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//===- llvm/LLVMContext.h - Class for managing "global" state ---*- 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 declares LLVMContext, a container of "global" state in LLVM, such

// as the global type and constant uniquing tables.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_LLVMCONTEXT_H

#define LLVM_IR_LLVMCONTEXT_H

#include "llvm-c/Types.h"

#include "llvm/IR/DiagnosticHandler.h"

#include "llvm/Support/CBindingWrapping.h"

#include <cstdint>

#include <memory>

#include <optional>

#include <string>

namespace llvm {

class DiagnosticInfo;

enum DiagnosticSeverity : char;

class Function;

class Instruction;

class LLVMContextImpl;

class Module;

class OptPassGate;

template <typename T> class SmallVectorImpl;

template <typename T> class StringMapEntry;

class StringRef;

class Twine;

class LLVMRemarkStreamer;

namespace remarks {

class RemarkStreamer;

}

namespace SyncScope {

typedef uint8_t ID;

/// Known synchronization scope IDs, which always have the same value.  All

/// synchronization scope IDs that LLVM has special knowledge of are listed

/// here.  Additionally, this scheme allows LLVM to efficiently check for

/// specific synchronization scope ID without comparing strings.

enum {

  /// Synchronized with respect to signal handlers executing in the same thread.

  SingleThread = 0,

  /// Synchronized with respect to all concurrently executing threads.

  System = 1

};

} // end namespace SyncScope

/// This is an important class for using LLVM in a threaded context.  It

/// (opaquely) owns and manages the core "global" data of LLVM's core

/// infrastructure, including the type and constant uniquing tables.

/// LLVMContext itself provides no locking guarantees, so you should be careful

/// to have one context per thread.

class LLVMContext {

public:

  LLVMContextImpl *const pImpl;

  LLVMContext();

  LLVMContext(LLVMContext &) = delete;

  LLVMContext &operator=(const LLVMContext &) = delete;

  ~LLVMContext();

  // Pinned metadata names, which always have the same value.  This is a

  // compile-time performance optimization, not a correctness optimization.

  enum : unsigned {

#define LLVM_FIXED_MD_KIND(EnumID, Name, Value) EnumID = Value,

#include "llvm/IR/FixedMetadataKinds.def"

#undef LLVM_FIXED_MD_KIND

  };

  /// Known operand bundle tag IDs, which always have the same value.  All

  /// operand bundle tags that LLVM has special knowledge of are listed here.

  /// Additionally, this scheme allows LLVM to efficiently check for specific

  /// operand bundle tags without comparing strings. Keep this in sync with

  /// LLVMContext::LLVMContext().

  enum : unsigned {

    OB_deopt = 0,                  // "deopt"

    OB_funclet = 1,                // "funclet"

    OB_gc_transition = 2,          // "gc-transition"

    OB_cfguardtarget = 3,          // "cfguardtarget"

    OB_preallocated = 4,           // "preallocated"

    OB_gc_live = 5,                // "gc-live"

    OB_clang_arc_attachedcall = 6, // "clang.arc.attachedcall"

    OB_ptrauth = 7,                // "ptrauth"

    OB_kcfi = 8,                   // "kcfi"

  };

  /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.

  /// This ID is uniqued across modules in the current LLVMContext.

  unsigned getMDKindID(StringRef Name) const;

  /// getMDKindNames - Populate client supplied SmallVector with the name for

  /// custom metadata IDs registered in this LLVMContext.

  void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;

  /// getOperandBundleTags - Populate client supplied SmallVector with the

  /// bundle tags registered in this LLVMContext.  The bundle tags are ordered

  /// by increasing bundle IDs.

  /// \see LLVMContext::getOperandBundleTagID

  void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;

  /// getOrInsertBundleTag - Returns the Tag to use for an operand bundle of

  /// name TagName.

  StringMapEntry<uint32_t> *getOrInsertBundleTag(StringRef TagName) const;

  /// getOperandBundleTagID - Maps a bundle tag to an integer ID.  Every bundle

  /// tag registered with an LLVMContext has an unique ID.

  uint32_t getOperandBundleTagID(StringRef Tag) const;

  /// getOrInsertSyncScopeID - Maps synchronization scope name to

  /// synchronization scope ID.  Every synchronization scope registered with

  /// LLVMContext has unique ID except pre-defined ones.

