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//===- ExecutionEngine.h - Abstract Execution Engine Interface --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the abstract interface that implements execution support
// for LLVM.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_EXECUTION_ENGINE_H
#define LLVM_EXECUTION_ENGINE_H
#include <vector>
#include <map>
#include <string>
#include "llvm/MC/MCCodeGenInfo.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/ValueMap.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/ValueHandle.h"
#include "llvm/Support/Mutex.h"
#include "llvm/Target/TargetMachine.h"
namespace llvm {
struct GenericValue;
class Constant;
class ExecutionEngine;
class Function;
class GlobalVariable;
class GlobalValue;
class JITEventListener;
class JITMemoryManager;
class MachineCodeInfo;
class Module;
class MutexGuard;
class TargetData;
class Type;
/// \brief Helper class for helping synchronize access to the global address map
/// table.
class ExecutionEngineState {
public:
struct AddressMapConfig : public ValueMapConfig<const GlobalValue*> {
typedef ExecutionEngineState *ExtraData;
static sys::Mutex *getMutex(ExecutionEngineState *EES);
static void onDelete(ExecutionEngineState *EES, const GlobalValue *Old);
static void onRAUW(ExecutionEngineState *, const GlobalValue *,
const GlobalValue *);
};
typedef ValueMap<const GlobalValue *, void *, AddressMapConfig>
GlobalAddressMapTy;
private:
ExecutionEngine &EE;
/// GlobalAddressMap - A mapping between LLVM global values and their
/// actualized version...
GlobalAddressMapTy GlobalAddressMap;
/// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap,
/// used to convert raw addresses into the LLVM global value that is emitted
/// at the address. This map is not computed unless getGlobalValueAtAddress
/// is called at some point.
std::map<void *, AssertingVH<const GlobalValue> > GlobalAddressReverseMap;
public:
ExecutionEngineState(ExecutionEngine &EE);
GlobalAddressMapTy &getGlobalAddressMap(const MutexGuard &) {
return GlobalAddressMap;
}
std::map<void*, AssertingVH<const GlobalValue> > &
getGlobalAddressReverseMap(const MutexGuard &) {
return GlobalAddressReverseMap;
}
/// \brief Erase an entry from the mapping table.
///
/// \returns The address that \arg ToUnmap was happed to.
void *RemoveMapping(const MutexGuard &, const GlobalValue *ToUnmap);
};
/// \brief Abstract interface for implementation execution of LLVM modules,
/// designed to support both interpreter and just-in-time (JIT) compiler
/// implementations.
class ExecutionEngine {
/// The state object holding the global address mapping, which must be
/// accessed synchronously.
//
// FIXME: There is no particular need the entire map needs to be
// synchronized. Wouldn't a reader-writer design be better here?
ExecutionEngineState EEState;
/// The target data for the platform for which execution is being performed.
const TargetData *TD;
/// Whether lazy JIT compilation is enabled.
bool CompilingLazily;
/// Whether JIT compilation of external global variables is allowed.
bool GVCompilationDisabled;
/// Whether the JIT should perform lookups of external symbols (e.g.,
/// using dlsym).
bool SymbolSearchingDisabled;
friend class EngineBuilder; // To allow access to JITCtor and InterpCtor.
protected:
/// The list of Modules that we are JIT'ing from. We use a SmallVector to
/// optimize for the case where there is only one module.
SmallVector<Module*, 1> Modules;
void setTargetData(const TargetData *td) { TD = td; }
/// getMemoryforGV - Allocate memory for a global variable.
virtual char *getMemoryForGV(const GlobalVariable *GV);
// To avoid having libexecutionengine depend on the JIT and interpreter
// libraries, the execution engine implementations set these functions to ctor
// pointers at startup time if they are linked in.
