//===-- llvm/CodeGen/MachineModuleInfo.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
//
//===----------------------------------------------------------------------===//
//
// Collect meta information for a module. This information should be in a
// neutral form that can be used by different debugging and exception handling
// schemes.
//
// The organization of information is primarily clustered around the source
// compile units. The main exception is source line correspondence where
// inlining may interleave code from various compile units.
//
// The following information can be retrieved from the MachineModuleInfo.
//
// -- Source directories - Directories are uniqued based on their canonical
// string and assigned a sequential numeric ID (base 1.)
// -- Source files - Files are also uniqued based on their name and directory
// ID. A file ID is sequential number (base 1.)
// -- Source line correspondence - A vector of file ID, line#, column# triples.
// A DEBUG_LOCATION instruction is generated by the DAG Legalizer
// corresponding to each entry in the source line list. This allows a debug
// emitter to generate labels referenced by debug information tables.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_MACHINEMODULEINFO_H
#define LLVM_CODEGEN_MACHINEMODULEINFO_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/IR/PassManager.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Pass.h"
#include <memory>
#include <utility>
#include <vector>
namespace llvm {
class Function;
class LLVMTargetMachine;
class MachineFunction;
class Module;
//===----------------------------------------------------------------------===//
/// This class can be derived from and used by targets to hold private
/// target-specific information for each Module. Objects of type are
/// accessed/created with MachineModuleInfo::getObjFileInfo and destroyed when
/// the MachineModuleInfo is destroyed.
///
class MachineModuleInfoImpl {
public:
using StubValueTy = PointerIntPair<MCSymbol *, 1, bool>;
using SymbolListTy = std::vector<std::pair<MCSymbol *, StubValueTy>>;
virtual ~MachineModuleInfoImpl();
protected:
/// Return the entries from a DenseMap in a deterministic sorted orer.
/// Clears the map.
static SymbolListTy getSortedStubs(DenseMap<MCSymbol*, StubValueTy>&);
};
//===----------------------------------------------------------------------===//
/// This class contains meta information specific to a module. Queries can be
/// made by different debugging and exception handling schemes and reformated
/// for specific use.
///
class MachineModuleInfo {
friend class MachineModuleInfoWrapperPass;
friend class MachineModuleAnalysis;
const LLVMTargetMachine &TM;
/// This is the MCContext used for the entire code generator.
MCContext Context;
// This is an external context, that if assigned, will be used instead of the
// internal context.
MCContext *ExternalContext = nullptr;
/// This is the LLVM Module being worked on.
const Module *TheModule;
/// This is the object-file-format-specific implementation of
/// MachineModuleInfoImpl, which lets targets accumulate whatever info they
/// want.
MachineModuleInfoImpl *ObjFileMMI;
/// \name Exception Handling
/// \{
/// The current call site index being processed, if any. 0 if none.
unsigned CurCallSite;
/// \}
// TODO: Ideally, what we'd like is to have a switch that allows emitting
// synchronous (precise at call-sites only) CFA into .eh_frame. However,
// even under this switch, we'd like .debug_frame to be precise when using
// -g. At this moment, there's no way to specify that some CFI directives
// go into .eh_frame only, while others go into .debug_frame only.
/// True if debugging information is available in this module.
bool DbgInfoAvailable;
/// True if this module is being built for windows/msvc, and uses floating
/// point. This is used to emit an undefined reference to _fltused.
bool UsesMSVCFloatingPoint;
/// Maps IR Functions to their corresponding MachineFunctions.
DenseMap<const Function*, std::unique_ptr<MachineFunction>> MachineFunctions;
/// Next unique number available for a MachineFunction.
unsigned NextFnNum = 0;
const Function *LastRequest = nullptr; ///< Used for shortcut/cache.
MachineFunction *LastResult = nullptr; ///< Used for shortcut/cache.
