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)>
getOption()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).
DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext,LLVMContextRef)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
wrap(const LLVMContext ** Tys)206 inline LLVMContextRef *wrap(const LLVMContext **Tys) {
207 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
208 }
209
210 }
211
212 #endif
213