Michael137 created this revision.
Michael137 added reviewers: erichkeane, aaron.ballman, dblaikie.
Herald added a project: All.
Michael137 requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
**Summary**
This patch adds a `IsDefaulted` field to `clang::TemplateArgument`.
To prevent memory footprint increase we still 1 bit from `ArgKind`.
**Background**
In LLDB we construct ASTs from debug-info and hand it to clang
to perform actions such as printing/formatting a typenames.
Some debug formats, specifically DWARF, may only encode information
about class template instantiations, losing the structure of the generic
class definition. However, the `clang::TypePrinter` needs a properly
constructed `ClassTemplateDecl` with generic default argument decls
to be able to deduce whether a `ClassTemplateSpecializationDecl` was
instantiatiated with `TemplateArgument`s that correspond to the
defaults. LLDB does know whether a particular template argument was
defaulted, but can't currently tell clang about it.
This patch allows LLDB to set the defaulted-ness of a `TemplateArgument`
and thus benefit more from `clang::TypePrinter`.
See discussion in https://reviews.llvm.org/D140423
**Testing**
- TODO
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D141826
Files:
clang/include/clang/AST/TemplateBase.h
clang/lib/AST/TemplateBase.cpp
Index: clang/lib/AST/TemplateBase.cpp
===================================================================
--- clang/lib/AST/TemplateBase.cpp
+++ clang/lib/AST/TemplateBase.cpp
@@ -162,6 +162,7 @@
TemplateArgument::TemplateArgument(ASTContext &Ctx, const llvm::APSInt &Value,
QualType Type) {
Integer.Kind = Integral;
+ Integer.IsDefaulted = false;
// Copy the APSInt value into our decomposed form.
Integer.BitWidth = Value.getBitWidth();
Integer.IsUnsigned = Value.isUnsigned();
Index: clang/include/clang/AST/TemplateBase.h
===================================================================
--- clang/include/clang/AST/TemplateBase.h
+++ clang/include/clang/AST/TemplateBase.h
@@ -103,12 +103,14 @@
/// The kind of template argument we're storing.
struct DA {
- unsigned Kind;
+ unsigned Kind : 31;
+ unsigned IsDefaulted : 1;
void *QT;
ValueDecl *D;
};
struct I {
- unsigned Kind;
+ unsigned Kind : 31;
+ unsigned IsDefaulted : 1;
// We store a decomposed APSInt with the data allocated by ASTContext if
// BitWidth > 64. The memory may be shared between multiple
// TemplateArgument instances.
@@ -124,17 +126,20 @@
void *Type;
};
struct A {
- unsigned Kind;
+ unsigned Kind : 31;
+ unsigned IsDefaulted : 1;
unsigned NumArgs;
const TemplateArgument *Args;
};
struct TA {
- unsigned Kind;
+ unsigned Kind : 31;
+ unsigned IsDefaulted : 1;
unsigned NumExpansions;
void *Name;
};
struct TV {
- unsigned Kind;
+ unsigned Kind : 31;
+ unsigned IsDefaulted : 1;
uintptr_t V;
};
union {
@@ -147,11 +152,12 @@
public:
/// Construct an empty, invalid template argument.
- constexpr TemplateArgument() : TypeOrValue({Null, 0}) {}
+ constexpr TemplateArgument() : TypeOrValue({Null, /* IsDefaulted */ 0, 0}) {}
/// Construct a template type argument.
TemplateArgument(QualType T, bool isNullPtr = false) {
TypeOrValue.Kind = isNullPtr ? NullPtr : Type;
+ TypeOrValue.IsDefaulted = false;
TypeOrValue.V = reinterpret_cast<uintptr_t>(T.getAsOpaquePtr());
}
@@ -161,6 +167,7 @@
TemplateArgument(ValueDecl *D, QualType QT) {
assert(D && "Expected decl");
DeclArg.Kind = Declaration;
+ DeclArg.IsDefaulted = false;
DeclArg.QT = QT.getAsOpaquePtr();
DeclArg.D = D;
}
@@ -186,6 +193,7 @@
/// \param Name The template name.
TemplateArgument(TemplateName Name) {
TemplateArg.Kind = Template;
+ TemplateArg.IsDefaulted = false;
TemplateArg.Name = Name.getAsVoidPointer();
TemplateArg.NumExpansions = 0;
}
@@ -203,6 +211,7 @@
/// instantiating
TemplateArgument(TemplateName Name, Optional<unsigned> NumExpansions) {
TemplateArg.Kind = TemplateExpansion;
+ TemplateArg.IsDefaulted = false;
TemplateArg.Name = Name.getAsVoidPointer();
if (NumExpansions)
TemplateArg.NumExpansions = *NumExpansions + 1;
@@ -217,6 +226,7 @@
/// occur in a non-dependent, canonical template argument list.
TemplateArgument(Expr *E) {
TypeOrValue.Kind = Expression;
+ TypeOrValue.IsDefaulted = false;
TypeOrValue.V = reinterpret_cast<uintptr_t>(E);
}
@@ -226,6 +236,7 @@
/// outlives the TemplateArgument itself.
explicit TemplateArgument(ArrayRef<TemplateArgument> Args) {
this->Args.Kind = Pack;
+ this->Args.IsDefaulted = false;
this->Args.Args = Args.data();
this->Args.NumArgs = Args.size();
}
@@ -334,6 +345,10 @@
Integer.Type = T.getAsOpaquePtr();
}
+ void setIsDefaulted(bool v) { TypeOrValue.IsDefaulted = v; }
+
+ bool getIsDefaulted() const { return (bool)TypeOrValue.IsDefaulted; }
+
/// If this is a non-type template argument, get its type. Otherwise,
/// returns a null QualType.
QualType getNonTypeTemplateArgumentType() const;
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