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| author | Pavel Labath <labath@google.com> | 2018-04-09 14:38:53 +0000 |
|---|---|---|
| committer | Pavel Labath <labath@google.com> | 2018-04-09 14:38:53 +0000 |
| commit | eadfac87480b76f2069e41da9b92fe9f745fac8a (patch) | |
| tree | d8b10e583630f313942e9185271305ccaba73e35 | |
| parent | c1d6b5e458ed8d9f21b5548ef10c96dbdab9f476 (diff) | |
| download | bcm5719-llvm-eadfac87480b76f2069e41da9b92fe9f745fac8a.tar.gz bcm5719-llvm-eadfac87480b76f2069e41da9b92fe9f745fac8a.zip | |
[CodeGen/AccelTable] Don't emit zero-CU name indexes
Summary:
If an input DICompileUnit is completely empty (e.g., the result of
running "clang -g" on an empty file), we don't bother emitting an empty
DWARF CU. When we do that, we must make sure we don't also emit a DWARF v5
name index, as DWARF specifies that each index must reference at least
one compilation unit.
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45435
llvm-svn: 329575
| -rw-r--r-- | llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp | 2 | ||||
| -rw-r--r-- | llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 4 | ||||
| -rw-r--r-- | llvm/test/DebugInfo/Generic/debug-names-empty-cu.ll | 19 |
3 files changed, 25 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp index d6cfbdb37e5..1107e020696 100644 --- a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp @@ -356,6 +356,8 @@ void AppleAccelTableEmitter::emit() const { void Dwarf5AccelTableEmitter::Header::emit( const Dwarf5AccelTableEmitter &Ctx) const { + assert(CompUnitCount > 0 && "Index must have at least one CU."); + AsmPrinter *Asm = Ctx.Asm; Asm->OutStreamer->AddComment("Header: unit length"); Asm->EmitLabelDifference(Ctx.ContributionEnd, Ctx.ContributionStart, diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp index 5cd59b4da9e..177a094b68b 100644 --- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -1468,6 +1468,10 @@ void DwarfDebug::emitAccel(AccelTableT &Accel, MCSection *Section, } void DwarfDebug::emitAccelDebugNames() { + // Don't emit anything if we have no compilation units to index. + if (getUnits().empty()) + return; + Asm->OutStreamer->SwitchSection( Asm->getObjFileLowering().getDwarfDebugNamesSection()); emitDWARF5AccelTable(Asm, AccelDebugNames, *this, getUnits()); diff --git a/llvm/test/DebugInfo/Generic/debug-names-empty-cu.ll b/llvm/test/DebugInfo/Generic/debug-names-empty-cu.ll new file mode 100644 index 00000000000..d6ccaeca98b --- /dev/null +++ b/llvm/test/DebugInfo/Generic/debug-names-empty-cu.ll @@ -0,0 +1,19 @@ +; REQUIRES: object-emission +; RUN: %llc_dwarf -accel-tables=Dwarf -filetype=obj -o %t < %s +; RUN: llvm-dwarfdump -debug-names %t | FileCheck %s +; RUN: llvm-dwarfdump -debug-names -verify %t | FileCheck --check-prefix=VERIFY %s + +; CHECK-NOT: CU count: 0 +; VERIFY: No errors. + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4, !5} +!llvm.ident = !{!6} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 7.0.0 (trunk 329543) (llvm/trunk 329551)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2) +!1 = !DIFile(filename: "-", directory: "/tmp") +!2 = !{} +!3 = !{i32 2, !"Dwarf Version", i32 4} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!5 = !{i32 1, !"wchar_size", i32 4} +!6 = !{!"clang version 7.0.0 (trunk 329543) (llvm/trunk 329551)"} |
