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 MD_dereferenceable = 12, // "dereferenceable"
63 MD_dereferenceable_or_null = 13 // "dereferenceable_or_null"
64 };
65
66 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
67 /// This ID is uniqued across modules in the current LLVMContext.
68 unsigned getMDKindID(StringRef Name) const;
69
70 /// getMDKindNames - Populate client supplied SmallVector with the name for
71 /// custom metadata IDs registered in this LLVMContext.
72 void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
73
74
75 typedef void (*InlineAsmDiagHandlerTy)(const SMDiagnostic&, void *Context,
76 unsigned LocCookie);
77
78 /// Defines the type of a diagnostic handler.
79 /// \see LLVMContext::setDiagnosticHandler.
80 /// \see LLVMContext::diagnose.
81 typedef void (*DiagnosticHandlerTy)(const DiagnosticInfo &DI, void *Context);
82
83 /// Defines the type of a yield callback.
84 /// \see LLVMContext::setYieldCallback.
85 typedef void (*YieldCallbackTy)(LLVMContext *Context, void *OpaqueHandle);
86
87 /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
88 /// when problems with inline asm are detected by the backend. The first
89 /// argument is a function pointer and the second is a context pointer that
90 /// gets passed into the DiagHandler.
91 ///
92 /// LLVMContext doesn't take ownership or interpret either of these
93 /// pointers.
94 void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
95 void *DiagContext = nullptr);
96
97 /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
98 /// setInlineAsmDiagnosticHandler.
99 InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const;
100
101 /// getInlineAsmDiagnosticContext - Return the diagnostic context set by
102 /// setInlineAsmDiagnosticHandler.
103 void *getInlineAsmDiagnosticContext() const;
104
105 /// setDiagnosticHandler - This method sets a handler that is invoked
106 /// when the backend needs to report anything to the user. The first
107 /// argument is a function pointer and the second is a context pointer that
108 /// gets passed into the DiagHandler. The third argument should be set to
109 /// true if the handler only expects enabled diagnostics.
110 ///
111 /// LLVMContext doesn't take ownership or interpret either of these
112 /// pointers.
113 void setDiagnosticHandler(DiagnosticHandlerTy DiagHandler,
114 void *DiagContext = nullptr,
115 bool RespectFilters = false);
116
117 /// getDiagnosticHandler - Return the diagnostic handler set by
118 /// setDiagnosticHandler.
119 DiagnosticHandlerTy getDiagnosticHandler() const;
120
121 /// getDiagnosticContext - Return the diagnostic context set by
122 /// setDiagnosticContext.
123 void *getDiagnosticContext() const;
124
125 /// \brief Report a message to the currently installed diagnostic handler.
126 ///
127 /// This function returns, in particular in the case of error reporting
128 /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
129 /// process in a self-consistent state, even though the generated code
130 /// need not be correct.
131 ///
132 /// The diagnostic message will be implicitly prefixed with a severity keyword
133 /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
134 /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
135 void diagnose(const DiagnosticInfo &DI);
136
137 /// \brief Registers a yield callback with the given context.
138 ///
139 /// The yield callback function may be called by LLVM to transfer control back
140 /// to the client that invoked the LLVM compilation. This can be used to yield
141 /// control of the thread, or perform periodic work needed by the client.
142 /// There is no guaranteed frequency at which callbacks must occur; in fact,
143 /// the client is not guaranteed to ever receive this callback. It is at the
144 /// sole discretion of LLVM to do so and only if it can guarantee that
145 /// suspending the thread won't block any forward progress in other LLVM
146 /// contexts in the same process.
147 ///
148 /// At a suspend point, the state of the current LLVM context is intentionally
149 /// undefined. No assumptions about it can or should be made. Only LLVM
150 /// context API calls that explicitly state that they can be used during a
151 /// yield callback are allowed to be used. Any other API calls into the
152 /// context are not supported until the yield callback function returns
153 /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
154 void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
155
156 /// \brief Calls the yield callback (if applicable).
157 ///
158 /// This transfers control of the current thread back to the client, which may
159 /// suspend the current thread. Only call this method when LLVM doesn't hold
160 /// any global mutex or cannot block the execution in another LLVM context.
161 void yield();
162
163 /// emitError - Emit an error message to the currently installed error handler
164 /// with optional location information. This function returns, so code should
165 /// be prepared to drop the erroneous construct on the floor and "not crash".
166 /// The generated code need not be correct. The error message will be
167 /// implicitly prefixed with "error: " and should not end with a ".".
168 void emitError(unsigned LocCookie, const Twine &ErrorStr);
169 void emitError(const Instruction *I, const Twine &ErrorStr);
170 void emitError(const Twine &ErrorStr);
171
172 /// \brief Query for a debug option's value.
173 ///
174 /// This function returns typed data populated from command line parsing.
175 template <typename ValT, typename Base, ValT(Base::*Mem)>
getOption()176 ValT getOption() const {
177 return OptionRegistry::instance().template get<ValT, Base, Mem>();
178 }
179
180 private:
181 LLVMContext(LLVMContext&) = delete;
182 void operator=(LLVMContext&) = delete;
183
184 /// addModule - Register a module as being instantiated in this context. If
185 /// the context is deleted, the module will be deleted as well.
186 void addModule(Module*);
187
188 /// removeModule - Unregister a module from this context.
189 void removeModule(Module*);
190
191 // Module needs access to the add/removeModule methods.
192 friend class Module;
193 };
194
195 /// getGlobalContext - Returns a global context. This is for LLVM clients that
196 /// only care about operating on a single thread.
197 extern LLVMContext &getGlobalContext();
198
199 // Create wrappers for C Binding types (see CBindingWrapping.h).
DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext,LLVMContextRef)200 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef)
201
202 /* Specialized opaque context conversions.
203 */
204 inline LLVMContext **unwrap(LLVMContextRef* Tys) {
205 return reinterpret_cast<LLVMContext**>(Tys);
206 }
207
wrap(const LLVMContext ** Tys)208 inline LLVMContextRef *wrap(const LLVMContext **Tys) {
209 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
210 }
211
212 }
213
214 #endif
215