[llvm] f69f233 - Revert "DebugInfo: Don't put types in type units if they reference internal linkage types"
David Blaikie via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 1 16:13:25 PST 2022
Author: David Blaikie
Date: 2022-02-01T16:13:07-08:00
New Revision: f69f23396d32c95dacf3765bc63af02b23ccff3e
URL: https://github.com/llvm/llvm-project/commit/f69f23396d32c95dacf3765bc63af02b23ccff3e
DIFF: https://github.com/llvm/llvm-project/commit/f69f23396d32c95dacf3765bc63af02b23ccff3e.diff
LOG: Revert "DebugInfo: Don't put types in type units if they reference internal linkage types"
This reverts commit ab4756338c5b2216d52d9152b2f7e65f233c4dac.
Breaks some cases, including this:
namespace {
template <typename> struct a {};
} // namespace
class c {
c();
};
class b {
b();
a<c> ax;
};
b::b() {}
c::c() {}
By producing a reference to a type unit for "c" but not producing the type unit.
Added:
Modified:
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
llvm/test/DebugInfo/X86/tu-to-non-tu.ll
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 680b9586228f7..609b568f28beb 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -3367,8 +3367,7 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
// Fast path if we're building some type units and one has already used the
// address pool we know we're going to throw away all this work anyway, so
// don't bother building dependent types.
- if (!TypeUnitsUnderConstruction.empty() &&
- (AddrPool.hasBeenUsed() || SeenLocalType))
+ if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
return;
auto Ins = TypeSignatures.insert(std::make_pair(CTy, 0));
@@ -3379,7 +3378,6 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
bool TopLevelType = TypeUnitsUnderConstruction.empty();
AddrPool.resetUsedFlag();
- SeenLocalType = false;
auto OwnedUnit = std::make_unique<DwarfTypeUnit>(CU, Asm, this, &InfoHolder,
getDwoLineTable(CU));
@@ -3423,7 +3421,7 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
// Types referencing entries in the address table cannot be placed in type
// units.
- if (AddrPool.hasBeenUsed() || SeenLocalType) {
+ if (AddrPool.hasBeenUsed()) {
// Remove all the types built while building this type.
// This is pessimistic as some of these types might not be dependent on
@@ -3451,18 +3449,14 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
DwarfDebug::NonTypeUnitContext::NonTypeUnitContext(DwarfDebug *DD)
: DD(DD),
- TypeUnitsUnderConstruction(std::move(DD->TypeUnitsUnderConstruction)),
- AddrPoolUsed(DD->AddrPool.hasBeenUsed()),
- SeenLocalType(DD->SeenLocalType) {
+ TypeUnitsUnderConstruction(std::move(DD->TypeUnitsUnderConstruction)), AddrPoolUsed(DD->AddrPool.hasBeenUsed()) {
DD->TypeUnitsUnderConstruction.clear();
DD->AddrPool.resetUsedFlag();
- DD->SeenLocalType = false;
}
DwarfDebug::NonTypeUnitContext::~NonTypeUnitContext() {
DD->TypeUnitsUnderConstruction = std::move(TypeUnitsUnderConstruction);
DD->AddrPool.resetUsedFlag(AddrPoolUsed);
- DD->SeenLocalType = SeenLocalType;
}
DwarfDebug::NonTypeUnitContext DwarfDebug::enterNonTypeUnitContext() {
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 0043000652e89..4e1a1b1e068df 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -433,7 +433,6 @@ class DwarfDebug : public DebugHandlerBase {
DenseMap<const DIStringType *, unsigned> StringTypeLocMap;
AddressPool AddrPool;
- bool SeenLocalType = false;
/// Accelerator tables.
