[llvm] r338487 - [DWARF] Basic support for producing DWARFv5 .debug_addr section

Victor Leschuk via llvm-commits llvm-commits at lists.llvm.org
Tue Jul 31 22:48:06 PDT 2018


Author: vleschuk
Date: Tue Jul 31 22:48:06 2018
New Revision: 338487

URL: http://llvm.org/viewvc/llvm-project?rev=338487&view=rev
Log:
[DWARF] Basic support for producing DWARFv5 .debug_addr section

This revision implements support for generating DWARFv5 .debug_addr section.
The implementation is pretty straight-forward: we just check the dwarf version
and emit section header if needed.

Reviewers: aprantl, dblaikie, probinson

Reviewed by: dblaikie

Differential Revision: https://reviews.llvm.org/D50005


Added:
    llvm/trunk/test/DebugInfo/X86/debug_addr.ll
Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp
    llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp?rev=338487&r1=338486&r2=338487&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp Tue Jul 31 22:48:06 2018
@@ -24,8 +24,26 @@ unsigned AddressPool::getIndex(const MCS
   return IterBool.first->second.Number;
 }
 
+
+void AddressPool::emitHeader(AsmPrinter &Asm, MCSection *Section) {
+  static const uint8_t AddrSize = Asm.getDataLayout().getPointerSize();
+  Asm.OutStreamer->SwitchSection(Section);
+
+  uint64_t Length = sizeof(uint16_t) // version
+                  + sizeof(uint8_t)  // address_size
+                  + sizeof(uint8_t)  // segment_selector_size
+                  + AddrSize * Pool.size(); // entries
+  Asm.emitInt32(Length); // TODO: Support DWARF64 format.
+  Asm.emitInt16(Asm.getDwarfVersion());
+  Asm.emitInt8(AddrSize);
+  Asm.emitInt8(0); // TODO: Support non-zero segment_selector_size.
+}
+
 // Emit addresses into the section given.
 void AddressPool::emit(AsmPrinter &Asm, MCSection *AddrSection) {
+  if (Asm.getDwarfVersion() >= 5)
+    emitHeader(Asm, AddrSection);
+
   if (Pool.empty())
     return;
 

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h?rev=338487&r1=338486&r2=338487&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h Tue Jul 31 22:48:06 2018
@@ -50,6 +50,9 @@ public:
   bool hasBeenUsed() const { return HasBeenUsed; }
 
   void resetUsedFlag() { HasBeenUsed = false; }
+
+private:
+  void emitHeader(AsmPrinter &Asm, MCSection *Section);
 };
 
 } // end namespace llvm

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=338487&r1=338486&r2=338487&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Tue Jul 31 22:48:06 2018
@@ -886,8 +886,7 @@ void DwarfDebug::endModule() {
     emitDebugInfoDWO();
     emitDebugAbbrevDWO();
     emitDebugLineDWO();
-    // Emit DWO addresses.
-    AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
+    emitDebugAddr();
   }
 
   // Emit info into the dwarf accelerator table sections.
@@ -2297,6 +2296,12 @@ void DwarfDebug::emitDebugStrDWO() {
                          OffSec, /* UseRelativeOffsets = */ false);
 }
 
+// Emit DWO addresses.
+void DwarfDebug::emitDebugAddr() {
+  assert(useSplitDwarf() && "No split dwarf?");
+  AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
+}
+
 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
   if (!useSplitDwarf())
     return nullptr;

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h?rev=338487&r1=338486&r2=338487&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h Tue Jul 31 22:48:06 2018
@@ -447,6 +447,9 @@ class DwarfDebug : public DebugHandlerBa
   /// Emit the debug str dwo section.
   void emitDebugStrDWO();
 
+  /// Emit DWO addresses.
+  void emitDebugAddr();
+
   /// Flags to let the linker know we have emitted new style pubnames. Only
   /// emit it here if we don't have a skeleton CU for split dwarf.
   void addGnuPubAttributes(DwarfCompileUnit &U, DIE &D) const;

