[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-18 Thread via cfe-commits 

https://github.com/cor3ntin closed 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-14 Thread Yanzuo Liu via cfe-commits 


@@ -3492,10 +3492,13 @@ VarDecl *BindingDecl::getHoldingVar() const {
   return VD;
 }
 
-llvm::ArrayRef BindingDecl::getBindingPackExprs() const {
+llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
-  auto *RP = cast(Binding);
-  return RP->getExprs();
+  auto *FP = cast(Binding);
+  ValueDecl *const *First = FP->getNumExpansions() > 0 ? FP->begin() : nullptr;
+  assert((!First || isa(*First)) && "expecting a BindingDecl");
+  return llvm::ArrayRef(
+  reinterpret_cast(First), FP->getNumExpansions());

zwuis wrote:

Can we use `static_cast` here?

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Jason Rice via cfe-commits 


@@ -1197,25 +1197,19 @@ Decl 
*TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
 for (auto *NewBD : NewBindings)
   NewBD->setInvalidDecl();
 
-  if (OldResolvedPack) {
-// Mark the holding vars (if any) in the pack as instantiated since
-// they are created implicitly.
+  if (OldBindingPack) {
+// Mark the bindings in the pack as instantiated.
 auto Bindings = NewDD->bindings();
-auto BPack = llvm::find_if(
+BindingDecl *NewBindingPack = *llvm::find_if(
 Bindings, [](BindingDecl *D) -> bool { return D->isParameterPack(); });

ricejasonf wrote:

What do you think about capturing the index of the old pack in the loop above 
and using that instead of searching?

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Jason Rice via cfe-commits 


@@ -3492,10 +3492,13 @@ VarDecl *BindingDecl::getHoldingVar() const {
   return VD;
 }
 
-llvm::ArrayRef BindingDecl::getBindingPackExprs() const {
+llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
-  auto *RP = cast(Binding);
-  return RP->getExprs();
+  auto *FP = cast(Binding);
+  ValueDecl *const *First = FP->getNumExpansions() > 0 ? FP->begin() : nullptr;
+  assert((!First || isa(*First)) && "expecting a BindingDecl");
+  return llvm::ArrayRef(
+  reinterpret_cast(First), FP->getNumExpansions());

ricejasonf wrote:

`llvm::cast` will not return a reference to the pointer so it cannot be used 
for the ArrayRef.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 edited 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Younan Zhang via cfe-commits 


@@ -980,24 +980,24 @@ static bool CheckBindingsCount(Sema &S, DecompositionDecl 
*DD,
   if (IsValid && HasPack) {
 // Create the pack expr and assign it to the binding.
 unsigned PackSize = MemberCount - Bindings.size() + 1;
-QualType PackType = S.Context.getPackExpansionType(
-S.Context.DependentTy, std::nullopt, /*ExpectsPackInType=*/false);
-BindingDecl *BD = (*BindingWithPackItr);
-auto *RP = ResolvedUnexpandedPackExpr::Create(S.Context, DD->getBeginLoc(),
-  DecompType, PackSize);
-BD->setDecomposedDecl(DD);
-BD->setBinding(PackType, RP);
 
 BindingDecl *BPack = *BindingWithPackItr;
+BPack->setDecomposedDecl(DD);
+SmallVector NestedBDs(PackSize);
 // Create the nested BindingDecls.
-for (Expr *&E : RP->getExprs()) {
-  auto *NestedBD = BindingDecl::Create(S.Context, BPack->getDeclContext(),
-   BPack->getLocation(),
-   BPack->getIdentifier(), QualType());
+for (ValueDecl *&VD : NestedBDs) {

zyn0217 wrote:

Maybe we can make it more straightforward like
```cpp
for (unsigned I = 0; I < PackSize; ++I) {
  ...
  NestedBDs[I] = ...
}
```
I feel like `*&` makes it a little visually awkward :)

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Younan Zhang via cfe-commits 

https://github.com/zyn0217 commented:

Thanks, a few more comments

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Younan Zhang via cfe-commits 


@@ -4649,49 +4649,48 @@ class SubstNonTypeTemplateParmPackExpr : public Expr {
 /// \endcode
 class FunctionParmPackExpr final
 : public Expr,
-  private llvm::TrailingObjects {
+  private llvm::TrailingObjects {

zyn0217 wrote:

Can we also update the attached comments to reflect it now supports structure 
binding pack?

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Younan Zhang via cfe-commits 


@@ -3492,10 +3492,13 @@ VarDecl *BindingDecl::getHoldingVar() const {
   return VD;
 }
 
-llvm::ArrayRef BindingDecl::getBindingPackExprs() const {
+llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
-  auto *RP = cast(Binding);
-  return RP->getExprs();
+  auto *FP = cast(Binding);
+  ValueDecl *const *First = FP->getNumExpansions() > 0 ? FP->begin() : nullptr;
+  assert((!First || isa(*First)) && "expecting a BindingDecl");
+  return llvm::ArrayRef(
+  reinterpret_cast(First), FP->getNumExpansions());

zyn0217 wrote:

can we use llvm::cast here? 

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Younan Zhang via cfe-commits 


@@ -1178,13 +1178,13 @@ Decl 
*TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
   // Transform the bindings first.
   // The transformed DD will have all of the concrete BindingDecls.
   SmallVector NewBindings;
-  ResolvedUnexpandedPackExpr *OldResolvedPack = nullptr;
+  BindingDecl *OldBindingPack = nullptr;
   for (auto *OldBD : D->bindings()) {
 Expr *BindingExpr = OldBD->getBinding();
-if (auto *RP =
-dyn_cast_if_present(BindingExpr)) {
-  assert(!OldResolvedPack && "no more than one pack is allowed");
-  OldResolvedPack = RP;
+if (isa_and_nonnull(BindingExpr)) {

zyn0217 wrote:

isa_and_present

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Younan Zhang via cfe-commits 


@@ -1197,25 +1197,19 @@ Decl 
*TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
 for (auto *NewBD : NewBindings)
   NewBD->setInvalidDecl();
 
-  if (OldResolvedPack) {
-// Mark the holding vars (if any) in the pack as instantiated since
-// they are created implicitly.
+  if (OldBindingPack) {
+// Mark the bindings in the pack as instantiated.
 auto Bindings = NewDD->bindings();
-auto BPack = llvm::find_if(
+BindingDecl *NewBindingPack = *llvm::find_if(
 Bindings, [](BindingDecl *D) -> bool { return D->isParameterPack(); });

zyn0217 wrote:

For sanity (we have lost the assertion of `cast`ing a non-null pointer), we'd 
better add an non-null assertion here

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Jason Rice via cfe-commits 

https://github.com/ricejasonf updated 
https://github.com/llvm/llvm-project/pull/125394

>From a323e058b2c8adf97f7f9a55a9187f74de9b8d17 Mon Sep 17 00:00:00 2001
From: Jason Rice 
Date: Sun, 2 Feb 2025 00:52:47 -0800
Subject: [PATCH 1/5] [Clang][P1061] Consolidate ResolvedUnexpandedPackExpr
 into FunctionParmPackExpr

---
 clang/include/clang/AST/DeclCXX.h | 28 +
 clang/include/clang/AST/ExprCXX.h | 21 +-
 clang/include/clang/Sema/Template.h   |  2 +-
 clang/lib/AST/DeclCXX.cpp |  9 +++--
 clang/lib/AST/ExprCXX.cpp | 14 +++
 clang/lib/Sema/SemaDeclCXX.cpp| 26 ++--
 clang/lib/Sema/SemaExpr.cpp   |  6 +--
 clang/lib/Sema/SemaTemplateInstantiate.cpp| 30 +-
 .../lib/Sema/SemaTemplateInstantiateDecl.cpp  | 40 +++
 clang/lib/Sema/SemaTemplateVariadic.cpp   | 32 +--
 clang/lib/Serialization/ASTReaderStmt.cpp |  6 +--
 clang/test/AST/ast-dump-binding-pack.cpp  | 13 ++
 clang/test/SemaCXX/cxx2c-binding-pack.cpp | 11 +
 13 files changed, 103 insertions(+), 135 deletions(-)

diff --git a/clang/include/clang/AST/DeclCXX.h 
b/clang/include/clang/AST/DeclCXX.h
index 766821b4fb25cb5..1c630d616903550 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -4194,8 +4194,8 @@ class BindingDecl : public ValueDecl {
   /// decomposition declaration, and when the initializer is type-dependent.
   Expr *getBinding() const { return Binding; }
 
-  // Get the array of Exprs when the binding represents a pack.
-  llvm::ArrayRef getBindingPackExprs() const;
+  // Get the array of nested BindingDecls when the binding represents a pack.
+  llvm::ArrayRef getBindingPackDecls() const;
 
   /// Get the decomposition declaration that this binding represents a
   /// decomposition of.
@@ -4246,10 +4246,8 @@ class DecompositionDecl final
 for (auto *B : Bindings) {
   B->setDecomposedDecl(this);
   if (B->isParameterPack() && B->getBinding()) {
-for (Expr *E : B->getBindingPackExprs()) {
-  auto *DRE = cast(E);
-  auto *NestedB = cast(DRE->getDecl());
-  NestedB->setDecomposedDecl(this);
+for (BindingDecl *NestedBD : B->getBindingPackDecls()) {
+  NestedBD->setDecomposedDecl(this);
 }
   }
 }
@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),
+std::move(PackBindings),
+std::move(Bindings));
   }
 
   void printName(raw_ostream &OS, const PrintingPolicy &Policy) const override;
diff --git a/clang/include/clang/AST/ExprCXX.h 
b/clang/include/clang/AST/ExprCXX.h
index 0b6c8cfb163c958..2b23fa51c6232b2 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -4649,13 +4649,13 @@ class SubstNonTypeTemplateParmPackExpr : public Expr {
 /// \endcode
 class FunctionParmPackExpr final
 : public Expr,
-  private llvm::TrailingObjects {
+  private llvm::TrailingObjects {
   friend class ASTReader;
   friend class ASTStmtReader;
   friend TrailingObjects;
 
   /// The function parameter pack which was referenced.
-  VarDecl *ParamPack;
+  ValueDecl *ParamPack;
 
   /// The location of the function parameter pack reference.
   SourceLocation NameLoc;
@@ -4663,35 +4663,34 @@ class FunctionParmPackExpr final
   /// The number of expansions of this pack.
   unsigned NumParameters;
 
-  FunctionParmPackExpr(QualType T, VarDecl *ParamPack,
-   SourceLocation NameLoc, unsigned NumParams,
-   VarDecl *const *Params);
+  FunctionParmPackExpr(QualType T, ValueDecl *ParamPack, SourceLocation 
NameLoc,
+   unsigned NumParams, ValueDecl *const *Params);
 
 public:
   static FunctionParmPackExpr *Create(const ASTContext &Context, QualType T,
-

[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-06 Thread Erich Keane via cfe-commits 


@@ -3492,10 +3492,13 @@ VarDecl *BindingDecl::getHoldingVar() const {
   return VD;
 }
 
-llvm::ArrayRef BindingDecl::getBindingPackExprs() const {
+llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
-  auto *RP = cast(Binding);
-  return RP->getExprs();
+  auto *FP = cast(Binding);
+  ValueDecl *const *First = FP->getNumExpansions() > 0 ? FP->begin() : nullptr;
+  assert((!First || isa(*First)) && "expecting a BindingDecl");
+  return llvm::ArrayRef((BindingDecl *const *)First,

erichkeane wrote:

This I did with the use of `cast`, which you gave some good reasons to skip.  
But I separately commented that I want the C cast gone.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-05 Thread Jason Rice via cfe-commits 

https://github.com/ricejasonf edited 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-05 Thread Jason Rice via cfe-commits 


@@ -124,6 +125,14 @@ void lambda_capture() {
   [&x...] { (void)sum(x...); }();
 }
 
+struct S2 {
+int a, b, c;
+};
+
+auto X = []  () {

ricejasonf wrote:

Oh, sorry, I added your test with `clsss` not realizing you were talking about 
modifying an existing test. :sweat_smile: 

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-05 Thread Jason Rice via cfe-commits 


@@ -3492,10 +3492,13 @@ VarDecl *BindingDecl::getHoldingVar() const {
   return VD;
 }
 
-llvm::ArrayRef BindingDecl::getBindingPackExprs() const {
+llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
-  auto *RP = cast(Binding);
-  return RP->getExprs();
+  auto *FP = cast(Binding);
+  ValueDecl *const *First = FP->getNumExpansions() > 0 ? FP->begin() : nullptr;
+  assert((!First || isa(*First)) && "expecting a BindingDecl");
+  return llvm::ArrayRef((BindingDecl *const *)First,

ricejasonf wrote:

