[DWARF] Revert sharing subprograms across CUs

[jmorse]

Summary

Over in D70350, DW_TAG_subprograms were permitted to be referenced across CU boundaries, to improve stack trace construction using call site information. Unfortunately, as documented in PR48790 [0], the way that subprograms are "owned" by dwarf units is sufficiently complicated that subprograms end up in unexpected units, invalidating cross-unit references.

I tried to fix this in D94976, however it uncovered additional problems with unit ownership of subprograms. @kyulee reports running into illegal DWARF references too, thus we're left with the choices of:

• Knowingly emitting illegal DWARF in certain circumstances,
• Damaging stack traces in certain circumstances.

Of which I would pick the latter: it's better to sometimes have a worse debugging experience, than to have scenarios where debugging is completely impossible. Opinions may vary; feedback most appreciated, especially @vsk @aprantl who'll suffer the backtrace damage. The intention is to cherry-pick this into llvm-13 too.

This patch is a revert of e08f205f5c2c, with some light conflicts around the declaration of constructCallSiteEntryDIE, nothing especially interesting. Three tests change in addition to the reversion:

• dbgcall-site-indirect-param.mir , has an additional function and DW_TAG_formal_parameter placed ahead of the targeted function in dwarfdump output,
• callsite-stack-value.mir , same problem as dbgcall-site-indirect-param.mir
• convert-loclist.ll : the DWO_id number changes, which I don't think is a suprise.

In addition I've added subprogram-across-cus.ll from D94976 as a regression test, it compiles some IR and then runs llvm-dwarfdump -verify on it.

[0] https://bugs.llvm.org/show_bug.cgi?id=48790

[dblaikie]

I'm generally in favor of this direction forward - I don't think it should fall to you to fix the debug info and if it isn't at the top of @vsk's list for a bit, let's fallback to known good-ish state for now.

@vsk - you might want to talk to @dexonsmith and @aprantl about the IR representation of these extra DISubprogram declarations that're being used for call site metadata, their lack of appropriate deduplication I think means you/we should consider some significant representational changes/fixes to make this work more reliably/consistently. See https://reviews.llvm.org/D94976#2508262 for more details.

[vsk]

Hi @jmorse, thanks so much for putting this together. I agree that reverting does seem like the best option right now.

llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h

public:
 
   /// This takes a DWARF 5 attribute and returns it or a GNU analog.
   dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const;
 
   /// This takes a DWARF 5 location atom and either returns it or a GNU analog.
   dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const;
 
   /// Construct a call site entry DIE describing a call within \p Scope to a
-  /// callee described by \p CalleeDIE.
-  /// \p CalleeDIE is a declaration or definition subprogram DIE for the callee.
-  /// For indirect calls \p CalleeDIE is set to nullptr.
+  /// callee described by \p CalleeSP.
   /// \p IsTail specifies whether the call is a tail call.
   /// \p PCAddr points to the PC value after the call instruction.
   /// \p CallAddr points to the PC value at the call instruction (or is null).
   /// \p CallReg is a register location for an indirect call. For direct calls
   /// the \p CallReg is set to 0.
-  DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, DIE *CalleeDIE, bool IsTail,
-                                 const MCSymbol *PCAddr,
+  DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP,
+                                 bool IsTail, const MCSymbol *PCAddr,
                                  const MCSymbol *CallAddr, unsigned CallReg);
   /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params
   /// were collected by the \ref collectCallSiteParameters.
   /// Note: The order of parameters does not matter, since debuggers recognize
   ///       call site parameters by the DW_AT_location attribute.
   void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE,
                                       SmallVector<DbgCallSiteParam, 4> &Params);
 

llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

DwarfCompileUnit::getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const {
   case dwarf::DW_OP_entry_value:
     return dwarf::DW_OP_GNU_entry_value;
   default:
     llvm_unreachable("DWARF5 location atom with no GNU analog");
   }
 }
 
 DIE &DwarfCompileUnit::constructCallSiteEntryDIE(DIE &ScopeDIE,
-                                                 DIE *CalleeDIE,
+                                                 const DISubprogram *CalleeSP,
                                                  bool IsTail,
                                                  const MCSymbol *PCAddr,
                                                  const MCSymbol *CallAddr,
                                                  unsigned CallReg) {
   // Insert a call site entry DIE within ScopeDIE.
   DIE &CallSiteDIE = createAndAddDIE(getDwarf5OrGNUTag(dwarf::DW_TAG_call_site),
                                      ScopeDIE, nullptr);
 
   if (CallReg) {
     // Indirect call.
     addAddress(CallSiteDIE, getDwarf5OrGNUAttr(dwarf::DW_AT_call_target),
                MachineLocation(CallReg));
   } else {
-    assert(CalleeDIE && "No 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);
   }
 
   if (IsTail) {
     // Attach DW_AT_call_tail_call to tail calls for standards compliance.
     addFlag(CallSiteDIE, getDwarf5OrGNUAttr(dwarf::DW_AT_call_tail_call));
 

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h

DbgEntity *createConcreteEntity(DwarfCompileUnit &TheCU,
                                   LexicalScope &Scope,
                                   const DINode *Node,
                                   const DILocation *Location,
                                   const MCSymbol *Sym = nullptr);
 
