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/Types.h"
19 #include "llvm/IR/DiagnosticHandler.h"
20 #include "llvm/Support/CBindingWrapping.h"
21 #include "llvm/Support/Options.h"
22 #include <cstdint>
23 #include <memory>
24 #include <string>
25
26 namespace llvm {
27
28 class DiagnosticInfo;
29 enum DiagnosticSeverity : char;
30 class Function;
31 class Instruction;
32 class LLVMContextImpl;
33 class Module;
34 class OptPassGate;
35 template <typename T> class SmallVectorImpl;
36 class SMDiagnostic;
37 class StringRef;
38 class Twine;
39
40 namespace yaml {
41
42 class Output;
43
44 } // end namespace yaml
45
46 namespace SyncScope {
47
48 typedef uint8_t ID;
49
50 /// Known synchronization scope IDs, which always have the same value. All
51 /// synchronization scope IDs that LLVM has special knowledge of are listed
52 /// here. Additionally, this scheme allows LLVM to efficiently check for
53 /// specific synchronization scope ID without comparing strings.
54 enum {
55 /// Synchronized with respect to signal handlers executing in the same thread.
56 SingleThread = 0,
57
58 /// Synchronized with respect to all concurrently executing threads.
59 System = 1
60 };
61
62 } // end namespace SyncScope
63
64 /// This is an important class for using LLVM in a threaded context. It
65 /// (opaquely) owns and manages the core "global" data of LLVM's core
66 /// infrastructure, including the type and constant uniquing tables.
67 /// LLVMContext itself provides no locking guarantees, so you should be careful
68 /// to have one context per thread.
69 class LLVMContext {
70 public:
71 LLVMContextImpl *const pImpl;
72 LLVMContext();
73 LLVMContext(LLVMContext &) = delete;
74 LLVMContext &operator=(const LLVMContext &) = delete;
75 ~LLVMContext();
76
77 // Pinned metadata names, which always have the same value. This is a
78 // compile-time performance optimization, not a correctness optimization.
79 enum : unsigned {
80 MD_dbg = 0, // "dbg"
81 MD_tbaa = 1, // "tbaa"
82 MD_prof = 2, // "prof"
83 MD_fpmath = 3, // "fpmath"
84 MD_range = 4, // "range"
85 MD_tbaa_struct = 5, // "tbaa.struct"
86 MD_invariant_load = 6, // "invariant.load"
87 MD_alias_scope = 7, // "alias.scope"
88 MD_noalias = 8, // "noalias",
89 MD_nontemporal = 9, // "nontemporal"
90 MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access"
91 MD_nonnull = 11, // "nonnull"
92 MD_dereferenceable = 12, // "dereferenceable"
93 MD_dereferenceable_or_null = 13, // "dereferenceable_or_null"
94 MD_make_implicit = 14, // "make.implicit"
95 MD_unpredictable = 15, // "unpredictable"
96 MD_invariant_group = 16, // "invariant.group"
97 MD_align = 17, // "align"
98 MD_loop = 18, // "llvm.loop"
99 MD_type = 19, // "type"
100 MD_section_prefix = 20, // "section_prefix"
101 MD_absolute_symbol = 21, // "absolute_symbol"
102 MD_associated = 22, // "associated"
103 MD_callees = 23, // "callees"
104 MD_irr_loop = 24, // "irr_loop"
105 };
106
107 /// Known operand bundle tag IDs, which always have the same value. All
108 /// operand bundle tags that LLVM has special knowledge of are listed here.
109 /// Additionally, this scheme allows LLVM to efficiently check for specific
110 /// operand bundle tags without comparing strings.
111 enum : unsigned {
112 OB_deopt = 0, // "deopt"
113 OB_funclet = 1, // "funclet"
114 OB_gc_transition = 2, // "gc-transition"
115 };
116
117 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
118 /// This ID is uniqued across modules in the current LLVMContext.
119 unsigned getMDKindID(StringRef Name) const;
120
121 /// getMDKindNames - Populate client supplied SmallVector with the name for
122 /// custom metadata IDs registered in this LLVMContext.
123 void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
124
125 /// getOperandBundleTags - Populate client supplied SmallVector with the
126 /// bundle tags registered in this LLVMContext. The bundle tags are ordered
127 /// by increasing bundle IDs.
128 /// \see LLVMContext::getOperandBundleTagID
129 void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;
130
131 /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle
132 /// tag registered with an LLVMContext has an unique ID.
