1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-24 03:33:20 +01:00
llvm-mirror/include/llvm/Pass.h
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

367 lines
15 KiB
C++

//===- llvm/Pass.h - Base class for Passes ----------------------*- 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 a base class that indicates that a specified class is a
// transformation pass implementation.
//
// Passes are designed this way so that it is possible to run passes in a cache
// and organizationally optimal order without having to specify it at the front
// end. This allows arbitrary passes to be strung together and have them
// executed as efficiently as possible.
//
// Passes should extend one of the classes below, depending on the guarantees
// that it can make about what will be modified as it is run. For example, most
// global optimizations should derive from FunctionPass, because they do not add
// or delete functions, they operate on the internals of the function.
//
// Note that this file #includes PassSupport.h and PassAnalysisSupport.h (at the
// bottom), so the APIs exposed by these files are also automatically available
// to all users of this file.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_PASS_H
#define LLVM_PASS_H
#include "llvm/ADT/StringRef.h"
#include <string>
namespace llvm {
class AnalysisResolver;
class AnalysisUsage;
class BasicBlock;
class Function;
class ImmutablePass;
class Module;
class PassInfo;
class PMDataManager;
class PMStack;
class raw_ostream;
// AnalysisID - Use the PassInfo to identify a pass...
using AnalysisID = const void *;
/// Different types of internal pass managers. External pass managers
/// (PassManager and FunctionPassManager) are not represented here.
/// Ordering of pass manager types is important here.
enum PassManagerType {
PMT_Unknown = 0,
PMT_ModulePassManager = 1, ///< MPPassManager
PMT_CallGraphPassManager, ///< CGPassManager
PMT_FunctionPassManager, ///< FPPassManager
PMT_LoopPassManager, ///< LPPassManager
PMT_RegionPassManager, ///< RGPassManager
PMT_BasicBlockPassManager, ///< BBPassManager
PMT_Last
};
// Different types of passes.
enum PassKind {
PT_BasicBlock,
PT_Region,
PT_Loop,
PT_Function,
PT_CallGraphSCC,
PT_Module,
PT_PassManager
};
//===----------------------------------------------------------------------===//
/// Pass interface - Implemented by all 'passes'. Subclass this if you are an
/// interprocedural optimization or you do not fit into any of the more
/// constrained passes described below.
///
class Pass {
AnalysisResolver *Resolver = nullptr; // Used to resolve analysis
const void *PassID;
PassKind Kind;
public:
explicit Pass(PassKind K, char &pid) : PassID(&pid), Kind(K) {}
Pass(const Pass &) = delete;
Pass &operator=(const Pass &) = delete;
virtual ~Pass();
PassKind getPassKind() const { return Kind; }
/// getPassName - Return a nice clean name for a pass. This usually
/// implemented in terms of the name that is registered by one of the
/// Registration templates, but can be overloaded directly.
virtual StringRef getPassName() const;
/// getPassID - Return the PassID number that corresponds to this pass.
AnalysisID getPassID() const {
return PassID;
}
/// doInitialization - Virtual method overridden by subclasses to do
/// any necessary initialization before any pass is run.
virtual bool doInitialization(Module &) { return false; }
/// doFinalization - Virtual method overriden by subclasses to do any
/// necessary clean up after all passes have run.
virtual bool doFinalization(Module &) { return false; }
/// print - Print out the internal state of the pass. This is called by
/// Analyze to print out the contents of an analysis. Otherwise it is not
/// necessary to implement this method. Beware that the module pointer MAY be
/// null. This automatically forwards to a virtual function that does not
/// provide the Module* in case the analysis doesn't need it it can just be
/// ignored.
virtual void print(raw_ostream &OS, const Module *M) const;
void dump() const; // dump - Print to stderr.
/// createPrinterPass - Get a Pass appropriate to print the IR this
/// pass operates on (Module, Function or MachineFunction).
virtual Pass *createPrinterPass(raw_ostream &OS,
const std::string &Banner) const = 0;
/// Each pass is responsible for assigning a pass manager to itself.