   /// 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);
 
   template <typename DataT>
   void addAccelNameImpl(const DICompileUnit &CU, AccelTable<DataT> &AppleAccel,
                         StringRef Name, const DIE &Die);
 

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

if (auto *SkelCU = CU.getSkeleton()) {
           .constructAbstractSubprogramScopeDIE(Scope);
       if (CU.getCUNode()->getSplitDebugInlining())
         SkelCU->constructAbstractSubprogramScopeDIE(Scope);
     } else
       CU.constructAbstractSubprogramScopeDIE(Scope);
   }
 }
 
-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);
-}
-
 /// Represents a parameter whose call site value can be described by applying a
 /// debug expression to a register in the forwarded register worklist.
 struct FwdRegParamInfo {
   /// The described parameter register.
   unsigned ParamReg;
 
   /// Debug expression that has been built up when walking through the
   /// instruction chain that produces the parameter's value.
for (const MachineInstr &MI : MBB.instrs()) {
       // the callee.
       const MachineOperand &CalleeOp = TII->getCalleeOperand(MI);
       if (!CalleeOp.isGlobal() &&
           (!CalleeOp.isReg() ||
            !Register::isPhysicalRegister(CalleeOp.getReg())))
         continue;
 
       unsigned CallReg = 0;
-      DIE *CalleeDIE = nullptr;
+      const DISubprogram *CalleeSP = nullptr;
       const Function *CalleeDecl = nullptr;
       if (CalleeOp.isReg()) {
         CallReg = CalleeOp.getReg();
         if (!CallReg)
           continue;
       } else {
         CalleeDecl = dyn_cast<Function>(CalleeOp.getGlobal());
         if (!CalleeDecl || !CalleeDecl->getSubprogram())
           continue;
-        const DISubprogram *CalleeSP = CalleeDecl->getSubprogram();
-
-        if (CalleeSP->isDefinition()) {
-          // Ensure that a subprogram DIE for the callee is available in the
-          // appropriate CU.
-          CalleeDIE = &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.
-          CalleeDIE = CU.getOrCreateSubprogramDIE(CalleeSP);
-        }
-        assert(CalleeDIE && "Must have a DIE for the callee");
+        CalleeSP = CalleeDecl->getSubprogram();
       }
 
       // TODO: Omit call site entries for runtime calls (objc_msgSend, etc).
 
       bool IsTail = TII->isTailCall(MI);
 
       // If MI is in a bundle, the label was created after the bundle since
       // EmitFunctionBody iterates over top-level MIs. Get that top-level MI
for (const MachineInstr &MI : MBB.instrs()) {
       LLVM_DEBUG(dbgs() << "CallSiteEntry: " << MF.getName() << " -> "
                         << (CalleeDecl ? CalleeDecl->getName()
                                        : StringRef(MF.getSubtarget()
                                                        .getRegisterInfo()
                                                        ->getName(CallReg)))
                         << (IsTail ? " [IsTail]" : "") << "\n");
 
       DIE &CallSiteDIE = CU.constructCallSiteEntryDIE(
-          ScopeDIE, CalleeDIE, IsTail, PCAddr, CallAddr, CallReg);
+          ScopeDIE, CalleeSP, IsTail, PCAddr, CallAddr, CallReg);
 
       // Optionally emit call-site-param debug info.
       if (emitDebugEntryValues()) {
         ParamSet Params;
         // Try to interpret values of call site parameters.
         collectCallSiteParameters(&MI, Params);
         CU.constructCallSiteParmEntryDIEs(CallSiteDIE, Params);
       }
DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) {
   if (useSplitDwarf()) {
     NewCU.setSkeleton(constructSkeletonCU(NewCU));
     NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
   } else {
     finishUnitAttributes(DIUnit, NewCU);
     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;
 }
 
 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
                                                   const DIImportedEntity *N) {
   if (isa<DILocalScope>(N->getScope()))

llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp

case dwarf::DW_LANG_Modula3:
     break;
   }
 
   return -1;
 }
 
 /// 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
   // building multiple independent libraries with LTO and then linking those
   // 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 {
   if (isShareableAcrossCUs(D))
     return DU->getDIE(D);
   return MDNodeToDieMap.lookup(D);
 }
 

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

-; 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)

llvm/test/DebugInfo/MIR/AArch64/dbgcall-site-indirect-param.mir

 # MIR:      renamable $w0 = LDRWui killed renamable $x8
 # MIR-NEXT: DBG_VALUE $x0, 0, {{.*}}, !DIExpression(DW_OP_LLVM_entry_value, 1)
 # MIR-NEXT: BL @baz
 # MIR-NEXT: frame-destroy LDPXpost
 # MIR-NEXT: TCRETURNdi @baz
 
 # After w0 is clobbered, we should get an indirect parameter entry value for "f".
 
+# DWARF-LABEL: DW_TAG_subprogram
+# DWARF:       DW_AT_name ("baz")
+
+# DWARF-LABEL: DW_TAG_subprogram
 # DWARF-LABEL: DW_TAG_formal_parameter
 # DWARF-NEXT: DW_AT_location
 # DWARF-NEXT: [0x0000000000000000, 0x0000000000000010): DW_OP_breg0 W0+0
 # DWARF-NEXT: [0x0000000000000010, 0x000000000000001c): DW_OP_entry_value(DW_OP_reg0 W0))
 # DWARF-NEXT: DW_AT_name    ("f")
 
