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DWARF: debug_names: Don't emit entries for skeleton type units

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When a type unit is emitted, the CU referencing the type unit ends up
with a little DW_TAG_*_type with the DW_AT_signature and
DW_AT_declaration sometimes referred to (by me? maybe other people?) as
a skeleton type.

We shouldn't produce .debug_names reference to these - only to the
actual type definition in the type unit. So this patch does that.

But, inversely, the .debug_gnu_pubtypes /does/ need to reference the
skeleton type (& gcc does this too, when it produces a skeleton type
(gcc doesn't always produce these - if the type is only referenced once
via DW_AT_type, gcc uses a direct DW_FORM_ref_sig8 on the DW_AT_type
without the intermediate skeleton type)) - so there's a little special
case added in to preserve that behavior which is covered by existing
tests.
This commit is contained in:
David Blaikie
2024-05-22 21:18:55 +00:00
parent ab29203e46
commit bd5c6367bd
5 changed files with 38 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
View File

@@ -1539,8 +1539,8 @@ void DwarfCompileUnit::addGlobalNameForTypeUnit(StringRef Name,
}
/// Add a new global type to the unit.
void DwarfCompileUnit::addGlobalType(const DIType *Ty, const DIE &Die,
const DIScope *Context) {
void DwarfCompileUnit::addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
const DIScope *Context) {
if (!hasDwarfPubSections())
return;
std::string FullName = getParentContextString(Context) + Ty->getName().str();

4
llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
View File

@@ -335,8 +335,8 @@ public:
void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context);
/// Add a new global type to the compile unit.
void addGlobalType(const DIType *Ty, const DIE &Die,
const DIScope *Context) override;
void addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
const DIScope *Context) override;
/// Add a new global type present in a type unit to this compile unit.
void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context);

44
llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
View File

@@ -578,28 +578,33 @@ DIE *DwarfUnit::createTypeDIE(const DIScope *Context, DIE &ContextDIE,
// Create new type.
DIE &TyDIE = createAndAddDIE(Ty->getTag(), ContextDIE, Ty);
updateAcceleratorTables(Context, Ty, TyDIE);
auto construct = [&](const auto *Ty) {
updateAcceleratorTables(Context, Ty, TyDIE);
constructTypeDIE(TyDIE, Ty);
};
if (auto *BT = dyn_cast<DIBasicType>(Ty))
constructTypeDIE(TyDIE, BT);
else if (auto *ST = dyn_cast<DIStringType>(Ty))
constructTypeDIE(TyDIE, ST);
else if (auto *STy = dyn_cast<DISubroutineType>(Ty))
constructTypeDIE(TyDIE, STy);
else if (auto *CTy = dyn_cast<DICompositeType>(Ty)) {
if (auto *CTy = dyn_cast<DICompositeType>(Ty)) {
if (DD->generateTypeUnits() && !Ty->isForwardDecl() &&
(Ty->getRawName() || CTy->getRawIdentifier())) {
// Skip updating the accelerator tables since this is not the full type.
if (MDString *TypeId = CTy->getRawIdentifier())
if (MDString *TypeId = CTy->getRawIdentifier()) {
addGlobalType(Ty, TyDIE, Context);
DD->addDwarfTypeUnitType(getCU(), TypeId->getString(), TyDIE, CTy);
else
} else {
updateAcceleratorTables(Context, Ty, TyDIE);
finishNonUnitTypeDIE(TyDIE, CTy);
}
return &TyDIE;
}
constructTypeDIE(TyDIE, CTy);
} else {
constructTypeDIE(TyDIE, cast<DIDerivedType>(Ty));
}
construct(CTy);
} else if (auto *BT = dyn_cast<DIBasicType>(Ty))
construct(BT);
else if (auto *ST = dyn_cast<DIStringType>(Ty))
construct(ST);
else if (auto *STy = dyn_cast<DISubroutineType>(Ty))
construct(STy);
else
construct(cast<DIDerivedType>(Ty));
return &TyDIE;
}
@@ -650,9 +655,14 @@ void DwarfUnit::updateAcceleratorTables(const DIScope *Context,
DD->addAccelType(*this, CUNode->getNameTableKind(), Ty->getName(), TyDIE,
Flags);
addGlobalType(Ty, TyDIE, Context);
}
void DwarfUnit::addGlobalType(const DIType *Ty, const DIE &TyDIE,
const DIScope *Context) {
if (!Context || isa<DICompileUnit>(Context) || isa<DIFile>(Context) ||
isa<DINamespace>(Context) || isa<DICommonBlock>(Context))
addGlobalType(Ty, TyDIE, Context);
addGlobalTypeImpl(Ty, TyDIE, Context);
}
void DwarfUnit::addType(DIE &Entity, const DIType *Ty,
@@ -1849,8 +1859,8 @@ void DwarfTypeUnit::addGlobalName(StringRef Name, const DIE &Die,
getCU().addGlobalNameForTypeUnit(Name, Context);
}
void DwarfTypeUnit::addGlobalType(const DIType *Ty, const DIE &Die,
const DIScope *Context) {
void DwarfTypeUnit::addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
const DIScope *Context) {
getCU().addGlobalTypeUnitType(Ty, Context);
}