It says you marked this as resolved.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread Shafik Yaghmour via cfe-commits 

https://github.com/shafik commented:

I think I would like to see some more test coverage.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread Shafik Yaghmour via cfe-commits 

https://github.com/shafik edited 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread Shafik Yaghmour via cfe-commits 


@@ -124,6 +125,14 @@ void lambda_capture() {
   [&x...] { (void)sum(x...); }();
 }
 
+struct S2 {
+int a, b, c;
+};
+
+auto X = []  () {

shafik wrote:

I feel like there are a bunch of varieties on this case we can test as well: 
https://godbolt.org/z/r9zxxfoW5 

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread Jason Rice via cfe-commits 


@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),

ricejasonf wrote:

They add... rvalue don't they? :rofl: . I added them to work around the 
dangling references.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread Jason Rice via cfe-commits 

ricejasonf wrote:

> Can i merge this for you?

@cor3ntin Whenever you think it is ready, yes please. I know Erich did not want 
the C-style cast.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread via cfe-commits 

cor3ntin wrote:

@ricejasonf Can i merge this for you?

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread via cfe-commits 

https://github.com/cor3ntin approved this pull request.


https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread Jason Rice via cfe-commits 

https://github.com/ricejasonf updated 
https://github.com/llvm/llvm-project/pull/125394

>From a323e058b2c8adf97f7f9a55a9187f74de9b8d17 Mon Sep 17 00:00:00 2001
From: Jason Rice 
Date: Sun, 2 Feb 2025 00:52:47 -0800
Subject: [PATCH 1/3] [Clang][P1061] Consolidate ResolvedUnexpandedPackExpr
 into FunctionParmPackExpr

---
 clang/include/clang/AST/DeclCXX.h | 28 +
 clang/include/clang/AST/ExprCXX.h | 21 +-
 clang/include/clang/Sema/Template.h   |  2 +-
 clang/lib/AST/DeclCXX.cpp |  9 +++--
 clang/lib/AST/ExprCXX.cpp | 14 +++
 clang/lib/Sema/SemaDeclCXX.cpp| 26 ++--
 clang/lib/Sema/SemaExpr.cpp   |  6 +--
 clang/lib/Sema/SemaTemplateInstantiate.cpp| 30 +-
 .../lib/Sema/SemaTemplateInstantiateDecl.cpp  | 40 +++
 clang/lib/Sema/SemaTemplateVariadic.cpp   | 32 +--
 clang/lib/Serialization/ASTReaderStmt.cpp |  6 +--
 clang/test/AST/ast-dump-binding-pack.cpp  | 13 ++
 clang/test/SemaCXX/cxx2c-binding-pack.cpp | 11 +
 13 files changed, 103 insertions(+), 135 deletions(-)

diff --git a/clang/include/clang/AST/DeclCXX.h 
b/clang/include/clang/AST/DeclCXX.h
index 766821b4fb25cb5..1c630d616903550 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -4194,8 +4194,8 @@ class BindingDecl : public ValueDecl {
   /// decomposition declaration, and when the initializer is type-dependent.
   Expr *getBinding() const { return Binding; }
 
-  // Get the array of Exprs when the binding represents a pack.
-  llvm::ArrayRef getBindingPackExprs() const;
+  // Get the array of nested BindingDecls when the binding represents a pack.
+  llvm::ArrayRef getBindingPackDecls() const;
 
   /// Get the decomposition declaration that this binding represents a
   /// decomposition of.
@@ -4246,10 +4246,8 @@ class DecompositionDecl final
 for (auto *B : Bindings) {
   B->setDecomposedDecl(this);
   if (B->isParameterPack() && B->getBinding()) {
-for (Expr *E : B->getBindingPackExprs()) {
-  auto *DRE = cast(E);
-  auto *NestedB = cast(DRE->getDecl());
-  NestedB->setDecomposedDecl(this);
+for (BindingDecl *NestedBD : B->getBindingPackDecls()) {
+  NestedBD->setDecomposedDecl(this);
 }
   }
 }
@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),
+std::move(PackBindings),
+std::move(Bindings));
   }
 
   void printName(raw_ostream &OS, const PrintingPolicy &Policy) const override;
diff --git a/clang/include/clang/AST/ExprCXX.h 
b/clang/include/clang/AST/ExprCXX.h
index 0b6c8cfb163c958..2b23fa51c6232b2 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -4649,13 +4649,13 @@ class SubstNonTypeTemplateParmPackExpr : public Expr {
 /// \endcode
 class FunctionParmPackExpr final
 : public Expr,
-  private llvm::TrailingObjects {
+  private llvm::TrailingObjects {
   friend class ASTReader;
   friend class ASTStmtReader;
   friend TrailingObjects;
 
   /// The function parameter pack which was referenced.
-  VarDecl *ParamPack;
+  ValueDecl *ParamPack;
 
   /// The location of the function parameter pack reference.
   SourceLocation NameLoc;
@@ -4663,35 +4663,34 @@ class FunctionParmPackExpr final
   /// The number of expansions of this pack.
   unsigned NumParameters;
 
-  FunctionParmPackExpr(QualType T, VarDecl *ParamPack,
-   SourceLocation NameLoc, unsigned NumParams,
-   VarDecl *const *Params);
+  FunctionParmPackExpr(QualType T, ValueDecl *ParamPack, SourceLocation 
NameLoc,
+   unsigned NumParams, ValueDecl *const *Params);
 
 public:
   static FunctionParmPackExpr *Create(const ASTContext &Context, QualType T,
-

[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-04 Thread Jason Rice via cfe-commits 

https://github.com/ricejasonf edited 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-03 Thread Erich Keane via cfe-commits 


@@ -3492,10 +3492,13 @@ VarDecl *BindingDecl::getHoldingVar() const {
   return VD;
 }
 
-llvm::ArrayRef BindingDecl::getBindingPackExprs() const {
+llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
-  auto *RP = cast(Binding);
-  return RP->getExprs();
+  auto *FP = cast(Binding);
+  ValueDecl *const *First = FP->getNumExpansions() > 0 ? FP->begin() : nullptr;
+  assert((!First || isa(*First)) && "expecting a BindingDecl");
+  return llvm::ArrayRef((BindingDecl *const *)First,

erichkeane wrote:

What you could do here is `&cast(*First)`, plus wrap that in a 
const-cast.  This would make the assert unnecessary.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-03 Thread Erich Keane via cfe-commits 

https://github.com/erichkeane commented:

A few nits, else this is great, thank you!