 --- |
   target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"

llvm/test/DebugInfo/MIR/AArch64/dbgcall-site-orr-moves.mir

bb.0.entry:
     DBG_VALUE $w0, $noreg, !23, !DIExpression(DW_OP_LLVM_entry_value, 1), debug-location !24
     $w0 = ORRWrs $wzr, $wzr, 0, debug-location !26
     early-clobber $sp, $fp, $lr = frame-destroy LDPXpost $sp, 2, debug-location !26 :: (load (s64) from %stack.1), (load (s64) from %stack.0)
     RET undef $lr, implicit killed $w0, debug-location !26
 
 ...
 
 # CHECK: DW_TAG_GNU_call_site
-# CHECK-NEXT: DW_AT_abstract_origin ({{.*}} "call_int")
+# CHECK-NEXT: DW_AT_abstract_origin (0x0000002a "call_int")
 #
 # CHECK: DW_TAG_GNU_call_site_parameter
 # CHECK-NEXT: DW_AT_location      (DW_OP_reg0 W0)
 # CHECK-NEXT: DW_AT_GNU_call_site_value   (DW_OP_GNU_entry_value(DW_OP_reg0 W0))
 
 ---
 name:            super_reg
 alignment:       4
bb.0.entry:
     BL @call_long, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit killed $x0, implicit-def $sp, debug-location !34
     $w0 = ORRWrs $wzr, $wzr, 0, debug-location !35
     early-clobber $sp, $fp, $lr = frame-destroy LDPXpost $sp, 2, debug-location !35 :: (load (s64) from %stack.1), (load (s64) from %stack.0)
     RET undef $lr, implicit killed $w0, debug-location !35
 
 ...
 
 # CHECK: DW_TAG_GNU_call_site
-# CHECK-NEXT: DW_AT_abstract_origin ({{.*}} "call_long")
+# CHECK-NEXT: DW_AT_abstract_origin (0x0000003e "call_long")
 #
 # CHECK: DW_TAG_GNU_call_site_parameter
 # CHECK-NEXT: DW_AT_location      (DW_OP_reg0 W0)
 # CHECK-NEXT: DW_AT_GNU_call_site_value   (DW_OP_GNU_entry_value(DW_OP_reg0 W0))
 
 ---
 name:            sub_reg
 alignment:       4
bb.0.entry:
     DBG_VALUE $w0, $noreg, !40, !DIExpression(), debug-location !42
     $x19 = frame-destroy LDRXui $sp, 2, debug-location !44 :: (load (s64) from %stack.0)
     early-clobber $sp, $fp, $lr = frame-destroy LDPXpost $sp, 4, debug-location !44 :: (load (s64) from %stack.2), (load (s64) from %stack.1)
     RET undef $lr, implicit killed $w0, debug-location !44
 
 ...
 
 # CHECK: DW_TAG_GNU_call_site
-# CHECK-NEXT: DW_AT_abstract_origin ({{.*}} "call_int_int")
+# CHECK-NEXT: DW_AT_abstract_origin (0x00000052 "call_int_int")
 #
 # CHECK: DW_TAG_GNU_call_site_parameter
 # CHECK-NEXT: DW_AT_location      (DW_OP_reg0 W0)
 # CHECK-NEXT: DW_AT_GNU_call_site_value   (DW_OP_GNU_entry_value(DW_OP_reg1 W1))

llvm/test/DebugInfo/MIR/X86/callsite-stack-value.mir

 # RUN: llc -start-after=livedebugvalues -mtriple=x86_64-apple-darwin -o - %s -filetype=obj \
 # RUN:   -emit-call-site-info | llvm-dwarfdump - | FileCheck %s -implicit-check-not=call_site_parameter
 
-# CHECK: DW_TAG_formal_parameter
-# CHECK-NEXT: DW_AT_location (DW_OP_reg17 XMM0)
+# CHECK-LABEL: DW_TAG_subprogram
+# CHECK:       DW_AT_name ("f")
+# CHECK-LABEL: DW_TAG_subprogram
+# CHECK:       DW_AT_name ("g")
+# CHECK:       DW_TAG_formal_parameter
+# CHECK-NEXT:  DW_AT_location (DW_OP_reg17 XMM0)
 
 # struct S {
 #   float w;
 # };
 # void f(long w, long b);
 # void g(struct S s) {
 #   int w = s.w;
 #   f(w, w*4);

llvm/test/DebugInfo/MIR/X86/debug-call-site-param.mir

 # CHECK-GNU-NEXT:      DW_AT_GNU_call_site_value   (DW_OP_fbreg +12)
 # CHECK-GNU:         DW_TAG_GNU_call_site_parameter
 # CHECK-GNU-NEXT:      DW_AT_location      (DW_OP_reg9 R9)
 # CHECK-GNU-NEXT:      DW_AT_GNU_call_site_value   (DW_OP_breg15 R15+0, DW_OP_breg3 RBX+0, DW_OP_plus)
 # CHECK-GNU:         DW_TAG_GNU_call_site_parameter
 # CHECK-GNU-NEXT:      DW_AT_location      (DW_OP_reg8 R8)
 # CHECK-GNU-NEXT:      DW_AT_GNU_call_site_value   (DW_OP_breg14 R14+3)
 
