Commit b516ca06 authored by Vedant Kumar's avatar Vedant Kumar Committed by Hans Wennborg
Browse files

Revert "Reland: [DWARF] Allow cross-CU references of subprogram definitions" 

... as well as:
Revert "[DWARF] Defer creating declaration DIEs until we prepare call site info"

This reverts commit fa4701e1.

This reverts commit 79daafc9.

There have been reports of this assert getting hit:

CalleeDIE && "Could not find DIE for call site entry origin

(cherry picked from commit 802bec89)
parent b28b38a5

llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

+2 −2
Original line number Diff line number Diff line
@@ -968,8 +968,8 @@ DIE &DwarfCompileUnit::constructCallSiteEntryDIE( 
    addAddress(CallSiteDIE, getDwarf5OrGNUAttr(dwarf::DW_AT_call_target),

               MachineLocation(CallReg));

  } else {

    DIE *CalleeDIE = getDIE(CalleeSP);

    assert(CalleeDIE && "Could not find DIE for call site entry origin");

    DIE *CalleeDIE = getOrCreateSubprogramDIE(CalleeSP);

    assert(CalleeDIE && "Could not create DIE for call site entry origin");

    addDIEEntry(CallSiteDIE, getDwarf5OrGNUAttr(dwarf::DW_AT_call_origin),

                *CalleeDIE);

  }

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

+5 −19
Original line number Diff line number Diff line
@@ -540,14 +540,6 @@ void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &SrcCU, 
  }

}



DIE &DwarfDebug::constructSubprogramDefinitionDIE(const DISubprogram *SP) {

  DICompileUnit *Unit = SP->getUnit();

  assert(SP->isDefinition() && "Subprogram not a definition");

  assert(Unit && "Subprogram definition without parent unit");

  auto &CU = getOrCreateDwarfCompileUnit(Unit);

  return *CU.getOrCreateSubprogramDIE(SP);

}



/// Try to interpret values loaded into registers that forward parameters

/// for \p CallMI. Store parameters with interpreted value into \p Params.

static void collectCallSiteParameters(const MachineInstr *CallMI,
@@ -758,17 +750,6 @@ void DwarfDebug::constructCallSiteEntryDIEs(const DISubprogram &SP, 
        if (!CalleeDecl || !CalleeDecl->getSubprogram())

          continue;

        CalleeSP = CalleeDecl->getSubprogram();



        if (CalleeSP->isDefinition()) {

          // Ensure that a subprogram DIE for the callee is available in the

          // appropriate CU.

          constructSubprogramDefinitionDIE(CalleeSP);

        } else {

          // Create the declaration DIE if it is missing. This is required to

          // support compilation of old bitcode with an incomplete list of

          // retained metadata.

          CU.getOrCreateSubprogramDIE(CalleeSP);

        }

      }



      // TODO: Omit call site entries for runtime calls (objc_msgSend, etc).
@@ -924,6 +905,11 @@ DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) { 
    NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoSection());

  }



  // Create DIEs for function declarations used for call site debug info.

  for (auto Scope : DIUnit->getRetainedTypes())

    if (auto *SP = dyn_cast_or_null<DISubprogram>(Scope))

      NewCU.getOrCreateSubprogramDIE(SP);



  CUMap.insert({DIUnit, &NewCU});

  CUDieMap.insert({&NewCU.getUnitDie(), &NewCU});

  return NewCU;

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h

+0 −3
Original line number Diff line number Diff line
@@ -442,9 +442,6 @@ class DwarfDebug : public DebugHandlerBase { 
  /// Construct a DIE for this abstract scope.

  void constructAbstractSubprogramScopeDIE(DwarfCompileUnit &SrcCU, LexicalScope *Scope);



  /// Construct a DIE for the subprogram definition \p SP and return it.

