LLVM  10.0.0svn
LLVMContext.h
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1 //===- llvm/LLVMContext.h - Class for managing "global" state ---*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file declares LLVMContext, a container of "global" state in LLVM, such
10 // as the global type and constant uniquing tables.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_IR_LLVMCONTEXT_H
15 #define LLVM_IR_LLVMCONTEXT_H
16 
17 #include "llvm-c/Types.h"
20 #include "llvm/Support/Options.h"
21 #include <cstdint>
22 #include <memory>
23 #include <string>
24 
25 namespace llvm {
26 
27 class DiagnosticInfo;
29 class Function;
30 class Instruction;
31 class LLVMContextImpl;
32 class Module;
33 class OptPassGate;
34 template <typename T> class SmallVectorImpl;
35 class SMDiagnostic;
36 class StringRef;
37 class Twine;
38 class RemarkStreamer;
39 class raw_ostream;
40 
41 namespace SyncScope {
42 
43 typedef uint8_t ID;
44 
45 /// Known synchronization scope IDs, which always have the same value. All
46 /// synchronization scope IDs that LLVM has special knowledge of are listed
47 /// here. Additionally, this scheme allows LLVM to efficiently check for
48 /// specific synchronization scope ID without comparing strings.
49 enum {
50  /// Synchronized with respect to signal handlers executing in the same thread.
52 
53  /// Synchronized with respect to all concurrently executing threads.
54  System = 1
55 };
56 
57 } // end namespace SyncScope
58 
59 /// This is an important class for using LLVM in a threaded context. It
60 /// (opaquely) owns and manages the core "global" data of LLVM's core
61 /// infrastructure, including the type and constant uniquing tables.
62 /// LLVMContext itself provides no locking guarantees, so you should be careful
63 /// to have one context per thread.
64 class LLVMContext {
65 public:
67  LLVMContext();
68  LLVMContext(LLVMContext &) = delete;
69  LLVMContext &operator=(const LLVMContext &) = delete;
70  ~LLVMContext();
71 
72  // Pinned metadata names, which always have the same value. This is a
73  // compile-time performance optimization, not a correctness optimization.
74  enum : unsigned {
75 #define LLVM_FIXED_MD_KIND(EnumID, Name, Value) EnumID = Value,
76 #include "llvm/IR/FixedMetadataKinds.def"
77 #undef LLVM_FIXED_MD_KIND
78  };
79 
80  /// Known operand bundle tag IDs, which always have the same value. All
81  /// operand bundle tags that LLVM has special knowledge of are listed here.
82  /// Additionally, this scheme allows LLVM to efficiently check for specific
83  /// operand bundle tags without comparing strings.
84  enum : unsigned {
85  OB_deopt = 0, // "deopt"
86  OB_funclet = 1, // "funclet"
87  OB_gc_transition = 2, // "gc-transition"
88  };
89 
90  /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
91  /// This ID is uniqued across modules in the current LLVMContext.
92  unsigned getMDKindID(StringRef Name) const;
93 
94  /// getMDKindNames - Populate client supplied SmallVector with the name for
95  /// custom metadata IDs registered in this LLVMContext.
96  void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
97 
98  /// getOperandBundleTags - Populate client supplied SmallVector with the
99  /// bundle tags registered in this LLVMContext. The bundle tags are ordered
100  /// by increasing bundle IDs.
101  /// \see LLVMContext::getOperandBundleTagID
102  void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;
103 
104  /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle
105  /// tag registered with an LLVMContext has an unique ID.
106  uint32_t getOperandBundleTagID(StringRef Tag) const;
107 
108  /// getOrInsertSyncScopeID - Maps synchronization scope name to
109  /// synchronization scope ID. Every synchronization scope registered with
110  /// LLVMContext has unique ID except pre-defined ones.
111  SyncScope::ID getOrInsertSyncScopeID(StringRef SSN);
112 
113  /// getSyncScopeNames - Populates client supplied SmallVector with
114  /// synchronization scope names registered with LLVMContext. Synchronization
115  /// scope names are ordered by increasing synchronization scope IDs.
116  void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const;
117 
118  /// Define the GC for a function
119  void setGC(const Function &Fn, std::string GCName);
120 
121  /// Return the GC for a function
122  const std::string &getGC(const Function &Fn);
123 
124  /// Remove the GC for a function
125  void deleteGC(const Function &Fn);
126 
127  /// Return true if the Context runtime configuration is set to discard all
128  /// value names. When true, only GlobalValue names will be available in the
129  /// IR.
130  bool shouldDiscardValueNames() const;
131 
132  /// Set the Context runtime configuration to discard all value name (but
133  /// GlobalValue). Clients can use this flag to save memory and runtime,
134  /// especially in release mode.
