1 //===- llvm/LLVMContext.h - Class for managing "global" state ---*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file declares LLVMContext, a container of "global" state in LLVM, such 10 // as the global type and constant uniquing tables. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_IR_LLVMCONTEXT_H 15 #define LLVM_IR_LLVMCONTEXT_H 16 17 #include "llvm-c/Types.h" 18 #include "llvm/IR/DiagnosticHandler.h" 19 #include "llvm/Support/CBindingWrapping.h" 20 #include <cstdint> 21 #include <memory> 22 #include <string> 23 24 namespace llvm { 25 26 class DiagnosticInfo; 27 enum DiagnosticSeverity : char; 28 class Function; 29 class Instruction; 30 class LLVMContextImpl; 31 class Module; 32 class OptPassGate; 33 template <typename T> class SmallVectorImpl; 34 class SMDiagnostic; 35 class StringRef; 36 class Twine; 37 class RemarkStreamer; 38 class raw_ostream; 39 40 namespace SyncScope { 41 42 typedef uint8_t ID; 43 44 /// Known synchronization scope IDs, which always have the same value. All 45 /// synchronization scope IDs that LLVM has special knowledge of are listed 46 /// here. Additionally, this scheme allows LLVM to efficiently check for 47 /// specific synchronization scope ID without comparing strings. 48 enum { 49 /// Synchronized with respect to signal handlers executing in the same thread. 50 SingleThread = 0, 51 52 /// Synchronized with respect to all concurrently executing threads. 53 System = 1 54 }; 55 56 } // end namespace SyncScope 57 58 /// This is an important class for using LLVM in a threaded context. It 59 /// (opaquely) owns and manages the core "global" data of LLVM's core 60 /// infrastructure, including the type and constant uniquing tables. 61 /// LLVMContext itself provides no locking guarantees, so you should be careful 62 /// to have one context per thread. 63 class LLVMContext { 64 public: 65 LLVMContextImpl *const pImpl; 66 LLVMContext(); 67 LLVMContext(LLVMContext &) = delete; 68 LLVMContext &operator=(const LLVMContext &) = delete; 69 ~LLVMContext(); 70 71 // Pinned metadata names, which always have the same value. This is a 72 // compile-time performance optimization, not a correctness optimization. 73 enum : unsigned { 74 #define LLVM_FIXED_MD_KIND(EnumID, Name, Value) EnumID = Value, 75 #include "llvm/IR/FixedMetadataKinds.def" 76 #undef LLVM_FIXED_MD_KIND 77 }; 78 79 /// Known operand bundle tag IDs, which always have the same value. All 80 /// operand bundle tags that LLVM has special knowledge of are listed here. 81 /// Additionally, this scheme allows LLVM to efficiently check for specific 82 /// operand bundle tags without comparing strings. 83 enum : unsigned { 84 OB_deopt = 0, // "deopt" 85 OB_funclet = 1, // "funclet" 86 OB_gc_transition = 2, // "gc-transition" 87 OB_cfguardtarget = 3, // "cfguardtarget" 88 }; 89 90 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind. 91 /// This ID is uniqued across modules in the current LLVMContext. 92 unsigned getMDKindID(StringRef Name) const; 93 94 /// getMDKindNames - Populate client supplied SmallVector with the name for 95 /// custom metadata IDs registered in this LLVMContext. 96 void getMDKindNames(SmallVectorImpl<StringRef> &Result) const; 97 98 /// getOperandBundleTags - Populate client supplied SmallVector with the 99 /// bundle tags registered in this LLVMContext. The bundle tags are ordered 100 /// by increasing bundle IDs. 101 /// \see LLVMContext::getOperandBundleTagID 102 void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const; 103 104 /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle 105 /// tag registered with an LLVMContext has an unique ID. 106 uint32_t getOperandBundleTagID(StringRef Tag) const; 107 108 /// getOrInsertSyncScopeID - Maps synchronization scope name to 109 /// synchronization scope ID. Every synchronization scope registered with 110 /// LLVMContext has unique ID except pre-defined ones. 111 SyncScope::ID getOrInsertSyncScopeID(StringRef SSN); 112 113 /// getSyncScopeNames - Populates client supplied SmallVector with 114 /// synchronization scope names registered with LLVMContext. Synchronization 115 /// scope names are ordered by increasing synchronization scope IDs. 116 void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const; 117 118 /// Define the GC for a function 119 void setGC(const Function &Fn, std::string GCName); 120 121 /// Return the GC for a function 122 const std::string &getGC(const Function &Fn); 123 124 /// Remove the GC for a function 125 void deleteGC(const Function &Fn); 126 127 /// Return true if the Context runtime configuration is set to discard all 128 /// value names. When true, only GlobalValue names will be available in the 129 /// IR. 130 bool shouldDiscardValueNames() const; 131 132 /// Set the Context runtime configuration to discard all value name (but 133 /// GlobalValue). Clients can use this flag to save memory and runtime, 134 /// especially in release mode. 135 void setDiscardValueNames(bool Discard); 136 137 /// Whether there is a string map for uniquing debug info 138 /// identifiers across the context. Off by default. 