[clang] [clang][bytecode] Add an `ExplicitThisParam` flag to `Function` (PR #203672)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr updated https://github.com/llvm/llvm-project/pull/203672

>From 559178c6cc7182c32b77552f54c0df8db7abd91a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Fri, 12 Jun 2026 15:31:19 +0200
Subject: [PATCH] func explicit flag

---
 clang/lib/AST/ByteCode/Function.cpp |  5 +++++
 clang/lib/AST/ByteCode/Function.h   | 18 ++++++------------
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/clang/lib/AST/ByteCode/Function.cpp b/clang/lib/AST/ByteCode/Function.cpp
index e08e2790dbd4f..cd0f7eb125230 100644
--- a/clang/lib/AST/ByteCode/Function.cpp
+++ b/clang/lib/AST/ByteCode/Function.cpp
@@ -29,12 +29,15 @@ Function::Function(Program &P, FunctionDeclTy Source, unsigned ArgSize,
     Constexpr = F->isConstexpr();
     if (const auto *CD = dyn_cast<CXXConstructorDecl>(F)) {
       Virtual = CD->isVirtual();
+      ExplicitThisPointer = CD->isExplicitObjectMemberFunction();
       Kind = CD->isCopyOrMoveConstructor() ? FunctionKind::CopyOrMoveCtor
                                            : FunctionKind::Ctor;
     } else if (const auto *CD = dyn_cast<CXXDestructorDecl>(F)) {
+      ExplicitThisPointer = CD->isExplicitObjectMemberFunction();
       Virtual = CD->isVirtual();
       Kind = FunctionKind::Dtor;
     } else if (const auto *MD = dyn_cast<CXXMethodDecl>(F)) {
+      ExplicitThisPointer = MD->isExplicitObjectMemberFunction();
       Virtual = MD->isVirtual();
       if (IsLambdaStaticInvoker)
         Kind = FunctionKind::LambdaStaticInvoker;
@@ -43,9 +46,11 @@ Function::Function(Program &P, FunctionDeclTy Source, unsigned ArgSize,
       else if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())
         Kind = FunctionKind::CopyOrMoveOperator;
     } else {
+      ExplicitThisPointer = false;
       Virtual = false;
     }
   } else {
+    ExplicitThisPointer = false;
     Variadic = false;
     Virtual = false;
     Immediate = false;
diff --git a/clang/lib/AST/ByteCode/Function.h b/clang/lib/AST/ByteCode/Function.h
index d9a286937cadd..289bd64124004 100644
--- a/clang/lib/AST/ByteCode/Function.h
+++ b/clang/lib/AST/ByteCode/Function.h
@@ -224,6 +224,10 @@ class Function final {
   bool isFullyCompiled() const { return IsFullyCompiled; }
 
   bool hasThisPointer() const { return HasThisPointer; }
+  bool isThisPointerExplicit() const { return ExplicitThisPointer; }
+  bool hasImplicitThisParam() const {
+    return hasThisPointer() && !ExplicitThisPointer;
+  }
 
   /// Checks if the function already has a body attached.
   bool hasBody() const { return HasBody; }
@@ -232,7 +236,6 @@ class Function final {
   bool isDefined() const { return Defined; }
 
   bool isVariadic() const { return Variadic; }
-
   unsigned getNumParams() const {
     return ParamDescriptors.size() + hasThisPointer() + hasRVO();
   }
@@ -247,17 +250,6 @@ class Function final {
     return ArgSize - (align(primSize(PT_Ptr)) * (hasThisPointer() + hasRVO()));
   }
 
-  bool isThisPointerExplicit() const {
-    if (const auto *MD = dyn_cast_if_present<CXXMethodDecl>(
-            dyn_cast<const FunctionDecl *>(Source)))
-      return MD->isExplicitObjectMemberFunction();
-    return false;
-  }
-
-  bool hasImplicitThisParam() const {
-    return hasThisPointer() && !isThisPointerExplicit();
-  }
-
 private:
   /// Construct a function representing an actual function.
   Function(Program &P, FunctionDeclTy Source, unsigned ArgSize,
@@ -315,6 +307,8 @@ class Function final {
   /// as the first implicit argument
   LLVM_PREFERRED_TYPE(bool)
   unsigned HasThisPointer : 1;
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned ExplicitThisPointer : 1;
   /// Whether this function has Return Value Optimization, i.e.
   /// the return value is constructed in the caller's stack frame.
   /// This is done for functions that return non-primive values.