LLVM  9.0.0svn
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 
39 namespace yaml {
40 
41 class Output;
42 
43 } // end namespace yaml
44 
45 namespace SyncScope {
46 
47 typedef uint8_t ID;
48 
49 /// Known synchronization scope IDs, which always have the same value. All
50 /// synchronization scope IDs that LLVM has special knowledge of are listed
51 /// here. Additionally, this scheme allows LLVM to efficiently check for
52 /// specific synchronization scope ID without comparing strings.
53 enum {
54  /// Synchronized with respect to signal handlers executing in the same thread.
56 
57  /// Synchronized with respect to all concurrently executing threads.
58  System = 1
59 };
60 
61 } // end namespace SyncScope
62 
63 /// This is an important class for using LLVM in a threaded context. It
64 /// (opaquely) owns and manages the core "global" data of LLVM's core
65 /// infrastructure, including the type and constant uniquing tables.
66 /// LLVMContext itself provides no locking guarantees, so you should be careful
67 /// to have one context per thread.
68 class LLVMContext {
69 public:
71  LLVMContext();
72  LLVMContext(LLVMContext &) = delete;
73  LLVMContext &operator=(const LLVMContext &) = delete;
74  ~LLVMContext();
75 
76  // Pinned metadata names, which always have the same value. This is a
77  // compile-time performance optimization, not a correctness optimization.
78  enum : unsigned {
79  MD_dbg = 0, // "dbg"
80  MD_tbaa = 1, // "tbaa"
81  MD_prof = 2, // "prof"
82  MD_fpmath = 3, // "fpmath"
83  MD_range = 4, // "range"
84  MD_tbaa_struct = 5, // "tbaa.struct"
85  MD_invariant_load = 6, // "invariant.load"
86  MD_alias_scope = 7, // "alias.scope"
87  MD_noalias = 8, // "noalias",
88  MD_nontemporal = 9, // "nontemporal"
89  MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access"
90  MD_nonnull = 11, // "nonnull"
91  MD_dereferenceable = 12, // "dereferenceable"
92  MD_dereferenceable_or_null = 13, // "dereferenceable_or_null"
93  MD_make_implicit = 14, // "make.implicit"
94  MD_unpredictable = 15, // "unpredictable"
95  MD_invariant_group = 16, // "invariant.group"
96  MD_align = 17, // "align"
97  MD_loop = 18, // "llvm.loop"
98  MD_type = 19, // "type"
99  MD_section_prefix = 20, // "section_prefix"
100  MD_absolute_symbol = 21, // "absolute_symbol"
101  MD_associated = 22, // "associated"
102  MD_callees = 23, // "callees"
103  MD_irr_loop = 24, // "irr_loop"
104  MD_access_group = 25, // "llvm.access.group"
105  MD_callback = 26, // "callback"
106  };
107 
108  /// Known operand bundle tag IDs, which always have the same value. All
109  /// operand bundle tags that LLVM has special knowledge of are listed here.
110  /// Additionally, this scheme allows LLVM to efficiently check for specific
111  /// operand bundle tags without comparing strings.
112  enum : unsigned {
113  OB_deopt = 0, // "deopt"
114  OB_funclet = 1, // "funclet"
115  OB_gc_transition = 2, // "gc-transition"
116  };
117 
118  /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
119  /// This ID is uniqued across modules in the current LLVMContext.
120  unsigned getMDKindID(StringRef Name) const;
121 
122  /// getMDKindNames - Populate client supplied SmallVector with the name for
123  /// custom metadata IDs registered in this LLVMContext.
124  void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
125 
126  /// getOperandBundleTags - Populate client supplied SmallVector with the
127  /// bundle tags registered in this LLVMContext. The bundle tags are ordered
128  /// by increasing bundle IDs.
129  /// \see LLVMContext::getOperandBundleTagID
130  void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;
131 
132  /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle
133  /// tag registered with an LLVMContext has an unique ID.
134  uint32_t getOperandBundleTagID(StringRef Tag) const;
135 
136  /// getOrInsertSyncScopeID - Maps synchronization scope name to
137  /// synchronization scope ID. Every synchronization scope registered with
138  /// LLVMContext has unique ID except pre-defined ones.