static ExecutionEngine *(*JITCtor)(
Module *M,
std::string *ErrorStr,
JITMemoryManager *JMM,
CodeGenOpt::Level OptLevel,
bool GVsWithCode,
TargetMachine *TM);
static ExecutionEngine *(*MCJITCtor)(
Module *M,
std::string *ErrorStr,
JITMemoryManager *JMM,
CodeGenOpt::Level OptLevel,
bool GVsWithCode,
TargetMachine *TM);
static ExecutionEngine *(*InterpCtor)(Module *M, std::string *ErrorStr);
/// LazyFunctionCreator - If an unknown function is needed, this function
/// pointer is invoked to create it. If this returns null, the JIT will
/// abort.
void *(*LazyFunctionCreator)(const std::string &);
/// ExceptionTableRegister - If Exception Handling is set, the JIT will
/// register dwarf tables with this function.
typedef void (*EERegisterFn)(void*);
EERegisterFn ExceptionTableRegister;
EERegisterFn ExceptionTableDeregister;
/// This maps functions to their exception tables frames.
DenseMap<const Function*, void*> AllExceptionTables;
public:
/// lock - This lock protects the ExecutionEngine, JIT, JITResolver and
/// JITEmitter classes. It must be held while changing the internal state of
/// any of those classes.
sys::Mutex lock;
//===--------------------------------------------------------------------===//
// ExecutionEngine Startup
//===--------------------------------------------------------------------===//
virtual ~ExecutionEngine();
/// create - This is the factory method for creating an execution engine which
/// is appropriate for the current machine. This takes ownership of the
/// module.
///
/// \param GVsWithCode - Allocating globals with code breaks
/// freeMachineCodeForFunction and is probably unsafe and bad for performance.
/// However, we have clients who depend on this behavior, so we must support
/// it. Eventually, when we're willing to break some backwards compatibility,
/// this flag should be flipped to false, so that by default
/// freeMachineCodeForFunction works.
static ExecutionEngine *create(Module *M,
bool ForceInterpreter = false,
std::string *ErrorStr = 0,
CodeGenOpt::Level OptLevel =
CodeGenOpt::Default,
bool GVsWithCode = true);
/// createJIT - This is the factory method for creating a JIT for the current
/// machine, it does not fall back to the interpreter. This takes ownership
/// of the Module and JITMemoryManager if successful.
///
/// Clients should make sure to initialize targets prior to calling this
/// function.
static ExecutionEngine *createJIT(Module *M,
std::string *ErrorStr = 0,
JITMemoryManager *JMM = 0,
CodeGenOpt::Level OptLevel =
CodeGenOpt::Default,
bool GVsWithCode = true,
Reloc::Model RM = Reloc::Default,
CodeModel::Model CMM =
CodeModel::JITDefault);
/// addModule - Add a Module to the list of modules that we can JIT from.
/// Note that this takes ownership of the Module: when the ExecutionEngine is
/// destroyed, it destroys the Module as well.
virtual void addModule(Module *M) {
Modules.push_back(M);
}
//===--------------------------------------------------------------------===//
const TargetData *getTargetData() const { return TD; }
/// removeModule - Remove a Module from the list of modules. Returns true if
/// M is found.
virtual bool removeModule(Module *M);
/// FindFunctionNamed - Search all of the active modules to find the one that
/// defines FnName. This is very slow operation and shouldn't be used for
/// general code.
Function *FindFunctionNamed(const char *FnName);
/// runFunction - Execute the specified function with the specified arguments,
/// and return the result.
virtual GenericValue runFunction(Function *F,
const std::vector<GenericValue> &ArgValues) = 0;
/// runStaticConstructorsDestructors - This method is used to execute all of
/// the static constructors or destructors for a program.
///
/// \param isDtors - Run the destructors instead of constructors.
void runStaticConstructorsDestructors(bool isDtors);
/// runStaticConstructorsDestructors - This method is used to execute all of
/// the static constructors or destructors for a particular module.
