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/Support/CBindingWrapping.h" 19 #include "llvm/Support/Compiler.h" 20 #include "llvm/Support/Options.h" 21 22 namespace llvm { 23 24 class LLVMContextImpl; 25 class StringRef; 26 class Twine; 27 class Instruction; 28 class Module; 29 class SMDiagnostic; 30 class DiagnosticInfo; 31 template <typename T> class SmallVectorImpl; 32 class Function; 33 class DebugLoc; 34 35 /// This is an important class for using LLVM in a threaded context. It 36 /// (opaquely) owns and manages the core "global" data of LLVM's core 37 /// infrastructure, including the type and constant uniquing tables. 38 /// LLVMContext itself provides no locking guarantees, so you should be careful 39 /// to have one context per thread. 40 class LLVMContext { 41 public: 42 LLVMContextImpl *const pImpl; 43 LLVMContext(); 44 ~LLVMContext(); 45 46 // Pinned metadata names, which always have the same value. This is a 47 // compile-time performance optimization, not a correctness optimization. 48 enum { 49 MD_dbg = 0, // "dbg" 50 MD_tbaa = 1, // "tbaa" 51 MD_prof = 2, // "prof" 52 MD_fpmath = 3, // "fpmath" 53 MD_range = 4, // "range" 54 MD_tbaa_struct = 5, // "tbaa.struct" 55 MD_invariant_load = 6, // "invariant.load" 56 MD_alias_scope = 7, // "alias.scope" 57 MD_noalias = 8, // "noalias", 58 MD_nontemporal = 9, // "nontemporal" 59 MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access" 60 MD_nonnull = 11, // "nonnull" 61 MD_dereferenceable = 12, // "dereferenceable" 62 MD_dereferenceable_or_null = 13, // "dereferenceable_or_null" 63 MD_make_implicit = 14, // "make.implicit" 64 MD_unpredictable = 15, // "unpredictable" 65 MD_invariant_group = 16, // "invariant.group" 66 MD_align = 17 // "align" 67 }; 68 69 /// Known operand bundle tag IDs, which always have the same value. All 70 /// operand bundle tags that LLVM has special knowledge of are listed here. 71 /// Additionally, this scheme allows LLVM to efficiently check for specific 72 /// operand bundle tags without comparing strings. 73 enum { 74 OB_deopt = 0, // "deopt" 75 OB_funclet = 1, // "funclet" 76 }; 77 78 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind. 79 /// This ID is uniqued across modules in the current LLVMContext. 80 unsigned getMDKindID(StringRef Name) const; 81 82 /// getMDKindNames - Populate client supplied SmallVector with the name for 83 /// custom metadata IDs registered in this LLVMContext. 84 void getMDKindNames(SmallVectorImpl<StringRef> &Result) const; 85 86 /// getOperandBundleTags - Populate client supplied SmallVector with the 87 /// bundle tags registered in this LLVMContext. The bundle tags are ordered 88 /// by increasing bundle IDs. 89 /// \see LLVMContext::getOperandBundleTagID 90 void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const; 91 92 /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle 93 /// tag registered with an LLVMContext has an unique ID. 94 uint32_t getOperandBundleTagID(StringRef Tag) const; 95 96 typedef void (*InlineAsmDiagHandlerTy)(const SMDiagnostic&, void *Context, 97 unsigned LocCookie); 98 99 /// Defines the type of a diagnostic handler. 100 /// \see LLVMContext::setDiagnosticHandler. 101 /// \see LLVMContext::diagnose. 102 typedef void (*DiagnosticHandlerTy)(const DiagnosticInfo &DI, void *Context); 103 104 /// Defines the type of a yield callback. 105 /// \see LLVMContext::setYieldCallback. 106 typedef void (*YieldCallbackTy)(LLVMContext *Context, void *OpaqueHandle); 107 108 /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked 109 /// when problems with inline asm are detected by the backend. The first 110 /// argument is a function pointer and the second is a context pointer that 111 /// gets passed into the DiagHandler. 112 /// 113 /// LLVMContext doesn't take ownership or interpret either of these 114 /// pointers. 115 void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler, 116 void *DiagContext = nullptr); 117 118 /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by 119 /// setInlineAsmDiagnosticHandler. 120 InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const; 121 122 /// getInlineAsmDiagnosticContext - Return the diagnostic context set by 123 /// setInlineAsmDiagnosticHandler. 124 void *getInlineAsmDiagnosticContext() const; 125 126 /// setDiagnosticHandler - This method sets a handler that is invoked 127 /// when the backend needs to report anything to the user. The first 128 /// argument is a function pointer and the second is a context pointer that 129 /// gets passed into the DiagHandler. The third argument should be set to 130 /// true if the handler only expects enabled diagnostics. 