  DIE &constructSubprogramDefinitionDIE(const DISubprogram *SP);



  /// Construct DIEs for call site entries describing the calls in \p MF.

  void constructCallSiteEntryDIEs(const DISubprogram &SP, DwarfCompileUnit &CU,

                                  DIE &ScopeDIE, const MachineFunction &MF);

llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp

+5 −4
Original line number Diff line number Diff line
@@ -188,9 +188,8 @@ int64_t DwarfUnit::getDefaultLowerBound() const { 


/// Check whether the DIE for this MDNode can be shared across CUs.

bool DwarfUnit::isShareableAcrossCUs(const DINode *D) const {

  // When the MDNode can be part of the type system (this includes subprogram

  // declarations *and* subprogram definitions, even local definitions), the

  // DIE must be shared across CUs.

  // When the MDNode can be part of the type system, the DIE can be shared

  // across CUs.

  // Combining type units and cross-CU DIE sharing is lower value (since

  // cross-CU DIE sharing is used in LTO and removes type redundancy at that

  // level already) but may be implementable for some value in projects
@@ -198,7 +197,9 @@ bool DwarfUnit::isShareableAcrossCUs(const DINode *D) const { 
  // together.

  if (isDwoUnit() && !DD->shareAcrossDWOCUs())

    return false;

  return (isa<DIType>(D) || isa<DISubprogram>(D)) && !DD->generateTypeUnits();

  return (isa<DIType>(D) ||

          (isa<DISubprogram>(D) && !cast<DISubprogram>(D)->isDefinition())) &&

         !DD->generateTypeUnits();

}



DIE *DwarfUnit::getDIE(const DINode *D) const {

llvm/test/DebugInfo/AArch64/unretained-declaration-subprogram.ll

deleted100644 → 0
+0 −44
Original line number Diff line number Diff line 
; RUN: llc -mtriple=arm64-apple-ios -filetype=obj < %s -o %t.o

; RUN: llvm-dwarfdump %t.o | FileCheck %s -implicit-check-not=DW_TAG_subprogram



; The declaration subprogram for "function" is not in the CU's list of

; retained types. Test that a DWARF call site entry can still be constructed.



; CHECK: DW_TAG_subprogram

; CHECK:   DW_AT_name {{.*}}__hidden#3_

; CHECK:   DW_TAG_call_site

; CHECK:     DW_AT_call_origin (0x{{0+}}[[FUNCTION_DIE:.*]])



; CHECK: 0x{{0+}}[[FUNCTION_DIE]]: DW_TAG_subprogram

; CHECK:   DW_AT_name {{.*}}function



target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"

target triple = "arm64-apple-ios9.0.0"



define i32 @main() local_unnamed_addr !dbg !8 {

  %1 = tail call [2 x i64] @function([2 x i64] zeroinitializer), !dbg !11

  %2 = extractvalue [2 x i64] %1, 0, !dbg !11

  %3 = trunc i64 %2 to i32, !dbg !11

  ret i32 %3, !dbg !12

}



declare !dbg !13 [2 x i64] @function([2 x i64]) local_unnamed_addr



!llvm.module.flags = !{!0, !1, !2, !3, !4}

!llvm.dbg.cu = !{!5}

!llvm.ident = !{!7}



!0 = !{i32 2, !"SDK Version", [2 x i32] [i32 13, i32 4]}

!1 = !{i32 7, !"Dwarf Version", i32 4}

!2 = !{i32 2, !"Debug Info Version", i32 3}

!3 = !{i32 1, !"wchar_size", i32 4}

!4 = !{i32 7, !"PIC Level", i32 2}

!5 = distinct !DICompileUnit(language: DW_LANG_C99, file: !6, producer: "__hidden#0_", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, nameTableKind: None)

!6 = !DIFile(filename: "__hidden#1_", directory: "__hidden#2_")

!7 = !{!"Apple clang version 11.0.0 (llvm-project fa407d93fd5e618d76378c1ce4e4f517e0563278) (+internal-os)"}

!8 = distinct !DISubprogram(name: "__hidden#3_", scope: !6, file: !6, line: 9, type: !9, scopeLine: 9, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !5)

!9 = !DISubroutineType(types: !10)

!10 = !{}

!11 = !DILocation(line: 12, column: 10, scope: !8)

!12 = !DILocation(line: 13, column: 3, scope: !8)

!13 = !DISubprogram(name: "function", scope: !6, file: !6, line: 7, type: !9, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)