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-03 Thread Erich Keane via cfe-commits 


@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),

erichkeane wrote:

I realize you're taking from the previous patch, but these `std::move` calls 
are a little silly :)  All of the types are an `ArrayRef`, so there is nothing 
to steal.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-03 Thread Erich Keane via cfe-commits 


@@ -1197,25 +1197,17 @@ Decl 
*TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
 for (auto *NewBD : NewBindings)
   NewBD->setInvalidDecl();
 
-  if (OldResolvedPack) {
-// Mark the holding vars (if any) in the pack as instantiated since
-// they are created implicitly.
+  if (OldBindingPack) {
+// Mark the bindings in the pack as instantiated.
 auto Bindings = NewDD->bindings();
-auto BPack = llvm::find_if(
+auto NewBindingPack = *llvm::find_if(
 Bindings, [](BindingDecl *D) -> bool { return D->isParameterPack(); });
-auto *NewResolvedPack =
-cast((*BPack)->getBinding());
-auto OldExprs = OldResolvedPack->getExprs();
-auto NewExprs = NewResolvedPack->getExprs();
-assert(OldExprs.size() == NewExprs.size());
-for (unsigned I = 0; I < OldResolvedPack->getNumExprs(); I++) {
-  DeclRefExpr *OldDRE = cast(OldExprs[I]);
-  BindingDecl *OldNestedBD = cast(OldDRE->getDecl());
-  DeclRefExpr *NewDRE = cast(NewExprs[I]);
-  BindingDecl *NewNestedBD = cast(NewDRE->getDecl());
-  SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldNestedBD,
-   NewNestedBD);
-}
+auto OldDecls = OldBindingPack->getBindingPackDecls();

erichkeane wrote:

We shouldn't be using 'auto' on either of these.  I realize they already were, 
but please change them anyway.,

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-03 Thread Erich Keane via cfe-commits 


@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(

erichkeane wrote:

```suggestion
llvm::ArrayRef BeforePackBindings = Bindings.take_until(
```

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-03 Thread Erich Keane via cfe-commits 

https://github.com/erichkeane edited 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

Sirraide wrote:

> @Sirraide I did try it and the bug persists. The `LHS` is a RecoveryExpr, so 
> I am not sure how to approach that.

Yeah, that one did look like the problem is probably elsewhere; thanks for 
trying though!

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

https://github.com/cor3ntin approved this pull request.


https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

https://github.com/cor3ntin edited 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

https://github.com/cor3ntin edited 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

cor3ntin wrote:

@ricejasonf yeah... really not a fan but i played with it an i don't see a way 
to meaningfully improve it. Thanks for trying though

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread Jason Rice via cfe-commits 

ricejasonf wrote:

@cor3ntin Sorry, I tried "Commit suggestion", but it didn't look like you can 
cast like that so I just reverted.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread Jason Rice via cfe-commits 

https://github.com/ricejasonf updated 
https://github.com/llvm/llvm-project/pull/125394

>From a323e058b2c8adf97f7f9a55a9187f74de9b8d17 Mon Sep 17 00:00:00 2001
From: Jason Rice 
Date: Sun, 2 Feb 2025 00:52:47 -0800
Subject: [PATCH 1/2] [Clang][P1061] Consolidate ResolvedUnexpandedPackExpr
 into FunctionParmPackExpr

---
 clang/include/clang/AST/DeclCXX.h | 28 +
 clang/include/clang/AST/ExprCXX.h | 21 +-
 clang/include/clang/Sema/Template.h   |  2 +-
 clang/lib/AST/DeclCXX.cpp |  9 +++--
 clang/lib/AST/ExprCXX.cpp | 14 +++
 clang/lib/Sema/SemaDeclCXX.cpp| 26 ++--
 clang/lib/Sema/SemaExpr.cpp   |  6 +--
 clang/lib/Sema/SemaTemplateInstantiate.cpp| 30 +-
 .../lib/Sema/SemaTemplateInstantiateDecl.cpp  | 40 +++
 clang/lib/Sema/SemaTemplateVariadic.cpp   | 32 +--
 clang/lib/Serialization/ASTReaderStmt.cpp |  6 +--
 clang/test/AST/ast-dump-binding-pack.cpp  | 13 ++
 clang/test/SemaCXX/cxx2c-binding-pack.cpp | 11 +
 13 files changed, 103 insertions(+), 135 deletions(-)

diff --git a/clang/include/clang/AST/DeclCXX.h 
b/clang/include/clang/AST/DeclCXX.h
index 766821b4fb25cb..1c630d61690355 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -4194,8 +4194,8 @@ class BindingDecl : public ValueDecl {
   /// decomposition declaration, and when the initializer is type-dependent.
   Expr *getBinding() const { return Binding; }
 
-  // Get the array of Exprs when the binding represents a pack.
-  llvm::ArrayRef getBindingPackExprs() const;
+  // Get the array of nested BindingDecls when the binding represents a pack.
+  llvm::ArrayRef getBindingPackDecls() const;
 
   /// Get the decomposition declaration that this binding represents a
   /// decomposition of.
@@ -4246,10 +4246,8 @@ class DecompositionDecl final
 for (auto *B : Bindings) {
   B->setDecomposedDecl(this);
   if (B->isParameterPack() && B->getBinding()) {
-for (Expr *E : B->getBindingPackExprs()) {
-  auto *DRE = cast(E);
-  auto *NestedB = cast(DRE->getDecl());
-  NestedB->setDecomposedDecl(this);
+for (BindingDecl *NestedBD : B->getBindingPackDecls()) {
+  NestedBD->setDecomposedDecl(this);
 }
   }
 }
@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),
+std::move(PackBindings),
+std::move(Bindings));
   }
 
   void printName(raw_ostream &OS, const PrintingPolicy &Policy) const override;
diff --git a/clang/include/clang/AST/ExprCXX.h 
b/clang/include/clang/AST/ExprCXX.h
index 0b6c8cfb163c95..2b23fa51c6232b 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -4649,13 +4649,13 @@ class SubstNonTypeTemplateParmPackExpr : public Expr {
 /// \endcode
 class FunctionParmPackExpr final
 : public Expr,
-  private llvm::TrailingObjects {
+  private llvm::TrailingObjects {
   friend class ASTReader;
   friend class ASTStmtReader;
   friend TrailingObjects;
 