133 uint32_t getOperandBundleTagID(StringRef Tag) const;
134
135 /// getOrInsertSyncScopeID - Maps synchronization scope name to
136 /// synchronization scope ID. Every synchronization scope registered with
137 /// LLVMContext has unique ID except pre-defined ones.
138 SyncScope::ID getOrInsertSyncScopeID(StringRef SSN);
139
140 /// getSyncScopeNames - Populates client supplied SmallVector with
141 /// synchronization scope names registered with LLVMContext. Synchronization
142 /// scope names are ordered by increasing synchronization scope IDs.
143 void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const;
144
145 /// Define the GC for a function
146 void setGC(const Function &Fn, std::string GCName);
147
148 /// Return the GC for a function
149 const std::string &getGC(const Function &Fn);
150
151 /// Remove the GC for a function
152 void deleteGC(const Function &Fn);
153
154 /// Return true if the Context runtime configuration is set to discard all
155 /// value names. When true, only GlobalValue names will be available in the
156 /// IR.
157 bool shouldDiscardValueNames() const;
158
159 /// Set the Context runtime configuration to discard all value name (but
160 /// GlobalValue). Clients can use this flag to save memory and runtime,
161 /// especially in release mode.
162 void setDiscardValueNames(bool Discard);
163
164 /// Whether there is a string map for uniquing debug info
165 /// identifiers across the context. Off by default.
166 bool isODRUniquingDebugTypes() const;
167 void enableDebugTypeODRUniquing();
168 void disableDebugTypeODRUniquing();
169
170 using InlineAsmDiagHandlerTy = void (*)(const SMDiagnostic&, void *Context,
171 unsigned LocCookie);
172
173 /// Defines the type of a yield callback.
174 /// \see LLVMContext::setYieldCallback.
175 using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle);
176
177 /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
178 /// when problems with inline asm are detected by the backend. The first
179 /// argument is a function pointer and the second is a context pointer that
180 /// gets passed into the DiagHandler.
181 ///
182 /// LLVMContext doesn't take ownership or interpret either of these
183 /// pointers.
184 void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
185 void *DiagContext = nullptr);
186
187 /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
188 /// setInlineAsmDiagnosticHandler.
189 InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const;
190
191 /// getInlineAsmDiagnosticContext - Return the diagnostic context set by
192 /// setInlineAsmDiagnosticHandler.
193 void *getInlineAsmDiagnosticContext() const;
194
195 /// setDiagnosticHandlerCallBack - This method sets a handler call back
196 /// that is invoked when the backend needs to report anything to the user.
197 /// The first argument is a function pointer and the second is a context pointer
198 /// that gets passed into the DiagHandler. The third argument should be set to
199 /// true if the handler only expects enabled diagnostics.
200 ///
201 /// LLVMContext doesn't take ownership or interpret either of these
202 /// pointers.
203 void setDiagnosticHandlerCallBack(
204 DiagnosticHandler::DiagnosticHandlerTy DiagHandler,
205 void *DiagContext = nullptr, bool RespectFilters = false);
206
207 /// setDiagnosticHandler - This method sets unique_ptr to object of DiagnosticHandler
208 /// to provide custom diagnostic handling. The first argument is unique_ptr of object
209 /// of type DiagnosticHandler or a derived of that. The third argument should be
210 /// set to true if the handler only expects enabled diagnostics.
211 ///
212 /// Ownership of this pointer is moved to LLVMContextImpl.
213 void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,
214 bool RespectFilters = false);
215
216 /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by
217 /// setDiagnosticHandlerCallBack.
218 DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const;
219
220 /// getDiagnosticContext - Return the diagnostic context set by
221 /// setDiagnosticContext.
222 void *getDiagnosticContext() const;
223
224 /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by
225 /// setDiagnosticHandler.
226 const DiagnosticHandler *getDiagHandlerPtr() const;
227
228 /// getDiagnosticHandler - transfers owenership of DiagnosticHandler unique_ptr
229 /// to caller.
230 std::unique_ptr<DiagnosticHandler> getDiagnosticHandler();
231
232 /// Return if a code hotness metric should be included in optimization
233 /// diagnostics.
234 bool getDiagnosticsHotnessRequested() const;
235 /// Set if a code hotness metric should be included in optimization
236 /// diagnostics.
237 void setDiagnosticsHotnessRequested(bool Requested);
238
239 /// Return the minimum hotness value a diagnostic would need in order
240 /// to be included in optimization diagnostics. If there is no minimum, this
241 /// returns None.
242 uint64_t getDiagnosticsHotnessThreshold() const;
243
244 /// Set the minimum hotness value a diagnostic needs in order to be
245 /// included in optimization diagnostics.