/// PMS is the stack of available pass manager.
virtual void assignPassManager(PMStack &,
PassManagerType) {}
/// Check if available pass managers are suitable for this pass or not.
virtual void preparePassManager(PMStack &);
/// Return what kind of Pass Manager can manage this pass.
virtual PassManagerType getPotentialPassManagerType() const;
// Access AnalysisResolver
void setResolver(AnalysisResolver *AR);
AnalysisResolver *getResolver() const { return Resolver; }
/// getAnalysisUsage - This function should be overriden by passes that need
/// analysis information to do their job. If a pass specifies that it uses a
/// particular analysis result to this function, it can then use the
/// getAnalysis<AnalysisType>() function, below.
virtual void getAnalysisUsage(AnalysisUsage &) const;
/// releaseMemory() - This member can be implemented by a pass if it wants to
/// be able to release its memory when it is no longer needed. The default
/// behavior of passes is to hold onto memory for the entire duration of their
/// lifetime (which is the entire compile time). For pipelined passes, this
/// is not a big deal because that memory gets recycled every time the pass is
/// invoked on another program unit. For IP passes, it is more important to
/// free memory when it is unused.
///
/// Optionally implement this function to release pass memory when it is no
/// longer used.
virtual void releaseMemory();
/// getAdjustedAnalysisPointer - This method is used when a pass implements
/// an analysis interface through multiple inheritance. If needed, it should
/// override this to adjust the this pointer as needed for the specified pass
/// info.
virtual void *getAdjustedAnalysisPointer(AnalysisID ID);
virtual ImmutablePass *getAsImmutablePass();
virtual PMDataManager *getAsPMDataManager();
/// verifyAnalysis() - This member can be implemented by a analysis pass to
/// check state of analysis information.
virtual void verifyAnalysis() const;
// dumpPassStructure - Implement the -debug-passes=PassStructure option
virtual void dumpPassStructure(unsigned Offset = 0);
// lookupPassInfo - Return the pass info object for the specified pass class,
// or null if it is not known.
static const PassInfo *lookupPassInfo(const void *TI);
// lookupPassInfo - Return the pass info object for the pass with the given
// argument string, or null if it is not known.
static const PassInfo *lookupPassInfo(StringRef Arg);
// createPass - Create a object for the specified pass class,
// or null if it is not known.
static Pass *createPass(AnalysisID ID);
/// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to
/// get analysis information that might be around, for example to update it.
/// This is different than getAnalysis in that it can fail (if the analysis
/// results haven't been computed), so should only be used if you can handle
/// the case when the analysis is not available. This method is often used by
/// transformation APIs to update analysis results for a pass automatically as
/// the transform is performed.
template<typename AnalysisType> AnalysisType *
getAnalysisIfAvailable() const; // Defined in PassAnalysisSupport.h
/// mustPreserveAnalysisID - This method serves the same function as
/// getAnalysisIfAvailable, but works if you just have an AnalysisID. This
/// obviously cannot give you a properly typed instance of the class if you
/// don't have the class name available (use getAnalysisIfAvailable if you
/// do), but it can tell you if you need to preserve the pass at least.
bool mustPreserveAnalysisID(char &AID) const;
/// getAnalysis<AnalysisType>() - This function is used by subclasses to get
/// to the analysis information that they claim to use by overriding the
/// getAnalysisUsage function.
template<typename AnalysisType>
AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h
template<typename AnalysisType>
AnalysisType &getAnalysis(Function &F); // Defined in PassAnalysisSupport.h
template<typename AnalysisType>
AnalysisType &getAnalysisID(AnalysisID PI) const;
template<typename AnalysisType>
AnalysisType &getAnalysisID(AnalysisID PI, Function &F);
};
//===----------------------------------------------------------------------===//
/// ModulePass class - This class is used to implement unstructured
/// interprocedural optimizations and analyses. ModulePasses may do anything
/// they want to the program.
///
class ModulePass : public Pass {
public:
explicit ModulePass(char &pid) : Pass(PT_Module, pid) {}
// Force out-of-line virtual method.
~ModulePass() override;
/// createPrinterPass - Get a module printer pass.
Pass *createPrinterPass(raw_ostream &OS,
const std::string &Banner) const override;
/// runOnModule - Virtual method overriden by subclasses to process the module
/// being operated on.
virtual bool runOnModule(Module &M) = 0;
void assignPassManager(PMStack &PMS, PassManagerType T) override;
/// Return what kind of Pass Manager can manage this pass.
