//===-- llvm/Module.h - C++ class to represent a VM module ------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // /// @file /// Module.h This file contains the declarations for the Module class. // //===----------------------------------------------------------------------===// #ifndef LLVM_IR_MODULE_H #define LLVM_IR_MODULE_H #include "llvm/ADT/Optional.h" #include "llvm/ADT/iterator_range.h" #include "llvm/IR/Comdat.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/Function.h" #include "llvm/IR/GlobalAlias.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/Metadata.h" #include "llvm/Support/CBindingWrapping.h" #include "llvm/Support/CodeGen.h" #include "llvm/Support/DataTypes.h" #include <system_error> namespace llvm { class FunctionType; class GVMaterializer; class LLVMContext; class RandomNumberGenerator; class StructType; template <class PtrType> class SmallPtrSetImpl; template<> struct ilist_traits<NamedMDNode> : public ilist_default_traits<NamedMDNode> { // createSentinel is used to get hold of a node that marks the end of // the list... NamedMDNode *createSentinel() const { return static_cast<NamedMDNode*>(&Sentinel); } static void destroySentinel(NamedMDNode*) {} NamedMDNode *provideInitialHead() const { return createSentinel(); } NamedMDNode *ensureHead(NamedMDNode*) const { return createSentinel(); } static void noteHead(NamedMDNode*, NamedMDNode*) {} void addNodeToList(NamedMDNode *) {} void removeNodeFromList(NamedMDNode *) {} private: mutable ilist_node<NamedMDNode> Sentinel; }; /// A Module instance is used to store all the information related to an /// LLVM module. Modules are the top level container of all other LLVM /// Intermediate Representation (IR) objects. Each module directly contains a /// list of globals variables, a list of functions, a list of libraries (or /// other modules) this module depends on, a symbol table, and various data /// about the target's characteristics. /// /// A module maintains a GlobalValRefMap object that is used to hold all /// constant references to global variables in the module. When a global /// variable is destroyed, it should have no entries in the GlobalValueRefMap. /// @brief The main container class for the LLVM Intermediate Representation. class Module { /// @name Types And Enumerations /// @{ public: /// The type for the list of global variables. typedef SymbolTableList<GlobalVariable> GlobalListType; /// The type for the list of functions. typedef SymbolTableList<Function> FunctionListType; /// The type for the list of aliases. typedef SymbolTableList<GlobalAlias> AliasListType; /// The type for the list of named metadata. typedef ilist<NamedMDNode> NamedMDListType; /// The type of the comdat "symbol" table. typedef StringMap<Comdat> ComdatSymTabType; /// The Global Variable iterator. typedef GlobalListType::iterator global_iterator; /// The Global Variable constant iterator. typedef GlobalListType::const_iterator const_global_iterator; /// The Function iterators. typedef FunctionListType::iterator iterator; /// The Function constant iterator typedef FunctionListType::const_iterator const_iterator; /// The Function reverse iterator. typedef FunctionListType::reverse_iterator reverse_iterator; /// The Function constant reverse iterator. typedef FunctionListType::const_reverse_iterator const_reverse_iterator; /// The Global Alias iterators. typedef AliasListType::iterator alias_iterator; /// The Global Alias constant iterator typedef AliasListType::const_iterator const_alias_iterator; /// The named metadata iterators. typedef NamedMDListType::iterator named_metadata_iterator; /// The named metadata constant iterators. typedef NamedMDListType::const_iterator const_named_metadata_iterator; /// This enumeration defines the supported behaviors of module flags. enum ModFlagBehavior { /// Emits an error if two values disagree, otherwise the resulting value is /// that of the operands. Error = 1, /// Emits a warning if two values disagree. The result value will be the /// operand for the flag from the first module being linked. Warning = 2, /// Adds a requirement that another module flag be present and have a /// specified value after linking is performed. The value must be a metadata /// pair, where the first element of the pair is the ID of the module flag /// to be restricted, and the second element of the pair is the value the /// module flag should be restricted to. This behavior can be used to /// restrict the allowable results (via triggering of an error) of linking /// IDs with the **Override** behavior. Require = 3, /// Uses the specified value, regardless of the behavior or value of the /// other module. If both modules specify **Override**, but the values /// differ, an error will be emitted. Override = 4, /// Appends the two values, which are required to be metadata nodes. Append = 5, /// Appends the two values, which are required to be metadata /// nodes. However, duplicate entries in the second list are dropped /// during the append operation. AppendUnique = 6, // Markers: ModFlagBehaviorFirstVal = Error, ModFlagBehaviorLastVal = AppendUnique }; /// Checks if Metadata represents a valid ModFlagBehavior, and stores the /// converted result in MFB. static bool isValidModFlagBehavior(Metadata *MD, ModFlagBehavior &MFB); struct ModuleFlagEntry { ModFlagBehavior Behavior; MDString *Key; Metadata *Val; ModuleFlagEntry(ModFlagBehavior B, MDString *K, Metadata *V) : Behavior(B), Key(K), Val(V) {} }; /// @} /// @name Member Variables /// @{ private: LLVMContext &Context; ///< The LLVMContext from which types and ///< constants are allocated. GlobalListType GlobalList; ///< The Global Variables in the module FunctionListType FunctionList; ///< The Functions in the module AliasListType AliasList; ///< The Aliases in the module NamedMDListType NamedMDList; ///< The named metadata in the module std::string GlobalScopeAsm; ///< Inline Asm at global scope. ValueSymbolTable *ValSymTab; ///< Symbol table for values ComdatSymTabType ComdatSymTab; ///< Symbol table for COMDATs std::unique_ptr<GVMaterializer> Materializer; ///< Used to materialize GlobalValues std::string ModuleID; ///< Human readable identifier for the module std::string SourceFileName; ///< Original source file name for module, ///< recorded in bitcode. std::string TargetTriple; ///< Platform target triple Module compiled on ///< Format: (arch)(sub)-(vendor)-(sys0-(abi) void *NamedMDSymTab; ///< NamedMDNode names. DataLayout DL; ///< DataLayout associated with the module friend class Constant; /// @} /// @name Constructors /// @{ public: /// The Module constructor. Note that there is no default constructor. You /// must provide a name for the module upon construction. explicit Module(StringRef ModuleID, LLVMContext& C); /// The module destructor. This will dropAllReferences. ~Module(); /// @} /// @name Module Level Accessors /// @{ /// Get the module identifier which is, essentially, the name of the module. /// @returns the module identifier as a string const std::string &getModuleIdentifier() const { return ModuleID; } /// Get the module's original source file name. When compiling from /// bitcode, this is taken from a bitcode record where it was recorded. /// For other compiles it is the same as the ModuleID, which would /// contain the source file name. const std::string &getSourceFileName() const { return SourceFileName; } /// \brief Get a short "name" for the module. /// /// This is useful for debugging or logging. It is essentially a convenience /// wrapper around getModuleIdentifier(). StringRef getName() const { return ModuleID; } /// Get the data layout string for the module's target platform. This is /// equivalent to getDataLayout()->getStringRepresentation(). const std::string &getDataLayoutStr() const { return DL.getStringRepresentation(); } /// Get the data layout for the module's target platform. const DataLayout &getDataLayout() const; /// Get the target triple which is a string describing the target host. /// @returns a string containing the target triple. const std::string &getTargetTriple() const { return TargetTriple; } /// Get the global data context. /// @returns LLVMContext - a container for LLVM's global information LLVMContext &getContext() const { return Context; } /// Get any module-scope inline assembly blocks. /// @returns a string containing the module-scope inline assembly blocks. const std::string &getModuleInlineAsm() const { return GlobalScopeAsm; } /// Get a RandomNumberGenerator salted for use with this module. The /// RNG can be seeded via -rng-seed=<uint64> and is salted with the /// ModuleID and the provided pass salt. The returned RNG should not /// be shared across threads or passes. /// /// A unique RNG per pass ensures