MachineModuleInfo &operator=(MachineModuleInfo &&MMII) = delete;
public:
explicit MachineModuleInfo(const LLVMTargetMachine *TM = nullptr);
explicit MachineModuleInfo(const LLVMTargetMachine *TM,
MCContext *ExtContext);
MachineModuleInfo(MachineModuleInfo &&MMII);
~MachineModuleInfo();
void initialize();
void finalize();
const LLVMTargetMachine &getTarget() const { return TM; }
const MCContext &getContext() const {
return ExternalContext ? *ExternalContext : Context;
}
MCContext &getContext() {
return ExternalContext ? *ExternalContext : Context;
}
const Module *getModule() const { return TheModule; }
/// Returns the MachineFunction constructed for the IR function \p F.
/// Creates a new MachineFunction if none exists yet.
MachineFunction &getOrCreateMachineFunction(Function &F);
/// \brief Returns the MachineFunction associated to IR function \p F if there
/// is one, otherwise nullptr.
MachineFunction *getMachineFunction(const Function &F) const;
/// Delete the MachineFunction \p MF and reset the link in the IR Function to
/// Machine Function map.
void deleteMachineFunctionFor(Function &F);
/// Add an externally created MachineFunction \p MF for \p F.
void insertFunction(const Function &F, std::unique_ptr<MachineFunction> &&MF);
/// Keep track of various per-module pieces of information for backends
/// that would like to do so.
template<typename Ty>
Ty &getObjFileInfo() {
if (ObjFileMMI == nullptr)
ObjFileMMI = new Ty(*this);
return *static_cast<Ty*>(ObjFileMMI);
}
template<typename Ty>
const Ty &getObjFileInfo() const {
return const_cast<MachineModuleInfo*>(this)->getObjFileInfo<Ty>();
}
/// Returns true if valid debug info is present.
bool hasDebugInfo() const { return DbgInfoAvailable; }
bool usesMSVCFloatingPoint() const { return UsesMSVCFloatingPoint; }
void setUsesMSVCFloatingPoint(bool b) { UsesMSVCFloatingPoint = b; }
/// \name Exception Handling
/// \{
/// Set the call site currently being processed.
void setCurrentCallSite(unsigned Site) { CurCallSite = Site; }
/// Get the call site currently being processed, if any. return zero if
/// none.
unsigned getCurrentCallSite() { return CurCallSite; }
/// \}
// MMI owes MCContext. It should never be invalidated.
bool invalidate(Module &, const PreservedAnalyses &,
ModuleAnalysisManager::Invalidator &) {
return false;
}
}; // End class MachineModuleInfo
class MachineModuleInfoWrapperPass : public ImmutablePass {
MachineModuleInfo MMI;
public:
static char ID; // Pass identification, replacement for typeid
explicit MachineModuleInfoWrapperPass(const LLVMTargetMachine *TM = nullptr);
explicit MachineModuleInfoWrapperPass(const LLVMTargetMachine *TM,
MCContext *ExtContext);
// Initialization and Finalization
bool doInitialization(Module &) override;
bool doFinalization(Module &) override;
MachineModuleInfo &getMMI() { return MMI; }
const MachineModuleInfo &getMMI() const { return MMI; }
};
/// An analysis that produces \c MachineInfo for a module.
class MachineModuleAnalysis : public AnalysisInfoMixin<MachineModuleAnalysis> {
friend AnalysisInfoMixin<MachineModuleAnalysis>;
static AnalysisKey Key;
const LLVMTargetMachine *TM;
public:
/// Provide the result type for this analysis pass.
using Result = MachineModuleInfo;
MachineModuleAnalysis(const LLVMTargetMachine *TM) : TM(TM) {}
/// Run the analysis pass and produce machine module information.
MachineModuleInfo run(Module &M, ModuleAnalysisManager &);
};
} // end namespace llvm
#endif // LLVM_CODEGEN_MACHINEMODULEINFO_H