1 //===-- llvm/LLVMContext.h - Class for managing "global" state --*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file declares LLVMContext, a container of "global" state in LLVM, such 11 // as the global type and constant uniquing tables. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_IR_LLVMCONTEXT_H 16 #define LLVM_IR_LLVMCONTEXT_H 17 18 #include "llvm-c/Core.h" 19 #include "llvm/Support/CBindingWrapping.h" 20 #include "llvm/Support/Compiler.h" 21 #include "llvm/Support/Options.h" 22 23 namespace llvm { 24 25 class LLVMContextImpl; 26 class StringRef; 27 class Twine; 28 class Instruction; 29 class Module; 30 class SMDiagnostic; 31 class DiagnosticInfo; 32 template <typename T> class SmallVectorImpl; 33 class Function; 34 class DebugLoc; 35 36 /// This is an important class for using LLVM in a threaded context. It 37 /// (opaquely) owns and manages the core "global" data of LLVM's core 38 /// infrastructure, including the type and constant uniquing tables. 39 /// LLVMContext itself provides no locking guarantees, so you should be careful 40 /// to have one context per thread. 41 class LLVMContext { 42 public: 43 LLVMContextImpl *const pImpl; 44 LLVMContext(); 45 ~LLVMContext(); 46 47 // Pinned metadata names, which always have the same value. This is a 48 // compile-time performance optimization, not a correctness optimization. 49 enum { 50 MD_dbg = 0, // "dbg" 51 MD_tbaa = 1, // "tbaa" 52 MD_prof = 2, // "prof" 53 MD_fpmath = 3, // "fpmath" 54 MD_range = 4, // "range" 55 MD_tbaa_struct = 5, // "tbaa.struct" 56 MD_invariant_load = 6, // "invariant.load" 57 MD_alias_scope = 7, // "alias.scope" 58 MD_noalias = 8, // "noalias", 59 MD_nontemporal = 9, // "nontemporal" 60 MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access" 61 MD_nonnull = 11 // "nonnull" 62 }; 63 64 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind. 65 /// This ID is uniqued across modules in the current LLVMContext. 66 unsigned getMDKindID(StringRef Name) const; 67 68 /// getMDKindNames - Populate client supplied SmallVector with the name for 69 /// custom metadata IDs registered in this LLVMContext. 70 void getMDKindNames(SmallVectorImpl<StringRef> &Result) const; 71 72 73 typedef void (*InlineAsmDiagHandlerTy)(const SMDiagnostic&, void *Context, 74 unsigned LocCookie); 75 76 /// Defines the type of a diagnostic handler. 77 /// \see LLVMContext::setDiagnosticHandler. 78 /// \see LLVMContext::diagnose. 79 typedef void (*DiagnosticHandlerTy)(const DiagnosticInfo &DI, void *Context); 80 81 /// Defines the type of a yield callback. 82 /// \see LLVMContext::setYieldCallback. 83 typedef void (*YieldCallbackTy)(LLVMContext *Context, void *OpaqueHandle); 84 85 /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked 86 /// when problems with inline asm are detected by the backend. The first 87 /// argument is a function pointer and the second is a context pointer that 88 /// gets passed into the DiagHandler. 89 /// 90 /// LLVMContext doesn't take ownership or interpret either of these 91 /// pointers. 92 void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler, 93 void *DiagContext = nullptr); 94 95 /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by 96 /// setInlineAsmDiagnosticHandler. 97 InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const; 98 99 /// getInlineAsmDiagnosticContext - Return the diagnostic context set by 100 /// setInlineAsmDiagnosticHandler. 101 void *getInlineAsmDiagnosticContext() const; 102 103 /// setDiagnosticHandler - This method sets a handler that is invoked 104 /// when the backend needs to report anything to the user. The first 105 /// argument is a function pointer and the second is a context pointer that 106 /// gets passed into the DiagHandler. The third argument should be set to 107 /// true if the handler only expects enabled diagnostics. 108 /// 109 /// LLVMContext doesn't take ownership or interpret either of these 110 /// pointers. 111 void setDiagnosticHandler(DiagnosticHandlerTy DiagHandler, 112 void *DiagContext = nullptr, 113 bool RespectFilters = false); 114 115 /// getDiagnosticHandler - Return the diagnostic handler set by 116 /// setDiagnosticHandler. 117 DiagnosticHandlerTy getDiagnosticHandler() const; 118 119 /// getDiagnosticContext - Return the diagnostic context set by 120 /// setDiagnosticContext. 