[clang] [clang] Migrate away from PointerUnion::dyn_cast (NFC) (PR #225614)

[via cfe-commits]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>

Note that PointerUnion::dyn_cast has been soft deprecated in
PointerUnion.h:

  // FIXME: Replace the uses of is(), get() and dyn_cast() with
  //        isa<T>, cast<T> and the llvm::dyn_cast<T>

Literal migration would result in dyn_cast_if_present (see the
definition of PointerUnion::dyn_cast), but this patch uses dyn_cast on
UnexpandedParameterPack::first because it is always nonnull.
Specifically, UnexpandedParameterPack is constructed only in the
following places, all of which store a nonnull pointer in first, and
first is never modified afterward:

- CollectUnexpandedParameterPacksVisitor::addUnexpanded in
  SemaTemplateVariadic.cpp
- TransformLambdaExpr in TreeTransform.h
- TransformSizeOfPackExpr in TreeTransform.h

Assisted-by: Antigravity


---
Full diff: https://github.com/llvm/llvm-project/pull/225614.diff


4 Files Affected:

- (modified) clang/lib/Sema/SemaTemplate.cpp (+1-1) 
- (modified) clang/lib/Sema/SemaTemplateInstantiate.cpp (+1-1) 
- (modified) clang/lib/Sema/SemaTemplateVariadic.cpp (+14-19) 
- (modified) clang/lib/Sema/TreeTransform.h (+1-1) 


``````````diff
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 466515550381a..593bfb051dfa1 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -5958,7 +5958,7 @@ bool Sema::CheckTemplateArgumentList(
       llvm::SmallVector<UnexpandedParameterPack> Unexpanded;
       collectUnexpandedParameterPacks(TL.getPatternLoc(), Unexpanded);
       for (const auto &UPP : Unexpanded) {
-        auto *TST = UPP.first.dyn_cast<const TemplateSpecializationType *>();
+        auto *TST = dyn_cast<const TemplateSpecializationType *>(UPP.first);
         if (!TST)
           continue;
         assert(isPackProducingBuiltinTemplateName(TST->getTemplateName()));
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index bbca1267461e4..06ea12ca7bd73 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -3406,7 +3406,7 @@ PreparePackForExpansion(Sema &S, const CXXBaseSpecifier &Base,
       // that required a substituion first.
       bool SawPackTypes =
           llvm::any_of(Unexpanded, [](UnexpandedParameterPack P) {
-            return P.first.dyn_cast<const SubstBuiltinTemplatePackType *>();
+            return isa<const SubstBuiltinTemplatePackType *>(P.first);
           });
       if (!SawPackTypes) {
         Info.Expand = false;
diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index 3235750f408ff..bbac53b5b2acf 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -505,10 +505,10 @@ Sema::DiagnoseUnexpandedParameterPacks(SourceLocation Loc,
 
   for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) {
     IdentifierInfo *Name = nullptr;
-    if (const TemplateTypeParmType *TTP
-          = Unexpanded[I].first.dyn_cast<const TemplateTypeParmType *>())
+    if (const TemplateTypeParmType *TTP =
+            dyn_cast<const TemplateTypeParmType *>(Unexpanded[I].first))
       Name = TTP->getIdentifier();
-    else if (NamedDecl *ND = Unexpanded[I].first.dyn_cast<NamedDecl *>())
+    else if (NamedDecl *ND = dyn_cast<NamedDecl *>(Unexpanded[I].first))
       Name = ND->getIdentifier();
 
     if (Name && NamesKnown.insert(Name).second)
@@ -583,7 +583,7 @@ bool Sema::DiagnoseUnexpandedParameterPackInRequiresExpr(RequiresExpr *RE) {
   llvm::SmallPtrSet<NamedDecl *, 8> ParmSet(llvm::from_range, Parms);
   SmallVector<UnexpandedParameterPack, 2> UnexpandedParms;
   for (auto Parm : Unexpanded)