///
/// \param isDtors - Run the destructors instead of constructors.
void runStaticConstructorsDestructors(Module *module, bool isDtors);
/// runFunctionAsMain - This is a helper function which wraps runFunction to
/// handle the common task of starting up main with the specified argc, argv,
/// and envp parameters.
int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
const char * const * envp);
/// addGlobalMapping - Tell the execution engine that the specified global is
/// at the specified location. This is used internally as functions are JIT'd
/// and as global variables are laid out in memory. It can and should also be
/// used by clients of the EE that want to have an LLVM global overlay
/// existing data in memory. Mappings are automatically removed when their
/// GlobalValue is destroyed.
void addGlobalMapping(const GlobalValue *GV, void *Addr);
/// clearAllGlobalMappings - Clear all global mappings and start over again,
/// for use in dynamic compilation scenarios to move globals.
void clearAllGlobalMappings();
/// clearGlobalMappingsFromModule - Clear all global mappings that came from a
/// particular module, because it has been removed from the JIT.
void clearGlobalMappingsFromModule(Module *M);
/// updateGlobalMapping - Replace an existing mapping for GV with a new
/// address. This updates both maps as required. If "Addr" is null, the
/// entry for the global is removed from the mappings. This returns the old
/// value of the pointer, or null if it was not in the map.
void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
/// getPointerToGlobalIfAvailable - This returns the address of the specified
/// global value if it is has already been codegen'd, otherwise it returns
/// null.
void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
/// getPointerToGlobal - This returns the address of the specified global
/// value. This may involve code generation if it's a function.
void *getPointerToGlobal(const GlobalValue *GV);
/// getPointerToFunction - The different EE's represent function bodies in
/// different ways. They should each implement this to say what a function
/// pointer should look like. When F is destroyed, the ExecutionEngine will
/// remove its global mapping and free any machine code. Be sure no threads
/// are running inside F when that happens.
virtual void *getPointerToFunction(Function *F) = 0;
/// getPointerToBasicBlock - The different EE's represent basic blocks in
/// different ways. Return the representation for a blockaddress of the
/// specified block.
virtual void *getPointerToBasicBlock(BasicBlock *BB) = 0;
/// getPointerToFunctionOrStub - If the specified function has been
/// code-gen'd, return a pointer to the function. If not, compile it, or use
/// a stub to implement lazy compilation if available. See
/// getPointerToFunction for the requirements on destroying F.
virtual void *getPointerToFunctionOrStub(Function *F) {
// Default implementation, just codegen the function.
return getPointerToFunction(F);
}
// The JIT overrides a version that actually does this.
virtual void runJITOnFunction(Function *, MachineCodeInfo * = 0) { }
/// getGlobalValueAtAddress - Return the LLVM global value object that starts
/// at the specified address.
///
const GlobalValue *getGlobalValueAtAddress(void *Addr);
/// StoreValueToMemory - Stores the data in Val of type Ty at address Ptr.
/// Ptr is the address of the memory at which to store Val, cast to
/// GenericValue *. It is not a pointer to a GenericValue containing the
/// address at which to store Val.
void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
Type *Ty);
void InitializeMemory(const Constant *Init, void *Addr);
/// recompileAndRelinkFunction - This method is used to force a function which
/// has already been compiled to be compiled again, possibly after it has been
/// modified. Then the entry to the old copy is overwritten with a branch to
/// the new copy. If there was no old copy, this acts just like
/// VM::getPointerToFunction().
virtual void *recompileAndRelinkFunction(Function *F) = 0;
/// freeMachineCodeForFunction - Release memory in the ExecutionEngine
/// corresponding to the machine code emitted to execute this function, useful
/// for garbage-collecting generated code.
virtual void freeMachineCodeForFunction(Function *F) = 0;
/// getOrEmitGlobalVariable - Return the address of the specified global
/// variable, possibly emitting it to memory if needed. This is used by the
/// Emitter.
virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
return getPointerToGlobal((GlobalValue*)GV);
}
/// Registers a listener to be called back on various events within
/// the JIT. See JITEventListener.h for more details. Does not
/// take ownership of the argument. The argument may be NULL, in
/// which case these functions do nothing.
virtual void RegisterJITEventListener(JITEventListener *) {}
virtual void UnregisterJITEventListener(JITEventListener *) {}
/// DisableLazyCompilation - When lazy compilation is off (the default), the
/// JIT will eagerly compile every function reachable from the argument to
/// getPointerToFunction. If lazy compilation is turned on, the JIT will only
/// compile the one function and emit stubs to compile the rest when they're
/// first called. If lazy compilation is turned off again while some lazy
/// stubs are still around, and one of those stubs is called, the program will
/// abort.