   /// The function parameter pack which was referenced.
-  VarDecl *ParamPack;
+  ValueDecl *ParamPack;
 
   /// The location of the function parameter pack reference.
   SourceLocation NameLoc;
@@ -4663,35 +4663,34 @@ class FunctionParmPackExpr final
   /// The number of expansions of this pack.
   unsigned NumParameters;
 
-  FunctionParmPackExpr(QualType T, VarDecl *ParamPack,
-   SourceLocation NameLoc, unsigned NumParams,
-   VarDecl *const *Params);
+  FunctionParmPackExpr(QualType T, ValueDecl *ParamPack, SourceLocation 
NameLoc,
+   unsigned NumParams, ValueDecl *const *Params);
 
 public:
   static FunctionParmPackExpr *Create(const ASTContext &Context, QualType T,
-

[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

github-actions[bot] wrote:




:warning: C/C++ code formatter, clang-format found issues in your code. 
:warning:



You can test this locally with the following command:


``bash
git-clang-format --diff d5a7a483a65f830a0c7a931781bc90046dc67ff4 
b2b85fdbe11dce02c6ba842b5a4949b70c47207b --extensions cpp,h -- 
clang/include/clang/AST/DeclCXX.h clang/include/clang/AST/ExprCXX.h 
clang/include/clang/AST/RecursiveASTVisitor.h clang/include/clang/Sema/Sema.h 
clang/include/clang/Sema/Template.h 
clang/include/clang/Serialization/ASTBitCodes.h clang/lib/AST/DeclCXX.cpp 
clang/lib/AST/Expr.cpp clang/lib/AST/ExprCXX.cpp 
clang/lib/AST/ExprClassification.cpp clang/lib/AST/ExprConstant.cpp 
clang/lib/AST/ItaniumMangle.cpp clang/lib/AST/StmtPrinter.cpp 
clang/lib/AST/StmtProfile.cpp clang/lib/Sema/SemaDeclCXX.cpp 
clang/lib/Sema/SemaExceptionSpec.cpp clang/lib/Sema/SemaExpr.cpp 
clang/lib/Sema/SemaTemplateInstantiate.cpp 
clang/lib/Sema/SemaTemplateInstantiateDecl.cpp 
clang/lib/Sema/SemaTemplateVariadic.cpp clang/lib/Sema/TreeTransform.h 
clang/lib/Serialization/ASTReaderStmt.cpp clang/lib/Serialization/ASTWriter.cpp 
clang/lib/Serialization/ASTWriterStmt.cpp 
clang/lib/StaticAnalyzer/Core/ExprEngine.cpp 
clang/test/AST/ast-dump-binding-pack.cpp 
clang/test/SemaCXX/cxx2c-binding-pack.cpp clang/tools/libclang/CXCursor.cpp
``





View the diff from clang-format here.


``diff
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 77cbf1362a..b0a14629f2 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -3495,9 +3495,10 @@ VarDecl *BindingDecl::getHoldingVar() const {
 llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
   auto *FP = cast(Binding);
-  if(FP->getNumExpansions() == 0)
-  return {};
-  return llvm::ArrayRef(cast(FP->begin()), 
FP->getNumExpansions());
+  if (FP->getNumExpansions() == 0)
+return {};
+  return llvm::ArrayRef(cast(FP->begin()),
+   FP->getNumExpansions());
 }
 
 void DecompositionDecl::anchor() {}

``




https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread Jason Rice via cfe-commits 

https://github.com/ricejasonf updated 
https://github.com/llvm/llvm-project/pull/125394

>From a323e058b2c8adf97f7f9a55a9187f74de9b8d17 Mon Sep 17 00:00:00 2001
From: Jason Rice 
Date: Sun, 2 Feb 2025 00:52:47 -0800
Subject: [PATCH 1/3] [Clang][P1061] Consolidate ResolvedUnexpandedPackExpr
 into FunctionParmPackExpr

---
 clang/include/clang/AST/DeclCXX.h | 28 +
 clang/include/clang/AST/ExprCXX.h | 21 +-
 clang/include/clang/Sema/Template.h   |  2 +-
 clang/lib/AST/DeclCXX.cpp |  9 +++--
 clang/lib/AST/ExprCXX.cpp | 14 +++
 clang/lib/Sema/SemaDeclCXX.cpp| 26 ++--
 clang/lib/Sema/SemaExpr.cpp   |  6 +--
 clang/lib/Sema/SemaTemplateInstantiate.cpp| 30 +-
 .../lib/Sema/SemaTemplateInstantiateDecl.cpp  | 40 +++
 clang/lib/Sema/SemaTemplateVariadic.cpp   | 32 +--
 clang/lib/Serialization/ASTReaderStmt.cpp |  6 +--
 clang/test/AST/ast-dump-binding-pack.cpp  | 13 ++
 clang/test/SemaCXX/cxx2c-binding-pack.cpp | 11 +
 13 files changed, 103 insertions(+), 135 deletions(-)

diff --git a/clang/include/clang/AST/DeclCXX.h 
b/clang/include/clang/AST/DeclCXX.h
index 766821b4fb25cb..1c630d61690355 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -4194,8 +4194,8 @@ class BindingDecl : public ValueDecl {
   /// decomposition declaration, and when the initializer is type-dependent.
   Expr *getBinding() const { return Binding; }
 
-  // Get the array of Exprs when the binding represents a pack.
-  llvm::ArrayRef getBindingPackExprs() const;
+  // Get the array of nested BindingDecls when the binding represents a pack.
+  llvm::ArrayRef getBindingPackDecls() const;
 