a reproducible random stream even /// when other randomness consuming passes are added or removed. In /// addition, the random stream will be reproducible across LLVM /// versions when the pass does not change. RandomNumberGenerator *createRNG(const Pass* P) const; /// @} /// @name Module Level Mutators /// @{ /// Set the module identifier. void setModuleIdentifier(StringRef ID) { ModuleID = ID; } /// Set the module's original source file name. void setSourceFileName(StringRef Name) { SourceFileName = Name; } /// Set the data layout void setDataLayout(StringRef Desc); void setDataLayout(const DataLayout &Other); /// Set the target triple. void setTargetTriple(StringRef T) { TargetTriple = T; } /// Set the module-scope inline assembly blocks. /// A trailing newline is added if the input doesn't have one. void setModuleInlineAsm(StringRef Asm) { GlobalScopeAsm = Asm; if (!GlobalScopeAsm.empty() && GlobalScopeAsm[GlobalScopeAsm.size()-1] != '\n') GlobalScopeAsm += '\n'; } /// Append to the module-scope inline assembly blocks. /// A trailing newline is added if the input doesn't have one. void appendModuleInlineAsm(StringRef Asm) { GlobalScopeAsm += Asm; if (!GlobalScopeAsm.empty() && GlobalScopeAsm[GlobalScopeAsm.size()-1] != '\n') GlobalScopeAsm += '\n'; } /// @} /// @name Generic Value Accessors /// @{ /// Return the global value in the module with the specified name, of /// arbitrary type. This method returns null if a global with the specified /// name is not found. GlobalValue *getNamedValue(StringRef Name) const; /// 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; /// Populate client supplied SmallVector with the name for custom metadata IDs /// registered in this LLVMContext. void getMDKindNames(SmallVectorImpl<StringRef> &Result) const; /// 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; /// Return the type with the specified name, or null if there is none by that /// name. StructType *getTypeByName(StringRef Name) const; std::vector<StructType *> getIdentifiedStructTypes() const; /// @} /// @name Function Accessors /// @{ /// Look up the specified function in the module symbol table. Four /// possibilities: /// 1. If it does not exist, add a prototype for the function and return it. /// 2. If it exists, and has a local linkage, the existing function is /// renamed and a new one is inserted. /// 3. Otherwise, if the existing function has the correct prototype, return /// the existing function. /// 4. Finally, the function exists but has the wrong prototype: return the /// function with a constantexpr cast to the right prototype. Constant *getOrInsertFunction(StringRef Name, FunctionType *T, AttributeSet AttributeList); Constant *getOrInsertFunction(StringRef Name, FunctionType *T); /// Look up the specified function in the module symbol table. If it does not /// exist, add a prototype for the function and return it. This function /// guarantees to return a constant of pointer to the specified function type /// or a ConstantExpr BitCast of that type if the named function has a /// different type. This version of the method takes a null terminated list of /// function arguments, which makes it easier for clients to use. Constant *getOrInsertFunction(StringRef Name, AttributeSet AttributeList, Type *RetTy, ...) LLVM_END_WITH_NULL; /// Same as above, but without the attributes. Constant *getOrInsertFunction(StringRef Name, Type *RetTy, ...) LLVM_END_WITH_NULL; /// Look up the specified function in the module symbol table. If it does not /// exist, return null. Function *getFunction(StringRef Name) const; /// @} /// @name Global Variable Accessors /// @{ /// Look up the specified global variable in the module symbol table. If it /// does not exist, return null. If AllowInternal is set to true, this /// function will return types that have InternalLinkage. By default, these /// types are not returned. GlobalVariable *getGlobalVariable(StringRef Name) const { return getGlobalVariable(Name, false); } GlobalVariable *getGlobalVariable(StringRef Name, bool AllowInternal) const { return const_cast<Module *>(this)->getGlobalVariable(Name, AllowInternal); } GlobalVariable *getGlobalVariable(StringRef Name, bool AllowInternal = false); /// Return the global variable in the module with the specified name, of /// arbitrary type. This method returns null if a global with the specified /// name