135  void setDiscardValueNames(bool Discard);
136 
137  /// Whether there is a string map for uniquing debug info
138  /// identifiers across the context. Off by default.
139  bool isODRUniquingDebugTypes() const;
140  void enableDebugTypeODRUniquing();
141  void disableDebugTypeODRUniquing();
142 
143  using InlineAsmDiagHandlerTy = void (*)(const SMDiagnostic&, void *Context,
144  unsigned LocCookie);
145 
146  /// Defines the type of a yield callback.
147  /// \see LLVMContext::setYieldCallback.
148  using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle);
149 
150  /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
151  /// when problems with inline asm are detected by the backend. The first
152  /// argument is a function pointer and the second is a context pointer that
153  /// gets passed into the DiagHandler.
154  ///
155  /// LLVMContext doesn't take ownership or interpret either of these
156  /// pointers.
157  void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
158  void *DiagContext = nullptr);
159 
160  /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
161  /// setInlineAsmDiagnosticHandler.
162  InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const;
163 
164  /// getInlineAsmDiagnosticContext - Return the diagnostic context set by
165  /// setInlineAsmDiagnosticHandler.
166  void *getInlineAsmDiagnosticContext() const;
167 
168  /// setDiagnosticHandlerCallBack - This method sets a handler call back
169  /// that is invoked when the backend needs to report anything to the user.
170  /// The first argument is a function pointer and the second is a context pointer
171  /// that gets passed into the DiagHandler. The third argument should be set to
172  /// true if the handler only expects enabled diagnostics.
173  ///
174  /// LLVMContext doesn't take ownership or interpret either of these
175  /// pointers.
176  void setDiagnosticHandlerCallBack(
178  void *DiagContext = nullptr, bool RespectFilters = false);
179 
180  /// setDiagnosticHandler - This method sets unique_ptr to object of DiagnosticHandler
181  /// to provide custom diagnostic handling. The first argument is unique_ptr of object
182  /// of type DiagnosticHandler or a derived of that. The third argument should be
183  /// set to true if the handler only expects enabled diagnostics.
184  ///
185  /// Ownership of this pointer is moved to LLVMContextImpl.
186  void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,
187  bool RespectFilters = false);
188 
189  /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by
190  /// setDiagnosticHandlerCallBack.
191  DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const;
192 
193  /// getDiagnosticContext - Return the diagnostic context set by
194  /// setDiagnosticContext.
195  void *getDiagnosticContext() const;
196 
197  /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by
198  /// setDiagnosticHandler.
199  const DiagnosticHandler *getDiagHandlerPtr() const;
200 
201  /// getDiagnosticHandler - transfers owenership of DiagnosticHandler unique_ptr
202  /// to caller.
203  std::unique_ptr<DiagnosticHandler> getDiagnosticHandler();
204 
205  /// Return if a code hotness metric should be included in optimization
206  /// diagnostics.
207  bool getDiagnosticsHotnessRequested() const;
208  /// Set if a code hotness metric should be included in optimization
209  /// diagnostics.
210  void setDiagnosticsHotnessRequested(bool Requested);
211 
212  /// Return the minimum hotness value a diagnostic would need in order
213  /// to be included in optimization diagnostics. If there is no minimum, this
214  /// returns None.
215  uint64_t getDiagnosticsHotnessThreshold() const;
216 
217  /// Set the minimum hotness value a diagnostic needs in order to be
218  /// included in optimization diagnostics.
219  void setDiagnosticsHotnessThreshold(uint64_t Threshold);
220 
221  /// Return the streamer used by the backend to save remark diagnostics. If it
222  /// does not exist, diagnostics are not saved in a file but only emitted via
223  /// the diagnostic handler.
224  RemarkStreamer *getRemarkStreamer();
225  const RemarkStreamer *getRemarkStreamer() const;
226 
227  /// Set the diagnostics output used for optimization diagnostics.
228  /// This filename may be embedded in a section for tools to find the
229  /// diagnostics whenever they're needed.
230  ///
231  /// If a remark streamer is already set, it will be replaced with
232  /// \p RemarkStreamer.
233  ///
234  /// By default, diagnostics are not saved in a file but only emitted via the
235  /// diagnostic handler. Even if an output file is set, the handler is invoked
236  /// for each diagnostic message.
237  void setRemarkStreamer(std::unique_ptr<RemarkStreamer> RemarkStreamer);
238 
239  /// Get the prefix that should be printed in front of a diagnostic of
240  /// the given \p Severity
241  static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
242 
243  /// Report a message to the currently installed diagnostic handler.
244  ///
245  /// This function returns, in particular in the case of error reporting
246  /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
247  /// process in a self-consistent state, even though the generated code
248  /// need not be correct.
