CIRABIRewriteContext.h

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//===- CIRABIRewriteContext.h - CIR ABI rewrite context ---------*- 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 CIRABIRewriteContext, the CIR dialect's implementation of the
// generic mlir::abi::ABIRewriteContext.  Given a FunctionClassification it
// rewrites a cir.func signature, the function body, and call sites to match
// the ABI-lowered shape.
//
// This file handles Direct (pass-through and coerce-in-registers), Extend,
// Ignore, Indirect (sret return, byval and byref arguments), and Expand
// (struct flattening into scalar fields).
//
//===----------------------------------------------------------------------===//
 
#ifndef CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_CIRABIREWRITECONTEXT_H
#define CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_CIRABIREWRITECONTEXT_H
 
#include "mlir/ABI/ABIRewriteContext.h"
#include "mlir/IR/BuiltinOps.h"
#include "mlir/Interfaces/DataLayoutInterfaces.h"
#include "clang/CIR/Dialect/IR/CIRDialect.h"
 
namespace cir {
 
/// CIR-specific implementation of mlir::abi::ABIRewriteContext.
///
/// The driver pass (CallConvLoweringPass) computes a FunctionClassification
/// for each cir.func / cir.call and dispatches to this class to perform the
/// actual IR rewriting using cir dialect operations.
///
/// Holds a reference to the module's DataLayout for coercion alignment
/// queries.  The DataLayout must outlive the rewrite context.
class CIRABIRewriteContext : public mlir::abi::ABIRewriteContext {
public:
  CIRABIRewriteContext(mlir::ModuleOp module, const mlir::DataLayout &dl)
      : module(module), dl(dl) {}
 
  mlir::LogicalResult
  rewriteFunctionDefinition(mlir::FunctionOpInterface funcOp,
                            const mlir::abi::FunctionClassification &fc,
                            mlir::OpBuilder &builder) override;
 
  mlir::LogicalResult
  rewriteCallSite(mlir::Operation *callOp,
                  const mlir::abi::FunctionClassification &fc,
                  mlir::OpBuilder &builder) override;
 
  /// Retype \p addrOp, which holds the address of \p funcOp, to the signature
  /// funcOp was rewritten to, and cast it back so existing uses keep the type
  /// they were built for.  A no-op when the ABI left funcOp's type alone.
  /// Call after funcOp has been rewritten.  Not an override, since taking a
  /// function's address has no counterpart in the generic contract.
  void rewriteFunctionAddress(cir::GetGlobalOp addrOp, cir::FuncOp funcOp,
                              mlir::OpBuilder &builder);
 
  mlir::StringRef getDialectNamespace() const override { return "cir"; }
 
private:
  mlir::ModuleOp module;
  const mlir::DataLayout &dl;
};
 
} // namespace cir
 
#endif // CLANG_LIB_CIR_DIALECT_TRANSFORMS_TARGETLOWERING_CIRABIREWRITECONTEXT_H