PassManagerType getPotentialPassManagerType() const override;
protected:
/// Optional passes call this function to check whether the pass should be
/// skipped. This is the case when optimization bisect is over the limit.
bool skipModule(Module &M) const;
};
//===----------------------------------------------------------------------===//
/// ImmutablePass class - This class is used to provide information that does
/// not need to be run. This is useful for things like target information and
/// "basic" versions of AnalysisGroups.
///
class ImmutablePass : public ModulePass {
public:
explicit ImmutablePass(char &pid) : ModulePass(pid) {}
// Force out-of-line virtual method.
~ImmutablePass() override;
/// initializePass - This method may be overriden by immutable passes to allow
/// them to perform various initialization actions they require. This is
/// primarily because an ImmutablePass can "require" another ImmutablePass,
/// and if it does, the overloaded version of initializePass may get access to
/// these passes with getAnalysis<>.
virtual void initializePass();
ImmutablePass *getAsImmutablePass() override { return this; }
/// ImmutablePasses are never run.
bool runOnModule(Module &) override { return false; }
};
//===----------------------------------------------------------------------===//
/// FunctionPass class - This class is used to implement most global
/// optimizations. Optimizations should subclass this class if they meet the
/// following constraints:
///
/// 1. Optimizations are organized globally, i.e., a function at a time
/// 2. Optimizing a function does not cause the addition or removal of any
/// functions in the module
///
class FunctionPass : public Pass {
public:
explicit FunctionPass(char &pid) : Pass(PT_Function, pid) {}
/// createPrinterPass - Get a function printer pass.
Pass *createPrinterPass(raw_ostream &OS,
const std::string &Banner) const override;
/// runOnFunction - Virtual method overriden by subclasses to do the
/// per-function processing of the pass.
virtual bool runOnFunction(Function &F) = 0;
void assignPassManager(PMStack &PMS, PassManagerType T) override;
/// Return what kind of Pass Manager can manage this pass.
PassManagerType getPotentialPassManagerType() const override;
protected:
/// Optional passes call this function to check whether the pass should be
/// skipped. This is the case when Attribute::OptimizeNone is set or when
/// optimization bisect is over the limit.
bool skipFunction(const Function &F) const;
};
//===----------------------------------------------------------------------===//
/// BasicBlockPass class - This class is used to implement most local
/// optimizations. Optimizations should subclass this class if they
/// meet the following constraints:
/// 1. Optimizations are local, operating on either a basic block or
/// instruction at a time.
/// 2. Optimizations do not modify the CFG of the contained function, or any
/// other basic block in the function.
/// 3. Optimizations conform to all of the constraints of FunctionPasses.
///
class BasicBlockPass : public Pass {
public:
explicit BasicBlockPass(char &pid) : Pass(PT_BasicBlock, pid) {}
/// createPrinterPass - Get a basic block printer pass.
Pass *createPrinterPass(raw_ostream &OS,
const std::string &Banner) const override;
using llvm::Pass::doInitialization;
using llvm::Pass::doFinalization;
/// doInitialization - Virtual method overridden by BasicBlockPass subclasses
/// to do any necessary per-function initialization.
virtual bool doInitialization(Function &);
/// runOnBasicBlock - Virtual method overriden by subclasses to do the
/// per-basicblock processing of the pass.
virtual bool runOnBasicBlock(BasicBlock &BB) = 0;
/// doFinalization - Virtual method overriden by BasicBlockPass subclasses to
/// do any post processing needed after all passes have run.
virtual bool doFinalization(Function &);
void assignPassManager(PMStack &PMS, PassManagerType T) override;
/// Return what kind of Pass Manager can manage this pass.
PassManagerType getPotentialPassManagerType() const override;
protected:
/// Optional passes call this function to check whether the pass should be
/// skipped. This is the case when Attribute::OptimizeNone is set or when
/// optimization bisect is over the limit.
bool skipBasicBlock(const BasicBlock &BB) const;
};
/// If the user specifies the -time-passes argument on an LLVM tool command line
/// then the value of this boolean will be true, otherwise false.
/// This is the storage for the -time-passes option.
extern bool TimePassesIsEnabled;
} // end namespace llvm
// Include support files that contain important APIs commonly used by Passes,
// but that we want to separate out to make it easier to read the header files.
#include "llvm/InitializePasses.h"
#include "llvm/PassAnalysisSupport.h"
#include "llvm/PassSupport.h"
#endif // LLVM_PASS_H