//===-- CLOptions.inc -- command line options -------------------*- 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
//
//===----------------------------------------------------------------------===//

/// This file defines some shared command-line options that can be used when
/// debugging the test tools. This file must be included into the tool.

#include "mlir/Conversion/SCFToControlFlow/SCFToControlFlow.h"
#include "mlir/Pass/PassManager.h"
#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
#include "mlir/Transforms/Passes.h"
#include "flang/Optimizer/CodeGen/CodeGen.h"
#include "flang/Optimizer/Transforms/Passes.h"
#include "llvm/Passes/OptimizationLevel.h"
#include "llvm/Support/CommandLine.h"

#define DisableOption(DOName, DOOption, DODescription) \
  static llvm::cl::opt<bool> disable##DOName("disable-" DOOption, \
      llvm::cl::desc("disable " DODescription " pass"), llvm::cl::init(false), \
      llvm::cl::Hidden)

/// Shared option in tools to control whether dynamically sized array
/// allocations should always be on the heap.
static llvm::cl::opt<bool> dynamicArrayStackToHeapAllocation(
    "fdynamic-heap-array",
    llvm::cl::desc("place all array allocations of dynamic size on the heap"),
    llvm::cl::init(false), llvm::cl::Hidden);

/// Shared option in tools to set a maximum value for the number of elements in
/// a compile-time sized array that can be allocated on the stack.
static llvm::cl::opt<std::size_t> arrayStackAllocationThreshold(
    "fstack-array-size",
    llvm::cl::desc(
        "place all array allocations more than <size> elements on the heap"),
    llvm::cl::init(~static_cast<std::size_t>(0)), llvm::cl::Hidden);

/// Shared option in tools to ignore missing runtime type descriptor objects
/// when translating FIR to LLVM. The resulting program will crash if the
/// runtime needs the derived type descriptors, this is only a debug option to
/// allow compiling manually written FIR programs involving derived types
/// without having to write the derived type descriptors which are normally
/// generated by the frontend.
static llvm::cl::opt<bool> ignoreMissingTypeDescriptors(
    "ignore-missing-type-desc",
    llvm::cl::desc("ignore failures to find derived type descriptors when "
                   "translating FIR to LLVM"),
    llvm::cl::init(false), llvm::cl::Hidden);

namespace {
/// Default optimization level used to create Flang pass pipeline is O0.
const static llvm::OptimizationLevel &defaultOptLevel{
    llvm::OptimizationLevel::O0};

/// Optimizer Passes
DisableOption(CfgConversion, "cfg-conversion", "disable FIR to CFG pass");
DisableOption(FirAvc, "avc", "array value copy analysis and transformation");
DisableOption(
    FirMao, "memory-allocation-opt", "memory allocation optimization");

/// CodeGen Passes
#if !defined(FLANG_EXCLUDE_CODEGEN)
DisableOption(CodeGenRewrite, "codegen-rewrite", "rewrite FIR for codegen");
DisableOption(TargetRewrite, "target-rewrite", "rewrite FIR for target");
DisableOption(FirToLlvmIr, "fir-to-llvmir", "FIR to LLVM-IR dialect");
DisableOption(LlvmIrToLlvm, "llvm", "conversion to LLVM");
DisableOption(BoxedProcedureRewrite, "boxed-procedure-rewrite",
    "rewrite boxed procedures");
#endif

DisableOption(ExternalNameConversion, "external-name-interop", "convert names with external convention");

/// Generic for adding a pass to the pass manager if it is not disabled.
template <typename F>
void addPassConditionally(
    mlir::PassManager &pm, llvm::cl::opt<bool> &disabled, F ctor) {
  if (!disabled)
    pm.addPass(ctor());
}

template <typename OP, typename F>
void addNestedPassConditionally(
    mlir::PassManager &pm, llvm::cl::opt<bool> &disabled, F ctor) {
  if (!disabled)
    pm.addNestedPass<OP>(ctor());
}

} // namespace

namespace fir {

static void defaultFlangInlinerOptPipeline(mlir::OpPassManager &pm) {
  mlir::GreedyRewriteConfig config;
  config.enableRegionSimplification = false;
  pm.addPass(mlir::createCanonicalizerPass(config));
}

inline void addCfgConversionPass(mlir::PassManager &pm) {
  addNestedPassConditionally<mlir::func::FuncOp>(
      pm, disableCfgConversion, fir::createFirToCfgPass);
}

inline void addAVC(mlir::PassManager &pm) {
  addNestedPassConditionally<mlir::func::FuncOp>(
      pm, disableFirAvc, fir::createArrayValueCopyPass);
}

inline void addMemoryAllocationOpt(mlir::PassManager &pm) {
  addNestedPassConditionally<mlir::func::FuncOp>(pm, disableFirMao, [&]() {
    return fir::createMemoryAllocationPass(
        dynamicArrayStackToHeapAllocation, arrayStackAllocationThreshold);
  });
}

