Coverage Report

Created: 2021-01-26 06:56

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/CodeGen/CGObjCRuntime.h
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//===----- CGObjCRuntime.h - Interface to ObjC Runtimes ---------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This provides an abstract class for Objective-C code generation.  Concrete
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// subclasses of this implement code generation for specific Objective-C
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// runtime libraries.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_LIB_CODEGEN_CGOBJCRUNTIME_H
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#define LLVM_CLANG_LIB_CODEGEN_CGOBJCRUNTIME_H
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#include "CGBuilder.h"
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#include "CGCall.h"
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#include "CGCleanup.h"
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#include "CGValue.h"
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#include "clang/AST/DeclObjC.h"
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#include "clang/Basic/IdentifierTable.h" // Selector
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#include "llvm/ADT/UniqueVector.h"
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namespace llvm {
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  class Constant;
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  class Function;
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  class Module;
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  class StructLayout;
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  class StructType;
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  class Type;
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  class Value;
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}
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namespace clang {
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namespace CodeGen {
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  class CodeGenFunction;
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}
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  class FieldDecl;
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  class ObjCAtTryStmt;
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  class ObjCAtThrowStmt;
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  class ObjCAtSynchronizedStmt;
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  class ObjCContainerDecl;
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  class ObjCCategoryImplDecl;
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  class ObjCImplementationDecl;
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  class ObjCInterfaceDecl;
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  class ObjCMessageExpr;
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  class ObjCMethodDecl;
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  class ObjCProtocolDecl;
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  class Selector;
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  class ObjCIvarDecl;
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  class ObjCStringLiteral;
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  class BlockDeclRefExpr;
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namespace CodeGen {
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  class CodeGenModule;
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  class CGBlockInfo;
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// FIXME: Several methods should be pure virtual but aren't to avoid the
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// partially-implemented subclass breaking.
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/// Implements runtime-specific code generation functions.
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class CGObjCRuntime {
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protected:
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  CodeGen::CodeGenModule &CGM;
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13.5k
  CGObjCRuntime(CodeGen::CodeGenModule &CGM) : CGM(CGM) {}
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  // Utility functions for unified ivar access. These need to
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  // eventually be folded into other places (the structure layout
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  // code).
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  /// Compute an offset to the given ivar, suitable for passing to
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  /// EmitValueForIvarAtOffset.  Note that the correct handling of
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  /// bit-fields is carefully coordinated by these two, use caution!
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  ///
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  /// The latter overload is suitable for computing the offset of a
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  /// sythesized ivar.
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  uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM,
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                                 const ObjCInterfaceDecl *OID,
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                                 const ObjCIvarDecl *Ivar);
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  uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM,
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                                 const ObjCImplementationDecl *OID,
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                                 const ObjCIvarDecl *Ivar);
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  LValue EmitValueForIvarAtOffset(CodeGen::CodeGenFunction &CGF,
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                                  const ObjCInterfaceDecl *OID,
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                                  llvm::Value *BaseValue,
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                                  const ObjCIvarDecl *Ivar,
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                                  unsigned CVRQualifiers,
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                                  llvm::Value *Offset);
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  /// Emits a try / catch statement.  This function is intended to be called by
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  /// subclasses, and provides a generic mechanism for generating these, which
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  /// should be usable by all runtimes.  The caller must provide the functions
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  /// to call when entering and exiting a \@catch() block, and the function
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  /// used to rethrow exceptions.  If the begin and end catch functions are
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  /// NULL, then the function assumes that the EH personality function provides
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  /// the thrown object directly.
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  void EmitTryCatchStmt(CodeGenFunction &CGF, const ObjCAtTryStmt &S,
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                        llvm::FunctionCallee beginCatchFn,
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                        llvm::FunctionCallee endCatchFn,
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                        llvm::FunctionCallee exceptionRethrowFn);
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  void EmitInitOfCatchParam(CodeGenFunction &CGF, llvm::Value *exn,
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                            const VarDecl *paramDecl);
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  /// Emits an \@synchronize() statement, using the \p syncEnterFn and
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  /// \p syncExitFn arguments as the functions called to lock and unlock
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  /// the object.  This function can be called by subclasses that use
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  /// zero-cost exception handling.
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  void EmitAtSynchronizedStmt(CodeGenFunction &CGF,
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                              const ObjCAtSynchronizedStmt &S,
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                              llvm::FunctionCallee syncEnterFn,
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                              llvm::FunctionCallee syncExitFn);
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public:
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  virtual ~CGObjCRuntime();
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  std::string getSymbolNameForMethod(const ObjCMethodDecl *method,
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                                     bool includeCategoryName = true);
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  /// Generate the function required to register all Objective-C components in
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  /// this compilation unit with the runtime library.
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  virtual llvm::Function *ModuleInitFunction() = 0;
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  /// Get a selector for the specified name and type values.
