD);
+ FixedValue -= getSymbolAddress(SD, Layout);
} else {
// The index is the section ordinal (1-based).
Index = SD->getFragment()->getParent()->getOrdinal() + 1;
+ FixedValue += getSectionAddress(SD->getFragment()->getParent());
+ if (IsPCRel)
+ FixedValue -= getSectionAddress(Fragment->getParent());
}
Type = macho::RIT_Vanilla;
@@ -1039,7 +1084,25 @@ public:
StringTable += '\x00';
}
- void ExecutePostLayoutBinding(MCAssembler &Asm) {
+ void computeSectionAddresses(const MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
+ uint64_t StartAddress = 0;
+ const SmallVectorImpl<MCSectionData*> &Order = Layout.getSectionOrder();
+ for (int i = 0, n = Order.size(); i != n ; ++i) {
+ const MCSectionData *SD = Order[i];
+ StartAddress = RoundUpToAlignment(StartAddress, SD->getAlignment());
+ SectionAddress[SD] = StartAddress;
+ StartAddress += Layout.getSectionAddressSize(SD);
+ // Explicitly pad the section to match the alignment requirements of the
+ // following one. This is for 'gas' compatibility, it shouldn't
+ /// strictly be necessary.
+ StartAddress += getPaddingSize(SD, Layout);
+ }
+ }
+
+ void ExecutePostLayoutBinding(MCAssembler &Asm, const MCAsmLayout &Layout) {
+ computeSectionAddresses(Asm, Layout);
+
// Create symbol data for any indirect symbols.
BindIndirectSymbols(Asm);
@@ -1113,9 +1176,10 @@ public:
for (MCAssembler::const_iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
const MCSectionData &SD = *it;
- uint64_t Address = Layout.getSectionAddress(&SD);
- uint64_t Size = Layout.getSectionSize(&SD);
+ uint64_t Address = getSectionAddress(&SD);
+ uint64_t Size = Layout.getSectionAddressSize(&SD);
uint64_t FileSize = Layout.getSectionFileSize(&SD);
+ FileSize += getPaddingSize(&SD, Layout);
VMSize = std::max(VMSize, Address + Size);
@@ -1144,7 +1208,7 @@ public:
ie = Asm.end(); it != ie; ++it) {
std::vector<macho::RelocationEntry> &Relocs = Relocations[it];
unsigned NumRelocs = Relocs.size();
- uint64_t SectionStart = SectionDataStart + Layout.getSectionAddress(it);
+ uint64_t SectionStart = SectionDataStart + getSectionAddress(it);
WriteSection(Asm, Layout, *it, SectionStart, RelocTableEnd, NumRelocs);
RelocTableEnd += NumRelocs * macho::RelocationInfoSize;
}
@@ -1185,9 +1249,14 @@ public:
// Write the actual section data.
for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it)
+ ie = Asm.end(); it != ie; ++it) {
Asm.WriteSectionData(it, Layout, this);
+ uint64_t Pad = getPaddingSize(it, Layout);
+ for (unsigned int i = 0; i < Pad; ++i)
+ Write8(0);
+ }
+
// Write the extra padding.
WriteZeros(SectionDataPadding);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-04-28 02:01:07 +0000