-# CHECK-DWARF5: DW_TAG_call_site
-# CHECK-DWARF5:   DW_AT_call_origin ([[getValue_SP:.*]])
+# CHECK-DWARF5: [[getValue_SP:.*]]: DW_TAG_subprogram
+# CHECK-DWARF5-NEXT: DW_AT_name      ("getVal")
 
+# CHECK-DWARF5: [[foo_SP:.*]]: DW_TAG_subprogram
+# CHECK-DWARF5-NEXT: DW_AT_name      ("foo")
+
+# CHECK-DWARF5: DW_TAG_call_site
+# CHECK-DWARF5:   DW_AT_call_origin ([[getValue_SP]])
+#
 # CHECK-DWARF5: DW_TAG_call_site
-# CHECK-DWARF5:   DW_AT_call_origin ([[foo_SP:.*]])
+# CHECK-DWARF5:   DW_AT_call_origin ([[foo_SP]])
 # CHECK-DWARF5:   DW_AT_call_return_pc {{.*}}
 # CHECK-DWARF5-EMPTY:
 # CHECK-DWARF5:         DW_TAG_call_site_parameter
 # CHECK-DWARF5-NEXT:      DW_AT_location      (DW_OP_reg2 RCX)
 # CHECK-DWARF5-NEXT:      DW_AT_call_value   (DW_OP_lit15)
 # CHECK-DWARF5:         DW_TAG_call_site_parameter
 # CHECK-DWARF5-NEXT:      DW_AT_location      (DW_OP_reg1 RDX)
 # CHECK-DWARF5-NEXT:      DW_AT_call_value   (DW_OP_lit10)
 # CHECK-DWARF5:         DW_TAG_call_site_parameter
 # CHECK-DWARF5-NEXT:      DW_AT_location      (DW_OP_reg4 RSI)
 # CHECK-DWARF5-NEXT:      DW_AT_call_value   (DW_OP_breg3 RBX+0)
 # CHECK-DWARF5:         DW_TAG_call_site_parameter
 # CHECK-DWARF5-NEXT:      DW_AT_location      (DW_OP_reg5 RDI)
 # CHECK-DWARF5-NEXT:      DW_AT_call_value   (DW_OP_fbreg +12)
 # CHECK-DWARF5:         DW_TAG_call_site_parameter
 # CHECK-DWARF5-NEXT:      DW_AT_location      (DW_OP_reg9 R9)
 # CHECK-DWARF5-NEXT:      DW_AT_call_value   (DW_OP_breg15 R15+0, DW_OP_breg3 RBX+0, DW_OP_plus)
 # CHECK-DWARF5:         DW_TAG_call_site_parameter
 # CHECK-DWARF5-NEXT:      DW_AT_location      (DW_OP_reg8 R8)
 # CHECK-DWARF5-NEXT:      DW_AT_call_value   (DW_OP_breg14 R14+3)
 
-# CHECK-DWARF5: [[getValue_SP]]: DW_TAG_subprogram
-# CHECK-DWARF5-NEXT: DW_AT_name      ("getVal")
-
-# CHECK-DWARF5: [[foo_SP]]: DW_TAG_subprogram
-# CHECK-DWARF5-NEXT: DW_AT_name      ("foo")
-
 --- |
   ; ModuleID = 'test.c'
   source_filename = "test.c"
   target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
   
   ; Function Attrs: nounwind uwtable
   define dso_local void @baa(i32 %arg1, i32 %arg2, i32 %arg3) local_unnamed_addr !dbg !10 {
   entry:

llvm/test/DebugInfo/X86/convert-loclist.ll

 ; RUN: llc -mtriple=x86_64 -filetype=obj < %s \
 ; RUN:   | llvm-dwarfdump -debug-info -debug-loclists - | FileCheck %s
 ; RUN: llc -mtriple=x86_64 -split-dwarf-file=foo.dwo -filetype=obj -dwarf-op-convert=Enable < %s \
 ; RUN:   | llvm-dwarfdump -debug-info -debug-loclists - | FileCheck --check-prefix=SPLIT --check-prefix=CHECK %s
 ; RUN: llc -mtriple=x86_64 -split-dwarf-file=foo.dwo -filetype=asm -dwarf-op-convert=Enable < %s \
 ; RUN:   | FileCheck --check-prefix=ASM %s
 
 ; A bit of a brittle test - this is testing the specific DWO_id. The
 ; alternative would be to test two files with different DW_OP_convert values &
 ; ensuring the DWO IDs differ when the DW_OP_convert parameter differs.
 
 ; So if this test ends up being a brittle pain to maintain, updating the DWO ID
 ; often - add another IR file with a different DW_OP_convert that's otherwise
 ; identical and demonstrate that they have different DWO IDs.
 
