[llvm] Overhaul the TargetMachine and LLVMTargetMachine Classes (PR #111234)

[Matt Arsenault via llvm-commits]

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+//===-- CodeGenCommonTMImpl.h -----------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file This file describes the CodeGenCommonTMImpl class, which
+/// implements a set of functionality used by \c TargetMachine classes in
+/// LLVM that make use of the target-independent code generator.
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_CODEGEN_CODEGENCOMMONTMIMPL_H
+#define LLVM_CODEGEN_CODEGENCOMMONTMIMPL_H
+#include "llvm/Target/TargetMachine.h"
+
+namespace llvm {
+
+/// \brief implements a set of functionality in the \c TargetMachine class
+/// for targets that make use of the independent code generator (CodeGen)
+/// library. Must not be used directly in code unless to inherit its
+/// implementation.
+class CodeGenCommonTMImpl : public TargetMachine {
+protected: // Can only create subclasses.
+  CodeGenCommonTMImpl(const Target &T, StringRef DataLayoutString,
+                      const Triple &TT, StringRef CPU, StringRef FS,
+                      const TargetOptions &Options, Reloc::Model RM,
+                      CodeModel::Model CM, CodeGenOptLevel OL);
+
+  void initAsmInfo();
+
+public:
+  /// Get a TargetTransformInfo implementation for the target.
+  ///
+  /// The TTI returned uses the common code generator to answer queries about
+  /// the IR.
+  TargetTransformInfo getTargetTransformInfo(const Function &F) const override;
+
+  /// Create a pass configuration object to be used by addPassToEmitX methods
+  /// for generating a pipeline of CodeGen passes.
+  virtual TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
+
+  /// Add passes to the specified pass manager to get the specified file
+  /// emitted.  Typically this will involve several steps of code generation.
+  /// \p MMIWP is an optional parameter that, if set to non-nullptr,
+  /// will be used to set the MachineModuloInfo for this PM.
+  bool
+  addPassesToEmitFile(PassManagerBase &PM, raw_pwrite_stream &Out,
+                      raw_pwrite_stream *DwoOut, CodeGenFileType FileType,
+                      bool DisableVerify = true,
+                      MachineModuleInfoWrapperPass *MMIWP = nullptr) override;
+
+  /// Add passes to the specified pass manager to get machine code emitted with
+  /// the MCJIT. This method returns true if machine code is not supported. It
+  /// fills the MCContext Ctx pointer which can be used to build custom
+  /// MCStreamer.
+  bool addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
+                         raw_pwrite_stream &Out,
+                         bool DisableVerify = true) override;
+
+  /// Adds an AsmPrinter pass to the pipeline that prints assembly or
+  /// machine code from the MI representation.
+  bool addAsmPrinter(PassManagerBase &PM, raw_pwrite_stream &Out,
+                     raw_pwrite_stream *DwoOut, CodeGenFileType FileType,
+                     MCContext &Context) override;
+
+  Expected<std::unique_ptr<MCStreamer>>
+  createMCStreamer(raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
+                   CodeGenFileType FileType, MCContext &Ctx) override;
+};
+
+/// Helper method for getting the code model, returning Default if
+/// CM does not have a value. The tiny and kernel models will produce
+/// an error, so targets that support them or require more complex codemodel
+/// selection logic should implement and call their own getEffectiveCodeModel.
+inline CodeModel::Model
+getEffectiveCodeModel(std::optional<CodeModel::Model> CM,
+                      CodeModel::Model Default) {
+  if (CM) {
+    // By default, targets do not support the tiny and kernel models.
+    if (*CM == CodeModel::Tiny)
+      report_fatal_error("Target does not support the tiny CodeModel", false);
+    if (*CM == CodeModel::Kernel)
+      report_fatal_error("Target does not support the kernel CodeModel", false);
+    return *CM;
+  }
+  return Default;
+}
+
+} // namespace llvm
+
+#endif
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arsenm wrote:

Missing end of file line 

https://github.com/llvm/llvm-project/pull/111234