LLVM  9.0.0svn
LLVMContext.h
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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"
21 #include "llvm/Support/Options.h"
22 #include <cstdint>
23 #include <memory>
24 #include <string>
25 
26 namespace llvm {
27 
28 class DiagnosticInfo;
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.
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:
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  MD_access_group = 25, // "llvm.access.group"
106  MD_callback = 26, // "callback"
107  };
108 
109  /// Known operand bundle tag IDs, which always have the same value. All
110  /// operand bundle tags that LLVM has special knowledge of are listed here.
111  /// Additionally, this scheme allows LLVM to efficiently check for specific
112  /// operand bundle tags without comparing strings.
113  enum : unsigned {
114  OB_deopt = 0, // "deopt"
115  OB_funclet = 1, // "funclet"
116  OB_gc_transition = 2, // "gc-transition"
117  };
118 
119  /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
120  /// This ID is uniqued across modules in the current LLVMContext.
121  unsigned getMDKindID(StringRef Name) const;
122 
123  /// getMDKindNames - Populate client supplied SmallVector with the name for
124  /// custom metadata IDs registered in this LLVMContext.
125  void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
126 
127  /// getOperandBundleTags - Populate client supplied SmallVector with the
128  /// bundle tags registered in this LLVMContext. The bundle tags are ordered
129  /// by increasing bundle IDs.
130  /// \see LLVMContext::getOperandBundleTagID
131  void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;
132 
133  /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle
134  /// tag registered with an LLVMContext has an unique ID.
135  uint32_t getOperandBundleTagID(StringRef Tag) const;
136 
137  /// getOrInsertSyncScopeID - Maps synchronization scope name to
138  /// synchronization scope ID. Every synchronization scope registered with
139  /// LLVMContext has unique ID except pre-defined ones.
140  SyncScope::ID getOrInsertSyncScopeID(StringRef SSN);
141 
142  /// getSyncScopeNames - Populates client supplied SmallVector with
143  /// synchronization scope names registered with LLVMContext. Synchronization
144  /// scope names are ordered by increasing synchronization scope IDs.
145  void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const;
146 
147  /// Define the GC for a function
148  void setGC(const Function &Fn, std::string GCName);
149 
150  /// Return the GC for a function
151  const std::string &getGC(const Function &Fn);
152 
153  /// Remove the GC for a function
154  void deleteGC(const Function &Fn);
155 
156  /// Return true if the Context runtime configuration is set to discard all
157  /// value names. When true, only GlobalValue names will be available in the
158  /// IR.
159  bool shouldDiscardValueNames() const;
160 
161  /// Set the Context runtime configuration to discard all value name (but
162  /// GlobalValue). Clients can use this flag to save memory and runtime,
163  /// especially in release mode.
164  void setDiscardValueNames(bool Discard);
165 
166  /// Whether there is a string map for uniquing debug info
167  /// identifiers across the context. Off by default.
168  bool isODRUniquingDebugTypes() const;
169  void enableDebugTypeODRUniquing();
170  void disableDebugTypeODRUniquing();
171 
172  using InlineAsmDiagHandlerTy = void (*)(const SMDiagnostic&, void *Context,
173  unsigned LocCookie);
174 
175  /// Defines the type of a yield callback.
176  /// \see LLVMContext::setYieldCallback.
177  using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle);
178 
179  /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
180  /// when problems with inline asm are detected by the backend. The first
181  /// argument is a function pointer and the second is a context pointer that
182  /// gets passed into the DiagHandler.
183  ///
184  /// LLVMContext doesn't take ownership or interpret either of these
185  /// pointers.
186  void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
187  void *DiagContext = nullptr);
188 
189  /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
190  /// setInlineAsmDiagnosticHandler.
191  InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const;
192 
193  /// getInlineAsmDiagnosticContext - Return the diagnostic context set by
194  /// setInlineAsmDiagnosticHandler.
195  void *getInlineAsmDiagnosticContext() const;
196 
197  /// setDiagnosticHandlerCallBack - This method sets a handler call back
198  /// that is invoked when the backend needs to report anything to the user.
199  /// The first argument is a function pointer and the second is a context pointer
200  /// that gets passed into the DiagHandler. The third argument should be set to
201  /// true if the handler only expects enabled diagnostics.
