[DWARF v5] Improved support for .debug_rnglists (consumer). Enables any consumer to
extract DWARF v5 encoded rangelists.
Reviewer: JDevlieghere
Differential Revision: https://reviews.llvm.org/D45549
llvm-svn: 332759
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index 6fa604c..11cec59 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -14,6 +14,7 @@
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h"
#include "llvm/DebugInfo/DWARF/DWARFDie.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/Support/DataExtractor.h"
@@ -150,6 +151,29 @@
return true;
}
+// Parse the rangelist table header, including the optional array of offsets
+// following it (DWARF v5 and later).
+static Expected<DWARFDebugRnglistTable>
+parseRngListTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
+ // TODO: Support DWARF64
+ // We are expected to be called with Offset 0 or pointing just past the table
+ // header, which is 12 bytes long for DWARF32.
+ if (Offset > 0) {
+ if (Offset < 12U) {
+ std::string Buffer;
+ raw_string_ostream Stream(Buffer);
+ Stream << format(
+ "Did not detect a valid range list table with base = 0x%x", Offset);
+ return make_error<StringError>(Stream.str(), inconvertibleErrorCode());
+ }
+ Offset -= 12U;
+ }
+ llvm::DWARFDebugRnglistTable Table;
+ if (Error E = Table.extractHeaderAndOffsets(DA, &Offset))
+ return E;
+ return Table;
+}
+
bool DWARFUnit::extractRangeList(uint32_t RangeListOffset,
DWARFDebugRangeList &RangeList) const {
// Require that compile unit is extracted.
@@ -281,6 +305,32 @@
StringOffsetsTableContribution = determineStringOffsetsTableContribution(
DA, StringOffsetsContributionBase);
+ // DWARF v5 uses the .debug_rnglists and .debug_rnglists.dwo sections to
+ // describe address ranges.
+ if (getVersion() >= 5) {
+ if (isDWO)
+ setRangesSection(&Context.getDWARFObj().getRnglistsDWOSection(), 0);
+ else
+ setRangesSection(&Context.getDWARFObj().getRnglistsSection(),
+ toSectionOffset(UnitDie.find(DW_AT_rnglists_base), 0));
+ // Parse the range list table header. Individual range lists are
+ // extracted lazily.
+ DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection,
+ isLittleEndian, 0);
+ if (auto TableOrError =
+ parseRngListTableHeader(RangesDA, RangeSectionBase))
+ RngListTable = TableOrError.get();
+ else
+ WithColor::error() << "parsing a range list table: "
+ << toString(std::move(TableOrError.takeError()))
+ << '\n';
+
+ // In a split dwarf unit, there is no DW_AT_rnglists_base attribute.
+ // Adjust RangeSectionBase to point past the table header.
+ if (isDWO && RngListTable)
+ RangeSectionBase = RngListTable->getHeaderSize();
+ }
+
// Don't fall back to DW_AT_GNU_ranges_base: it should be ignored for
// skeleton CU DIE, so that DWARF users not aware of it are not broken.
}
@@ -319,8 +369,23 @@
DWO = std::shared_ptr<DWARFCompileUnit>(std::move(DWOContext), DWOCU);
// Share .debug_addr and .debug_ranges section with compile unit in .dwo
DWO->setAddrOffsetSection(AddrOffsetSection, AddrOffsetSectionBase);
- auto DWORangesBase = UnitDie.getRangesBaseAttribute();
- DWO->setRangesSection(RangeSection, DWORangesBase ? *DWORangesBase : 0);
+ if (getVersion() >= 5) {
+ DWO->setRangesSection(&Context.getDWARFObj().getRnglistsDWOSection(), 0);
+ DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection,
+ isLittleEndian, 0);
+ if (auto TableOrError = parseRngListTableHeader(RangesDA, RangeSectionBase))
+ DWO->RngListTable = TableOrError.get();
+ else
+ WithColor::error() << "parsing a range list table: "
+ << toString(std::move(TableOrError.takeError()))
+ << '\n';
+ if (DWO->RngListTable)
+ DWO->RangeSectionBase = DWO->RngListTable->getHeaderSize();
+ } else {
+ auto DWORangesBase = UnitDie.getRangesBaseAttribute();
+ DWO->setRangesSection(RangeSection, DWORangesBase ? *DWORangesBase : 0);
+ }
+
return true;
}
@@ -331,6 +396,28 @@
}
}
+DWARFAddressRangesVector DWARFUnit::findRnglistFromOffset(uint32_t Offset) {
+ if (getVersion() <= 4) {
+ DWARFDebugRangeList RangeList;
+ if (extractRangeList(Offset, RangeList))
+ return RangeList.getAbsoluteRanges(getBaseAddress());
+ return DWARFAddressRangesVector();
+ }
+ if (RngListTable) {
+ DWARFDataExtractor RangesData(Context.getDWARFObj(), *RangeSection,
+ isLittleEndian, RngListTable->getAddrSize());
+ if (auto RangeList = RngListTable->findRangeList(RangesData, Offset))
+ return RangeList->getAbsoluteRanges(getBaseAddress());
+ }
+ return DWARFAddressRangesVector();
+}
+
+DWARFAddressRangesVector DWARFUnit::findRnglistFromIndex(uint32_t Index) {
+ if (auto Offset = getRnglistOffset(Index))
+ return findRnglistFromOffset(*Offset + RangeSectionBase);
+ return DWARFAddressRangesVector();
+}
+
void DWARFUnit::collectAddressRanges(DWARFAddressRangesVector &CURanges) {
DWARFDie UnitDie = getUnitDIE();
if (!UnitDie)