-; SPLIT: 0x00000000: Compile Unit: {{.*}} DWO_id = 0xecf2563326b0bdd3
+; SPLIT: 0x00000000: Compile Unit: {{.*}} DWO_id = 0x693879c39196a3ff
 
 ; Regression testing a fairly quirky bug where instead of hashing (see above),
 ; extra bytes would be emitted into the output assembly in no
 ; particular/intentional section - so let's check they don't show up at all:
 ; ASM-NOT: .asciz  "\200\200\200"
 
 ; CHECK: 0x{{0*}}[[TYPE:.*]]: DW_TAG_base_type
 ; CHECK-NEXT:                   DW_AT_name ("DW_ATE_unsigned_32")

llvm/test/DebugInfo/X86/fission-call-site.ll

-; Check that call site entries are emitted correctly when using split-dwarf
-; together with some form of LTO.
-
-; Original C source:
-;
-; // cu1.c
-; extern void callee(void);
-; void caller(void) {
-;   callee();
-; }
-;
-; // cu2.c
-; __attribute__((optnone)) void callee(void) {}
-;
-; Steps to reproduce:
-;
-; (The -O1 here is needed to trigger call site entry emission, as these tags are
-; generally not emitted at -O0.)
-;
-; clang -target x86_64-unknown-linux-gnu -gsplit-dwarf=split -O1 ~/tmp/cu1.c -S -emit-llvm -o ~/tmp/cu1.ll
-; clang -target x86_64-unknown-linux-gnu -gsplit-dwarf=split -O1 ~/tmp/cu2.c -S -emit-llvm -o ~/tmp/cu2.ll
-; llvm-link -o ~/tmp/cu-merged.bc ~/tmp/cu1.ll ~/tmp/cu2.ll
-; llc -split-dwarf-file=foo.dwo -O0 -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o - ~/tmp/cu-merged.bc
-
-; RUN: llc -split-dwarf-file=foo.dwo -O0 %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
-; RUN: llvm-dwarfdump %t | FileCheck %s
-
-; CHECK: DW_TAG_GNU_call_site
-; CHECK-NEXT: DW_AT_abstract_origin {{.*}} "callee"
-
-target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64-unknown-linux-gnu"
-
-define dso_local void @caller() local_unnamed_addr !dbg !14 {
-entry:
-  call void @callee(), !dbg !15
-  ret void, !dbg !16
-}
-
-define dso_local void @callee() local_unnamed_addr noinline optnone !dbg !17 {
-entry:
-  ret void, !dbg !19
-}
-
-!llvm.dbg.cu = !{!0, !8}
-!llvm.ident = !{!10, !10}
-!llvm.module.flags = !{!11, !12, !13}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 11.0.0 ([e-mail]:llvm/llvm-project.git 170f4b972e7bcf1f2af98bdd7145954efd16e038)", isOptimized: true, runtimeVersion: 0, splitDebugFilename: "cu1.dwo", emissionKind: FullDebug, enums: !2, retainedTypes: !3, splitDebugInlining: false, nameTableKind: GNU)
-!1 = !DIFile(filename: "/Users/vsk/tmp/cu1.c", directory: "/Users/vsk/src/builds/llvm-project-master-RA")
-!2 = !{}
-!3 = !{!4}
-!4 = !DISubprogram(name: "callee", scope: !5, file: !5, line: 1, type: !6, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
-!5 = !DIFile(filename: "tmp/cu1.c", directory: "/Users/vsk")
-!6 = !DISubroutineType(types: !7)
-!7 = !{null}
-!8 = distinct !DICompileUnit(language: DW_LANG_C99, file: !9, producer: "clang version 11.0.0 ([e-mail]:llvm/llvm-project.git 170f4b972e7bcf1f2af98bdd7145954efd16e038)", isOptimized: true, runtimeVersion: 0, splitDebugFilename: "cu2.dwo", emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: GNU)
-!9 = !DIFile(filename: "/Users/vsk/tmp/cu2.c", directory: "/Users/vsk/src/builds/llvm-project-master-RA")
-!10 = !{!"clang version 11.0.0 ([e-mail]:llvm/llvm-project.git 170f4b972e7bcf1f2af98bdd7145954efd16e038)"}
-!11 = !{i32 7, !"Dwarf Version", i32 4}
-!12 = !{i32 2, !"Debug Info Version", i32 3}
-!13 = !{i32 1, !"wchar_size", i32 4}
-!14 = distinct !DISubprogram(name: "caller", scope: !5, file: !5, line: 2, type: !6, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
-!15 = !DILocation(line: 3, column: 3, scope: !14)
-!16 = !DILocation(line: 4, column: 1, scope: !14)
-!17 = distinct !DISubprogram(name: "callee", scope: !18, file: !18, line: 1, type: !6, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !8, retainedNodes: !2)
-!18 = !DIFile(filename: "tmp/cu2.c", directory: "/Users/vsk")
-!19 = !DILocation(line: 1, column: 45, scope: !17)