is not found. GlobalVariable *getNamedGlobal(StringRef Name) { return getGlobalVariable(Name, true); } const GlobalVariable *getNamedGlobal(StringRef Name) const { return const_cast<Module *>(this)->getNamedGlobal(Name); } /// Look up the specified global in the module symbol table. /// 1. If it does not exist, add a declaration of the global and return it. /// 2. Else, the global exists but has the wrong type: return the function /// with a constantexpr cast to the right type. /// 3. Finally, if the existing global is the correct declaration, return /// the existing global. Constant *getOrInsertGlobal(StringRef Name, Type *Ty); /// @} /// @name Global Alias Accessors /// @{ /// Return the global alias in the module with the specified name, of /// arbitrary type. This method returns null if a global with the specified /// name is not found. GlobalAlias *getNamedAlias(StringRef Name) const; /// @} /// @name Named Metadata Accessors /// @{ /// Return the first NamedMDNode in the module with the specified name. This /// method returns null if a NamedMDNode with the specified name is not found. NamedMDNode *getNamedMetadata(const Twine &Name) const; /// Return the named MDNode in the module with the specified name. This method /// returns a new NamedMDNode if a NamedMDNode with the specified name is not /// found. NamedMDNode *getOrInsertNamedMetadata(StringRef Name); /// Remove the given NamedMDNode from this module and delete it. void eraseNamedMetadata(NamedMDNode *NMD); /// @} /// @name Comdat Accessors /// @{ /// Return the Comdat in the module with the specified name. It is created /// if it didn't already exist. Comdat *getOrInsertComdat(StringRef Name); /// @} /// @name Module Flags Accessors /// @{ /// Returns the module flags in the provided vector. void getModuleFlagsMetadata(SmallVectorImpl<ModuleFlagEntry> &Flags) const; /// Return the corresponding value if Key appears in module flags, otherwise /// return null. Metadata *getModuleFlag(StringRef Key) const; /// Returns the NamedMDNode in the module that represents module-level flags. /// This method returns null if there are no module-level flags. NamedMDNode *getModuleFlagsMetadata() const; /// Returns the NamedMDNode in the module that represents module-level flags. /// If module-level flags aren't found, it creates the named metadata that /// contains them. NamedMDNode *getOrInsertModuleFlagsMetadata(); /// Add a module-level flag to the module-level flags metadata. It will create /// the module-level flags named metadata if it doesn't already exist. void addModuleFlag(ModFlagBehavior Behavior, StringRef Key, Metadata *Val); void addModuleFlag(ModFlagBehavior Behavior, StringRef Key, Constant *Val); void addModuleFlag(ModFlagBehavior Behavior, StringRef Key, uint32_t Val); void addModuleFlag(MDNode *Node); /// @} /// @name Materialization /// @{ /// Sets the GVMaterializer to GVM. This module must not yet have a /// Materializer. To reset the materializer for a module that already has one, /// call materializeAll first. Destroying this module will destroy /// its materializer without materializing any more GlobalValues. Without /// destroying the Module, there is no way to detach or destroy a materializer /// without materializing all the GVs it controls, to avoid leaving orphan /// unmaterialized GVs. void setMaterializer(GVMaterializer *GVM); /// Retrieves the GVMaterializer, if any, for this Module. GVMaterializer *getMaterializer() const { return Materializer.get(); } bool isMaterialized() const { return !getMaterializer(); } /// Make sure the GlobalValue is fully read. If the module is corrupt, this /// returns true and fills in the optional string with information about the /// problem. If successful, this returns false. std::error_code materialize(GlobalValue *GV); /// Make sure all GlobalValues in this Module are fully read and clear the /// Materializer. std::error_code materializeAll(); std::error_code materializeMetadata(); /// @} /// @name Direct access to the globals list, functions list, and symbol table /// @{ /// Get the Module's list of global variables (constant). const GlobalListType &getGlobalList() const { return GlobalList; } /// Get the Module's list of global variables. GlobalListType &getGlobalList() { return GlobalList; } static GlobalListType Module::*getSublistAccess(GlobalVariable*) { return &Module::GlobalList; } /// Get the Module's list of functions (constant). const FunctionListType &getFunctionList() const { return FunctionList; } /// Get the Module's list of functions. FunctionListType &getFunctionList() { return FunctionList; } static FunctionListType Module::*getSublistAccess(Function*) { return &Module::FunctionList; } /// Get the Module's list of aliases (constant). const AliasListType &getAliasList() const { return AliasList; } /// Get the Module's list of aliases. AliasListType &getAliasList() { return AliasList; } static AliasListType Module::*getSublistAccess(GlobalAlias*) { return &Module::AliasList; } /// Get the Module's list of named metadata (constant). const NamedMDListType &getNamedMDList() const { return NamedMDList; } /// Get the Module's list of named metadata. NamedMDListType &getNamedMDList() { return NamedMDList; } static NamedMDListType Module::*getSublistAccess(NamedMDNode*) { return &Module::NamedMDList; } /// Get the symbol table of global variable and function identifiers const ValueSymbolTable &getValueSymbolTable() const { return *ValSymTab; } /// Get the Module's symbol table of global variable and function identifiers. ValueSymbolTable &getValueSymbolTable() { return *ValSymTab; } /// Get the Module's symbol table for COMDATs (constant). const ComdatSymTabType &getComdatSymbolTable() const { return ComdatSymTab; } /// Get the Module's symbol table for COMDATs. ComdatSymTabType &getComdatSymbolTable() { return ComdatSymTab; } /// @} /// @name Global Variable Iteration /// @{ global_iterator global_begin() { return GlobalList.begin(); } const_global_iterator global_begin() const { return GlobalList.begin(); } global_iterator global_end () { return GlobalList.end(); } const_global_iterator global_end () const { return GlobalList.end(); } bool global_empty() const { return GlobalList.empty(); } iterator_range<global_iterator> globals() { return make_range(global_begin(), global_end()); } iterator_range<const_global_iterator> globals() const { return make_range(global_begin(), global_end()); } /// @} /// @name Function Iteration /// @{ iterator begin() { return FunctionList.begin(); } const_iterator begin() const { return FunctionList.begin(); } iterator end () { return FunctionList.end(); } const_iterator end () const { return FunctionList.end(); } reverse_iterator rbegin() { return FunctionList.rbegin(); } const_reverse_iterator rbegin() const{ return FunctionList.rbegin(); } reverse_iterator rend() { return FunctionList.rend(); } const_reverse_iterator rend() const { return FunctionList.rend(); } size_t size() const { return FunctionList.size(); } bool empty() const { return FunctionList.empty(); } iterator_range<iterator> functions() { return make_range(begin(), end()); } iterator_range<const_iterator> functions() const { return make_range(begin(), end()); } /// @} /// @name Alias Iteration /// @{ alias_iterator alias_begin() { return AliasList.begin(); } const_alias_iterator alias_begin() const { return AliasList.begin(); } alias_iterator alias_end () { return AliasList.end(); } const_alias_iterator alias_end () const { return AliasList.end(); } size_t alias_size () const { return AliasList.size(); } bool alias_empty() const { return AliasList.empty(); } iterator_range<alias_iterator> aliases() { return make_range(alias_begin(), alias_end()); } iterator_range<const_alias_iterator> aliases() const { return make_range(alias_begin(), alias_end()); } /// @} /// @name Named Metadata Iteration /// @{ named_metadata_iterator named_metadata_begin() { return NamedMDList.begin(); } const_named_metadata_iterator named_metadata_begin() const { return NamedMDList.begin(); } named_metadata_iterator named_metadata_end() { return NamedMDList.end(); } const_named_metadata_iterator named_metadata_end() const { return NamedMDList.end(); } size_t named_metadata_size() const { return NamedMDList.size(); } bool named_metadata_empty() const { return NamedMDList.empty(); } iterator_range<named_metadata_iterator> named_metadata() { return make_range(named_metadata_begin(), named_metadata_end()); } iterator_range<const_named_metadata_iterator> named_metadata() const { return make_range(named_metadata_begin(), named_metadata_end()); } /// An iterator for DICompileUnits that skips those marked NoDebug. class debug_compile_units_iterator : public std::iterator<std::input_iterator_tag, DICompileUnit *> { NamedMDNode *CUs; unsigned Idx; void SkipNoDebugCUs(); public: explicit debug_compile_units_iterator(NamedMDNode *CUs, unsigned Idx) : CUs(CUs), Idx(Idx) { SkipNoDebugCUs(); } debug_compile_units_iterator &operator++() { ++Idx; SkipNoDebugCUs(); return *this; } debug_compile_units_iterator operator++(int) { debug_compile_units_iterator T(*this); ++Idx; return T; } bool operator==(const debug_compile_units_iterator &I) const { return Idx == I.Idx; } bool operator!