#if !defined(FLANG_EXCLUDE_CODEGEN)
inline void addCodeGenRewritePass(mlir::PassManager &pm) {
  addPassConditionally(
      pm, disableCodeGenRewrite, fir::createFirCodeGenRewritePass);
}

inline void addTargetRewritePass(mlir::PassManager &pm) {
  addPassConditionally(pm, disableTargetRewrite, []() {
    return fir::createFirTargetRewritePass(fir::TargetRewriteOptions{});
  });
}

inline void addFIRToLLVMPass(mlir::PassManager &pm) {
  fir::FIRToLLVMPassOptions options;
  options.ignoreMissingTypeDescriptors = ignoreMissingTypeDescriptors;
  addPassConditionally(pm, disableFirToLlvmIr,
      [&]() { return fir::createFIRToLLVMPass(options); });
}

inline void addLLVMDialectToLLVMPass(
    mlir::PassManager &pm, llvm::raw_ostream &output) {
  addPassConditionally(pm, disableLlvmIrToLlvm,
      [&]() { return fir::createLLVMDialectToLLVMPass(output); });
}

inline void addBoxedProcedurePass(mlir::PassManager &pm) {
  addPassConditionally(pm, disableBoxedProcedureRewrite,
      [&]() { return fir::createBoxedProcedurePass(); });
}
#endif

inline void addExternalNameConversionPass(mlir::PassManager &pm) {
  addPassConditionally(pm, disableExternalNameConversion,
      [&]() { return fir::createExternalNameConversionPass(); });
}

/// Create a pass pipeline for running default optimization passes for
/// incremental conversion of FIR.
///
/// \param pm - MLIR pass manager that will hold the pipeline definition
inline void createDefaultFIROptimizerPassPipeline(
    mlir::PassManager &pm, llvm::OptimizationLevel optLevel = defaultOptLevel) {
  // simplify the IR
  mlir::GreedyRewriteConfig config;
  config.enableRegionSimplification = false;
  pm.addPass(mlir::createCSEPass());
  fir::addAVC(pm);
  pm.addNestedPass<mlir::func::FuncOp>(fir::createCharacterConversionPass());
  pm.addPass(mlir::createCanonicalizerPass(config));
  pm.addPass(fir::createSimplifyRegionLitePass());
  // Algebraic simplifications may increase code size.
  if (optLevel.isOptimizingForSpeed())
    pm.addPass(fir::createAlgebraicSimplificationPass());
  pm.addPass(mlir::createCSEPass());
  fir::addMemoryAllocationOpt(pm);

  // The default inliner pass adds the canonicalizer pass with the default
  // configuration. Create the inliner pass with tco config.
  llvm::StringMap<mlir::OpPassManager> pipelines;
  pm.addPass(
      mlir::createInlinerPass(pipelines, defaultFlangInlinerOptPipeline));
  pm.addPass(fir::createSimplifyRegionLitePass());
  pm.addPass(mlir::createCSEPass());

  // convert control flow to CFG form
  fir::addCfgConversionPass(pm);
  pm.addPass(mlir::createConvertSCFToCFPass());

  pm.addPass(mlir::createCanonicalizerPass(config));
  pm.addPass(fir::createSimplifyRegionLitePass());
  pm.addPass(mlir::createCSEPass());
}

#if !defined(FLANG_EXCLUDE_CODEGEN)
inline void createDefaultFIRCodeGenPassPipeline(mlir::PassManager &pm) {
  fir::addBoxedProcedurePass(pm);
  pm.addNestedPass<mlir::func::FuncOp>(fir::createAbstractResultOptPass());
  fir::addCodeGenRewritePass(pm);
  fir::addTargetRewritePass(pm);
  fir::addExternalNameConversionPass(pm);
  fir::addFIRToLLVMPass(pm);
}

/// Create a pass pipeline for lowering from MLIR to LLVM IR
///
/// \param pm - MLIR pass manager that will hold the pipeline definition
/// \param optLevel - optimization level used for creating FIR optimization
///   passes pipeline
inline void createMLIRToLLVMPassPipeline(
    mlir::PassManager &pm, llvm::OptimizationLevel optLevel = defaultOptLevel) {
  // Add default optimizer pass pipeline.
  fir::createDefaultFIROptimizerPassPipeline(pm, optLevel);

  // Add codegen pass pipeline.
  fir::createDefaultFIRCodeGenPassPipeline(pm);
}
#undef FLANG_EXCLUDE_CODEGEN
#endif

} // namespace fir