10
llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
View File

@@ -128,8 +128,10 @@ public:
const DIScope *Context) = 0;
/// Add a new global type to the compile unit.
virtual void addGlobalType(const DIType *Ty, const DIE &Die,
const DIScope *Context) = 0;
virtual void addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
const DIScope *Context) = 0;
void addGlobalType(const DIType *Ty, const DIE &Die, const DIScope *Context);
/// Returns the DIE map slot for the specified debug variable.
///
@@ -397,8 +399,8 @@ public:
}
void addGlobalName(StringRef Name, const DIE &Die,
const DIScope *Context) override;
void addGlobalType(const DIType *Ty, const DIE &Die,
const DIScope *Context) override;
void addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
const DIScope *Context) override;
DwarfCompileUnit &getCU() override { return CU; }
};
} // end llvm namespace

24
llvm/test/DebugInfo/X86/debug-names-types.ll
View File

@@ -48,11 +48,6 @@
; CHECK-NEXT: DW_IDX_die_offset: DW_FORM_ref4
; CHECK-NEXT: DW_IDX_parent: DW_FORM_flag_present
; CHECK-NEXT: }
; CHECK-NEXT: Abbreviation [[ABBREV1:0x[0-9a-f]*]] {
; CHECK-NEXT: Tag: DW_TAG_structure_type
; CHECK-NEXT: DW_IDX_die_offset: DW_FORM_ref4
; CHECK-NEXT: DW_IDX_parent: DW_FORM_flag_present
; CHECK-NEXT: }
; CHECK-NEXT: Abbreviation [[ABBREV2:0x[0-9a-f]*]] {
; CHECK-NEXT: Tag: DW_TAG_subprogram
; CHECK-NEXT: DW_IDX_die_offset: DW_FORM_ref4
@@ -88,12 +83,6 @@
; CHECK-NEXT: DW_IDX_die_offset: 0x00000023
; CHECK-NEXT: DW_IDX_parent: <parent not indexed>
; CHECK-NEXT: }
; CHECK-NEXT: Entry @ {{.+}} {
; CHECK-NEXT: Abbrev: [[ABBREV1]]
; CHECK-NEXT: Tag: DW_TAG_structure_type
; CHECK-NEXT: DW_IDX_die_offset: 0x00000042
; CHECK-NEXT: DW_IDX_parent: <parent not indexed>
; CHECK-NEXT: }
; CHECK-NEXT: }
; CHECK-NEXT: ]
; CHECK-NEXT: Bucket 2 [
@@ -130,7 +119,7 @@
; CHECK-SPLIT: Foreign TU count: 1
; CHECK-SPLIT-NEXT: Bucket count: 4
; CHECK-SPLIT-NEXT: Name count: 4
; CHECK-SPLIT-NEXT: Abbreviations table size: 0x2D
; CHECK-SPLIT-NEXT: Abbreviations table size: 0x25
; CHECK-SPLIT-NEXT: Augmentation: 'LLVM0700'
; CHECK-SPLIT-NEXT: }
; CHECK-SPLIT-NEXT: Compilation Unit offsets [
@@ -151,11 +140,6 @@
; CHECK-SPLIT-NEXT: DW_IDX_die_offset: DW_FORM_ref4
; CHECK-SPLIT-NEXT: DW_IDX_parent: DW_FORM_flag_present
; CHECK-SPLIT-NEXT: }
; CHECK-SPLIT-NEXT: Abbreviation [[ABBREV:0x[0-9a-f]*]] {
; CHECK-SPLIT-NEXT: Tag: DW_TAG_structure_type
; CHECK-SPLIT-NEXT: DW_IDX_die_offset: DW_FORM_ref4
; CHECK-SPLIT-NEXT: DW_IDX_parent: DW_FORM_flag_present
; CHECK-SPLIT-NEXT: }
; CHECK-SPLIT-NEXT: Abbreviation [[ABBREV3:0x[0-9a-f]*]] {
; CHECK-SPLIT-NEXT: Tag: DW_TAG_subprogram
; CHECK-SPLIT-NEXT: DW_IDX_die_offset: DW_FORM_ref4
@@ -191,12 +175,6 @@
; CHECK-SPLIT-NEXT: DW_IDX_die_offset: 0x00000021
; CHECK-SPLIT-NEXT: DW_IDX_parent: <parent not indexed>
; CHECK-SPLIT-NEXT: }
; CHECK-SPLIT-NEXT: Entry @ {{.*}} {
; CHECK-SPLIT-NEXT: Abbrev: [[ABBREV]]
; CHECK-SPLIT-NEXT: Tag: DW_TAG_structure_type
; CHECK-SPLIT-NEXT: DW_IDX_die_offset: 0x00000039
; CHECK-SPLIT-NEXT: DW_IDX_parent: <parent not indexed>
; CHECK-SPLIT-NEXT: }
; CHECK-SPLIT-NEXT: }
; CHECK-SPLIT-NEXT: ]
; CHECK-SPLIT-NEXT: Bucket 2 [