202  ///
203  /// LLVMContext doesn't take ownership or interpret either of these
204  /// pointers.
205  void setDiagnosticHandlerCallBack(
207  void *DiagContext = nullptr, bool RespectFilters = false);
208 
209  /// setDiagnosticHandler - This method sets unique_ptr to object of DiagnosticHandler
210  /// to provide custom diagnostic handling. The first argument is unique_ptr of object
211  /// of type DiagnosticHandler or a derived of that. The third argument should be
212  /// set to true if the handler only expects enabled diagnostics.
213  ///
214  /// Ownership of this pointer is moved to LLVMContextImpl.
215  void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,
216  bool RespectFilters = false);
217 
218  /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by
219  /// setDiagnosticHandlerCallBack.
220  DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const;
221 
222  /// getDiagnosticContext - Return the diagnostic context set by
223  /// setDiagnosticContext.
224  void *getDiagnosticContext() const;
225 
226  /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by
227  /// setDiagnosticHandler.
228  const DiagnosticHandler *getDiagHandlerPtr() const;
229 
230  /// getDiagnosticHandler - transfers owenership of DiagnosticHandler unique_ptr
231  /// to caller.
232  std::unique_ptr<DiagnosticHandler> getDiagnosticHandler();
233 
234  /// Return if a code hotness metric should be included in optimization
235  /// diagnostics.
236  bool getDiagnosticsHotnessRequested() const;
237  /// Set if a code hotness metric should be included in optimization
238  /// diagnostics.
239  void setDiagnosticsHotnessRequested(bool Requested);
240 
241  /// Return the minimum hotness value a diagnostic would need in order
242  /// to be included in optimization diagnostics. If there is no minimum, this
243  /// returns None.
244  uint64_t getDiagnosticsHotnessThreshold() const;
245 
246  /// Set the minimum hotness value a diagnostic needs in order to be
247  /// included in optimization diagnostics.
248  void setDiagnosticsHotnessThreshold(uint64_t Threshold);
249 
250  /// Return the YAML file used by the backend to save optimization
251  /// diagnostics. If null, diagnostics are not saved in a file but only
252  /// emitted via the diagnostic handler.
253  yaml::Output *getDiagnosticsOutputFile();
254  /// Set the diagnostics output file used for optimization diagnostics.
255  ///
256  /// By default or if invoked with null, diagnostics are not saved in a file
257  /// but only emitted via the diagnostic handler. Even if an output file is
258  /// set, the handler is invoked for each diagnostic message.
259  void setDiagnosticsOutputFile(std::unique_ptr<yaml::Output> F);
260 
261  /// Get the prefix that should be printed in front of a diagnostic of
262  /// the given \p Severity
263  static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
264 
265  /// Report a message to the currently installed diagnostic handler.
266  ///
267  /// This function returns, in particular in the case of error reporting
268  /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
269  /// process in a self-consistent state, even though the generated code
270  /// need not be correct.
271  ///
272  /// The diagnostic message will be implicitly prefixed with a severity keyword
273  /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
274  /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
275  void diagnose(const DiagnosticInfo &DI);
276 
277  /// Registers a yield callback with the given context.
278  ///
279  /// The yield callback function may be called by LLVM to transfer control back
280  /// to the client that invoked the LLVM compilation. This can be used to yield
281  /// control of the thread, or perform periodic work needed by the client.
282  /// There is no guaranteed frequency at which callbacks must occur; in fact,
283  /// the client is not guaranteed to ever receive this callback. It is at the
284  /// sole discretion of LLVM to do so and only if it can guarantee that
285  /// suspending the thread won't block any forward progress in other LLVM
286  /// contexts in the same process.
287  ///
288  /// At a suspend point, the state of the current LLVM context is intentionally
289  /// undefined. No assumptions about it can or should be made. Only LLVM
290  /// context API calls that explicitly state that they can be used during a
291  /// yield callback are allowed to be used. Any other API calls into the
292  /// context are not supported until the yield callback function returns
293  /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
294  void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
295 
296  /// Calls the yield callback (if applicable).
297  ///
298  /// This transfers control of the current thread back to the client, which may
299  /// suspend the current thread. Only call this method when LLVM doesn't hold
300  /// any global mutex or cannot block the execution in another LLVM context.
