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 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 }; 57 58 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind. 59 /// This ID is uniqued across modules in the current LLVMContext. 60 unsigned getMDKindID(StringRef Name) const; 61 62 /// getMDKindNames - Populate client supplied SmallVector with the name for 63 /// custom metadata IDs registered in this LLVMContext. 64 void getMDKindNames(SmallVectorImpl<StringRef> &Result) const; 65 66 67 typedef void (*InlineAsmDiagHandlerTy)(const SMDiagnostic&, void *Context, 68 unsigned LocCookie); 69 70 /// Defines the type of a diagnostic handler. 71 /// \see LLVMContext::setDiagnosticHandler. 72 /// \see LLVMContext::diagnose. 73 typedef void (*DiagnosticHandlerTy)(const DiagnosticInfo &DI, void *Context); 74 75 /// Defines the type of a yield callback. 76 /// \see LLVMContext::setYieldCallback. 77 typedef void (*YieldCallbackTy)(LLVMContext *Context, void *OpaqueHandle); 78 79 /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked 80 /// when problems with inline asm are detected by the backend. The first 81 /// argument is a function pointer and the second is a context pointer that 82 /// gets passed into the DiagHandler. 83 /// 84 /// LLVMContext doesn't take ownership or interpret either of these 85 /// pointers. 86 void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler, 87 void *DiagContext = nullptr); 88 89 /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by 90 /// setInlineAsmDiagnosticHandler. 91 InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const; 92 93 /// getInlineAsmDiagnosticContext - Return the diagnostic context set by 94 /// setInlineAsmDiagnosticHandler. 95 void *getInlineAsmDiagnosticContext() const; 96 97 /// setDiagnosticHandler - This method sets a handler that is invoked 98 /// when the backend needs to report anything to the user. The first 99 /// argument is a function pointer and the second is a context pointer that 100 /// gets passed into the DiagHandler. 101 /// 102 /// LLVMContext doesn't take ownership or interpret either of these 103 /// pointers. 104 void setDiagnosticHandler(DiagnosticHandlerTy DiagHandler, 105 void *DiagContext = nullptr); 106 107 /// getDiagnosticHandler - Return the diagnostic handler set by 108 /// setDiagnosticHandler. 109 DiagnosticHandlerTy getDiagnosticHandler() const; 110 111 /// getDiagnosticContext - Return the diagnostic context set by 112 /// setDiagnosticContext. 113 void *getDiagnosticContext() const; 114 115 /// diagnose - Report a message to the currently installed diagnostic handler. 116 /// This function returns, in particular in the case of error reporting 117 /// (DI.Severity == RS_Error), so the caller should leave the compilation 118 /// process in a self-consistent state, even though the generated code 119 /// need not be correct. 120 /// The diagnostic message will be implicitly prefixed with a severity 121 /// keyword according to \p DI.getSeverity(), i.e., "error: " 122 /// for RS_Error, "warning: " for RS_Warning, and "note: " for RS_Note. 123 void diagnose(const DiagnosticInfo &DI); 124 125 /// \brief Registers a yield callback with the given context. 126 /// 127 /// The yield callback function may be called by LLVM to transfer control back 128 /// to the client that invoked the LLVM compilation. This can be used to yield 129 /// control of the thread, or perform periodic work needed by the client. 130 /// There is no guaranteed frequency at which callbacks must occur; in fact, 131 /// the client is not guaranteed to ever receive this callback. It is at the 132 /// sole discretion of LLVM to do so and only if it can guarantee that 133 /// suspending the thread won't block any forward progress in other LLVM 134 /// contexts in the same process. 135 /// 136 /// At a suspend point, the state of the current LLVM context is intentionally 137 /// undefined. No assumptions about it can or should be made. Only LLVM 138 /// context API calls that explicitly state that they can be used during a 139 /// yield callback are allowed to be used. Any other API calls into the 140 /// context are not supported until the yield callback function returns 141 /// control to LLVM. Other LLVM contexts are unaffected by this restriction. 142 void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle); 143 144 /// \brief Calls the yield callback (if applicable). 145 /// 146 /// This transfers control of the current thread back to the client, which may 147 /// suspend the current thread. Only call this method when LLVM doesn't hold 148 /// any global mutex or cannot block the execution in another LLVM context. 149 void yield(); 150 151 /// emitError - Emit an error message to the currently installed error handler 152 /// with optional location information. This function returns, so code should 153 /// be prepared to drop the erroneous construct on the floor and "not crash". 154 /// The generated code need not be correct. The error message will be 155 /// implicitly prefixed with "error: " and should not end with a ".". 156 void emitError(unsigned LocCookie, const Twine &ErrorStr); 157 void emitError(const Instruction *I, const Twine &ErrorStr); 158 void emitError(const Twine &ErrorStr); 159 160 private: 161 LLVMContext(LLVMContext&) LLVM_DELETED_FUNCTION; 162 void operator=(LLVMContext&) LLVM_DELETED_FUNCTION; 163 164 /// addModule - Register a module as being instantiated in this context. If 165 /// the context is deleted, the module will be deleted as well. 166 void addModule(Module*); 167 168 /// removeModule - Unregister a module from this context. 169 void removeModule(Module*); 170 171 // Module needs access to the add/removeModule methods. 172 friend class Module; 173 }; 174 175 /// getGlobalContext - Returns a global context. This is for LLVM clients that 176 /// only care about operating on a single thread. 177 extern LLVMContext &getGlobalContext(); 178 179 // Create wrappers for C Binding types (see CBindingWrapping.h). 180 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef) 181 182 /* Specialized opaque context conversions. 183 */ 184 inline LLVMContext **unwrap(LLVMContextRef* Tys) { 185 return reinterpret_cast<LLVMContext**>(Tys); 186 } 187 188 inline LLVMContextRef *wrap(const LLVMContext **Tys) { 189 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys)); 190 } 191 192 } 193 194 #endif 195