   /// Get the decomposition declaration that this binding represents a
   /// decomposition of.
@@ -4246,10 +4246,8 @@ class DecompositionDecl final
 for (auto *B : Bindings) {
   B->setDecomposedDecl(this);
   if (B->isParameterPack() && B->getBinding()) {
-for (Expr *E : B->getBindingPackExprs()) {
-  auto *DRE = cast(E);
-  auto *NestedB = cast(DRE->getDecl());
-  NestedB->setDecomposedDecl(this);
+for (BindingDecl *NestedBD : B->getBindingPackDecls()) {
+  NestedBD->setDecomposedDecl(this);
 }
   }
 }
@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),
+std::move(PackBindings),
+std::move(Bindings));
   }
 
   void printName(raw_ostream &OS, const PrintingPolicy &Policy) const override;
diff --git a/clang/include/clang/AST/ExprCXX.h 
b/clang/include/clang/AST/ExprCXX.h
index 0b6c8cfb163c95..2b23fa51c6232b 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -4649,13 +4649,13 @@ class SubstNonTypeTemplateParmPackExpr : public Expr {
 /// \endcode
 class FunctionParmPackExpr final
 : public Expr,
-  private llvm::TrailingObjects {
+  private llvm::TrailingObjects {
   friend class ASTReader;
   friend class ASTStmtReader;
   friend TrailingObjects;
 
   /// The function parameter pack which was referenced.
-  VarDecl *ParamPack;
+  ValueDecl *ParamPack;
 
   /// The location of the function parameter pack reference.
   SourceLocation NameLoc;
@@ -4663,35 +4663,34 @@ class FunctionParmPackExpr final
   /// The number of expansions of this pack.
   unsigned NumParameters;
 
-  FunctionParmPackExpr(QualType T, VarDecl *ParamPack,
-   SourceLocation NameLoc, unsigned NumParams,
-   VarDecl *const *Params);
+  FunctionParmPackExpr(QualType T, ValueDecl *ParamPack, SourceLocation 
NameLoc,
+   unsigned NumParams, ValueDecl *const *Params);
 
 public:
   static FunctionParmPackExpr *Create(const ASTContext &Context, QualType T,
-

[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread Jason Rice via cfe-commits 


@@ -3492,10 +3492,13 @@ VarDecl *BindingDecl::getHoldingVar() const {
   return VD;
 }
 
-llvm::ArrayRef BindingDecl::getBindingPackExprs() const {
+llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
-  auto *RP = cast(Binding);
-  return RP->getExprs();
+  auto *FP = cast(Binding);
+  ValueDecl *const *First = FP->getNumExpansions() > 0 ? FP->begin() : nullptr;
+  assert((!First || isa(*First)) && "expecting a BindingDecl");
+  return llvm::ArrayRef((BindingDecl *const *)First,
+   FP->getNumExpansions());

ricejasonf wrote:

Ah, I had something like that, but I didn't think to `cast` to a pointer type 
(or know that you could like that).

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread Jason Rice via cfe-commits 

ricejasonf wrote:

@Sirraide I did try it and the bug persists. The `LHS` is a RecoveryExpr, so I 
am not sure how to approach that.

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

Sirraide wrote:

Can you test if that also fixes #125165?

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

https://github.com/cor3ntin commented:

Thanks for doing that, this is neat

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 


@@ -3492,10 +3492,13 @@ VarDecl *BindingDecl::getHoldingVar() const {
   return VD;
 }
 
-llvm::ArrayRef BindingDecl::getBindingPackExprs() const {
+llvm::ArrayRef BindingDecl::getBindingPackDecls() const {
   assert(Binding && "expecting a pack expr");
-  auto *RP = cast(Binding);
-  return RP->getExprs();
+  auto *FP = cast(Binding);
+  ValueDecl *const *First = FP->getNumExpansions() > 0 ? FP->begin() : nullptr;
+  assert((!First || isa(*First)) && "expecting a BindingDecl");
+  return llvm::ArrayRef((BindingDecl *const *)First,
+   FP->getNumExpansions());

cor3ntin wrote:

```suggestion
  auto *FP = cast(Binding);
  if(FP->getNumExpansions() == 0)
  return {};
  return llvm::ArrayRef(cast(FP->begin()), 
FP->getNumExpansions());
```

I haven't tested but something like that looks simpler (the cast does the 
assert, and if there is nothing to expand we can as well return early)

https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

https://github.com/cor3ntin edited 
https://github.com/llvm/llvm-project/pull/125394
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[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread Jason Rice via cfe-commits 

https://github.com/ricejasonf created 
https://github.com/llvm/llvm-project/pull/125394

This merges the functionality of ResolvedUnexpandedPackExpr into 
FunctionParmPackExpr. I also added a test to show that 
https://github.com/llvm/llvm-project/issues/125103 should be fixed with this. I 
put the removal of ResolvedUnexpandedPackExpr in its own commit. Let me know 
what you think.

@cor3ntin 

>From a323e058b2c8adf97f7f9a55a9187f74de9b8d17 Mon Sep 17 00:00:00 2001
From: Jason Rice 
Date: Sun, 2 Feb 2025 00:52:47 -0800
Subject: [PATCH 1/2] [Clang][P1061] Consolidate ResolvedUnexpandedPackExpr
 into FunctionParmPackExpr

---
 clang/include/clang/AST/DeclCXX.h | 28 +
 clang/include/clang/AST/ExprCXX.h | 21 +-
 clang/include/clang/Sema/Template.h   |  2 +-
 clang/lib/AST/DeclCXX.cpp |  9 +++--
 clang/lib/AST/ExprCXX.cpp | 14 +++
 clang/lib/Sema/SemaDeclCXX.cpp| 26 ++--
 clang/lib/Sema/SemaExpr.cpp   |  6 +--
 clang/lib/Sema/SemaTemplateInstantiate.cpp| 30 +-
 .../lib/Sema/SemaTemplateInstantiateDecl.cpp  | 40 +++
 clang/lib/Sema/SemaTemplateVariadic.cpp   | 32 +--
 clang/lib/Serialization/ASTReaderStmt.cpp |  6 +--
 clang/test/AST/ast-dump-binding-pack.cpp  | 13 ++
 clang/test/SemaCXX/cxx2c-binding-pack.cpp | 11 +
 13 files changed, 103 insertions(+), 135 deletions(-)

diff --git a/clang/include/clang/AST/DeclCXX.h 
b/clang/include/clang/AST/DeclCXX.h
index 766821b4fb25cb..1c630d61690355 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -4194,8 +4194,8 @@ class BindingDecl : public ValueDecl {
   /// decomposition declaration, and when the initializer is type-dependent.
   Expr *getBinding() const { return Binding; }
 