llvm/test/DebugInfo/X86/lto-cross-cu-call-origin-ref.ll

-; RUN: llc -mtriple=x86_64-apple-darwin -filetype=obj < %s -o %t.o
-; RUN: llvm-dwarfdump %t.o | FileCheck %s -implicit-check-not=DW_TAG_subprogram
-; RUN: llvm-dwarfdump --verify %t.o
-
-; This test checks that cross-CU references within call site tags to subprogram
-; definitions are well-formed. There are 5 cases checked in this test. Each set
-; of checks is numbered and has a brief summary.
-
-; Instructions to regenerate the IR:
-; clang -O1 -g -emit-llvm -o a.bc -c a.c
-; clang -O1 -g -emit-llvm -o b.bc -c b.c
-; llvm-link -o linked.bc a.bc b.bc
-; opt -O1 linked.bc -o merged.bc
-
-; Source:
-; // a.c
-; __attribute__((optnone)) void noinline_func_in_a() {}
-;
-; __attribute__((optnone)) static void foo() {}
-; __attribute__((always_inline)) void always_inline_helper_in_a_that_calls_foo() {
-;   foo();
-; }
-;
-; extern void func_from_b();
-; void call_func_in_b_from_a() {
-;   func_from_b();
-; }
-;
-; // b.c
-; extern void noinline_func_in_a();
-; void call_noinline_func_in_a_from_b() {
-;   noinline_func_in_a();
-; }
-;
-; __attribute__((optnone)) void foo() {}
-; extern void always_inline_helper_in_a_that_calls_foo();
-; void call_both_foos_from_b() {
-;   foo();
-;   always_inline_helper_in_a_that_calls_foo();
-; }
-;
-; __attribute__((optnone)) void func_from_b() {}
-; void call_func_in_b_from_b() {
-;   func_from_b();
-; }
-
-; === CU for a.c ===
-
-; CHECK: DW_TAG_compile_unit
-; CHECK:   DW_AT_name ("a.c")
-
-; CHECK: 0x{{0+}}[[NOINLINE_FUNC_IN_A:.*]]: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("noinline_func_in_a")
-
-; 1) Check that "always_inline_helper_in_a_that_calls_foo" calls the "foo" in
-; a.c, and *not* the "foo" in b.c.
-; CHECK: 0x{{0+}}[[ALWAYS_INLINE_HELPER_IN_A:.*]]: DW_TAG_subprogram
-; CHECK:   DW_AT_abstract_origin ({{.*}} "always_inline_helper_in_a_that_calls_foo")
-; CHECK:   DW_TAG_call_site
-; CHECK-NEXT: DW_AT_call_origin (0x{{0+}}[[FOO_IN_A:.*]])
-
-; CHECK: 0x{{0+}}[[FOO_IN_A]]: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("foo")
-
-; 2) Check that "call_func_in_b_from_a" has a cross-CU ref into b.c.
-; CHECK: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("call_func_in_b_from_a")
-; CHECK:   DW_TAG_call_site
-; CHECK-NEXT: DW_AT_call_origin (0x{{0+}}[[FUNC_FROM_B:.*]])
-
-; CHECK: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("always_inline_helper_in_a_that_calls_foo")
-; CHECK:   DW_AT_inline (DW_INL_inlined)
-
-; === CU for b.c ===
-
-; CHECK: DW_TAG_compile_unit
-; CHECK:   DW_AT_name ("b.c")
-
-; 3) Validate the cross-CU ref from "call_func_in_b_from_a" in a.c.
-; CHECK: 0x{{0+}}[[FUNC_FROM_B]]: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("func_from_b")
-
-; 4) Validate the cross-CU ref from "call_noinline_func_in_a_from_b" in b.c.
-; CHECK: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("call_noinline_func_in_a_from_b")
-; CHECK:   DW_TAG_call_site
-; CHECK-NEXT: DW_AT_call_origin (0x{{0+}}[[NOINLINE_FUNC_IN_A]])
-
-; CHECK: 0x{{0+}}[[FOO_IN_B:.*]]: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("foo")
-
-; 5) Validate that we correctly emit a cross-CU ref when the call is inlined
-; from another CU.
-; CHECK: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("call_both_foos_from_b")
-; CHECK:   DW_TAG_call_site
-; CHECK-NEXT: DW_AT_call_origin (0x{{0+}}[[FOO_IN_B]])
-; CHECK:   DW_TAG_call_site
-; CHECK-NEXT: DW_AT_call_origin (0x{{0+}}[[FOO_IN_A]])
-
-; CHECK: DW_TAG_subprogram
-; CHECK:   DW_AT_name ("call_func_in_b_from_b")
-; CHECK:   DW_TAG_call_site
-; CHECK-NEXT: DW_AT_call_origin (0x{{0+}}[[FUNC_FROM_B]])
-
-target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64-apple-macosx10.14.0"
-
-define void @noinline_func_in_a() local_unnamed_addr #0 !dbg !17 {
-entry:
-  ret void, !dbg !20
-}
-
-define void @always_inline_helper_in_a_that_calls_foo() local_unnamed_addr #1 !dbg !21 {
-entry:
-  tail call fastcc void @foo.2(), !dbg !22
-  ret void, !dbg !23
-}
-
-define internal fastcc void @foo.2() unnamed_addr #0 !dbg !24 {
-entry:
-  ret void, !dbg !25
-}
-
-define void @call_func_in_b_from_a() local_unnamed_addr !dbg !26 {
-entry:
-  tail call void @func_from_b() #3, !dbg !27
-  ret void, !dbg !28
-}
-
-define void @call_noinline_func_in_a_from_b() local_unnamed_addr !dbg !29 {
-entry:
-  tail call void @noinline_func_in_a() #3, !dbg !30
-  ret void, !dbg !31
-}
-
-define void @foo() local_unnamed_addr #0 !dbg !32 {
-entry:
-  ret void, !dbg !33
