Revert "[CIR][ABI][NFC] Add CC lowering for void CallOps (#668)"

This reverts commit 66bb15b.

This broke the build:
```
/usr/bin/ld: lib/libMLIRCIRTransforms.a(LoweringPrepare.cpp.o): in function `(anonymous namespace)::LoweringPreparePass::lowerVAArgOp(mlir::cir::VAArgOp)':
/local/home/dolsen/clangir/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp:340: undefined reference to `cir::CIRDataLayout::CIRDataLayout(mlir::ModuleOp)'
/usr/bin/ld: lib/libTargetLowering.a(LowerTypes.cpp.o): in function `cir::CIRDataLayout::CIRDataLayout(llvm::StringRef, mlir::ModuleOp)':
/local/home/dolsen/clangir/clang/include/clang/CIR/Dialect/IR/CIRDataLayout.h:31: undefined reference to `cir::CIRDataLayout::reset(llvm::StringRef)'`'
```

Steps to reproduce:
```
$ cmake -GNinja -DCMAKE_INSTALL_PREFIX=/<some-path>/clangir-install "-DLLVM_ENABLE_PROJECTS=clang;mlir" -DCLANG_ENABLE_CIR=ON -DLLVM_TARGETS_TO_BUILD=host -DCMAKE_BUILD_TYPE=Debug ../clangir/llvm
$ ninja install
```

Author: bcardosolopes

clang/include/clang/CIR/Dialect/IR/CIRDataLayout.h

@@ -15,7 +15,6 @@
 #include "mlir/Dialect/DLTI/DLTI.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
-#include "llvm/ADT/StringRef.h"
 
 namespace cir {
 
@@ -25,18 +24,6 @@ class CIRDataLayout {
 public:
   mlir::DataLayout layout;
 
-  /// Constructs a DataLayout from a specification string. See reset().
-  explicit CIRDataLayout(llvm::StringRef dataLayout, mlir::ModuleOp module)
-      : layout(module) {
-    reset(dataLayout);
-  }
-
-  /// Parse a data layout string (with fallback to default values).
-  void reset(llvm::StringRef dataLayout);
-
-  // Free all internal data structures.
-  void clear();
-
   CIRDataLayout(mlir::ModuleOp modOp);
   bool isBigEndian() const { return bigEndian; }
 

clang/include/clang/CIR/FnInfoOpts.h

@@ -156,6 +156,7 @@ struct MissingFeatures {
   static bool zeroInitializer() { return false; }
   static bool targetCodeGenInfoIsProtoCallVariadic() { return false; }
   static bool targetCodeGenInfoGetNullPointer() { return false; }
+  static bool chainCalls() { return false; }
   static bool operandBundles() { return false; }
   static bool exceptions() { return false; }
   static bool metaDataNode() { return false; }
@@ -189,50 +190,24 @@ struct MissingFeatures {
 
   //===--- ABI lowering --===//
 
-  //-- Missing AST queries
-
-  static bool recordDeclCanPassInRegisters() { return false; }
-
-  //-- Missing types
-
-  static bool vectorType() { return false; }
-
-  //-- Other missing features
-
-  // Calls with a static chain pointer argument may be optimized (p.e. freeing
-  // up argument registers), but we do not yet track such cases.
-  static bool chainCall() { return false; }
-
-  // ABI-lowering has special handling for regcall calling convention (tries to
-  // pass every argument in regs). We don't support it just yet.
-  static bool regCall() { return false; }
-
-  // Some ABIs (e.g. x86) require special handling for returning large structs
-  // by value. The sret argument parameter aids in this, but it is current NYI.
-  static bool sretArgs() { return false; }
-
-  // Inalloca parameter attributes are mostly used for Windows x86_32 ABI. We
-  // do not yet support this yet.
-  static bool inallocaArgs() { return false; }
-
   // Parameters may have additional attributes (e.g. [[noescape]]) that affect
   // the compiler. This is not yet supported in CIR.
-  static bool extParamInfo() { return false; }
+  static bool extParamInfo() { return true; }
 
   // LangOpts may affect lowering, but we do not carry this information into CIR
   // just yet. Right now, it only instantiates the default lang options.
-  static bool langOpts() { return false; }
+  static bool langOpts() { return true; }
 
   // Several type qualifiers are not yet supported in CIR, but important when
   // evaluating ABI-specific lowering.
-  static bool qualifiedTypes() { return false; }
+  static bool qualifiedTypes() { return true; }
 
   // We're ignoring several details regarding ABI-halding for Swift.
-  static bool swift() { return false; }
+  static bool swift() { return true; }
 