301  void yield();
302 
303  /// emitError - Emit an error message to the currently installed error handler
304  /// with optional location information. This function returns, so code should
305  /// be prepared to drop the erroneous construct on the floor and "not crash".
306  /// The generated code need not be correct. The error message will be
307  /// implicitly prefixed with "error: " and should not end with a ".".
308  void emitError(unsigned LocCookie, const Twine &ErrorStr);
309  void emitError(const Instruction *I, const Twine &ErrorStr);
310  void emitError(const Twine &ErrorStr);
311 
312  /// Query for a debug option's value.
313  ///
314  /// This function returns typed data populated from command line parsing.
315  template <typename ValT, typename Base, ValT(Base::*Mem)>
316  ValT getOption() const {
317  return OptionRegistry::instance().template get<ValT, Base, Mem>();
318  }
319 
320  /// Access the object which can disable optional passes and individual
321  /// optimizations at compile time.
322  OptPassGate &getOptPassGate() const;
323 
324  /// Set the object which can disable optional passes and individual
325  /// optimizations at compile time.
326  ///
327  /// The lifetime of the object must be guaranteed to extend as long as the
328  /// LLVMContext is used by compilation.
329  void setOptPassGate(OptPassGate&);
330 
331 private:
332  // Module needs access to the add/removeModule methods.
333  friend class Module;
334 
335  /// addModule - Register a module as being instantiated in this context. If
336  /// the context is deleted, the module will be deleted as well.
337  void addModule(Module*);
338 
339  /// removeModule - Unregister a module from this context.
340  void removeModule(Module*);
341 };
342 
343 // Create wrappers for C Binding types (see CBindingWrapping.h).
345 
346 /* Specialized opaque context conversions.
347  */
349  return reinterpret_cast<LLVMContext**>(Tys);
350 }
351 
352 inline LLVMContextRef *wrap(const LLVMContext **Tys) {
353  return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
354 }
355 
356 } // end namespace llvm
357 
358 #endif // LLVM_IR_LLVMCONTEXT_H
This is the base class for diagnostic handling in LLVM.
LLVMContext & Context
This class represents lattice values for constants.
Definition: AllocatorList.h:24
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:65
Extensions to this class implement mechanisms to disable passes and individual optimizations at compi...
Definition: OptBisect.h:32
void(*)(LLVMContext *Context, void *OpaqueHandle) YieldCallbackTy
Defines the type of a yield callback.
Definition: LLVMContext.h:177
F(f)
amdgpu Simplify well known AMD library false Value Value const Twine & Name
DiagnosticSeverity
Defines the different supported severity of a diagnostic.
#define DEFINE_SIMPLE_CONVERSION_FUNCTIONS(ty, ref)
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
Attribute unwrap(LLVMAttributeRef Attr)
Definition: Attributes.h:195
static OptionRegistry & instance()
Returns a reference to the singleton instance.
Definition: Options.cpp:33
struct LLVMOpaqueContext * LLVMContextRef
The top-level container for all LLVM global data.
Definition: Types.h:54
void(*)(const DiagnosticInfo &DI, void *Context) DiagnosticHandlerTy
This is the base abstract class for diagnostic reporting in the backend.
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:69
amdgpu inline
LLVMContextImpl *const pImpl
Definition: LLVMContext.h:71
ValT getOption() const
Query for a debug option&#39;s value.
Definition: LLVMContext.h:316
This file declares helper objects for defining debug options that can be configured via the command l...
void(*)(const SMDiagnostic &, void *Context, unsigned LocCookie) InlineAsmDiagHandlerTy
Definition: LLVMContext.h:173
static cl::opt< unsigned > Threshold("loop-unswitch-threshold", cl::desc("Max loop size to unswitch"), cl::init(100), cl::Hidden)
LLVMAttributeRef wrap(Attribute Attr)
Definition: Attributes.h:190
#define I(x, y, z)
Definition: MD5.cpp:58
Synchronized with respect to signal handlers executing in the same thread.
Definition: LLVMContext.h:56
Synchronized with respect to all concurrently executing threads.
Definition: LLVMContext.h:59
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
Instances of this class encapsulate one diagnostic report, allowing printing to a raw_ostream as a ca...
Definition: SourceMgr.h:260