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[dwarf][NFC] refactor emitRangeList function #164811

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[dwarf][NFC] refactor emitRangeList function #164811

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116 changes: 76 additions & 40 deletions llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3290,30 +3290,68 @@ static MCSymbol *emitLoclistsTableHeader(AsmPrinter *Asm,
return TableEnd;
}

template <typename Ranges, typename PayloadEmitter>
static void emitRangeList(
DwarfDebug &DD, AsmPrinter *Asm, MCSymbol *Sym, const Ranges &R,
const DwarfCompileUnit &CU, unsigned BaseAddressx, unsigned OffsetPair,
unsigned StartxLength, unsigned EndOfList,
StringRef (*StringifyEnum)(unsigned),
bool ShouldUseBaseAddress,
PayloadEmitter EmitPayload) {
namespace {

struct DebugLocSpanList {
MCSymbol *Label;
const DwarfCompileUnit *CU;
llvm::ArrayRef<llvm::DebugLocStream::Entry> Ranges;
};

template <typename DWARFSpanList> struct DwarfRangeListTraits {};

template <> struct DwarfRangeListTraits<DebugLocSpanList> {
static constexpr unsigned BaseAddressx = dwarf::DW_LLE_base_addressx;
static constexpr unsigned OffsetPair = dwarf::DW_LLE_offset_pair;
static constexpr unsigned StartxLength = dwarf::DW_LLE_startx_length;
static constexpr unsigned EndOfList = dwarf::DW_LLE_end_of_list;

static StringRef StringifyRangeKind(unsigned Encoding) {
return llvm::dwarf::LocListEncodingString(Encoding);
}

static void EmitPayload(DwarfDebug &DD, const DwarfCompileUnit *CU,
const llvm::DebugLocStream::Entry &E) {
DD.emitDebugLocEntryLocation(E, CU);
}
};

template <> struct DwarfRangeListTraits<RangeSpanList> {
static constexpr unsigned BaseAddressx = dwarf::DW_RLE_base_addressx;
static constexpr unsigned OffsetPair = dwarf::DW_RLE_offset_pair;
static constexpr unsigned StartxLength = dwarf::DW_RLE_startx_length;
static constexpr unsigned EndOfList = dwarf::DW_RLE_end_of_list;

static StringRef StringifyRangeKind(unsigned Encoding) {
return llvm::dwarf::RangeListEncodingString(Encoding);
}

static void EmitPayload(DwarfDebug &DD, const DwarfCompileUnit *CU,
const RangeSpan &E) {}
};

} // namespace

template <typename Ranges>
static void emitRangeList(DwarfDebug &DD, AsmPrinter *Asm, const Ranges &R,
bool ShouldUseBaseAddress) {

auto Size = Asm->MAI->getCodePointerSize();
bool UseDwarf5 = DD.getDwarfVersion() >= 5;

// Emit our symbol so we can find the beginning of the range.
Asm->OutStreamer->emitLabel(Sym);
Asm->OutStreamer->emitLabel(R.Label);

// Gather all the ranges that apply to the same section so they can share
// a base address entry.
SmallMapVector<const MCSection *, std::vector<decltype(&*R.begin())>, 16>
SmallMapVector<const MCSection *, std::vector<decltype(&*R.Ranges.begin())>,
16>
SectionRanges;

for (const auto &Range : R)
for (const auto &Range : R.Ranges)
SectionRanges[&Range.Begin->getSection()].push_back(&Range);

