From d61468959556ddc180c6c28edff476244fd0e8a6 Mon Sep 17 00:00:00 2001

From: tstellar <tstellar@91177308-0d34-0410-b5e6-96231b3b80d8>

Date: Fri, 17 Nov 2017 18:48:34 +0000

Subject: [PATCH] Merging r318289:

------------------------------------------------------------------------

r318289 | jdevlieghere | 2017-11-15 02:57:05 -0800 (Wed, 15 Nov 2017) | 14 lines

[DebugInfo] Fix potential CU mismatch for SubprogramScopeDIEs.

In constructAbstractSubprogramScopeDIE there can be a potential mismatch

between `this` and the CU of ContextDIE when a scope is shared between

two DISubprograms belonging to a different CU. In that case, `this` is

the CU that was specified in the IR, but the CU of ContextDIE is that of

the first subprogram that was emitted. This patch fixes the mismatch by

looking up the CU of ContextDIE, and switching to use that.

This fixes PR35212 (https://bugs.llvm.org/show_bug.cgi?id=35212)

Patch by Philip Craig!

Differential revision: https://reviews.llvm.org/D39981

------------------------------------------------------------------------

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_50@318542 91177308-0d34-0410-b5e6-96231b3b80d8

---

 lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp | 20 ++++++++----

 lib/CodeGen/AsmPrinter/DwarfDebug.h         |  5 ++-

 test/DebugInfo/cross-cu-scope.ll            | 50 +++++++++++++++++++++++++++++

 3 files changed, 67 insertions(+), 8 deletions(-)

 create mode 100644 test/DebugInfo/cross-cu-scope.ll

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

index 676c48f..333d14a 100644

--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

@@ -621,6 +621,7 @@ void DwarfCompileUnit::constructAbstractSubprogramScopeDIE(

   auto *SP = cast<DISubprogram>(Scope->getScopeNode());

   DIE *ContextDIE;

+  DwarfCompileUnit *ContextCU = this;

   if (includeMinimalInlineScopes())

     ContextDIE = &getUnitDie();

@@ -631,18 +632,23 @@ void DwarfCompileUnit::constructAbstractSubprogramScopeDIE(

   else if (auto *SPDecl = SP->getDeclaration()) {

     ContextDIE = &getUnitDie();

     getOrCreateSubprogramDIE(SPDecl);

-  } else

+  } else {

     ContextDIE = getOrCreateContextDIE(resolve(SP->getScope()));

+    // The scope may be shared with a subprogram that has already been

+    // constructed in another CU, in which case we need to construct this

+    // subprogram in the same CU.

+    ContextCU = DD->lookupCU(ContextDIE->getUnitDie());

+  }

   // Passing null as the associated node because the abstract definition

   // shouldn't be found by lookup.

-  AbsDef = &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);

-  applySubprogramAttributesToDefinition(SP, *AbsDef);

+  AbsDef = &ContextCU->createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);

+  ContextCU->applySubprogramAttributesToDefinition(SP, *AbsDef);

-  if (!includeMinimalInlineScopes())

-    addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);

-  if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))

-    addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);

+  if (!ContextCU->includeMinimalInlineScopes())

+    ContextCU->addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);

+  if (DIE *ObjectPointer = ContextCU->createAndAddScopeChildren(Scope, *AbsDef))

+    ContextCU->addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);

 }

 DIE *DwarfCompileUnit::constructImportedEntityDIE(

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h

index 5dfe06c..78ee9a1 100644

--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h

+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -283,7 +283,7 @@ class DwarfDebug : public DebugHandlerBase {

   // 0, referencing the comp_dir of all the type units that use it.

   MCDwarfDwoLineTable SplitTypeUnitFileTable;

   /// @}

-  

+

   /// True iff there are multiple CUs in this module.

   bool SingleCU;

   bool IsDarwin;

@@ -562,6 +562,9 @@ public:

   bool isLexicalScopeDIENull(LexicalScope *Scope);

   bool hasDwarfPubSections(bool includeMinimalInlineScopes) const;

+

+  /// Find the matching DwarfCompileUnit for the given CU DIE.