139  SyncScope::ID getOrInsertSyncScopeID(StringRef SSN);
140 
141  /// getSyncScopeNames - Populates client supplied SmallVector with
142  /// synchronization scope names registered with LLVMContext. Synchronization
143  /// scope names are ordered by increasing synchronization scope IDs.
144  void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const;
145 
146  /// Define the GC for a function
147  void setGC(const Function &Fn, std::string GCName);
148 
149  /// Return the GC for a function
150  const std::string &getGC(const Function &Fn);
151 
152  /// Remove the GC for a function
153  void deleteGC(const Function &Fn);
154 
155  /// Return true if the Context runtime configuration is set to discard all
156  /// value names. When true, only GlobalValue names will be available in the
157  /// IR.
158  bool shouldDiscardValueNames() const;
159 
160  /// Set the Context runtime configuration to discard all value name (but
161  /// GlobalValue). Clients can use this flag to save memory and runtime,
162  /// especially in release mode.
163  void setDiscardValueNames(bool Discard);
164 
165  /// Whether there is a string map for uniquing debug info
166  /// identifiers across the context. Off by default.
167  bool isODRUniquingDebugTypes() const;
168  void enableDebugTypeODRUniquing();
169  void disableDebugTypeODRUniquing();
170 
171  using InlineAsmDiagHandlerTy = void (*)(const SMDiagnostic&, void *Context,
172  unsigned LocCookie);
173 
174  /// Defines the type of a yield callback.
175  /// \see LLVMContext::setYieldCallback.
176  using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle);
177 
178  /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
179  /// when problems with inline asm are detected by the backend. The first
180  /// argument is a function pointer and the second is a context pointer that
181  /// gets passed into the DiagHandler.
182  ///
183  /// LLVMContext doesn't take ownership or interpret either of these
184  /// pointers.
185  void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
186  void *DiagContext = nullptr);
187 
188  /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
189  /// setInlineAsmDiagnosticHandler.
190  InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const;
191 
192  /// getInlineAsmDiagnosticContext - Return the diagnostic context set by
193  /// setInlineAsmDiagnosticHandler.
194  void *getInlineAsmDiagnosticContext() const;
195 
196  /// setDiagnosticHandlerCallBack - This method sets a handler call back
197  /// that is invoked when the backend needs to report anything to the user.
198  /// The first argument is a function pointer and the second is a context pointer
199  /// that gets passed into the DiagHandler. The third argument should be set to
200  /// true if the handler only expects enabled diagnostics.
201  ///
202  /// LLVMContext doesn't take ownership or interpret either of these
203  /// pointers.
204  void setDiagnosticHandlerCallBack(
206  void *DiagContext = nullptr, bool RespectFilters = false);
207 
208  /// setDiagnosticHandler - This method sets unique_ptr to object of DiagnosticHandler
209  /// to provide custom diagnostic handling. The first argument is unique_ptr of object
210  /// of type DiagnosticHandler or a derived of that. The third argument should be
211  /// set to true if the handler only expects enabled diagnostics.
212  ///
213  /// Ownership of this pointer is moved to LLVMContextImpl.
214  void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,
215  bool RespectFilters = false);
216 
217  /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by
218  /// setDiagnosticHandlerCallBack.
219  DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const;
220 
221  /// getDiagnosticContext - Return the diagnostic context set by
222  /// setDiagnosticContext.
223  void *getDiagnosticContext() const;
224 
225  /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by
226  /// setDiagnosticHandler.
227  const DiagnosticHandler *getDiagHandlerPtr() const;
228 
229  /// getDiagnosticHandler - transfers owenership of DiagnosticHandler unique_ptr
230  /// to caller.
231  std::unique_ptr<DiagnosticHandler> getDiagnosticHandler();
232 
233  /// Return if a code hotness metric should be included in optimization
234  /// diagnostics.
235  bool getDiagnosticsHotnessRequested() const;
236  /// Set if a code hotness metric should be included in optimization
237  /// diagnostics.
238  void setDiagnosticsHotnessRequested(bool Requested);
239 
240  /// Return the minimum hotness value a diagnostic would need in order
241  /// to be included in optimization diagnostics. If there is no minimum, this
242  /// returns None.