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  /// The result should have the LLVM type for ASTContext::getObjCSelType().
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  virtual llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) = 0;
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  /// Get the address of a selector for the specified name and type values.
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  /// This is a rarely-used language extension, but sadly it exists.
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  ///
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  /// The result should have the LLVM type for a pointer to
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  /// ASTContext::getObjCSelType().
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  virtual Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) = 0;
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  /// Get a typed selector.
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  virtual llvm::Value *GetSelector(CodeGenFunction &CGF,
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                                   const ObjCMethodDecl *Method) = 0;
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  /// Get the type constant to catch for the given ObjC pointer type.
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  /// This is used externally to implement catching ObjC types in C++.
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  /// Runtimes which don't support this should add the appropriate
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  /// error to Sema.
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  virtual llvm::Constant *GetEHType(QualType T) = 0;
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  virtual CatchTypeInfo getCatchAllTypeInfo() { return { nullptr, 0 }; }
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  /// Generate a constant string object.
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  virtual ConstantAddress GenerateConstantString(const StringLiteral *) = 0;
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  /// Generate a category.  A category contains a list of methods (and
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  /// accompanying metadata) and a list of protocols.
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  virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0;
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  /// Generate a class structure for this class.
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  virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0;
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  /// Register an class alias.
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  virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) = 0;
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  /// Generate an Objective-C message send operation.
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  ///
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  /// \param Method - The method being called, this may be null if synthesizing
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  /// a property setter or getter.
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  virtual CodeGen::RValue
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  GenerateMessageSend(CodeGen::CodeGenFunction &CGF,
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                      ReturnValueSlot ReturnSlot,
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                      QualType ResultType,
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                      Selector Sel,
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                      llvm::Value *Receiver,
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                      const CallArgList &CallArgs,
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                      const ObjCInterfaceDecl *Class = nullptr,
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                      const ObjCMethodDecl *Method = nullptr) = 0;
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  /// Generate an Objective-C message send operation.
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  ///
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  /// This variant allows for the call to be substituted with an optimized
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  /// variant.
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  CodeGen::RValue
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  GeneratePossiblySpecializedMessageSend(CodeGenFunction &CGF,
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                                         ReturnValueSlot Return,
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                                         QualType ResultType,
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                                         Selector Sel,
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                                         llvm::Value *Receiver,
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                                         const CallArgList& Args,
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                                         const ObjCInterfaceDecl *OID,
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                                         const ObjCMethodDecl *Method,
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                                         bool isClassMessage);
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  /// Generate an Objective-C message send operation to the super
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  /// class initiated in a method for Class and with the given Self
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  /// object.
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  ///
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  /// \param Method - The method being called, this may be null if synthesizing
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  /// a property setter or getter.
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  virtual CodeGen::RValue
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  GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF,
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                           ReturnValueSlot ReturnSlot,
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                           QualType ResultType,
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                           Selector Sel,
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                           const ObjCInterfaceDecl *Class,
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                           bool isCategoryImpl,
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                           llvm::Value *Self,
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                           bool IsClassMessage,
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                           const CallArgList &CallArgs,
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                           const ObjCMethodDecl *Method = nullptr) = 0;
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  /// Walk the list of protocol references from a class, category or
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  /// protocol to traverse the DAG formed from it's inheritance hierarchy. Find
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  /// the list of protocols that ends each walk at either a runtime
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  /// protocol or a non-runtime protocol with no parents. For the common case of
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  /// just a list of standard runtime protocols this just returns the same list
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  /// that was passed in.
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  std::vector<const ObjCProtocolDecl *>
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  GetRuntimeProtocolList(ObjCProtocolDecl::protocol_iterator begin,
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                         ObjCProtocolDecl::protocol_iterator end);
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  /// Emit the code to return the named protocol as an object, as in a
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  /// \@protocol expression.
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  virtual llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
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                                           const ObjCProtocolDecl *OPD) = 0;
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  /// Generate the named protocol.  Protocols contain method metadata but no
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  /// implementations.
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  virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0;
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  /// GetOrEmitProtocol - Get the protocol object for the given
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  /// declaration, emitting it if necessary. The return value has type
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  /// ProtocolPtrTy.
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  virtual llvm::Constant *GetOrEmitProtocol(const ObjCProtocolDecl *PD) = 0;
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  /// Generate a function preamble for a method with the specified
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  /// types.
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  // FIXME: Current this just generates the Function definition, but really this
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  // should also be generating the loads of the parameters, as the runtime
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  // should have full control over how parameters are passed.
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  virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
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                                         const ObjCContainerDecl *CD) = 0;
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  /// Generates prologue for direct Objective-C Methods.
