From 5b88d78753d21e9f9215933233007b3aee722c62 Mon Sep 17 00:00:00 2001
From: duckdoom5 <duckdoom5@users.noreply.github.com>
Date: Thu, 6 Feb 2025 18:40:43 +0100
Subject: [PATCH] Remove llvm backend mangeling

---
 src/CppParser/ASTNameMangler.cpp | 33 ++++++++++----------------------
 src/CppParser/ASTNameMangler.h   |  2 +-
 src/CppParser/Parser.cpp         |  2 +-
 3 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/src/CppParser/ASTNameMangler.cpp b/src/CppParser/ASTNameMangler.cpp
index d7bb20f0..e79c4f7d 100644
--- a/src/CppParser/ASTNameMangler.cpp
+++ b/src/CppParser/ASTNameMangler.cpp
@@ -9,6 +9,7 @@
 
 #include <clang/AST/GlobalDecl.h>
 #include <clang/AST/Mangle.h>
+#include <clang/AST/VTableBuilder.h>
 #include <clang/Basic/TargetInfo.h>
 #include <llvm/IR/Mangler.h>
 
@@ -34,8 +35,8 @@ namespace {
 }
 
 ASTNameMangler::ASTNameMangler(ASTContext& Ctx)
-    : MC(Ctx.createMangleContext())
-    , DL(Ctx.getTargetInfo().getDataLayoutString())
+    : DL(Ctx.getTargetInfo().getDataLayoutString())
+    , MC(Ctx.createMangleContext())
 {
 }
 
@@ -50,16 +51,14 @@ std::string ASTNameMangler::GetName(const Decl* D) {
 
 bool ASTNameMangler::WriteName(const Decl* D, raw_ostream& OS) {
     // First apply frontend mangling.
-    SmallString<128> FrontendBuf;
-    llvm::raw_svector_ostream FrontendBufOS(FrontendBuf);
     if (auto* FD = dyn_cast<FunctionDecl>(D)) {
         if (FD->isDependentContext())
             return true;
-        if (WriteFuncOrVarName(FD, FrontendBufOS))
+        if (WriteFuncOrVarName(FD, OS))
             return true;
     }
     else if (auto* VD = dyn_cast<VarDecl>(D)) {
-        if (WriteFuncOrVarName(VD, FrontendBufOS))
+        if (WriteFuncOrVarName(VD, OS))
             return true;
     }
     else if (auto* MD = dyn_cast<ObjCMethodDecl>(D)) {
@@ -68,14 +67,12 @@ bool ASTNameMangler::WriteName(const Decl* D, raw_ostream& OS) {
         return false;
     }
     else if (auto* ID = dyn_cast<ObjCInterfaceDecl>(D)) {
-        WriteObjCClassName(ID, FrontendBufOS);
+        WriteObjCClassName(ID, OS);
     }
     else {
         return true;
     }
 
-    // Now apply backend mangling.
-    llvm::Mangler::getNameWithPrefix(OS, FrontendBufOS.str(), DL);
     return false;
 }
 
@@ -90,12 +87,7 @@ std::string ASTNameMangler::GetMangledStructor(const NamedDecl* ND, unsigned Str
         GD = GlobalDecl(DD, static_cast<CXXDtorType>(StructorType));
     MC->mangleName(GD, FOS);
 
-    std::string BackendBuf;
-    llvm::raw_string_ostream BOS(BackendBuf);
-
-    llvm::Mangler::getNameWithPrefix(BOS, FrontendBuf, DL);
-
-    return BackendBuf;
+    return FrontendBuf;
 }
 
 std::string ASTNameMangler::GetMangledThunk(const CXXMethodDecl* MD, const ThunkInfo& T, bool /*ElideOverrideInfo*/) {
@@ -105,12 +97,7 @@ std::string ASTNameMangler::GetMangledThunk(const CXXMethodDecl* MD, const Thunk
     // TODO: Enable `ElideOverrideInfo` param if clang is updated to 19
     MC->mangleThunk(MD, T, /*ElideOverrideInfo,*/ FOS);
 
-    std::string BackendBuf;
-    llvm::raw_string_ostream BOS(BackendBuf);
-
-    llvm::Mangler::getNameWithPrefix(BOS, FrontendBuf, DL);
-
-    return BackendBuf;
+    return FrontendBuf;
 }
 
 bool ASTNameMangler::WriteFuncOrVarName(const NamedDecl* D, raw_ostream& OS) const
@@ -125,9 +112,9 @@ bool ASTNameMangler::WriteFuncOrVarName(const NamedDecl* D, raw_ostream& OS) con
 
     GlobalDecl GD;
     if (const auto* CtorD = dyn_cast<CXXConstructorDecl>(D))
-        GD = GlobalDecl(CtorD, Ctor_Complete);
+        GD = GlobalDecl(CtorD, Ctor_Base);
     else if (const auto* DtorD = dyn_cast<CXXDestructorDecl>(D))
-        GD = GlobalDecl(DtorD, Dtor_Complete);
+        GD = GlobalDecl(DtorD, Dtor_Base);
     else if (D->hasAttr<CUDAGlobalAttr>())
         GD = GlobalDecl(cast<FunctionDecl>(D));
     else
diff --git a/src/CppParser/ASTNameMangler.h b/src/CppParser/ASTNameMangler.h
index acd8e14d..93099cb7 100644
--- a/src/CppParser/ASTNameMangler.h
+++ b/src/CppParser/ASTNameMangler.h
@@ -43,8 +43,8 @@ private:
     std::string GetMangledThunk(const clang::CXXMethodDecl* MD, const clang::ThunkInfo& T, bool ElideOverrideInfo);
     bool WriteFuncOrVarName(const clang::NamedDecl* D, llvm::raw_ostream& OS) const;
     
-    std::unique_ptr<clang::MangleContext> MC;
     llvm::DataLayout DL;
+    std::unique_ptr<clang::MangleContext> MC;
 };
 
 }
diff --git a/src/CppParser/Parser.cpp b/src/CppParser/Parser.cpp
index 5ab3b02a..a2db0e2c 100644
--- a/src/CppParser/Parser.cpp
+++ b/src/CppParser/Parser.cpp
@@ -507,7 +507,7 @@ std::string Parser::GetDeclMangledName(const clang::Decl* D) const
         return {};
 
     // Mangled names are not meaningful for locals, and may not be well-defined
-        // in the case of VLAs.
+    // in the case of VLAs.
     auto* VD = dyn_cast<VarDecl>(ND);
     if (VD && VD->hasLocalStorage())
         return {};