[clang] [clang][bytecode] Remove unused members from `EvalEmitter` (PR #186601)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/186601

Remove the DenseMap handling lambda paramter mappings from `EvalEmitter`. This was always unused. Remove it and use `if constexpr` to keep things compiling.

>From 1abd61c75196232981545b5c7261cb4fc3d12eba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Sat, 14 Mar 2026 06:29:35 +0100
Subject: [PATCH] smaller EvalEmitter

---
 clang/lib/AST/ByteCode/Compiler.cpp  | 26 +++++++++++++++-----------
 clang/lib/AST/ByteCode/EvalEmitter.h |  4 ----
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index 13d6dcc92356d..8bbdf284b313d 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -5776,10 +5776,12 @@ bool Compiler<Emitter>::VisitCXXThisExpr(const CXXThisExpr *E) {
   if (DiscardResult)
     return true;
 
-  if (this->LambdaThisCapture.Offset > 0) {
-    if (this->LambdaThisCapture.IsPtr)
-      return this->emitGetThisFieldPtr(this->LambdaThisCapture.Offset, E);
-    return this->emitGetPtrThisField(this->LambdaThisCapture.Offset, E);
+  if constexpr (!std::is_same_v<Emitter, EvalEmitter>) {
+    if (this->LambdaThisCapture.Offset > 0) {
+      if (this->LambdaThisCapture.IsPtr)
+        return this->emitGetThisFieldPtr(this->LambdaThisCapture.Offset, E);
+      return this->emitGetPtrThisField(this->LambdaThisCapture.Offset, E);
+    }
   }
 
   // In some circumstances, the 'this' pointer does not actually refer to the
@@ -7491,14 +7493,16 @@ bool Compiler<Emitter>::visitDeclRef(const ValueDecl *D, const Expr *E) {
     return this->visitDeclRef(D, E);
   };
 
-  // Lambda captures.
-  if (auto It = this->LambdaCaptures.find(D);
-      It != this->LambdaCaptures.end()) {
-    auto [Offset, IsPtr] = It->second;
+  if constexpr (!std::is_same_v<Emitter, EvalEmitter>) {
+    // Lambda captures.
+    if (auto It = this->LambdaCaptures.find(D);
+        It != this->LambdaCaptures.end()) {
+      auto [Offset, IsPtr] = It->second;
 
-    if (IsPtr)
-      return this->emitGetThisFieldPtr(Offset, E);
-    return this->emitGetPtrThisField(Offset, E);
+      if (IsPtr)
+        return this->emitGetThisFieldPtr(Offset, E);
+      return this->emitGetPtrThisField(Offset, E);
+    }
   }
 
   if (const auto *DRE = dyn_cast<DeclRefExpr>(E);
diff --git a/clang/lib/AST/ByteCode/EvalEmitter.h b/clang/lib/AST/ByteCode/EvalEmitter.h
index a9f87db5d7f8d..f5c51c5f3dfa0 100644
--- a/clang/lib/AST/ByteCode/EvalEmitter.h
+++ b/clang/lib/AST/ByteCode/EvalEmitter.h
@@ -92,10 +92,6 @@ class EvalEmitter : public SourceMapper {
 
   /// Parameter indices.
   llvm::DenseMap<const ParmVarDecl *, ParamOffset> Params;
-  /// Lambda captures.
-  llvm::DenseMap<const ValueDecl *, ParamOffset> LambdaCaptures;
-  /// Offset of the This parameter in a lambda record.
-  ParamOffset LambdaThisCapture{0, false};
   /// Local descriptors.
   llvm::SmallVector<SmallVector<Local, 8>, 2> Descriptors;
   std::optional<SourceInfo> LocOverride = std::nullopt;