-}
-
-define void @call_both_foos_from_b() local_unnamed_addr !dbg !34 {
-entry:
-  tail call void @foo(), !dbg !35
-  tail call fastcc void @foo.2() #3, !dbg !36
-  ret void, !dbg !38
-}
-
-define void @func_from_b() local_unnamed_addr #0 !dbg !39 {
-entry:
-  ret void, !dbg !40
-}
-
-define void @call_func_in_b_from_b() local_unnamed_addr !dbg !41 {
-entry:
-  tail call void @func_from_b(), !dbg !42
-  ret void, !dbg !43
-}
-
-attributes #0 = { noinline }
-attributes #1 = { alwaysinline }
-
-!llvm.dbg.cu = !{!0, !7}
-!llvm.ident = !{!12, !12}
-!llvm.module.flags = !{!13, !14, !15, !16}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 ([e-mail]:llvm/llvm-project.git 310e85309f870ee7347ef979d7d8da9bf28e92ea)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, nameTableKind: None)
-!1 = !DIFile(filename: "a.c", directory: "/Users/vsk/tmp/lto-entry-vals")
-!2 = !{}
-!3 = !{!4}
-!4 = !DISubprogram(name: "func_from_b", scope: !1, file: !1, line: 8, type: !5, spFlags: DISPFlagOptimized, retainedNodes: !2)
-!5 = !DISubroutineType(types: !6)
-!6 = !{null, null}
-!7 = distinct !DICompileUnit(language: DW_LANG_C99, file: !8, producer: "clang version 10.0.0 ([e-mail]:llvm/llvm-project.git 310e85309f870ee7347ef979d7d8da9bf28e92ea)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !9, nameTableKind: None)
-!8 = !DIFile(filename: "b.c", directory: "/Users/vsk/tmp/lto-entry-vals")
-!9 = !{!10, !11}
-!10 = !DISubprogram(name: "noinline_func_in_a", scope: !8, file: !8, line: 1, type: !5, spFlags: DISPFlagOptimized, retainedNodes: !2)
-!11 = !DISubprogram(name: "always_inline_helper_in_a_that_calls_foo", scope: !8, file: !8, line: 7, type: !5, spFlags: DISPFlagOptimized, retainedNodes: !2)
-!12 = !{!"clang version 10.0.0 ([e-mail]:llvm/llvm-project.git 310e85309f870ee7347ef979d7d8da9bf28e92ea)"}
-!13 = !{i32 7, !"Dwarf Version", i32 4}
-!14 = !{i32 2, !"Debug Info Version", i32 3}
-!15 = !{i32 1, !"wchar_size", i32 4}
-!16 = !{i32 7, !"PIC Level", i32 2}
-!17 = distinct !DISubprogram(name: "noinline_func_in_a", scope: !1, file: !1, line: 1, type: !18, scopeLine: 1, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
-!18 = !DISubroutineType(types: !19)
-!19 = !{null}
-!20 = !DILocation(line: 1, column: 53, scope: !17)
-!21 = distinct !DISubprogram(name: "always_inline_helper_in_a_that_calls_foo", scope: !1, file: !1, line: 4, type: !18, scopeLine: 4, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
-!22 = !DILocation(line: 5, column: 3, scope: !21)
-!23 = !DILocation(line: 6, column: 1, scope: !21)
-!24 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 3, type: !18, scopeLine: 3, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
-!25 = !DILocation(line: 3, column: 45, scope: !24)
-!26 = distinct !DISubprogram(name: "call_func_in_b_from_a", scope: !1, file: !1, line: 9, type: !18, scopeLine: 9, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
-!27 = !DILocation(line: 10, column: 3, scope: !26)
-!28 = !DILocation(line: 11, column: 1, scope: !26)
-!29 = distinct !DISubprogram(name: "call_noinline_func_in_a_from_b", scope: !8, file: !8, line: 2, type: !18, scopeLine: 2, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !7, retainedNodes: !2)
-!30 = !DILocation(line: 3, column: 3, scope: !29)
-!31 = !DILocation(line: 4, column: 1, scope: !29)
-!32 = distinct !DISubprogram(name: "foo", scope: !8, file: !8, line: 6, type: !18, scopeLine: 6, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !7, retainedNodes: !2)
-!33 = !DILocation(line: 6, column: 38, scope: !32)
-!34 = distinct !DISubprogram(name: "call_both_foos_from_b", scope: !8, file: !8, line: 8, type: !18, scopeLine: 8, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !7, retainedNodes: !2)
-!35 = !DILocation(line: 9, column: 3, scope: !34)
-!36 = !DILocation(line: 5, column: 3, scope: !21, inlinedAt: !37)
-!37 = distinct !DILocation(line: 10, column: 3, scope: !34)
-!38 = !DILocation(line: 11, column: 1, scope: !34)
-!39 = distinct !DISubprogram(name: "func_from_b", scope: !8, file: !8, line: 13, type: !18, scopeLine: 13, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !7, retainedNodes: !2)
-!40 = !DILocation(line: 13, column: 46, scope: !39)
-!41 = distinct !DISubprogram(name: "call_func_in_b_from_b", scope: !8, file: !8, line: 14, type: !18, scopeLine: 14, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !7, retainedNodes: !2)
-!42 = !DILocation(line: 15, column: 3, scope: !41)
-!43 = !DILocation(line: 16, column: 1, scope: !41)