///
/// In order to safely compile lazily in a threaded program, the user must
/// ensure that 1) only one thread at a time can call any particular lazy
/// stub, and 2) any thread modifying LLVM IR must hold the JIT's lock
/// (ExecutionEngine::lock) or otherwise ensure that no other thread calls a
/// lazy stub. See http://llvm.org/PR5184 for details.
void DisableLazyCompilation(bool Disabled = true) {
CompilingLazily = !Disabled;
}
bool isCompilingLazily() const {
return CompilingLazily;
}
// Deprecated in favor of isCompilingLazily (to reduce double-negatives).
// Remove this in LLVM 2.8.
bool isLazyCompilationDisabled() const {
return !CompilingLazily;
}
/// DisableGVCompilation - If called, the JIT will abort if it's asked to
/// allocate space and populate a GlobalVariable that is not internal to
/// the module.
void DisableGVCompilation(bool Disabled = true) {
GVCompilationDisabled = Disabled;
}
bool isGVCompilationDisabled() const {
return GVCompilationDisabled;
}
/// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
/// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
/// resolve symbols in a custom way.
void DisableSymbolSearching(bool Disabled = true) {
SymbolSearchingDisabled = Disabled;
}
bool isSymbolSearchingDisabled() const {
return SymbolSearchingDisabled;
}
/// InstallLazyFunctionCreator - If an unknown function is needed, the
/// specified function pointer is invoked to create it. If it returns null,
/// the JIT will abort.
void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
LazyFunctionCreator = P;
}
/// InstallExceptionTableRegister - The JIT will use the given function
/// to register the exception tables it generates.
void InstallExceptionTableRegister(EERegisterFn F) {
ExceptionTableRegister = F;
}
void InstallExceptionTableDeregister(EERegisterFn F) {
ExceptionTableDeregister = F;
}
/// RegisterTable - Registers the given pointer as an exception table. It
/// uses the ExceptionTableRegister function.
void RegisterTable(const Function *fn, void* res) {
if (ExceptionTableRegister) {
ExceptionTableRegister(res);
AllExceptionTables[fn] = res;
}
}
/// DeregisterTable - Deregisters the exception frame previously registered
/// for the given function.
void DeregisterTable(const Function *Fn) {
if (ExceptionTableDeregister) {
DenseMap<const Function*, void*>::iterator frame =
AllExceptionTables.find(Fn);
if(frame != AllExceptionTables.end()) {
ExceptionTableDeregister(frame->second);
AllExceptionTables.erase(frame);
}
}
}
/// DeregisterAllTables - Deregisters all previously registered pointers to an
/// exception tables. It uses the ExceptionTableoDeregister function.
void DeregisterAllTables();
protected:
explicit ExecutionEngine(Module *M);
void emitGlobals();
void EmitGlobalVariable(const GlobalVariable *GV);
GenericValue getConstantValue(const Constant *C);
void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
Type *Ty);
};
namespace EngineKind {
// These are actually bitmasks that get or-ed together.
enum Kind {
JIT = 0x1,
Interpreter = 0x2
};
const static Kind Either = (Kind)(JIT | Interpreter);
}
/// EngineBuilder - Builder class for ExecutionEngines. Use this by
/// stack-allocating a builder, chaining the various set* methods, and
/// terminating it with a .create() call.
class EngineBuilder {
private:
Module *M;
EngineKind::Kind WhichEngine;
std::string *ErrorStr;
CodeGenOpt::Level OptLevel;
JITMemoryManager *JMM;
bool AllocateGVsWithCode;
Reloc::Model RelocModel;
CodeModel::Model CMModel;
std::string MArch;
std::string MCPU;
SmallVector<std::string, 4> MAttrs;
bool UseMCJIT;
/// InitEngine - Does the common initialization of default options.