=(const debug_compile_units_iterator &I) const { return Idx != I.Idx; } DICompileUnit *operator*() const; DICompileUnit *operator->() const; }; debug_compile_units_iterator debug_compile_units_begin() const { auto *CUs = getNamedMetadata("llvm.dbg.cu"); return debug_compile_units_iterator(CUs, 0); } debug_compile_units_iterator debug_compile_units_end() const { auto *CUs = getNamedMetadata("llvm.dbg.cu"); return debug_compile_units_iterator(CUs, CUs ? CUs->getNumOperands() : 0); } /// Return an iterator for all DICompileUnits listed in this Module's /// llvm.dbg.cu named metadata node and aren't explicitly marked as /// NoDebug. iterator_range<debug_compile_units_iterator> debug_compile_units() const { auto *CUs = getNamedMetadata("llvm.dbg.cu"); return make_range( debug_compile_units_iterator(CUs, 0), debug_compile_units_iterator(CUs, CUs ? CUs->getNumOperands() : 0)); } /// @} /// Destroy ConstantArrays in LLVMContext if they are not used. /// ConstantArrays constructed during linking can cause quadratic memory /// explosion. Releasing all unused constants can cause a 20% LTO compile-time /// slowdown for a large application. /// /// NOTE: Constants are currently owned by LLVMContext. This can then only /// be called where all uses of the LLVMContext are understood. void dropTriviallyDeadConstantArrays(); /// @name Utility functions for printing and dumping Module objects /// @{ /// Print the module to an output stream with an optional /// AssemblyAnnotationWriter. If \c ShouldPreserveUseListOrder, then include /// uselistorder directives so that use-lists can be recreated when reading /// the assembly. void print(raw_ostream &OS, AssemblyAnnotationWriter *AAW, bool ShouldPreserveUseListOrder = false, bool IsForDebug = false) const; /// Dump the module to stderr (for debugging). void dump() const; /// This function causes all the subinstructions to "let go" of all references /// that they are maintaining. This allows one to 'delete' a whole class at /// a time, even though there may be circular references... first all /// references are dropped, and all use counts go to zero. Then everything /// is delete'd for real. Note that no operations are valid on an object /// that has "dropped all references", except operator delete. void dropAllReferences(); /// @} /// @name Utility functions for querying Debug information. /// @{ /// \brief Returns the Dwarf Version by checking module flags. unsigned getDwarfVersion() const; /// \brief Returns the CodeView Version by checking module flags. /// Returns zero if not present in module. unsigned getCodeViewFlag() const; /// @} /// @name Utility functions for querying and setting PIC level /// @{ /// \brief Returns the PIC level (small or large model) PICLevel::Level getPICLevel() const; /// \brief Set the PIC level (small or large model) void setPICLevel(PICLevel::Level PL); /// @} /// @name Utility functions for querying and setting PGO counts /// @{ /// \brief Set maximum function count in PGO mode void setMaximumFunctionCount(uint64_t); /// \brief Returns maximum function count in PGO mode Optional<uint64_t> getMaximumFunctionCount(); /// @} }; /// \brief Given "llvm.used" or "llvm.compiler.used" as a global name, collect /// the initializer elements of that global in Set and return the global itself. GlobalVariable *collectUsedGlobalVariables(const Module &M, SmallPtrSetImpl<GlobalValue *> &Set, bool CompilerUsed); /// An raw_ostream inserter for modules. inline raw_ostream &operator<<(raw_ostream &O, const Module &M) { M.print(O, nullptr); return O; } // Create wrappers for C Binding types (see CBindingWrapping.h). DEFINE_SIMPLE_CONVERSION_FUNCTIONS(Module, LLVMModuleRef) /* LLVMModuleProviderRef exists for historical reasons, but now just holds a * Module. */ inline Module *unwrap(LLVMModuleProviderRef MP) { return reinterpret_cast<Module*>(MP); } } // End llvm namespace #endif