   // Despite carrying some information about variadics, we are currently
   // ignoring this to focus only on the code necessary to lower non-variadics.
-  static bool variadicFunctions() { return false; }
+  static bool variadicFunctions() { return true; }
 };
 
 } // namespace cir

clang/include/clang/CIR/MissingFeatures.h

@@ -23,7 +23,6 @@
 #include "clang/AST/GlobalDecl.h"
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
-#include "clang/CIR/FnInfoOpts.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 

clang/include/clang/CIR/Target/x86.h

@@ -290,6 +290,13 @@ class ReturnValueSlot {
   Address getAddress() const { return Addr; }
 };
 
+enum class FnInfoOpts {
+  None = 0,
+  IsInstanceMethod = 1 << 0,
+  IsChainCall = 1 << 1,
+  IsDelegateCall = 1 << 2,
+};
+
 } // namespace cir
 
 #endif

clang/lib/CIR/CodeGen/CIRGenCall.cpp

@@ -1435,7 +1435,7 @@ RValue CIRGenFunction::buildCall(clang::QualType CalleeType,
   // Chain calls use the same code path to add the inviisble chain parameter to
   // the function type.
   if (isa<FunctionNoProtoType>(FnType) || Chain) {
-    assert(!MissingFeatures::chainCall());
+    assert(!MissingFeatures::chainCalls());
     assert(!MissingFeatures::addressSpace());
     auto CalleeTy = getTypes().GetFunctionType(FnInfo);
     // get non-variadic function type

clang/lib/CIR/CodeGen/CIRGenCall.h

@@ -16,7 +16,6 @@
 #include "clang/AST/GlobalDecl.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
-#include "clang/CIR/FnInfoOpts.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/ErrorHandling.h"

clang/lib/CIR/CodeGen/CIRGenExpr.cpp

@@ -22,7 +22,6 @@
 #include "clang/AST/Type.h"
 #include "clang/Basic/ABI.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
-#include "clang/CIR/FnInfoOpts.h"
 
 #include "llvm/ADT/SmallPtrSet.h"
 

clang/lib/CIR/CodeGen/CIRGenTypes.cpp

@@ -748,7 +748,3 @@ CIRDataLayout::CIRDataLayout(mlir::ModuleOp modOp) : layout{modOp} {
     }
   }
 }
-
-void CIRDataLayout::reset(StringRef Desc) { clear(); }
-
-void CIRDataLayout::clear() {}

clang/lib/CIR/CodeGen/CIRGenTypes.h

@@ -6,7 +6,6 @@
 #include "CallingConv.h"
 
 #include "clang/Basic/TargetInfo.h"
-#include "clang/CIR/Target/x86.h"
 
 using namespace cir;
 using namespace clang;
@@ -80,7 +79,16 @@ namespace {
 enum class X86AVXABILevel { None, AVX, AVX512 };
 
 class X86_64ABIInfo : public ABIInfo {
-  using Class = X86ArgClass;
+  enum Class {
+    Integer = 0,
+    SSE,
+    SSEUp,
+    X87,
+    X87Up,
+    ComplexX87,
+    NoClass,
+    Memory
+  };
 
   // X86AVXABILevel AVXLevel;
   // Some ABIs (e.g. X32 ABI and Native Client OS) use 32 bit pointers on 64-bit

clang/lib/CIR/CodeGen/CIRRecordLayoutBuilder.cpp

@@ -45,7 +45,7 @@ LowerModule createLowerModule(FuncOp op, PatternRewriter &rewriter) {
   // FIXME(cir): This just uses the default language options. We need to account
   // for custom options.
   // Create context.
-  assert(!::cir::MissingFeatures::langOpts());
+  assert(::cir::MissingFeatures::langOpts());
   clang::LangOptions langOpts;
   auto context = CIRLowerContext(module.getContext(), langOpts);
   context.initBuiltinTypes(*targetInfo);
@@ -64,27 +64,11 @@ struct CallConvLoweringPattern : public OpRewritePattern<FuncOp> {
 
   LogicalResult matchAndRewrite(FuncOp op,
                                 PatternRewriter &rewriter) const final {
-    const auto module = op->getParentOfType<mlir::ModuleOp>();
-
     if (!op.getAst())
       return op.emitError("function has no AST information");
 
     LowerModule lowerModule = createLowerModule(op, rewriter);
 
