Michael137 created this revision.
Michael137 added reviewers: aprantl, dblaikie.
Herald added a project: All.
Michael137 requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
With this patch, we now emit a `DW_AT_LLVM_preferred_name` for
the `[clang::preferred_name]]` attribute attached to a class template.
This is useful for consumers in case they want to display the
name in terms of the preferred name, e.g., LLDB's type-summaries.
For now this is behind an LLDB tuning.
E.g., for following code:
template<typename T> struct Foo;
typedef Foo<int> BarInt;
typedef Foo<double> BarDouble;
template<typename T>
struct [[clang::preferred_name(BarInt),
clang::preferred_name(BarDouble)]] Foo {};
...the generated DWARF with this patch looks as follows:
0x0000006b: DW_TAG_structure_type
DW_AT_LLVM_preferred_name (0x00000082)
DW_AT_name ("Foo<int>")
0x00000082: DW_TAG_typedef
DW_AT_type (0x0000006b "Foo<int>")
DW_AT_name ("BarInt")
0x0000008d: DW_TAG_structure_type
DW_AT_LLVM_preferred_name (0x000000ab)
DW_AT_name ("Foo<double>")
0x000000ab: DW_TAG_typedef
DW_AT_type (0x0000008d "Foo<double>")
DW_AT_name ("BarDouble")
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D145077
Files:
clang/lib/CodeGen/CGDebugInfo.cpp
clang/lib/CodeGen/CGDebugInfo.h
clang/test/CodeGen/attr-preferred_name-alias-template.cpp
clang/test/CodeGen/attr-preferred_name-typedef.cpp
Index: clang/test/CodeGen/attr-preferred_name-typedef.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGen/attr-preferred_name-typedef.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang -target x86_64 -glldb -S -emit-llvm -o - %s | FileCheck %s --check-prefix=LLDB
+// RUN: %clang -target x86_64 -ggdb -S -emit-llvm -o - %s | FileCheck %s --check-prefix=GDB
+
+template<typename T>
+struct Foo;
+
+typedef Foo<int> BarInt;
+typedef Foo<double> BarDouble;
+
+template<typename T>
+struct [[clang::preferred_name(BarInt),
+ clang::preferred_name(BarDouble)]] Foo {};
+
+Foo<int> varInt;
+Foo<double> varDouble;
+
+// LLDB: ![[FOO_DOUBLE:[0-9]+]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo<double>"
+// GDB-NOT: preferredName: ![[DOUBLE_PREF:[0-9]+]])
+// LLDB-SAME: preferredName: ![[DOUBLE_PREF:[0-9]+]])
+// LLDB: !DIDerivedType(tag: DW_TAG_typedef, name: "BarDouble",
+// LLDB-SAME: baseType: ![[FOO_DOUBLE]])
+
+// LLDB: ![[FOO_INT:[0-9]+]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo<int>"
+// GDB-NOT: preferredName: ![[INT_PREF:[0-9]+]])
+// LLDB-SAME: preferredName: ![[INT_PREF:[0-9]+]])
+// LLDB: !DIDerivedType(tag: DW_TAG_typedef, name: "BarInt",
+// LLDB-SAME: baseType: ![[FOO_INT]])
Index: clang/test/CodeGen/attr-preferred_name-alias-template.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGen/attr-preferred_name-alias-template.cpp
@@ -0,0 +1,19 @@
+// RUN: %clang -target x86_64 -glldb -S -emit-llvm -o - %s | FileCheck %s --check-prefix=LLDB
+// RUN: %clang -target x86_64 -ggdb -S -emit-llvm -o - %s | FileCheck %s --check-prefix=GDB
+
+template<typename T>
+struct Foo;
+
+template<typename T>
+using Bar = Foo<T>;
+
+template<typename T>
+struct [[clang::preferred_name(Bar<T>)]] Foo {};
+
+Foo<int> varInt;
+
+// LLDB: ![[FOO_INT:[0-9]+]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo<int>"
+// GDB-NOT: preferredName: ![[INT_PREF:[0-9]+]])
+// LLDB-SAME: preferredName: ![[INT_PREF:[0-9]+]])
+// LLDB: !DIDerivedType(tag: DW_TAG_typedef, name: "Bar<int>",
+// LLDB-SAME: baseType: ![[FOO_INT]])
Index: clang/lib/CodeGen/CGDebugInfo.h
===================================================================
--- clang/lib/CodeGen/CGDebugInfo.h
+++ clang/lib/CodeGen/CGDebugInfo.h
@@ -267,6 +267,11 @@
SmallVectorImpl<llvm::Metadata *> &EltTys,
llvm::DIType *RecordTy);
+ /// Helper class that retrieves returns llvm::DIType the that
+ /// PreferredNameAttr attribute on \ref RD refers to. If no such
+ /// attribute exists, returns nullptr.
+ llvm::DIType * GetPreferredNameType(const CXXRecordDecl *RD, llvm::DIFile *Unit);
+
/// Helper function for CollectCXXBases.
/// Adds debug info entries for types in Bases that are not in SeenTypes.
void CollectCXXBasesAux(
Index: clang/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- clang/lib/CodeGen/CGDebugInfo.cpp
+++ clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1301,6 +1301,8 @@
llvm::raw_svector_ostream OS(NS);
auto PP = getPrintingPolicy();
+ // TODO: Not strictly needed for std::string?
+ PP.UsePreferredNames = CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::LLDB;
Ty->getTemplateName().print(OS, PP, TemplateName::Qualified::None);
// Disable PrintCanonicalTypes here because we want
@@ -2576,6 +2578,18 @@
return CreateTypeDefinition(Ty);
}
+llvm::DIType * CGDebugInfo::GetPreferredNameType(
+ const CXXRecordDecl *RD, llvm::DIFile *Unit) {
+ if (!RD)
+ return nullptr;
+
+ auto const* PNA = RD->getAttr<PreferredNameAttr>();
+ if (!PNA)
+ return nullptr;
+
+ return getOrCreateType(PNA->getTypedefType(), Unit);
+}
+
llvm::DIType *CGDebugInfo::CreateTypeDefinition(const RecordType *Ty) {
RecordDecl *RD = Ty->getDecl();
@@ -2630,6 +2644,9 @@
FwdDecl =
llvm::MDNode::replaceWithPermanent(llvm::TempDICompositeType(FwdDecl));
+ if (CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::LLDB)
+ FwdDecl->replacePreferredName(GetPreferredNameType(CXXDecl, DefUnit));
+
RegionMap[Ty->getDecl()].reset(FwdDecl);
return FwdDecl;
}
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