139 bool isODRUniquingDebugTypes() const; 140 void enableDebugTypeODRUniquing(); 141 void disableDebugTypeODRUniquing(); 142 143 using InlineAsmDiagHandlerTy = void (*)(const SMDiagnostic&, void *Context, 144 unsigned LocCookie); 145 146 /// Defines the type of a yield callback. 147 /// \see LLVMContext::setYieldCallback. 148 using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle); 149 150 /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked 151 /// when problems with inline asm are detected by the backend. The first 152 /// argument is a function pointer and the second is a context pointer that 153 /// gets passed into the DiagHandler. 154 /// 155 /// LLVMContext doesn't take ownership or interpret either of these 156 /// pointers. 157 void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler, 158 void *DiagContext = nullptr); 159 160 /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by 161 /// setInlineAsmDiagnosticHandler. 162 InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const; 163 164 /// getInlineAsmDiagnosticContext - Return the diagnostic context set by 165 /// setInlineAsmDiagnosticHandler. 166 void *getInlineAsmDiagnosticContext() const; 167 168 /// setDiagnosticHandlerCallBack - This method sets a handler call back 169 /// that is invoked when the backend needs to report anything to the user. 170 /// The first argument is a function pointer and the second is a context pointer 171 /// that gets passed into the DiagHandler. The third argument should be set to 172 /// true if the handler only expects enabled diagnostics. 173 /// 174 /// LLVMContext doesn't take ownership or interpret either of these 175 /// pointers. 176 void setDiagnosticHandlerCallBack( 177 DiagnosticHandler::DiagnosticHandlerTy DiagHandler, 178 void *DiagContext = nullptr, bool RespectFilters = false); 179 180 /// setDiagnosticHandler - This method sets unique_ptr to object of DiagnosticHandler 181 /// to provide custom diagnostic handling. The first argument is unique_ptr of object 182 /// of type DiagnosticHandler or a derived of that. The third argument should be 183 /// set to true if the handler only expects enabled diagnostics. 184 /// 185 /// Ownership of this pointer is moved to LLVMContextImpl. 186 void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH, 187 bool RespectFilters = false); 188 189 /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by 190 /// setDiagnosticHandlerCallBack. 191 DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const; 192 193 /// getDiagnosticContext - Return the diagnostic context set by 194 /// setDiagnosticContext. 195 void *getDiagnosticContext() const; 196 197 /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by 198 /// setDiagnosticHandler. 199 const DiagnosticHandler *getDiagHandlerPtr() const; 200 201 /// getDiagnosticHandler - transfers owenership of DiagnosticHandler unique_ptr 202 /// to caller. 203 std::unique_ptr<DiagnosticHandler> getDiagnosticHandler(); 204 205 /// Return if a code hotness metric should be included in optimization 206 /// diagnostics. 207 bool getDiagnosticsHotnessRequested() const; 208 /// Set if a code hotness metric should be included in optimization 209 /// diagnostics. 210 void setDiagnosticsHotnessRequested(bool Requested); 211 212 /// Return the minimum hotness value a diagnostic would need in order 213 /// to be included in optimization diagnostics. If there is no minimum, this 214 /// returns None. 215 uint64_t getDiagnosticsHotnessThreshold() const; 216 217 /// Set the minimum hotness value a diagnostic needs in order to be 218 /// included in optimization diagnostics. 219 void setDiagnosticsHotnessThreshold(uint64_t Threshold); 220 221 /// Return the streamer used by the backend to save remark diagnostics. If it 222 /// does not exist, diagnostics are not saved in a file but only emitted via 223 /// the diagnostic handler. 224 RemarkStreamer *getRemarkStreamer(); 225 const RemarkStreamer *getRemarkStreamer() const; 226 227 /// Set the diagnostics output used for optimization diagnostics. 228 /// This filename may be embedded in a section for tools to find the 229 /// diagnostics whenever they're needed. 