Added: llvm/trunk/test/DebugInfo/X86/debug_addr.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/debug_addr.ll?rev=338487&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/debug_addr.ll (added)
+++ llvm/trunk/test/DebugInfo/X86/debug_addr.ll Tue Jul 31 22:48:06 2018
@@ -0,0 +1,79 @@
+; RUN: llc -split-dwarf-file=test.dwo -dwarf-version=4 %s -mtriple=i386-unknown-linux-gnu -filetype=obj -o - | \
+; RUN: llvm-dwarfdump -v - | FileCheck %s -check-prefix=DWARF4
+
+; RUN: llc -split-dwarf-file=test.dwo -dwarf-version=5 %s -mtriple=i386-unknown-linux-gnu -filetype=obj -o - | \
+; RUN: llvm-dwarfdump -v - | FileCheck %s -check-prefix=DWARF5
+
+; Source:
+; void foo() {
+; }
+;
+; void bar() {
+; }
+
+; DWARF4: .debug_info contents:
+; DWARF4: Compile Unit:{{.*}}version = 0x0004
+; DWARF4-NOT: Compile Unit
+; DWARF4: DW_TAG_compile_unit
+; DWARF4-NOT: DW_TAG_{{.*}}
+; DWARF4: DW_AT_GNU_dwo_name{{.*}}test.dwo
+; DWARF4: DW_AT_GNU_addr_base{{.*}}0x00000000
+; DWARF4: .debug_addr contents:
+; DWARF4-NEXT: 0x00000000: Addr Section: length = 0x00000000, version = 0x0004, addr_size = 0x04, seg_size = 0x00
+; DWARF4-NEXT: Addrs: [
+; DWARF4-NEXT: 0x00000000
+; DWARF4-NEXT: 0x00000010
+; DWARF4-NEXT: ]
+
+; DWARF5: .debug_info contents:
+; DWARF5: Compile Unit:{{.*}}version = 0x0005
+; DWARF5-NOT: Compile Unit
+; DWARF5: DW_TAG_compile_unit
+; DWARF5-NOT: DW_TAG_{{.*}}
+; DWARF5: DW_AT_GNU_dwo_name{{.*}}test.dwo
+; DWARF5: DW_AT_GNU_addr_base{{.*}}0x00000000
+; DWARF5: .debug_addr contents:
+; DWARF5-NEXT: 0x00000000: Addr Section: length = 0x0000000c, version = 0x0005, addr_size = 0x04, seg_size = 0x00
+; DWARF5-NEXT: Addrs: [
+; DWARF5-NEXT: 0x00000000
+; DWARF5-NEXT: 0x00000010
+; DWARF5-NEXT: ]
+
+; ModuleID = './test.c'
+source_filename = "./test.c"
+target datalayout = "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i386-unknown-linux-gnu"
+
+; Function Attrs: noinline nounwind optnone
+define void @foo() #0 !dbg !8 {
+entry:
+  ret void, !dbg !12
+}
+
+; Function Attrs: noinline nounwind optnone
+define void @bar() #0 !dbg !13 {
+entry:
+  ret void, !dbg !14
+}
+
+attributes #0 = { noinline nounwind optnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.1", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "test.c", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 1, !"NumRegisterParameters", i32 0}
+!4 = !{i32 2, !"Dwarf Version", i32 5}
+!5 = !{i32 2, !"Debug Info Version", i32 3}
+!6 = !{i32 1, !"wchar_size", i32 4}
+!7 = !{!"clang version 6.0.1"}
+!8 = distinct !DISubprogram(name: "foo", scope: !9, file: !9, line: 1, type: !10, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, unit: !0)
+!9 = !DIFile(filename: "./test.c", directory: "/tmp")
+!10 = !DISubroutineType(types: !11)
+!11 = !{null}
+!12 = !DILocation(line: 2, column: 3, scope: !8)
+!13 = distinct !DISubprogram(name: "bar", scope: !9, file: !9, line: 5, type: !10, isLocal: false, isDefinition: true, scopeLine: 5, isOptimized: false, unit: !0)
+!14 = !DILocation(line: 6, column: 3, scope: !13)




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