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
26namespace llvm {
27
28class DiagnosticInfo;
29enum DiagnosticSeverity : char;
30class Function;
31class Instruction;
32class LLVMContextImpl;
33class Module;
34class OptBisect;
35template <typename T> class SmallVectorImpl;
36class SMDiagnostic;
37class StringRef;
38class Twine;
39
40namespace yaml {
41
42class Output;
43
44} // end namespace yaml
45
46namespace SyncScope {
47
48typedef 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.
54enum {
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.
69class LLVMContext {
70public:
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 {
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  };
105
106  /// Known operand bundle tag IDs, which always have the same value.  All
107  /// operand bundle tags that LLVM has special knowledge of are listed here.
108  /// Additionally, this scheme allows LLVM to efficiently check for specific
109  /// operand bundle tags without comparing strings.
110  enum {
111    OB_deopt = 0,         // "deopt"
112    OB_funclet = 1,       // "funclet"
113    OB_gc_transition = 2, // "gc-transition"
114  };
115
116  /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
117  /// This ID is uniqued across modules in the current LLVMContext.
118  unsigned getMDKindID(StringRef Name) const;
119
120  /// getMDKindNames - Populate client supplied SmallVector with the name for
121  /// custom metadata IDs registered in this LLVMContext.
122  void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
123
124  /// getOperandBundleTags - Populate client supplied SmallVector with the
125  /// bundle tags registered in this LLVMContext.  The bundle tags are ordered
126  /// by increasing bundle IDs.
127  /// \see LLVMContext::getOperandBundleTagID
128  void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;
129
130  /// getOperandBundleTagID - Maps a bundle tag to an integer ID.  Every bundle
131  /// tag registered with an LLVMContext has an unique ID.
132  uint32_t getOperandBundleTagID(StringRef Tag) const;
133
134  /// getOrInsertSyncScopeID - Maps synchronization scope name to
135  /// synchronization scope ID.  Every synchronization scope registered with
136  /// LLVMContext has unique ID except pre-defined ones.
137  SyncScope::ID getOrInsertSyncScopeID(StringRef SSN);
138
139  /// getSyncScopeNames - Populates client supplied SmallVector with
140  /// synchronization scope names registered with LLVMContext.  Synchronization
141  /// scope names are ordered by increasing synchronization scope IDs.
142  void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const;
143
144  /// Define the GC for a function
145  void setGC(const Function &Fn, std::string GCName);
146
147  /// Return the GC for a function
148  const std::string &getGC(const Function &Fn);
149
150  /// Remove the GC for a function
151  void deleteGC(const Function &Fn);
152
153  /// Return true if the Context runtime configuration is set to discard all
154  /// value names. When true, only GlobalValue names will be available in the
155  /// IR.
156  bool shouldDiscardValueNames() const;
157
158  /// Set the Context runtime configuration to discard all value name (but
159  /// GlobalValue). Clients can use this flag to save memory and runtime,
160  /// especially in release mode.
161  void setDiscardValueNames(bool Discard);
162
163  /// Whether there is a string map for uniquing debug info
164  /// identifiers across the context.  Off by default.
165  bool isODRUniquingDebugTypes() const;
166  void enableDebugTypeODRUniquing();
167  void disableDebugTypeODRUniquing();
168
169  using InlineAsmDiagHandlerTy = void (*)(const SMDiagnostic&, void *Context,
170                                          unsigned LocCookie);
171
172  /// Defines the type of a yield callback.
173  /// \see LLVMContext::setYieldCallback.
174  using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle);
175
176  /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
177  /// when problems with inline asm are detected by the backend.  The first
178  /// argument is a function pointer and the second is a context pointer that
179  /// gets passed into the DiagHandler.
180  ///
181  /// LLVMContext doesn't take ownership or interpret either of these
182  /// pointers.
183  void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
184                                     void *DiagContext = nullptr);
185
186  /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
187  /// setInlineAsmDiagnosticHandler.
188  InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const;
189
190  /// getInlineAsmDiagnosticContext - Return the diagnostic context set by
191  /// setInlineAsmDiagnosticHandler.
192  void *getInlineAsmDiagnosticContext() const;
193
194  /// setDiagnosticHandlerCallBack - This method sets a handler call back
195  /// that is invoked when the backend needs to report anything to the user.
196  /// The first argument is a function pointer and the second is a context pointer
197  /// that gets passed into the DiagHandler.  The third argument should be set to
198  /// true if the handler only expects enabled diagnostics.
199  ///
200  /// LLVMContext doesn't take ownership or interpret either of these
201  /// pointers.
202  void setDiagnosticHandlerCallBack(
203      DiagnosticHandler::DiagnosticHandlerTy DiagHandler,
204      void *DiagContext = nullptr, bool RespectFilters = false);
205
206  /// setDiagnosticHandler - This method sets unique_ptr to object of DiagnosticHandler
207  /// to provide custom diagnostic handling. The first argument is unique_ptr of object
208  /// of type DiagnosticHandler or a derived of that.   The third argument should be
209  /// set to true if the handler only expects enabled diagnostics.
210  ///
211  /// Ownership of this pointer is moved to LLVMContextImpl.
212  void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,
213                            bool RespectFilters = false);
214
215  /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by
216  /// setDiagnosticHandlerCallBack.