AccelTable<DWARF5AccelTableData> AccelDebugNames;
@@ -672,7 +671,6 @@ class DwarfDebug : public DebugHandlerBase {
DwarfDebug *DD;
decltype(DwarfDebug::TypeUnitsUnderConstruction) TypeUnitsUnderConstruction;
bool AddrPoolUsed;
- bool SeenLocalType;
friend class DwarfDebug;
NonTypeUnitContext(DwarfDebug *DD);
public:
@@ -681,7 +679,6 @@ class DwarfDebug : public DebugHandlerBase {
};
NonTypeUnitContext enterNonTypeUnitContext();
- void seenLocalType() { SeenLocalType = true; }
/// Add a label so that arange data can be generated for it.
void addArangeLabel(SymbolCU SCU) { ArangeLabels.push_back(SCU); }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 132579aedbc96..5a2bd479f2774 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -596,8 +596,10 @@ DIE *DwarfUnit::createTypeDIE(const DIScope *Context, DIE &ContextDIE,
// Skip updating the accelerator tables since this is not the full type.
if (MDString *TypeId = CTy->getRawIdentifier())
DD->addDwarfTypeUnitType(getCU(), TypeId->getString(), TyDIE, CTy);
- else
+ else {
+ auto X = DD->enterNonTypeUnitContext();
finishNonUnitTypeDIE(TyDIE, CTy);
+ }
return &TyDIE;
}
constructTypeDIE(TyDIE, CTy);
@@ -1851,23 +1853,5 @@ void DwarfTypeUnit::finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) {
addString(D, dwarf::DW_AT_name, Name);
if (Name.startswith("_STN") || !Name.contains('<'))
addTemplateParams(D, CTy->getTemplateParams());
- // If the type is in an anonymous namespace, we can't reference it from a TU
- // (since the type would be CU local and the TU doesn't specify which TU has
- // the appropriate type definition) - so flag this emission as such and skip
- // the rest of the emission now since we're going to throw out all this work
- // and put the outer/referencing type in the CU instead.
- // FIXME: Probably good to generalize this to a DICompositeType flag populated
- // by the frontend, then we could use that to have types that can have
- // decl+def merged by LTO but where the definition still doesn't go in a type
- // unit because the type has only one definition.
- for (DIScope *S = CTy->getScope(); S; S = S->getScope()) {
- if (auto *NS = dyn_cast<DINamespace>(S)) {
- if (NS->getName().empty()) {
- DD->seenLocalType();
- break;
- }
- }
- }
- auto X = DD->enterNonTypeUnitContext();
getCU().createTypeDIE(CTy);
}
diff --git a/llvm/test/DebugInfo/X86/tu-to-non-tu.ll b/llvm/test/DebugInfo/X86/tu-to-non-tu.ll
index 517872d2b92e9..4b8ea04bedc5c 100644
--- a/llvm/test/DebugInfo/X86/tu-to-non-tu.ll
+++ b/llvm/test/DebugInfo/X86/tu-to-non-tu.ll
@@ -1,15 +1,17 @@
; RUN: llc -filetype=obj -O0 -generate-type-units -mtriple=x86_64-unknown-linux-gnu < %s \
; RUN: | llvm-dwarfdump -debug-info -debug-types - | FileCheck %s
-; Test that a type unit referencing a non-type unit produces a declaration of
-; the referent in the referee.
-
-; Also check that an attempt to reference an internal linkage (defined in an anonymous
-; namespace) type from a type unit (could happen with a pimpl idiom, for instance -
-; it does mean the linkage-having type can only be defined in one translation
-; unit anyway) forces the referent to not be placed in a type unit (because the
-; declaration of the internal linkage type would be ambiguous/wouldn't allow a
-; consumer to find the definition with certainty)
+; Test that a type unit referencing a non-type unit (in this case, it's
+; bordering on an ODR violation - a type with linkage references a type without
+; linkage, so there's no way for the first type to be defined in more than one
+; translation unit, so there's no need for it to be in a type unit - but this
+; is quirky/rare and an easy way to test a broader issue). The type unit should
+; not end up with a whole definition of the referenced type - instead it should
+; have a declaration of the type, while the definition remains in the primary
+; CU.
+; (again, arguably in this instance - since the type is only referenced once, it
+; could go in the TU only - but that requires tracking usage & then deciding
+; where to put types, which isn't worthwhile right now)
; Built from the following source, compiled with this command:
; $ clang++-tot decl.cpp -g -fdebug-types-section -c
@@ -118,6 +120,8 @@
; CHECK-NEXT: DW_AT_declaration (true)
; CHECK-NEXT: DW_AT_signature (0xb1cde890d320f5c2)
+; CHECK: DW_TAG_namespace
+; CHECK-NOT: {{DW_AT_name|DW_TAG}}
; CHECK: DW_TAG_structure_type
; CHECK-NOT: DW_TAG
; CHECK: DW_AT_name {{.*}}"non_tu"
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