-  // Get the array of Exprs when the binding represents a pack.
-  llvm::ArrayRef getBindingPackExprs() const;
+  // Get the array of nested BindingDecls when the binding represents a pack.
+  llvm::ArrayRef getBindingPackDecls() const;
 
   /// Get the decomposition declaration that this binding represents a
   /// decomposition of.
@@ -4246,10 +4246,8 @@ class DecompositionDecl final
 for (auto *B : Bindings) {
   B->setDecomposedDecl(this);
   if (B->isParameterPack() && B->getBinding()) {
-for (Expr *E : B->getBindingPackExprs()) {
-  auto *DRE = cast(E);
-  auto *NestedB = cast(DRE->getDecl());
-  NestedB->setDecomposedDecl(this);
+for (BindingDecl *NestedBD : B->getBindingPackDecls()) {
+  NestedBD->setDecomposedDecl(this);
 }
   }
 }
@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),
+std::move(PackBindings),
+std::move(Bindings));
   }
 
   void printName(raw_ostream &OS, const PrintingPolicy &Policy) const override;
diff --git a/clang/include/clang/AST/ExprCXX.h 
b/clang/include/clang/AST/ExprCXX.h
index 0b6c8cfb163c95..2b23fa51c6232b 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -4649,13 +4649,13 @@ class SubstNonTypeTemplateParmPackExpr : public Expr {
 /// \endcode
 class FunctionParmPackExpr final
 : public Expr,
-  private llvm::TrailingObjects {
+  private llvm::TrailingObjects {
   friend class ASTReader;
   friend class ASTStmtReader;
   friend TrailingObjects;
 
   /// The function parameter pack which was referenced.
-  VarDecl *ParamPack;
+  ValueDecl *ParamPack;
 
   /// The location of the function parameter pack reference.
   SourceLocation NameLoc;
@@ -4663,35 +4663,34 @@ class FunctionParmPackExpr final
   /// The number of expansions of this pack.
   unsigned NumParameters;
 
-  FunctionParmPackExpr(QualType T, VarDecl *ParamPack,
-   SourceLocation NameLoc, unsigned NumParams

[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

llvmbot wrote:




@llvm/pr-subscribers-clang-modules

Author: Jason Rice (ricejasonf)


Changes

This merges the functionality of ResolvedUnexpandedPackExpr into 
FunctionParmPackExpr. I also added a test to show that 
https://github.com/llvm/llvm-project/issues/125103 should be fixed with this. I 
put the removal of ResolvedUnexpandedPackExpr in its own commit. Let me know 
what you think.

@cor3ntin 

---

Patch is 46.18 KiB, truncated to 20.00 KiB below, full version: 
https://github.com/llvm/llvm-project/pull/125394.diff


29 Files Affected:

- (modified) clang/include/clang/AST/DeclCXX.h (+11-17) 
- (modified) clang/include/clang/AST/ExprCXX.h (+10-64) 
- (modified) clang/include/clang/AST/RecursiveASTVisitor.h (-1) 
- (modified) clang/include/clang/Basic/StmtNodes.td (-1) 
- (modified) clang/include/clang/Sema/Sema.h (+1-2) 
- (modified) clang/include/clang/Sema/Template.h (+1-1) 
- (modified) clang/include/clang/Serialization/ASTBitCodes.h (-1) 
- (modified) clang/lib/AST/DeclCXX.cpp (+6-3) 
- (modified) clang/lib/AST/Expr.cpp (-1) 
- (modified) clang/lib/AST/ExprCXX.cpp (+7-56) 
- (modified) clang/lib/AST/ExprClassification.cpp (-7) 
- (modified) clang/lib/AST/ExprConstant.cpp (-1) 
- (modified) clang/lib/AST/ItaniumMangle.cpp (+1-2) 
- (modified) clang/lib/AST/StmtPrinter.cpp (-9) 
- (modified) clang/lib/AST/StmtProfile.cpp (-4) 
- (modified) clang/lib/Sema/SemaDeclCXX.cpp (+13-13) 
- (modified) clang/lib/Sema/SemaExceptionSpec.cpp (-1) 
- (modified) clang/lib/Sema/SemaExpr.cpp (+3-3) 
- (modified) clang/lib/Sema/SemaTemplateInstantiate.cpp (+11-36) 
- (modified) clang/lib/Sema/SemaTemplateInstantiateDecl.cpp (+15-25) 
- (modified) clang/lib/Sema/SemaTemplateVariadic.cpp (+10-38) 
- (modified) clang/lib/Sema/TreeTransform.h (-25) 
- (modified) clang/lib/Serialization/ASTReaderStmt.cpp (+3-19) 
- (modified) clang/lib/Serialization/ASTWriter.cpp (-1) 
- (modified) clang/lib/Serialization/ASTWriterStmt.cpp (-10) 
- (modified) clang/lib/StaticAnalyzer/Core/ExprEngine.cpp (-1) 
- (modified) clang/test/AST/ast-dump-binding-pack.cpp (+3-10) 
- (modified) clang/test/SemaCXX/cxx2c-binding-pack.cpp (+11) 
- (modified) clang/tools/libclang/CXCursor.cpp (-1) 


``diff
diff --git a/clang/include/clang/AST/DeclCXX.h 
b/clang/include/clang/AST/DeclCXX.h
index 766821b4fb25cb5..1c630d616903550 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -4194,8 +4194,8 @@ class BindingDecl : public ValueDecl {
   /// decomposition declaration, and when the initializer is type-dependent.
   Expr *getBinding() const { return Binding; }
 
-  // Get the array of Exprs when the binding represents a pack.
-  llvm::ArrayRef getBindingPackExprs() const;
+  // Get the array of nested BindingDecls when the binding represents a pack.
+  llvm::ArrayRef getBindingPackDecls() const;
 
   /// Get the decomposition declaration that this binding represents a
   /// decomposition of.
@@ -4246,10 +4246,8 @@ class DecompositionDecl final
 for (auto *B : Bindings) {
   B->setDecomposedDecl(this);
   if (B->isParameterPack() && B->getBinding()) {
-for (Expr *E : B->getBindingPackExprs()) {
-  auto *DRE = cast(E);
-  auto *NestedB = cast(DRE->getDecl());
-  NestedB->setDecomposedDecl(this);
+for (BindingDecl *NestedBD : B->getBindingPackDecls()) {
+  NestedBD->setDecomposedDecl(this);
 }
   }
 }
@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),
+std::move(PackBindings),
+std::move(Bindings));
   }
 
   void printName(raw_ostream &OS, const PrintingPolicy &Policy) const override;
diff --git a/clang/include/clang/AST/ExprCXX.h 
b/clang/include/clang/AST/ExprCXX.h
index 0b6c8cfb163c958..f6cf48cb66b801a 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -4649,13 +4649,13 @@ class SubstNo

[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

2025-02-02 Thread via cfe-commits 

llvmbot wrote:




@llvm/pr-subscribers-clang

Author: Jason Rice (ricejasonf)


Changes

This merges the functionality of ResolvedUnexpandedPackExpr into 
FunctionParmPackExpr. I also added a test to show that 
https://github.com/llvm/llvm-project/issues/125103 should be fixed with this. I 
put the removal of ResolvedUnexpandedPackExpr in its own commit. Let me know 
what you think.