+  DwarfCompileUnit *lookupCU(const DIE *Die) { return CUDieMap.lookup(Die); }

 };

 } // End of namespace llvm

diff --git a/test/DebugInfo/cross-cu-scope.ll b/test/DebugInfo/cross-cu-scope.ll

new file mode 100644

index 0000000..7c71f27

--- /dev/null

+++ b/test/DebugInfo/cross-cu-scope.ll

@@ -0,0 +1,50 @@

+; RUN: %llc_dwarf %s -filetype=obj -o %t

+; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s

+

+; Reduced test case from PR35212. Two DISubprogram belong to a different CU but

+; share a scope. Both are declarations and end up in the scope's CU. We want to

+; check that the CU from the context DIE is used (rather than from the IR).

+; This manifests itself by the DW_base_type ending up in the second CU, rather

+; than in the first one as specified in the IR.

+

+; CHECK: DW_TAG_compile_unit

+; CHECK-NEXT: discriminator 0

+; CHECK: DW_TAG_compile_unit

+; CHECK-NEXT: discriminator 1

+; CHECK: DW_TAG_structure_type

+; CHECK-NOT: NULL

+; CHECK: DW_TAG_subprogram

+; CHECK-NOT: NULL

+; CHECK: DW_TAG_formal_parameter

+; CHECK-NOT: NULL

+; CHECK: DW_AT_type{{.*}}{[[USIZE_LABEL:0x[0-9a-f]+]]}

+; CHECK: NULL

+; CHECK: [[USIZE_LABEL]]: DW_TAG_base_type

+; CHECK-NOT: NULL

+; CHECK: DW_AT_name{{.*}}"usize"

+

+define hidden void @foo() !dbg !4 {

+  ret void, !dbg !7

+}

+

+!llvm.dbg.cu = !{!0, !2}

+!llvm.module.flags = !{!3}

+

+!0 = distinct !DICompileUnit(language: DW_LANG_Rust, file: !1, producer: "clang LLVM (rustc version 1.23.0-nightly (discriminator 0))", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)

+!1 = !DIFile(filename: "../lib.rs", directory: "/home/alex/code/rust4/lol")

+!2 = distinct !DICompileUnit(language: DW_LANG_Rust, file: !1, producer: "clang LLVM (rustc version 1.23.0-nightly (discriminator 1))", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)

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

+!4 = distinct !DISubprogram(name: "clone<alloc::string::String>", linkageName: "_ZN5alloc3vec8{{impl}}28clone<alloc::string::String>E", scope: null, file: !1, line: 1519, type: !5, isLocal: false, isDefinition: true, scopeLine: 1519, flags: DIFlagPrototyped, isOptimized: true, unit: !0, templateParams: !6, variables: !6)

+!5 = !DISubroutineType(types: !6)

+!6 = !{}

+!7 = !DILocation(line: 1612, scope: !8, inlinedAt: !11)

+!8 = distinct !DILexicalBlock(scope: !9, file: !1, line: 86, column: 12)

+!9 = distinct !DISubprogram(name: "allocate_in<alloc::string::String,alloc::heap::Heap>", linkageName: "_ZN5alloc7raw_vec8{{impl}}52allocate_in<alloc::string::String,alloc::heap::Heap>E", scope: !10, file: !1, line: 82, type: !5, isLocal: false, isDefinition: true, scopeLine: 82, flags: DIFlagPrototyped, isOptimized: true, unit: !2, templateParams: !6, variables: !6)

+!10 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "RawVec<alloc::string::String, alloc::heap::Heap>", file: !1, size: 128, align: 64, elements: !6, identifier: "5c6e4db16d2c64555e40661d70c4d81e")

+!11 = distinct !DILocation(line: 86, scope: !8, inlinedAt: !12)

+!12 = distinct !DILocation(line: 141, scope: !13, inlinedAt: !17)

+!13 = distinct !DISubprogram(name: "with_capacity<alloc::string::String>", linkageName: "_ZN5alloc7raw_vec8{{impl}}36with_capacity<alloc::string::String>E", scope: !10, file: !1, line: 140, type: !5, isLocal: false, isDefinition: true, scopeLine: 140, flags: DIFlagPrototyped, isOptimized: true, unit: !0, templateParams: !6, variables: !14)

+!14 = !{!15}

+!15 = !DILocalVariable(name: "cap", arg: 1, scope: !13, file: !1, line: 1, type: !16)

+!16 = !DIBasicType(name: "usize", size: 64, encoding: DW_ATE_unsigned)

+!17 = !DILocation(line: 1521, scope: !4)

-- 

1.8.3.1