void InitEngine() {
WhichEngine = EngineKind::Either;
ErrorStr = NULL;
OptLevel = CodeGenOpt::Default;
JMM = NULL;
AllocateGVsWithCode = false;
RelocModel = Reloc::Default;
CMModel = CodeModel::JITDefault;
UseMCJIT = false;
}
public:
/// EngineBuilder - Constructor for EngineBuilder. If create() is called and
/// is successful, the created engine takes ownership of the module.
EngineBuilder(Module *m) : M(m) {
InitEngine();
}
/// setEngineKind - Controls whether the user wants the interpreter, the JIT,
/// or whichever engine works. This option defaults to EngineKind::Either.
EngineBuilder &setEngineKind(EngineKind::Kind w) {
WhichEngine = w;
return *this;
}
/// setJITMemoryManager - Sets the memory manager to use. This allows
/// clients to customize their memory allocation policies. If create() is
/// called and is successful, the created engine takes ownership of the
/// memory manager. This option defaults to NULL.
EngineBuilder &setJITMemoryManager(JITMemoryManager *jmm) {
JMM = jmm;
return *this;
}
/// setErrorStr - Set the error string to write to on error. This option
/// defaults to NULL.
EngineBuilder &setErrorStr(std::string *e) {
ErrorStr = e;
return *this;
}
/// setOptLevel - Set the optimization level for the JIT. This option
/// defaults to CodeGenOpt::Default.
EngineBuilder &setOptLevel(CodeGenOpt::Level l) {
OptLevel = l;
return *this;
}
/// setRelocationModel - Set the relocation model that the ExecutionEngine
/// target is using. Defaults to target specific default "Reloc::Default".
EngineBuilder &setRelocationModel(Reloc::Model RM) {
RelocModel = RM;
return *this;
}
/// setCodeModel - Set the CodeModel that the ExecutionEngine target
/// data is using. Defaults to target specific default
/// "CodeModel::JITDefault".
EngineBuilder &setCodeModel(CodeModel::Model M) {
CMModel = M;
return *this;
}
/// setAllocateGVsWithCode - Sets whether global values should be allocated
/// into the same buffer as code. For most applications this should be set
/// to false. Allocating globals with code breaks freeMachineCodeForFunction
/// and is probably unsafe and bad for performance. However, we have clients
/// who depend on this behavior, so we must support it. This option defaults
/// to false so that users of the new API can safely use the new memory
/// manager and free machine code.
EngineBuilder &setAllocateGVsWithCode(bool a) {
AllocateGVsWithCode = a;
return *this;
}
/// setMArch - Override the architecture set by the Module's triple.
EngineBuilder &setMArch(StringRef march) {
MArch.assign(march.begin(), march.end());
return *this;
}
/// setMCPU - Target a specific cpu type.
EngineBuilder &setMCPU(StringRef mcpu) {
MCPU.assign(mcpu.begin(), mcpu.end());
return *this;
}
/// setUseMCJIT - Set whether the MC-JIT implementation should be used
/// (experimental).
EngineBuilder &setUseMCJIT(bool Value) {
UseMCJIT = Value;
return *this;
}
/// setMAttrs - Set cpu-specific attributes.
template<typename StringSequence>
EngineBuilder &setMAttrs(const StringSequence &mattrs) {
MAttrs.clear();
MAttrs.append(mattrs.begin(), mattrs.end());
return *this;
}
/// selectTarget - Pick a target either via -march or by guessing the native
/// arch. Add any CPU features specified via -mcpu or -mattr.
static TargetMachine *selectTarget(Module *M,
StringRef MArch,
StringRef MCPU,
const SmallVectorImpl<std::string>& MAttrs,
Reloc::Model RM,
CodeModel::Model CM,
std::string *Err);
ExecutionEngine *create();
};
} // End llvm namespace
#endif