@cor3ntin 

---

Patch is 46.18 KiB, truncated to 20.00 KiB below, full version: 
https://github.com/llvm/llvm-project/pull/125394.diff


29 Files Affected:

- (modified) clang/include/clang/AST/DeclCXX.h (+11-17) 
- (modified) clang/include/clang/AST/ExprCXX.h (+10-64) 
- (modified) clang/include/clang/AST/RecursiveASTVisitor.h (-1) 
- (modified) clang/include/clang/Basic/StmtNodes.td (-1) 
- (modified) clang/include/clang/Sema/Sema.h (+1-2) 
- (modified) clang/include/clang/Sema/Template.h (+1-1) 
- (modified) clang/include/clang/Serialization/ASTBitCodes.h (-1) 
- (modified) clang/lib/AST/DeclCXX.cpp (+6-3) 
- (modified) clang/lib/AST/Expr.cpp (-1) 
- (modified) clang/lib/AST/ExprCXX.cpp (+7-56) 
- (modified) clang/lib/AST/ExprClassification.cpp (-7) 
- (modified) clang/lib/AST/ExprConstant.cpp (-1) 
- (modified) clang/lib/AST/ItaniumMangle.cpp (+1-2) 
- (modified) clang/lib/AST/StmtPrinter.cpp (-9) 
- (modified) clang/lib/AST/StmtProfile.cpp (-4) 
- (modified) clang/lib/Sema/SemaDeclCXX.cpp (+13-13) 
- (modified) clang/lib/Sema/SemaExceptionSpec.cpp (-1) 
- (modified) clang/lib/Sema/SemaExpr.cpp (+3-3) 
- (modified) clang/lib/Sema/SemaTemplateInstantiate.cpp (+11-36) 
- (modified) clang/lib/Sema/SemaTemplateInstantiateDecl.cpp (+15-25) 
- (modified) clang/lib/Sema/SemaTemplateVariadic.cpp (+10-38) 
- (modified) clang/lib/Sema/TreeTransform.h (-25) 
- (modified) clang/lib/Serialization/ASTReaderStmt.cpp (+3-19) 
- (modified) clang/lib/Serialization/ASTWriter.cpp (-1) 
- (modified) clang/lib/Serialization/ASTWriterStmt.cpp (-10) 
- (modified) clang/lib/StaticAnalyzer/Core/ExprEngine.cpp (-1) 
- (modified) clang/test/AST/ast-dump-binding-pack.cpp (+3-10) 
- (modified) clang/test/SemaCXX/cxx2c-binding-pack.cpp (+11) 
- (modified) clang/tools/libclang/CXCursor.cpp (-1) 


``diff
diff --git a/clang/include/clang/AST/DeclCXX.h 
b/clang/include/clang/AST/DeclCXX.h
index 766821b4fb25cb5..1c630d616903550 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -4194,8 +4194,8 @@ class BindingDecl : public ValueDecl {
   /// decomposition declaration, and when the initializer is type-dependent.
   Expr *getBinding() const { return Binding; }
 
-  // Get the array of Exprs when the binding represents a pack.
-  llvm::ArrayRef getBindingPackExprs() const;
+  // Get the array of nested BindingDecls when the binding represents a pack.
+  llvm::ArrayRef getBindingPackDecls() const;
 
   /// Get the decomposition declaration that this binding represents a
   /// decomposition of.
@@ -4246,10 +4246,8 @@ class DecompositionDecl final
 for (auto *B : Bindings) {
   B->setDecomposedDecl(this);
   if (B->isParameterPack() && B->getBinding()) {
-for (Expr *E : B->getBindingPackExprs()) {
-  auto *DRE = cast(E);
-  auto *NestedB = cast(DRE->getDecl());
-  NestedB->setDecomposedDecl(this);
+for (BindingDecl *NestedBD : B->getBindingPackDecls()) {
+  NestedBD->setDecomposedDecl(this);
 }
   }
 }
@@ -4278,25 +4276,21 @@ class DecompositionDecl final
   // Provide a flattened range to visit each binding.
   auto flat_bindings() const {
 llvm::ArrayRef Bindings = bindings();
-llvm::ArrayRef PackExprs;
+llvm::ArrayRef PackBindings;
 
 // Split the bindings into subranges split by the pack.
-auto S1 = Bindings.take_until(
+auto BeforePackBindings = Bindings.take_until(
 [](BindingDecl *BD) { return BD->isParameterPack(); });
 
-Bindings = Bindings.drop_front(S1.size());
+Bindings = Bindings.drop_front(BeforePackBindings.size());
 if (!Bindings.empty()) {
-  PackExprs = Bindings.front()->getBindingPackExprs();
+  PackBindings = Bindings.front()->getBindingPackDecls();
   Bindings = Bindings.drop_front();
 }
 
-auto S2 = llvm::map_range(PackExprs, [](Expr *E) {
-  auto *DRE = cast(E);
-  return cast(DRE->getDecl());
-});
-
-return llvm::concat(std::move(S1), std::move(S2),
-   std::move(Bindings));
+return llvm::concat(std::move(BeforePackBindings),
+std::move(PackBindings),
+std::move(Bindings));
   }
 
   void printName(raw_ostream &OS, const PrintingPolicy &Policy) const override;
diff --git a/clang/include/clang/AST/ExprCXX.h 
b/clang/include/clang/AST/ExprCXX.h
index 0b6c8cfb163c958..f6cf48cb66b801a 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -4649,13 +4649,13 @@ class SubstNonTypeTem