249  ///
250  /// The diagnostic message will be implicitly prefixed with a severity keyword
251  /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
252  /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
253  void diagnose(const DiagnosticInfo &DI);
254 
255  /// Registers a yield callback with the given context.
256  ///
257  /// The yield callback function may be called by LLVM to transfer control back
258  /// to the client that invoked the LLVM compilation. This can be used to yield
259  /// control of the thread, or perform periodic work needed by the client.
260  /// There is no guaranteed frequency at which callbacks must occur; in fact,
261  /// the client is not guaranteed to ever receive this callback. It is at the
262  /// sole discretion of LLVM to do so and only if it can guarantee that
263  /// suspending the thread won't block any forward progress in other LLVM
264  /// contexts in the same process.
265  ///
266  /// At a suspend point, the state of the current LLVM context is intentionally
267  /// undefined. No assumptions about it can or should be made. Only LLVM
268  /// context API calls that explicitly state that they can be used during a
269  /// yield callback are allowed to be used. Any other API calls into the
270  /// context are not supported until the yield callback function returns
271  /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
272  void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
273 
274  /// Calls the yield callback (if applicable).
275  ///
276  /// This transfers control of the current thread back to the client, which may
277  /// suspend the current thread. Only call this method when LLVM doesn't hold
278  /// any global mutex or cannot block the execution in another LLVM context.
279  void yield();
280 
281  /// emitError - Emit an error message to the currently installed error handler
282  /// with optional location information. This function returns, so code should
283  /// be prepared to drop the erroneous construct on the floor and "not crash".
284  /// The generated code need not be correct. The error message will be
285  /// implicitly prefixed with "error: " and should not end with a ".".
286  void emitError(unsigned LocCookie, const Twine &ErrorStr);
287  void emitError(const Instruction *I, const Twine &ErrorStr);
288  void emitError(const Twine &ErrorStr);
289 
290  /// Query for a debug option's value.
291  ///
292  /// This function returns typed data populated from command line parsing.
293  template <typename ValT, typename Base, ValT(Base::*Mem)>
294  ValT getOption() const {
295  return OptionRegistry::instance().template get<ValT, Base, Mem>();
296  }
297 
298  /// Access the object which can disable optional passes and individual
299  /// optimizations at compile time.
300  OptPassGate &getOptPassGate() const;
301 
302  /// Set the object which can disable optional passes and individual
303  /// optimizations at compile time.
304  ///
305  /// The lifetime of the object must be guaranteed to extend as long as the
306  /// LLVMContext is used by compilation.
307  void setOptPassGate(OptPassGate&);
308 
309 private:
310  // Module needs access to the add/removeModule methods.
311  friend class Module;
312 
313  /// addModule - Register a module as being instantiated in this context. If
314  /// the context is deleted, the module will be deleted as well.
315  void addModule(Module*);
316 
317  /// removeModule - Unregister a module from this context.
318  void removeModule(Module*);
319 };
320 
321 // Create wrappers for C Binding types (see CBindingWrapping.h).
323 
324 /* Specialized opaque context conversions.
325  */
327  return reinterpret_cast<LLVMContext**>(Tys);
328 }
329 
330 inline LLVMContextRef *wrap(const LLVMContext **Tys) {
331  return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
332 }
333 
334 } // end namespace llvm
335 
336 #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:23
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:25
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
void(*)(LLVMContext *Context, void *OpaqueHandle) YieldCallbackTy
Defines the type of a yield callback.
Definition: LLVMContext.h:148
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:80
Attribute unwrap(LLVMAttributeRef Attr)
Definition: Attributes.h:204
static void DiagHandler(const SMDiagnostic &Diag, void *Context)
Definition: TextStub.cpp:611
static OptionRegistry & instance()
Returns a reference to the singleton instance.
Definition: Options.cpp:32
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:64
amdgpu inline
LLVMContextImpl *const pImpl
Definition: LLVMContext.h:66
ValT getOption() const
Query for a debug option&#39;s value.
Definition: LLVMContext.h:294
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:144
Synchronized with respect to all concurrently executing threads.
Definition: LLVMContext.h:54
static cl::opt< unsigned > Threshold("loop-unswitch-threshold", cl::desc("Max loop size to unswitch"), cl::init(100), cl::Hidden)
Streamer for remarks.
LLVMAttributeRef wrap(Attribute Attr)
Definition: Attributes.h:199
#define I(x, y, z)
Definition: MD5.cpp:58
Synchronized with respect to signal handlers executing in the same thread.
Definition: LLVMContext.h:51
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
Instances of this class encapsulate one diagnostic report, allowing printing to a raw_ostream as a ca...
Definition: SourceMgr.h:261