[DWARF v5] Reposting r337981, which was reverted in r337997 due to a test failure in debuginfo_tests.
The test failure was caused by the compiler not emitting a __debug_ranges section with DWARF 4 and
earlier when no ranges are needed. The test checks for the existence regardless.
llvm-svn: 338081
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 5c3e6c8..32271a0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -426,8 +426,6 @@
} else {
addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
RangeSectionSym);
- if (DD->getDwarfVersion() >= 5)
- addRnglistsBase();
}
// Add the range list to the set of ranges to be emitted.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index d2f123c..8761fae 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -820,6 +820,10 @@
U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
}
+ if (getDwarfVersion() >= 5 && !useSplitDwarf() &&
+ !U.getRangeLists().empty())
+ U.addRnglistsBase();
+
auto *CUNode = cast<DICompileUnit>(P.first);
// If compile Unit has macros, emit "DW_AT_macro_info" attribute.
if (CUNode->getMacros())
@@ -2087,23 +2091,10 @@
}
}
-void DwarfDebug::emitDebugRnglists() {
-
- // Don't emit a rangelist table if there are no ranges.
- if (llvm::all_of(CUMap,
- [](const decltype(CUMap)::const_iterator::value_type &Pair) {
- DwarfCompileUnit *TheCU = Pair.second;
- if (auto *Skel = TheCU->getSkeleton())
- TheCU = Skel;
- return TheCU->getRangeLists().empty();
- }))
- return;
-
- assert(getDwarfVersion() >= 5 && "Dwarf version must be 5 or greater");
- // FIXME: As long as we don't support DW_RLE_base_addrx, we cannot generate
- // any tables in the .debug_rnglists.dwo section.
- Asm->OutStreamer->SwitchSection(
- Asm->getObjFileLowering().getDwarfRnglistsSection());
+// Emit the header of a DWARF 5 range list table. Returns the symbol that
+// designates the end of the table for the caller to emit when the table is
+// complete.
+static MCSymbol *emitRnglistsTableHeader(AsmPrinter *Asm, DwarfFile &Holder) {
// The length is described by a starting label right after the length field
// and an end label.
MCSymbol *TableStart = Asm->createTempSymbol("debug_rnglist_table_start");
@@ -2112,56 +2103,52 @@
Asm->EmitLabelDifference(TableEnd, TableStart, 4);
Asm->OutStreamer->EmitLabel(TableStart);
// Version number (DWARF v5 and later).
- Asm->emitInt16(getDwarfVersion());
+ Asm->emitInt16(Asm->OutStreamer->getContext().getDwarfVersion());
// Address size.
Asm->emitInt8(Asm->MAI->getCodePointerSize());
// Segment selector size.
Asm->emitInt8(0);
- MCSymbol *RnglistTableBaseSym =
- (useSplitDwarf() ? SkeletonHolder : InfoHolder).getRnglistsTableBaseSym();
+ MCSymbol *RnglistTableBaseSym = Holder.getRnglistsTableBaseSym();
// FIXME: Generate the offsets table and use DW_FORM_rnglistx with the
// DW_AT_ranges attribute. Until then set the number of offsets to 0.
Asm->emitInt32(0);
Asm->OutStreamer->EmitLabel(RnglistTableBaseSym);
-
- // Emit the individual range lists.
- for (const auto &I : CUMap) {
- DwarfCompileUnit *TheCU = I.second;
- if (auto *Skel = TheCU->getSkeleton())
- TheCU = Skel;
- for (const RangeSpanList &List : TheCU->getRangeLists())
- emitRangeList(Asm, TheCU, List);
- }
-
- Asm->OutStreamer->EmitLabel(TableEnd);
+ return TableEnd;
}
-/// Emit address ranges into the .debug_ranges section or DWARF v5 rangelists
-/// into the .debug_rnglists section.
+/// Emit address ranges into the .debug_ranges section or into the DWARF v5
+/// .debug_rnglists section.
void DwarfDebug::emitDebugRanges() {
if (CUMap.empty())
return;
+ auto NoRangesPresent = [this]() {
+ return llvm::all_of(
+ CUMap, [](const decltype(CUMap)::const_iterator::value_type &Pair) {
+ return Pair.second->getRangeLists().empty();
+ });
+ };
+
if (!useRangesSection()) {
- assert(llvm::all_of(
- CUMap,
- [](const decltype(CUMap)::const_iterator::value_type &Pair) {
- return Pair.second->getRangeLists().empty();
- }) &&
- "No debug ranges expected.");
+ assert(NoRangesPresent() && "No debug ranges expected.");
return;
}
- if (getDwarfVersion() >= 5) {
- emitDebugRnglists();
+ if (getDwarfVersion() >= 5 && NoRangesPresent())
return;
- }
// Start the dwarf ranges section.
- Asm->OutStreamer->SwitchSection(
- Asm->getObjFileLowering().getDwarfRangesSection());
+ MCSymbol *TableEnd = nullptr;
+ if (getDwarfVersion() >= 5) {
+ Asm->OutStreamer->SwitchSection(
+ Asm->getObjFileLowering().getDwarfRnglistsSection());
+ TableEnd = emitRnglistsTableHeader(Asm, useSplitDwarf() ? SkeletonHolder
+ : InfoHolder);
+ } else
+ Asm->OutStreamer->SwitchSection(
+ Asm->getObjFileLowering().getDwarfRangesSection());
// Grab the specific ranges for the compile units in the module.
for (const auto &I : CUMap) {
@@ -2174,6 +2161,9 @@
for (const RangeSpanList &List : TheCU->getRangeLists())
emitRangeList(Asm, TheCU, List);
}
+
+ if (TableEnd)
+ Asm->OutStreamer->EmitLabel(TableEnd);
}
void DwarfDebug::handleMacroNodes(DIMacroNodeArray Nodes, DwarfCompileUnit &U) {
@@ -2249,9 +2239,6 @@
SkeletonHolder.addUnit(std::move(NewU));
}
-// This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
-// DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
-// DW_AT_addr_base, DW_AT_ranges_base or DW_AT_rnglists_base.
DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
auto OwnedUnit = llvm::make_unique<DwarfCompileUnit>(
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 99dbac1..0c7be5d 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -423,8 +423,13 @@
void initSkeletonUnit(const DwarfUnit &U, DIE &Die,
std::unique_ptr<DwarfCompileUnit> NewU);
- /// Construct the split debug info compile unit for the debug info
- /// section.
+ /// Construct the split debug info compile unit for the debug info section.
+ /// In DWARF v5, the skeleton unit DIE may have the following attributes:
+ /// DW_AT_addr_base, DW_AT_comp_dir, DW_AT_dwo_name, DW_AT_high_pc,
+ /// DW_AT_low_pc, DW_AT_ranges, DW_AT_stmt_list, and DW_AT_str_offsets_base.
+ /// Prior to DWARF v5 it may also have DW_AT_GNU_dwo_id. DW_AT_GNU_dwo_name
+ /// is used instead of DW_AT_dwo_name, Dw_AT_GNU_addr_base instead of
+ /// DW_AT_addr_base, and DW_AT_GNU_ranges_base instead of DW_AT_rnglists_base.
DwarfCompileUnit &constructSkeletonCU(const DwarfCompileUnit &CU);
/// Emit the debug info dwo section.