  SyncScope::ID getOrInsertSyncScopeID(StringRef SSN);

  /// getSyncScopeNames - Populates client supplied SmallVector with

  /// synchronization scope names registered with LLVMContext.  Synchronization

  /// scope names are ordered by increasing synchronization scope IDs.

  void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const;

  /// Define the GC for a function

  void setGC(const Function &Fn, std::string GCName);

  /// Return the GC for a function

  const std::string &getGC(const Function &Fn);

  /// Remove the GC for a function

  void deleteGC(const Function &Fn);

  /// Return true if the Context runtime configuration is set to discard all

  /// value names. When true, only GlobalValue names will be available in the

  /// IR.

  bool shouldDiscardValueNames() const;

  /// Set the Context runtime configuration to discard all value name (but

  /// GlobalValue). Clients can use this flag to save memory and runtime,

  /// especially in release mode.

  void setDiscardValueNames(bool Discard);

  /// Whether there is a string map for uniquing debug info

  /// identifiers across the context.  Off by default.

  bool isODRUniquingDebugTypes() const;

  void enableDebugTypeODRUniquing();

  void disableDebugTypeODRUniquing();

  /// Defines the type of a yield callback.

  /// \see LLVMContext::setYieldCallback.

  using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle);

  /// setDiagnosticHandlerCallBack - This method sets a handler call back

  /// that is invoked when the backend needs to report anything to the user.

  /// The first argument is a function pointer and the second is a context pointer

  /// that gets passed into the DiagHandler.  The third argument should be set to

  /// true if the handler only expects enabled diagnostics.

  ///

  /// LLVMContext doesn't take ownership or interpret either of these

  /// pointers.

  void setDiagnosticHandlerCallBack(

      DiagnosticHandler::DiagnosticHandlerTy DiagHandler,

      void *DiagContext = nullptr, bool RespectFilters = false);

  /// setDiagnosticHandler - This method sets unique_ptr to object of

  /// DiagnosticHandler to provide custom diagnostic handling. The first

  /// argument is unique_ptr of object of type DiagnosticHandler or a derived

  /// of that. The second argument should be set to true if the handler only

  /// expects enabled diagnostics.

  ///

  /// Ownership of this pointer is moved to LLVMContextImpl.

  void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,

                            bool RespectFilters = false);

  /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by

  /// setDiagnosticHandlerCallBack.

  DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const;

  /// getDiagnosticContext - Return the diagnostic context set by

  /// setDiagnosticContext.

  void *getDiagnosticContext() const;

  /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by

  /// setDiagnosticHandler.

  const DiagnosticHandler *getDiagHandlerPtr() const;

  /// getDiagnosticHandler - transfers ownership of DiagnosticHandler unique_ptr

  /// to caller.

  std::unique_ptr<DiagnosticHandler> getDiagnosticHandler();

  /// Return if a code hotness metric should be included in optimization

  /// diagnostics.

  bool getDiagnosticsHotnessRequested() const;

  /// Set if a code hotness metric should be included in optimization

  /// diagnostics.

  void setDiagnosticsHotnessRequested(bool Requested);

  bool getMisExpectWarningRequested() const;

  void setMisExpectWarningRequested(bool Requested);

  void setDiagnosticsMisExpectTolerance(std::optional<uint32_t> Tolerance);

  uint32_t getDiagnosticsMisExpectTolerance() const;

  /// Return the minimum hotness value a diagnostic would need in order

  /// to be included in optimization diagnostics.

  ///

  /// Three possible return values:

  /// 0            - threshold is disabled. Everything will be printed out.

  /// positive int - threshold is set.

  /// UINT64_MAX   - threshold is not yet set, and needs to be synced from

  ///                profile summary. Note that in case of missing profile

  ///                summary, threshold will be kept at "MAX", effectively

  ///                suppresses all remarks output.

  uint64_t getDiagnosticsHotnessThreshold() const;

  /// Set the minimum hotness value a diagnostic needs in order to be

  /// included in optimization diagnostics.

  void setDiagnosticsHotnessThreshold(std::optional<uint64_t> Threshold);

  /// Return if hotness threshold is requested from PSI.

  bool isDiagnosticsHotnessThresholdSetFromPSI() const;

  /// The "main remark streamer" used by all the specialized remark streamers.

  /// This streamer keeps generic remark metadata in memory throughout the life

  /// of the LLVMContext. This metadata may be emitted in a section in object

  /// files depending on the format requirements.