131 /// 132 /// LLVMContext doesn't take ownership or interpret either of these 133 /// pointers. 134 void setDiagnosticHandler(DiagnosticHandlerTy DiagHandler, 135 void *DiagContext = nullptr, 136 bool RespectFilters = false); 137 138 /// getDiagnosticHandler - Return the diagnostic handler set by 139 /// setDiagnosticHandler. 140 DiagnosticHandlerTy getDiagnosticHandler() const; 141 142 /// getDiagnosticContext - Return the diagnostic context set by 143 /// setDiagnosticContext. 144 void *getDiagnosticContext() const; 145 146 /// \brief Report a message to the currently installed diagnostic handler. 147 /// 148 /// This function returns, in particular in the case of error reporting 149 /// (DI.Severity == \a DS_Error), so the caller should leave the compilation 150 /// process in a self-consistent state, even though the generated code 151 /// need not be correct. 152 /// 153 /// The diagnostic message will be implicitly prefixed with a severity keyword 154 /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error, 155 /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note. 156 void diagnose(const DiagnosticInfo &DI); 157 158 /// \brief Registers a yield callback with the given context. 159 /// 160 /// The yield callback function may be called by LLVM to transfer control back 161 /// to the client that invoked the LLVM compilation. This can be used to yield 162 /// control of the thread, or perform periodic work needed by the client. 163 /// There is no guaranteed frequency at which callbacks must occur; in fact, 164 /// the client is not guaranteed to ever receive this callback. It is at the 165 /// sole discretion of LLVM to do so and only if it can guarantee that 166 /// suspending the thread won't block any forward progress in other LLVM 167 /// contexts in the same process. 168 /// 169 /// At a suspend point, the state of the current LLVM context is intentionally 170 /// undefined. No assumptions about it can or should be made. Only LLVM 171 /// context API calls that explicitly state that they can be used during a 172 /// yield callback are allowed to be used. Any other API calls into the 173 /// context are not supported until the yield callback function returns 174 /// control to LLVM. Other LLVM contexts are unaffected by this restriction. 175 void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle); 176 177 /// \brief Calls the yield callback (if applicable). 178 /// 179 /// This transfers control of the current thread back to the client, which may 180 /// suspend the current thread. Only call this method when LLVM doesn't hold 181 /// any global mutex or cannot block the execution in another LLVM context. 182 void yield(); 183 184 /// emitError - Emit an error message to the currently installed error handler 185 /// with optional location information. This function returns, so code should 186 /// be prepared to drop the erroneous construct on the floor and "not crash". 187 /// The generated code need not be correct. The error message will be 188 /// implicitly prefixed with "error: " and should not end with a ".". 189 void emitError(unsigned LocCookie, const Twine &ErrorStr); 190 void emitError(const Instruction *I, const Twine &ErrorStr); 191 void emitError(const Twine &ErrorStr); 192 193 /// \brief Query for a debug option's value. 194 /// 195 /// This function returns typed data populated from command line parsing. 196 template <typename ValT, typename Base, ValT(Base::*Mem)> 197 ValT getOption() const { 198 return OptionRegistry::instance().template get<ValT, Base, Mem>(); 199 } 200 201 private: 202 LLVMContext(LLVMContext&) = delete; 203 void operator=(LLVMContext&) = delete; 204 205 /// addModule - Register a module as being instantiated in this context. If 206 /// the context is deleted, the module will be deleted as well. 207 void addModule(Module*); 208 209 /// removeModule - Unregister a module from this context. 210 void removeModule(Module*); 211 212 // Module needs access to the add/removeModule methods. 213 friend class Module; 214 }; 215 216 /// getGlobalContext - Returns a global context. This is for LLVM clients that 217 /// only care about operating on a single thread. 218 extern LLVMContext &getGlobalContext(); 219 220 // Create wrappers for C Binding types (see CBindingWrapping.h). 221 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef) 222 223 /* Specialized opaque context conversions. 224 */ 225 inline LLVMContext **unwrap(LLVMContextRef* Tys) { 226 return reinterpret_cast<LLVMContext**>(Tys); 227 } 228 229 inline LLVMContextRef *wrap(const LLVMContext **Tys) { 230 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys)); 231 } 232 233 } 234 235 #endif 236