246 void setDiagnosticsHotnessThreshold(uint64_t Threshold);
247
248 /// Return the YAML file used by the backend to save optimization
249 /// diagnostics. If null, diagnostics are not saved in a file but only
250 /// emitted via the diagnostic handler.
251 yaml::Output *getDiagnosticsOutputFile();
252 /// Set the diagnostics output file used for optimization diagnostics.
253 ///
254 /// By default or if invoked with null, diagnostics are not saved in a file
255 /// but only emitted via the diagnostic handler. Even if an output file is
256 /// set, the handler is invoked for each diagnostic message.
257 void setDiagnosticsOutputFile(std::unique_ptr<yaml::Output> F);
258
259 /// Get the prefix that should be printed in front of a diagnostic of
260 /// the given \p Severity
261 static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
262
263 /// Report a message to the currently installed diagnostic handler.
264 ///
265 /// This function returns, in particular in the case of error reporting
266 /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
267 /// process in a self-consistent state, even though the generated code
268 /// need not be correct.
269 ///
270 /// The diagnostic message will be implicitly prefixed with a severity keyword
271 /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
272 /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
273 void diagnose(const DiagnosticInfo &DI);
274
275 /// Registers a yield callback with the given context.
276 ///
277 /// The yield callback function may be called by LLVM to transfer control back
278 /// to the client that invoked the LLVM compilation. This can be used to yield
279 /// control of the thread, or perform periodic work needed by the client.
280 /// There is no guaranteed frequency at which callbacks must occur; in fact,
281 /// the client is not guaranteed to ever receive this callback. It is at the
282 /// sole discretion of LLVM to do so and only if it can guarantee that
283 /// suspending the thread won't block any forward progress in other LLVM
284 /// contexts in the same process.
285 ///
286 /// At a suspend point, the state of the current LLVM context is intentionally
287 /// undefined. No assumptions about it can or should be made. Only LLVM
288 /// context API calls that explicitly state that they can be used during a
289 /// yield callback are allowed to be used. Any other API calls into the
290 /// context are not supported until the yield callback function returns
291 /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
292 void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
293
294 /// Calls the yield callback (if applicable).
295 ///
296 /// This transfers control of the current thread back to the client, which may
297 /// suspend the current thread. Only call this method when LLVM doesn't hold
298 /// any global mutex or cannot block the execution in another LLVM context.
299 void yield();
300
301 /// emitError - Emit an error message to the currently installed error handler
302 /// with optional location information. This function returns, so code should
303 /// be prepared to drop the erroneous construct on the floor and "not crash".
304 /// The generated code need not be correct. The error message will be
305 /// implicitly prefixed with "error: " and should not end with a ".".
306 void emitError(unsigned LocCookie, const Twine &ErrorStr);
307 void emitError(const Instruction *I, const Twine &ErrorStr);
308 void emitError(const Twine &ErrorStr);
309
310 /// Query for a debug option's value.
311 ///
312 /// This function returns typed data populated from command line parsing.
313 template <typename ValT, typename Base, ValT(Base::*Mem)>
getOption()314 ValT getOption() const {
315 return OptionRegistry::instance().template get<ValT, Base, Mem>();
316 }
317
318 /// Access the object which can disable optional passes and individual
319 /// optimizations at compile time.
320 OptPassGate &getOptPassGate() const;
321
322 /// Set the object which can disable optional passes and individual
323 /// optimizations at compile time.
324 ///
325 /// The lifetime of the object must be guaranteed to extend as long as the
326 /// LLVMContext is used by compilation.
327 void setOptPassGate(OptPassGate&);
328
329 private:
330 // Module needs access to the add/removeModule methods.
331 friend class Module;
332
333 /// addModule - Register a module as being instantiated in this context. If
334 /// the context is deleted, the module will be deleted as well.
335 void addModule(Module*);
336
337 /// removeModule - Unregister a module from this context.
338 void removeModule(Module*);
339 };
340
341 // Create wrappers for C Binding types (see CBindingWrapping.h).
DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext,LLVMContextRef)342 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef)
343
344 /* Specialized opaque context conversions.
345 */
346 inline LLVMContext **unwrap(LLVMContextRef* Tys) {
347 return reinterpret_cast<LLVMContext**>(Tys);
348 }
349
wrap(const LLVMContext ** Tys)350 inline LLVMContextRef *wrap(const LLVMContext **Tys) {
351 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
352 }
353
354 } // end namespace llvm
355
356 #endif // LLVM_IR_LLVMCONTEXT_H
357