121 void *getDiagnosticContext() const; 122 123 /// \brief Report a message to the currently installed diagnostic handler. 124 /// 125 /// This function returns, in particular in the case of error reporting 126 /// (DI.Severity == \a DS_Error), so the caller should leave the compilation 127 /// process in a self-consistent state, even though the generated code 128 /// need not be correct. 129 /// 130 /// The diagnostic message will be implicitly prefixed with a severity keyword 131 /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error, 132 /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note. 133 void diagnose(const DiagnosticInfo &DI); 134 135 /// \brief Registers a yield callback with the given context. 136 /// 137 /// The yield callback function may be called by LLVM to transfer control back 138 /// to the client that invoked the LLVM compilation. This can be used to yield 139 /// control of the thread, or perform periodic work needed by the client. 140 /// There is no guaranteed frequency at which callbacks must occur; in fact, 141 /// the client is not guaranteed to ever receive this callback. It is at the 142 /// sole discretion of LLVM to do so and only if it can guarantee that 143 /// suspending the thread won't block any forward progress in other LLVM 144 /// contexts in the same process. 145 /// 146 /// At a suspend point, the state of the current LLVM context is intentionally 147 /// undefined. No assumptions about it can or should be made. Only LLVM 148 /// context API calls that explicitly state that they can be used during a 149 /// yield callback are allowed to be used. Any other API calls into the 150 /// context are not supported until the yield callback function returns 151 /// control to LLVM. Other LLVM contexts are unaffected by this restriction. 152 void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle); 153 154 /// \brief Calls the yield callback (if applicable). 155 /// 156 /// This transfers control of the current thread back to the client, which may 157 /// suspend the current thread. Only call this method when LLVM doesn't hold 158 /// any global mutex or cannot block the execution in another LLVM context. 159 void yield(); 160 161 /// emitError - Emit an error message to the currently installed error handler 162 /// with optional location information. This function returns, so code should 163 /// be prepared to drop the erroneous construct on the floor and "not crash". 164 /// The generated code need not be correct. The error message will be 165 /// implicitly prefixed with "error: " and should not end with a ".". 166 void emitError(unsigned LocCookie, const Twine &ErrorStr); 167 void emitError(const Instruction *I, const Twine &ErrorStr); 168 void emitError(const Twine &ErrorStr); 169 170 /// \brief Query for a debug option's value. 171 /// 172 /// This function returns typed data populated from command line parsing. 173 template <typename ValT, typename Base, ValT(Base::*Mem)> 174 ValT getOption() const { 175 return OptionRegistry::instance().template get<ValT, Base, Mem>(); 176 } 177 178 private: 179 LLVMContext(LLVMContext&) = delete; 180 void operator=(LLVMContext&) = delete; 181 182 /// addModule - Register a module as being instantiated in this context. If 183 /// the context is deleted, the module will be deleted as well. 184 void addModule(Module*); 185 186 /// removeModule - Unregister a module from this context. 187 void removeModule(Module*); 188 189 // Module needs access to the add/removeModule methods. 190 friend class Module; 191 }; 192 193 /// getGlobalContext - Returns a global context. This is for LLVM clients that 194 /// only care about operating on a single thread. 195 extern LLVMContext &getGlobalContext(); 196 197 // Create wrappers for C Binding types (see CBindingWrapping.h). 198 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef) 199 200 /* Specialized opaque context conversions. 201 */ 202 inline LLVMContext **unwrap(LLVMContextRef* Tys) { 203 return reinterpret_cast<LLVMContext**>(Tys); 204 } 205 206 inline LLVMContextRef *wrap(const LLVMContext **Tys) { 207 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys)); 208 } 209 210 } 211 212 #endif 213