const MCSymbol *CUBase = CU.getBaseAddress();
const MCSymbol *CUBase = R.CU->getBaseAddress();
bool BaseIsSet = false;
for (const auto &P : SectionRanges) {
auto *Base = CUBase;
Expand Down Expand Up @@ -3342,8 +3380,10 @@ static void emitRangeList(
// * or, there's more than one entry to share the base address
Base = NewBase;
BaseIsSet = true;
Asm->OutStreamer->AddComment(StringifyEnum(BaseAddressx));
Asm->emitInt8(BaseAddressx);
Asm->OutStreamer->AddComment(
DwarfRangeListTraits<Ranges>::StringifyRangeKind(
DwarfRangeListTraits<Ranges>::BaseAddressx));
Asm->emitInt8(DwarfRangeListTraits<Ranges>::BaseAddressx);
Asm->OutStreamer->AddComment(" base address index");
Asm->emitULEB128(DD.getAddressPool().getIndex(Base));
}
Expand All @@ -3362,8 +3402,10 @@ static void emitRangeList(
if (Base) {
if (UseDwarf5) {
// Emit offset_pair when we have a base.
Asm->OutStreamer->AddComment(StringifyEnum(OffsetPair));
Asm->emitInt8(OffsetPair);
Asm->OutStreamer->AddComment(
DwarfRangeListTraits<Ranges>::StringifyRangeKind(
DwarfRangeListTraits<Ranges>::OffsetPair));
Asm->emitInt8(DwarfRangeListTraits<Ranges>::OffsetPair);
Asm->OutStreamer->AddComment(" starting offset");
Asm->emitLabelDifferenceAsULEB128(Begin, Base);
Asm->OutStreamer->AddComment(" ending offset");
Expand All @@ -3373,8 +3415,10 @@ static void emitRangeList(
Asm->emitLabelDifference(End, Base, Size);
}
} else if (UseDwarf5) {
Asm->OutStreamer->AddComment(StringifyEnum(StartxLength));
Asm->emitInt8(StartxLength);
Asm->OutStreamer->AddComment(
DwarfRangeListTraits<Ranges>::StringifyRangeKind(
DwarfRangeListTraits<Ranges>::StartxLength));
Asm->emitInt8(DwarfRangeListTraits<Ranges>::StartxLength);
Asm->OutStreamer->AddComment(" start index");
Asm->emitULEB128(DD.getAddressPool().getIndex(Begin));
Asm->OutStreamer->AddComment(" length");
Expand All @@ -3383,13 +3427,15 @@ static void emitRangeList(
Asm->OutStreamer->emitSymbolValue(Begin, Size);
Asm->OutStreamer->emitSymbolValue(End, Size);
}
EmitPayload(*RS);
DwarfRangeListTraits<Ranges>::EmitPayload(DD, R.CU, *RS);
}
}

if (UseDwarf5) {
Asm->OutStreamer->AddComment(StringifyEnum(EndOfList));
Asm->emitInt8(EndOfList);
Asm->OutStreamer->AddComment(
DwarfRangeListTraits<Ranges>::StringifyRangeKind(
DwarfRangeListTraits<Ranges>::EndOfList));
Asm->emitInt8(DwarfRangeListTraits<Ranges>::EndOfList);
} else {
// Terminate the list with two 0 values.
Asm->OutStreamer->emitIntValue(0, Size);
Expand All @@ -3399,14 +3445,9 @@ static void emitRangeList(

// Handles emission of both debug_loclist / debug_loclist.dwo
static void emitLocList(DwarfDebug &DD, AsmPrinter *Asm, const DebugLocStream::List &List) {
emitRangeList(DD, Asm, List.Label, DD.getDebugLocs().getEntries(List),
*List.CU, dwarf::DW_LLE_base_addressx,
dwarf::DW_LLE_offset_pair, dwarf::DW_LLE_startx_length,
dwarf::DW_LLE_end_of_list, llvm::dwarf::LocListEncodingString,
/* ShouldUseBaseAddress */ true,
[&](const DebugLocStream::Entry &E) {
DD.emitDebugLocEntryLocation(E, List.CU);
});
DebugLocSpanList Ranges = {List.Label, List.CU,
DD.getDebugLocs().getEntries(List)};
emitRangeList(DD, Asm, Ranges, /* ShouldUseBaseAddress */ true);
}

void DwarfDebug::emitDebugLocImpl(MCSection *Sec) {
Expand All @@ -3428,10 +3469,9 @@ void DwarfDebug::emitDebugLocImpl(MCSection *Sec) {

// Emit locations into the .debug_loc/.debug_loclists section.
void DwarfDebug::emitDebugLoc() {
emitDebugLocImpl(
getDwarfVersion() >= 5
? Asm->getObjFileLowering().getDwarfLoclistsSection()
: Asm->getObjFileLowering().getDwarfLocSection());
emitDebugLocImpl(getDwarfVersion() >= 5
? Asm->getObjFileLowering().getDwarfLoclistsSection()
: Asm->getObjFileLowering().getDwarfLocSection());
}

// Emit locations into the .debug_loc.dwo/.debug_loclists.dwo section.
Expand Down Expand Up @@ -3626,13 +3666,9 @@ void DwarfDebug::emitDebugARanges() {
/// Emit a single range list. We handle both DWARF v5 and earlier.
static void emitRangeList(DwarfDebug &DD, AsmPrinter *Asm,
const RangeSpanList &List) {
emitRangeList(DD, Asm, List.Label, List.Ranges, *List.CU,
dwarf::DW_RLE_base_addressx, dwarf::DW_RLE_offset_pair,
dwarf::DW_RLE_startx_length, dwarf::DW_RLE_end_of_list,
llvm::dwarf::RangeListEncodingString,
List.CU->getCUNode()->getRangesBaseAddress() ||
DD.getDwarfVersion() >= 5,
[](auto) {});
bool ShouldUseBaseAddress =
List.CU->getCUNode()->getRangesBaseAddress() || DD.getDwarfVersion() >= 5;
emitRangeList(DD, Asm, List, ShouldUseBaseAddress);
}

void DwarfDebug::emitDebugRangesImpl(const DwarfFile &Holder, MCSection *Section) {
Expand Down