  ///

  /// All specialized remark streamers should convert remarks to

  /// llvm::remarks::Remark and emit them through this streamer.

  remarks::RemarkStreamer *getMainRemarkStreamer();

  const remarks::RemarkStreamer *getMainRemarkStreamer() const;

  void setMainRemarkStreamer(

      std::unique_ptr<remarks::RemarkStreamer> MainRemarkStreamer);

  /// The "LLVM remark streamer" used by LLVM to serialize remark diagnostics

  /// comming from IR and MIR passes.

  ///

  /// If it does not exist, diagnostics are not saved in a file but only emitted

  /// via the diagnostic handler.

  LLVMRemarkStreamer *getLLVMRemarkStreamer();

  const LLVMRemarkStreamer *getLLVMRemarkStreamer() const;

  void

  setLLVMRemarkStreamer(std::unique_ptr<LLVMRemarkStreamer> RemarkStreamer);

  /// Get the prefix that should be printed in front of a diagnostic of

  ///        the given \p Severity

  static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);

  /// Report a message to the currently installed diagnostic handler.

  ///

  /// This function returns, in particular in the case of error reporting

  /// (DI.Severity == \a DS_Error), so the caller should leave the compilation

  /// process in a self-consistent state, even though the generated code

  /// need not be correct.

  ///

  /// The diagnostic message will be implicitly prefixed with a severity keyword

  /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,

  /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.

  void diagnose(const DiagnosticInfo &DI);

  /// Registers a yield callback with the given context.

  ///

  /// The yield callback function may be called by LLVM to transfer control back

  /// to the client that invoked the LLVM compilation. This can be used to yield

  /// control of the thread, or perform periodic work needed by the client.

  /// There is no guaranteed frequency at which callbacks must occur; in fact,

  /// the client is not guaranteed to ever receive this callback. It is at the

  /// sole discretion of LLVM to do so and only if it can guarantee that

  /// suspending the thread won't block any forward progress in other LLVM

  /// contexts in the same process.

  ///

  /// At a suspend point, the state of the current LLVM context is intentionally

  /// undefined. No assumptions about it can or should be made. Only LLVM

  /// context API calls that explicitly state that they can be used during a

  /// yield callback are allowed to be used. Any other API calls into the

  /// context are not supported until the yield callback function returns

  /// control to LLVM. Other LLVM contexts are unaffected by this restriction.

  void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);

  /// Calls the yield callback (if applicable).

  ///

  /// This transfers control of the current thread back to the client, which may

  /// suspend the current thread. Only call this method when LLVM doesn't hold

  /// any global mutex or cannot block the execution in another LLVM context.

  void yield();

  /// emitError - Emit an error message to the currently installed error handler

  /// with optional location information.  This function returns, so code should

  /// be prepared to drop the erroneous construct on the floor and "not crash".

  /// The generated code need not be correct.  The error message will be

  /// implicitly prefixed with "error: " and should not end with a ".".

  void emitError(uint64_t LocCookie, const Twine &ErrorStr);

  void emitError(const Instruction *I, const Twine &ErrorStr);

  void emitError(const Twine &ErrorStr);

  /// Access the object which can disable optional passes and individual

  /// optimizations at compile time.

  OptPassGate &getOptPassGate() const;

  /// Set the object which can disable optional passes and individual

  /// optimizations at compile time.

  ///

  /// The lifetime of the object must be guaranteed to extend as long as the

  /// LLVMContext is used by compilation.

  void setOptPassGate(OptPassGate&);

  /// Set whether opaque pointers are enabled. The method may be called multiple

  /// times, but only with the same value. Note that creating a pointer type or

  /// otherwise querying the opaque pointer mode performs an implicit set to

  /// the default value.

  void setOpaquePointers(bool Enable) const;

  /// Whether typed pointers are supported. If false, all pointers are opaque.

  bool supportsTypedPointers() const;

private:

  // Module needs access to the add/removeModule methods.

  friend class Module;

  /// addModule - Register a module as being instantiated in this context.  If

  /// the context is deleted, the module will be deleted as well.

  void addModule(Module*);

  /// removeModule - Unregister a module from this context.

  void removeModule(Module*);

};

// Create wrappers for C Binding types (see CBindingWrapping.h).

DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef)

/* Specialized opaque context conversions.

 */

inline LLVMContext **unwrap(LLVMContextRef* Tys) {

  return reinterpret_cast<LLVMContext**>(Tys);

}

inline LLVMContextRef *wrap(const LLVMContext **Tys) {

  return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));

}

} // end namespace llvm

#endif // LLVM_IR_LLVMCONTEXT_H