230 /// 231 /// If a remark streamer is already set, it will be replaced with 232 /// \p RemarkStreamer. 233 /// 234 /// By default, diagnostics are not saved in a file but only emitted via the 235 /// diagnostic handler. Even if an output file is set, the handler is invoked 236 /// for each diagnostic message. 237 void setRemarkStreamer(std::unique_ptr<RemarkStreamer> RemarkStreamer); 238 239 /// Get the prefix that should be printed in front of a diagnostic of 240 /// the given \p Severity 241 static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity); 242 243 /// Report a message to the currently installed diagnostic handler. 244 /// 245 /// This function returns, in particular in the case of error reporting 246 /// (DI.Severity == \a DS_Error), so the caller should leave the compilation 247 /// process in a self-consistent state, even though the generated code 248 /// need not be correct. 249 /// 250 /// The diagnostic message will be implicitly prefixed with a severity keyword 251 /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error, 252 /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note. 253 void diagnose(const DiagnosticInfo &DI); 254 255 /// Registers a yield callback with the given context. 256 /// 257 /// The yield callback function may be called by LLVM to transfer control back 258 /// to the client that invoked the LLVM compilation. This can be used to yield 259 /// control of the thread, or perform periodic work needed by the client. 260 /// There is no guaranteed frequency at which callbacks must occur; in fact, 261 /// the client is not guaranteed to ever receive this callback. It is at the 262 /// sole discretion of LLVM to do so and only if it can guarantee that 263 /// suspending the thread won't block any forward progress in other LLVM 264 /// contexts in the same process. 265 /// 266 /// At a suspend point, the state of the current LLVM context is intentionally 267 /// undefined. No assumptions about it can or should be made. Only LLVM 268 /// context API calls that explicitly state that they can be used during a 269 /// yield callback are allowed to be used. Any other API calls into the 270 /// context are not supported until the yield callback function returns 271 /// control to LLVM. Other LLVM contexts are unaffected by this restriction. 272 void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle); 273 274 /// Calls the yield callback (if applicable). 275 /// 276 /// This transfers control of the current thread back to the client, which may 277 /// suspend the current thread. Only call this method when LLVM doesn't hold 278 /// any global mutex or cannot block the execution in another LLVM context. 279 void yield(); 280 281 /// emitError - Emit an error message to the currently installed error handler 282 /// with optional location information. This function returns, so code should 283 /// be prepared to drop the erroneous construct on the floor and "not crash". 284 /// The generated code need not be correct. The error message will be 285 /// implicitly prefixed with "error: " and should not end with a ".". 286 void emitError(unsigned LocCookie, const Twine &ErrorStr); 287 void emitError(const Instruction *I, const Twine &ErrorStr); 288 void emitError(const Twine &ErrorStr); 289 290 /// Access the object which can disable optional passes and individual 291 /// optimizations at compile time. 292 OptPassGate &getOptPassGate() const; 293 294 /// Set the object which can disable optional passes and individual 295 /// optimizations at compile time. 296 /// 297 /// The lifetime of the object must be guaranteed to extend as long as the 298 /// LLVMContext is used by compilation. 299 void setOptPassGate(OptPassGate&); 300 301 private: 302 // Module needs access to the add/removeModule methods. 303 friend class Module; 304 305 /// addModule - Register a module as being instantiated in this context. If 306 /// the context is deleted, the module will be deleted as well. 307 void addModule(Module*); 308 309 /// removeModule - Unregister a module from this context. 310 void removeModule(Module*); 311 }; 312 313 // Create wrappers for C Binding types (see CBindingWrapping.h). 314 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef) 315 316 /* Specialized opaque context conversions. 317 */ 318 inline LLVMContext **unwrap(LLVMContextRef* Tys) { 319 return reinterpret_cast<LLVMContext**>(Tys); 320 } 321 322 inline LLVMContextRef *wrap(const LLVMContext **Tys) { 323 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys)); 324 } 325 326 } // end namespace llvm 327 328 #endif // LLVM_IR_LLVMCONTEXT_H 329