-    if (ParmSet.contains(Parm.first.dyn_cast<NamedDecl *>()))
+    if (ParmSet.contains(dyn_cast<NamedDecl *>(Parm.first)))
       UnexpandedParms.push_back(Parm);
   if (UnexpandedParms.empty())
     return false;
@@ -875,13 +875,12 @@ bool Sema::CheckParameterPacksForExpansion(
     FunctionParmPackExpr *BindingPack = nullptr;
     std::optional<unsigned> NumPrecomputedArguments;
 
-    if (auto *TTP = ParmPack.first.dyn_cast<const TemplateTypeParmType *>()) {
+    if (auto *TTP = dyn_cast<const TemplateTypeParmType *>(ParmPack.first)) {
       Depth = TTP->getDepth();
       Index = TTP->getIndex();
       Name = TTP->getIdentifier();
-    } else if (auto *TST =
-                   ParmPack.first
-                       .dyn_cast<const TemplateSpecializationType *>()) {
+    } else if (auto *TST = dyn_cast<const TemplateSpecializationType *>(
+                   ParmPack.first)) {
       assert(isPackProducingBuiltinTemplateName(TST->getTemplateName()));
       // Delay expansion, substitution is required to know the size.
       ShouldExpand = false;
@@ -896,9 +895,8 @@ bool Sema::CheckParameterPacksForExpansion(
                                                     : EllipsisLoc,
                   diag::err_unsupported_builtin_template_pack_expansion)
              << TST->getTemplateName();
-    } else if (auto *S =
-                   ParmPack.first
-                       .dyn_cast<const SubstBuiltinTemplatePackType *>()) {
+    } else if (auto *S = dyn_cast<const SubstBuiltinTemplatePackType *>(
+                   ParmPack.first)) {
       Name = nullptr;
       NumPrecomputedArguments = S->getNumArgs();
     } else {
@@ -1088,20 +1086,17 @@ UnsignedOrNone Sema::getNumArgumentsInExpansionFromUnexpanded(
     unsigned Index;
 
     if (const TemplateTypeParmType *TTP =
-            Unexpanded[I].first.dyn_cast<const TemplateTypeParmType *>()) {
+            dyn_cast<const TemplateTypeParmType *>(Unexpanded[I].first)) {
       Depth = TTP->getDepth();
       Index = TTP->getIndex();
-    } else if (auto *TST =
-                   Unexpanded[I]
-                       .first.dyn_cast<const TemplateSpecializationType *>()) {
+    } else if (auto *TST = dyn_cast<const TemplateSpecializationType *>(
+                   Unexpanded[I].first)) {
       // This is a dependent pack, we are not ready to expand it yet.
       assert(isPackProducingBuiltinTemplateName(TST->getTemplateName()));
       (void)TST;
       return std::nullopt;
-    } else if (auto *PST =
-                   Unexpanded[I]
-                       .first
-                       .dyn_cast<const SubstBuiltinTemplatePackType *>()) {
+    } else if (auto *PST = dyn_cast<const SubstBuiltinTemplatePackType *>(
+                   Unexpanded[I].first)) {
       assert((!Result || *Result == PST->getNumArgs()) &&
              "inconsistent pack sizes");
       Result = PST->getNumArgs();
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 942fb586b1f23..8cd2e2e62a81c 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -5466,7 +5466,7 @@ bool TreeTransform<Derived>::PreparePackForExpansion(TemplateArgumentLoc In,
       // that required a substituion first.
       bool SawPackTypes =
           llvm::any_of(Unexpanded, [](UnexpandedParameterPack P) {
-            return P.first.dyn_cast<const SubstBuiltinTemplatePackType *>();
+            return isa<const SubstBuiltinTemplatePackType *>(P.first);
           });
       if (!SawPackTypes) {
         Info.Expand = false;

``````````

</details>


https://github.com/llvm/llvm-project/pull/225614