-    // Rewrite function calls before definitions. This should be done before
-    // lowering the definition.
-    auto calls = op.getSymbolUses(module);
-    if (calls.has_value()) {
-      for (auto call : calls.value()) {
-        auto callOp = cast<CallOp>(call.getUser());
-        if (lowerModule.rewriteFunctionCall(callOp, op).failed())
-          return failure();
-      }
-    }
-
-    // Rewrite function definition.
-    // FIXME(cir): This is a workaround to avoid an infinite loop in the driver.
-    rewriter.replaceOp(op, rewriter.clone(*op));
     return success();
   }
 };

clang/lib/CIR/CodeGen/TargetInfo.cpp

@@ -12,16 +12,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "ABIInfo.h"
-#include "CIRCXXABI.h"
-#include "LowerTypes.h"
 
 namespace mlir {
 namespace cir {
 
 // Pin the vtable to this file.
 ABIInfo::~ABIInfo() = default;
 
-CIRCXXABI &ABIInfo::getCXXABI() const { return LT.getCXXABI(); }
-
 } // namespace cir
 } // namespace mlir

clang/lib/CIR/Dialect/Transforms/CallConvLowering.cpp

@@ -14,8 +14,6 @@
 #ifndef LLVM_CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_ABIINFO_H
 #define LLVM_CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_ABIINFO_H
 
-#include "CIRCXXABI.h"
-#include "LowerFunctionInfo.h"
 #include "llvm/IR/CallingConv.h"
 
 namespace mlir {
@@ -34,10 +32,6 @@ class ABIInfo {
 public:
   ABIInfo(LowerTypes &LT) : LT(LT), RuntimeCC(llvm::CallingConv::C) {}
   virtual ~ABIInfo();
-
-  CIRCXXABI &getCXXABI() const;
-
-  virtual void computeInfo(LowerFunctionInfo &FI) const = 0;
 };
 
 } // namespace cir

clang/lib/CIR/Dialect/Transforms/TargetLowering/ABIInfo.cpp

@@ -10,25 +10,3 @@
 // adapted to operate on the CIR dialect, however.
 //
 //===----------------------------------------------------------------------===//
-
-#include "ABIInfo.h"
-#include "CIRCXXABI.h"
-#include "LowerFunctionInfo.h"
-#include "llvm/Support/ErrorHandling.h"
-
-namespace mlir {
-namespace cir {
-
-bool classifyReturnType(const CIRCXXABI &CXXABI, LowerFunctionInfo &FI,
-                        const ABIInfo &Info) {
-  Type Ty = FI.getReturnType();
-
-  if (const auto RT = Ty.dyn_cast<StructType>()) {
-    llvm_unreachable("NYI");
-  }
-
-  return CXXABI.classifyReturnType(FI);
-}
-
-} // namespace cir
-} // namespace mlir

clang/lib/CIR/Dialect/Transforms/TargetLowering/ABIInfo.h

@@ -14,17 +14,8 @@
 #ifndef LLVM_CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_ABIINFOIMPL_H
 #define LLVM_CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_ABIINFOIMPL_H
 
-#include "ABIInfo.h"
-#include "CIRCXXABI.h"
-#include "LowerFunctionInfo.h"
-
 namespace mlir {
-namespace cir {
-
-bool classifyReturnType(const CIRCXXABI &CXXABI, LowerFunctionInfo &FI,
-                        const ABIInfo &Info);
-
-} // namespace cir
+namespace cir {} // namespace cir
 } // namespace mlir
 
 #endif // LLVM_CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_ABIINFOIMPL_H

clang/lib/CIR/Dialect/Transforms/TargetLowering/ABIInfoImpl.cpp

@@ -14,7 +14,6 @@
 #ifndef LLVM_CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_CIRCXXABI_H
 #define LLVM_CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_CIRCXXABI_H
 
-#include "LowerFunctionInfo.h"
 #include "mlir/IR/Value.h"
 #include "clang/CIR/Dialect/Builder/CIRBaseBuilder.h"
 #include "clang/CIR/Dialect/IR/CIRDataLayout.h"
@@ -35,10 +34,6 @@ class CIRCXXABI {
 
 public:
   virtual ~CIRCXXABI();
-
-  /// If the C++ ABI requires the given type be returned in a particular way,
-  /// this method sets RetAI and returns true.
-  virtual bool classifyReturnType(LowerFunctionInfo &FI) const = 0;
 };
 
 /// Creates an Itanium-family ABI.

clang/lib/CIR/Dialect/Transforms/TargetLowering/ABIInfoImpl.h

@@ -31,7 +31,7 @@ Type CIRLowerContext::initBuiltinType(clang::BuiltinType::Kind K) {
   Type Ty;
 
   // NOTE(cir): Clang does more stuff here. Not sure if we need to do the same.
-  assert(!::cir::MissingFeatures::qualifiedTypes());
+  assert(::cir::MissingFeatures::qualifiedTypes());
   switch (K) {
   case clang::BuiltinType::Char_S:
     Ty = IntType::get(getMLIRContext(), 8, true);