llvm/test/DebugInfo/X86/subprogram-across-cus.ll

+; RUN: llc %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
+; RUN: llvm-dwarfdump -verify %t
+; RUN: llvm-dwarfdump -debug-info %t | FileCheck %s
+; RUN: rm %t
+;
+;$ cat -n 1.cpp
+;     1  struct HHH;
+;     2  HHH *zzz;
+;
+;$ cat -n 2.cpp
+;     1  void __attribute__((optnone)) __attribute__((nodebug)) f1()  { }
+;     2
+;     3  struct HHH {
+;     4    template <typename bbb>
+;     5    static int __attribute__((always_inline)) ccc() {
+;     6      f1();
+;     7    }
+;     8  };
+;     9
+;    10  int main() {
+;    11    struct local { };
+;    12    HHH::ccc<local>();
+;    13  }
+;
+; $ clang -flto -O2 -g 1.cpp 2.cpp -o a.out
+;
+; Given this input, LLVM attempts to create a DIE for subprogram "main" in the
+; wrong context. The definition of struct "HHH" is placed in the CU for 1.cpp.
+; While creating the template instance in "HHH", function "ccc" is referenced
+; via the struct local type, and "main" is created in the CU for 1.cpp, which
+; is incorrect.
+;
+; See PR48790 for more discussion and original compile commands.
+;
+; Check that there are no verifier failures, and that the SP for "main" appears
+; in the correct CU.
+; CHECK-LABEL:      DW_TAG_compile_unit
+; CHECK:              DW_AT_name ("1.cpp")
+; CHECK-NOT:          DW_AT_name ("main")
+; CHECK-LABEL:      DW_TAG_compile_unit
+; CHECK:              DW_AT_name ("2.cpp")
+; CHECK:            DW_TAG_subprogram
+; CHECK:              DW_AT_name ("main")
+
+source_filename = "ld-temp.o"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: noinline norecurse nounwind optnone uwtable mustprogress
+define internal fastcc void @_Z2f1v() unnamed_addr {
+entry:
+  ret void
+}
+
+; Function Attrs: norecurse noreturn nounwind uwtable mustprogress
+define dso_local i32 @main() local_unnamed_addr !dbg !17 {
+entry:
+  tail call fastcc void @_Z2f1v(), !dbg !21
+  unreachable, !dbg !21
+}
+
+!llvm.dbg.cu = !{!0, !9}
+!llvm.ident = !{!10, !10}
+!llvm.module.flags = !{!11, !12, !13, !14, !15, !16}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 12.0.0 ([e-mail]:llvm/llvm-project bc9ab9a5cd6bafc5e1293f3d5d51638f8f5cd26c)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "1.cpp", directory: "/tmp/bees")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+!5 = distinct !DIGlobalVariable(name: "zzz", scope: !0, file: !1, line: 2, type: !6, isLocal: false, isDefinition: true)
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "HHH", file: !8, line: 3, size: 8, flags: DIFlagTypePassByValue, elements: !2, identifier: "_ZTS3HHH")
+!8 = !DIFile(filename: "2.cpp", directory: "/tmp/bees")
+!9 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !8, producer: "clang version 12.0.0 ([e-mail]:llvm/llvm-project bc9ab9a5cd6bafc5e1293f3d5d51638f8f5cd26c)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+!10 = !{!"clang version 12.0.0 ([e-mail]:llvm/llvm-project bc9ab9a5cd6bafc5e1293f3d5d51638f8f5cd26c)"}
+!11 = !{i32 7, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{i32 1, !"ThinLTO", i32 0}
+!15 = !{i32 1, !"EnableSplitLTOUnit", i32 1}
+!16 = !{i32 1, !"LTOPostLink", i32 1}
+!17 = distinct !DISubprogram(name: "main", scope: !8, file: !8, line: 10, type: !18, scopeLine: 10, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !9, retainedNodes: !2)
+!18 = !DISubroutineType(types: !19)
+!19 = !{!20}
+!20 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!21 = !DILocation(line: 6, column: 5, scope: !22, inlinedAt: !27)
+!22 = distinct !DISubprogram(name: "ccc<local>", linkageName: "_ZN3HHH3cccIZ4mainE5localEEiv", scope: !7, file: !8, line: 5, type: !18, scopeLine: 5, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !9, templateParams: !24, declaration: !23, retainedNodes: !2)
+!23 = !DISubprogram(name: "ccc<local>", linkageName: "_ZN3HHH3cccIZ4mainE5localEEiv", scope: !7, file: !8, line: 5, type: !18, scopeLine: 5, flags: DIFlagPrototyped | DIFlagStaticMember, spFlags: DISPFlagOptimized, templateParams: !24)
+!24 = !{!25}
+!25 = !DITemplateTypeParameter(name: "bbb", type: !26)
+!26 = !DICompositeType(tag: DW_TAG_structure_type, name: "local", scope: !17, file: !8, line: 11, size: 8, flags: DIFlagFwdDecl)
+!27 = distinct !DILocation(line: 12, column: 3, scope: !17)