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  virtual void GenerateDirectMethodPrologue(CodeGenFunction &CGF,
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                                            llvm::Function *Fn,
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                                            const ObjCMethodDecl *OMD,
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                                            const ObjCContainerDecl *CD) = 0;
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  /// Return the runtime function for getting properties.
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  virtual llvm::FunctionCallee GetPropertyGetFunction() = 0;
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  /// Return the runtime function for setting properties.
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  virtual llvm::FunctionCallee GetPropertySetFunction() = 0;
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  /// Return the runtime function for optimized setting properties.
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  virtual llvm::FunctionCallee GetOptimizedPropertySetFunction(bool atomic,
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                                                               bool copy) = 0;
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  // API for atomic copying of qualified aggregates in getter.
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  virtual llvm::FunctionCallee GetGetStructFunction() = 0;
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  // API for atomic copying of qualified aggregates in setter.
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  virtual llvm::FunctionCallee GetSetStructFunction() = 0;
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  /// API for atomic copying of qualified aggregates with non-trivial copy
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  /// assignment (c++) in setter.
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  virtual llvm::FunctionCallee GetCppAtomicObjectSetFunction() = 0;
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  /// API for atomic copying of qualified aggregates with non-trivial copy
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  /// assignment (c++) in getter.
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  virtual llvm::FunctionCallee GetCppAtomicObjectGetFunction() = 0;
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  /// GetClass - Return a reference to the class for the given
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  /// interface decl.
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  virtual llvm::Value *GetClass(CodeGenFunction &CGF,
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                                const ObjCInterfaceDecl *OID) = 0;
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  virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
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    llvm_unreachable("autoreleasepool unsupported in this ABI");
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  }
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  /// EnumerationMutationFunction - Return the function that's called by the
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  /// compiler when a mutation is detected during foreach iteration.
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  virtual llvm::FunctionCallee EnumerationMutationFunction() = 0;
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  virtual void EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
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                                    const ObjCAtSynchronizedStmt &S) = 0;
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  virtual void EmitTryStmt(CodeGen::CodeGenFunction &CGF,
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                           const ObjCAtTryStmt &S) = 0;
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  virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
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                             const ObjCAtThrowStmt &S,
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                             bool ClearInsertionPoint=true) = 0;
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  virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF,
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                                        Address AddrWeakObj) = 0;
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  virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF,
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                                  llvm::Value *src, Address dest) = 0;
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  virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
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                                    llvm::Value *src, Address dest,
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                                    bool threadlocal=false) = 0;
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  virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
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                                  llvm::Value *src, Address dest,
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                                  llvm::Value *ivarOffset) = 0;
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  virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
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                                        llvm::Value *src, Address dest) = 0;
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  virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF,
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                                      QualType ObjectTy,
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                                      llvm::Value *BaseValue,
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                                      const ObjCIvarDecl *Ivar,
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                                      unsigned CVRQualifiers) = 0;
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  virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
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                                      const ObjCInterfaceDecl *Interface,
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                                      const ObjCIvarDecl *Ivar) = 0;
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  virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
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                                        Address DestPtr,
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                                        Address SrcPtr,
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                                        llvm::Value *Size) = 0;
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  virtual llvm::Constant *BuildGCBlockLayout(CodeGen::CodeGenModule &CGM,
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                                  const CodeGen::CGBlockInfo &blockInfo) = 0;
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  virtual llvm::Constant *BuildRCBlockLayout(CodeGen::CodeGenModule &CGM,
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                                  const CodeGen::CGBlockInfo &blockInfo) = 0;
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  virtual std::string getRCBlockLayoutStr(CodeGen::CodeGenModule &CGM,
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                                          const CGBlockInfo &blockInfo) {
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    return {};
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  }
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  /// Returns an i8* which points to the byref layout information.
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  virtual llvm::Constant *BuildByrefLayout(CodeGen::CodeGenModule &CGM,
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                                           QualType T) = 0;
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  struct MessageSendInfo {
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    const CGFunctionInfo &CallInfo;
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    llvm::PointerType *MessengerType;
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    MessageSendInfo(const CGFunctionInfo &callInfo,
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                    llvm::PointerType *messengerType)
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12.3k
      : CallInfo(callInfo), MessengerType(messengerType) {}
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  };
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  MessageSendInfo getMessageSendInfo(const ObjCMethodDecl *method,
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                                     QualType resultType,
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                                     CallArgList &callArgs);
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  // FIXME: This probably shouldn't be here, but the code to compute
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  // it is here.
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  unsigned ComputeBitfieldBitOffset(CodeGen::CodeGenModule &CGM,
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                                    const ObjCInterfaceDecl *ID,
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                                    const ObjCIvarDecl *Ivar);
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};
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/// Creates an instance of an Objective-C runtime class.
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//TODO: This should include some way of selecting which runtime to target.
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CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM);
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CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM);
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}
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}
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#endif