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