217  DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const;
218
219  /// getDiagnosticContext - Return the diagnostic context set by
220  /// setDiagnosticContext.
221  void *getDiagnosticContext() const;
222
223  /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by
224  /// setDiagnosticHandler.
225  const DiagnosticHandler *getDiagHandlerPtr() const;
226
227  /// getDiagnosticHandler - transfers owenership of DiagnosticHandler unique_ptr
228  /// to caller.
229  std::unique_ptr<DiagnosticHandler> getDiagnosticHandler();
230
231  /// \brief Return if a code hotness metric should be included in optimization
232  /// diagnostics.
233  bool getDiagnosticsHotnessRequested() const;
234  /// \brief Set if a code hotness metric should be included in optimization
235  /// diagnostics.
236  void setDiagnosticsHotnessRequested(bool Requested);
237
238  /// \brief Return the minimum hotness value a diagnostic would need in order
239  /// to be included in optimization diagnostics. If there is no minimum, this
240  /// returns None.
241  uint64_t getDiagnosticsHotnessThreshold() const;
242
243  /// \brief Set the minimum hotness value a diagnostic needs in order to be
244  /// included in optimization diagnostics.
245  void setDiagnosticsHotnessThreshold(uint64_t Threshold);
246
247  /// \brief Return the YAML file used by the backend to save optimization
248  /// diagnostics.  If null, diagnostics are not saved in a file but only
249  /// emitted via the diagnostic handler.
250  yaml::Output *getDiagnosticsOutputFile();
251  /// Set the diagnostics output file used for optimization diagnostics.
252  ///
253  /// By default or if invoked with null, diagnostics are not saved in a file
254  /// but only emitted via the diagnostic handler.  Even if an output file is
255  /// set, the handler is invoked for each diagnostic message.
256  void setDiagnosticsOutputFile(std::unique_ptr<yaml::Output> F);
257
258  /// \brief Get the prefix that should be printed in front of a diagnostic of
259  ///        the given \p Severity
260  static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
261
262  /// \brief Report a message to the currently installed diagnostic handler.
263  ///
264  /// This function returns, in particular in the case of error reporting
265  /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
266  /// process in a self-consistent state, even though the generated code
267  /// need not be correct.
268  ///
269  /// The diagnostic message will be implicitly prefixed with a severity keyword
270  /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
271  /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
272  void diagnose(const DiagnosticInfo &DI);
273
274  /// \brief Registers a yield callback with the given context.
275  ///
276  /// The yield callback function may be called by LLVM to transfer control back
277  /// to the client that invoked the LLVM compilation. This can be used to yield
278  /// control of the thread, or perform periodic work needed by the client.
279  /// There is no guaranteed frequency at which callbacks must occur; in fact,
280  /// the client is not guaranteed to ever receive this callback. It is at the
281  /// sole discretion of LLVM to do so and only if it can guarantee that
282  /// suspending the thread won't block any forward progress in other LLVM
283  /// contexts in the same process.
284  ///
285  /// At a suspend point, the state of the current LLVM context is intentionally
286  /// undefined. No assumptions about it can or should be made. Only LLVM
287  /// context API calls that explicitly state that they can be used during a
288  /// yield callback are allowed to be used. Any other API calls into the
289  /// context are not supported until the yield callback function returns
290  /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
291  void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
292
293  /// \brief Calls the yield callback (if applicable).
294  ///
295  /// This transfers control of the current thread back to the client, which may
296  /// suspend the current thread. Only call this method when LLVM doesn't hold
297  /// any global mutex or cannot block the execution in another LLVM context.
298  void yield();
299
300  /// emitError - Emit an error message to the currently installed error handler
301  /// with optional location information.  This function returns, so code should
302  /// be prepared to drop the erroneous construct on the floor and "not crash".
303  /// The generated code need not be correct.  The error message will be
304  /// implicitly prefixed with "error: " and should not end with a ".".
305  void emitError(unsigned LocCookie, const Twine &ErrorStr);
306  void emitError(const Instruction *I, const Twine &ErrorStr);
307  void emitError(const Twine &ErrorStr);
308
309  /// \brief Query for a debug option's value.
310  ///
311  /// This function returns typed data populated from command line parsing.
312  template <typename ValT, typename Base, ValT(Base::*Mem)>
313  ValT getOption() const {
314    return OptionRegistry::instance().template get<ValT, Base, Mem>();
315  }
316
317  /// \brief Access the object which manages optimization bisection for failure
318  /// analysis.
319  OptBisect &getOptBisect();
320private:
321  // Module needs access to the add/removeModule methods.
322  friend class Module;
323
324  /// addModule - Register a module as being instantiated in this context.  If
325  /// the context is deleted, the module will be deleted as well.
326  void addModule(Module*);
327
328  /// removeModule - Unregister a module from this context.
329  void removeModule(Module*);
330};
331
332// Create wrappers for C Binding types (see CBindingWrapping.h).
333DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef)
334
335/* Specialized opaque context conversions.
336 */
337inline LLVMContext **unwrap(LLVMContextRef* Tys) {
338  return reinterpret_cast<LLVMContext**>(Tys);
339}
340
341inline LLVMContextRef *wrap(const LLVMContext **Tys) {
342  return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
343}
344
345} // end namespace llvm
346
347#endif // LLVM_IR_LLVMCONTEXT_H
348