[clang] [llvm] [WIP] ABI Lowering Library (PR #140112)

[Nikita Popov via llvm-commits]

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@@ -0,0 +1,172 @@
+//===----- ABIFunctionInfo.h - ABI Function Information ----- C++ ---------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Defines ABIFunctionInfo and associated types used in representing the
+// ABI-coerced types for function arguments and return values.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ABI_ABIFUNCTIONINFO_H
+#define LLVM_ABI_ABIFUNCTIONINFO_H
+
+#include "ABIInfo.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/IR/CallingConv.h"
+#include "llvm/Support/TrailingObjects.h"
+
+namespace llvm {
+namespace abi {
+
+struct FunctionABIInfo {
+  llvm::CallingConv::ID CC = llvm::CallingConv::C;
+  llvm::CallingConv::ID EffectiveCC = llvm::CallingConv::C;
+
+  // Core ABI attributes
+  bool NoReturn = false;
+  bool NoUnwind = false;
+  bool HasSRet = false;
+  bool IsVariadic = false;
+  bool IsInstanceMethod = false;
+  // Are these ABI Relavent(?)
+  bool IsChainCall = false;
+  bool IsDelegateCall = false;
+
+  // Register usage controls
+  bool HasRegParm = false;
+  unsigned RegParm = 0;
+  bool NoCallerSavedRegs = false;
+  // Security/extensions(are they ABI related?)
+  bool NoCfCheck = false;
+  bool CmseNSCall = false;
+
+  // Optimization hints
+  bool ReturnsRetained = false;
+  unsigned MaxVectorWidth = 0;
+
+  FunctionABIInfo() = default;
+  FunctionABIInfo(llvm::CallingConv::ID CC) : CC(CC), EffectiveCC(CC) {}
+};
+
+// Not an Immediate requirement for BPF
+struct RequiredArgs {
+private:
+  unsigned NumRequired;
+  static constexpr unsigned All = ~0U;
+
+public:
+  RequiredArgs() : NumRequired(All) {}
+  explicit RequiredArgs(unsigned N) : NumRequired(N) {}
+
+  static RequiredArgs forPrototypedFunction(unsigned NumArgs) {
+    return RequiredArgs(NumArgs);
+  }
+
+  static RequiredArgs forVariadicFunction(unsigned NumRequired) {
+    return RequiredArgs(NumRequired);
+  }
+
+  bool allowsOptionalArgs() const { return NumRequired != All; }
+
+  unsigned getNumRequiredArgs() const {
+    return allowsOptionalArgs() ? NumRequired : 0;
+  }
+
+  bool operator==(const RequiredArgs &Other) const {
+    return NumRequired == Other.NumRequired;
+  }
+};
+
+// Implementation detail of ABIFunctionInfo, factored out so it can be named
+// in the TrailingObjects base class of ABIFunctionInfo.
+struct ABIFunctionInfoArgInfo {
+  const Type *ABIType;
+  ABIArgInfo ArgInfo;
+
+  ABIFunctionInfoArgInfo()
+      : ABIType(nullptr), ArgInfo(ABIArgInfo::getDirect()) {}
+  ABIFunctionInfoArgInfo(Type *T)
+      : ABIType(T), ArgInfo(ABIArgInfo::getDirect()) {}
+  ABIFunctionInfoArgInfo(Type *T, ABIArgInfo A) : ABIType(T), ArgInfo(A) {}
+};
+
+class ABIFunctionInfo final
----------------
nikic wrote:

Having both FunctionABIInfo and ABIFunctionInfo is pretty confusing... do these need to be separate?

https://github.com/llvm/llvm-project/pull/140112