243  uint64_t getDiagnosticsHotnessThreshold() const;
244 
245  /// Set the minimum hotness value a diagnostic needs in order to be
246  /// included in optimization diagnostics.
247  void setDiagnosticsHotnessThreshold(uint64_t Threshold);
248 
249  /// Return the YAML file used by the backend to save optimization
250  /// diagnostics. If null, diagnostics are not saved in a file but only
251  /// emitted via the diagnostic handler.
252  yaml::Output *getDiagnosticsOutputFile();
253  /// Set the diagnostics output file used for optimization diagnostics.
254  ///
255  /// By default or if invoked with null, diagnostics are not saved in a file
256  /// but only emitted via the diagnostic handler. Even if an output file is
257  /// set, the handler is invoked for each diagnostic message.
258  void setDiagnosticsOutputFile(std::unique_ptr<yaml::Output> F);
259 
260  /// Get the prefix that should be printed in front of a diagnostic of
261  /// the given \p Severity
262  static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
263 
264  /// Report a message to the currently installed diagnostic handler.
265  ///
266  /// This function returns, in particular in the case of error reporting
267  /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
268  /// process in a self-consistent state, even though the generated code
269  /// need not be correct.
270  ///
271  /// The diagnostic message will be implicitly prefixed with a severity keyword
272  /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
273  /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
274  void diagnose(const DiagnosticInfo &DI);
275 
276  /// Registers a yield callback with the given context.
277  ///
278  /// The yield callback function may be called by LLVM to transfer control back
279  /// to the client that invoked the LLVM compilation. This can be used to yield
280  /// control of the thread, or perform periodic work needed by the client.
281  /// There is no guaranteed frequency at which callbacks must occur; in fact,
282  /// the client is not guaranteed to ever receive this callback. It is at the
283  /// sole discretion of LLVM to do so and only if it can guarantee that
284  /// suspending the thread won't block any forward progress in other LLVM
285  /// contexts in the same process.
286  ///
287  /// At a suspend point, the state of the current LLVM context is intentionally
288  /// undefined. No assumptions about it can or should be made. Only LLVM
289  /// context API calls that explicitly state that they can be used during a
290  /// yield callback are allowed to be used. Any other API calls into the
291  /// context are not supported until the yield callback function returns
292  /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
293  void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
294 
295  /// Calls the yield callback (if applicable).
296  ///
297  /// This transfers control of the current thread back to the client, which may
298  /// suspend the current thread. Only call this method when LLVM doesn't hold
299  /// any global mutex or cannot block the execution in another LLVM context.
300  void yield();
301 
302  /// emitError - Emit an error message to the currently installed error handler
303  /// with optional location information. This function returns, so code should
304  /// be prepared to drop the erroneous construct on the floor and "not crash".
305  /// The generated code need not be correct. The error message will be
306  /// implicitly prefixed with "error: " and should not end with a ".".
307  void emitError(unsigned LocCookie, const Twine &ErrorStr);
308  void emitError(const Instruction *I, const Twine &ErrorStr);
309  void emitError(const Twine &ErrorStr);
310 
311  /// Query for a debug option's value.
312  ///
313  /// This function returns typed data populated from command line parsing.
314  template <typename ValT, typename Base, ValT(Base::*Mem)>
315  ValT getOption() const {
316  return OptionRegistry::instance().template get<ValT, Base, Mem>();
317  }
318 
319  /// Access the object which can disable optional passes and individual
320  /// optimizations at compile time.
321  OptPassGate &getOptPassGate() const;
322 
323  /// Set the object which can disable optional passes and individual
324  /// optimizations at compile time.
325  ///
326  /// The lifetime of the object must be guaranteed to extend as long as the
327  /// LLVMContext is used by compilation.
328  void setOptPassGate(OptPassGate&);
329 
330 private:
331  // Module needs access to the add/removeModule methods.
332  friend class Module;
333 
334  /// addModule - Register a module as being instantiated in this context. If
335  /// the context is deleted, the module will be deleted as well.
336  void addModule(Module*);
337 
338  /// removeModule - Unregister a module from this context.
339  void removeModule(Module*);
340 };
341 
342 // Create wrappers for C Binding types (see CBindingWrapping.h).
344 
345 /* Specialized opaque context conversions.
346  */
348  return reinterpret_cast<LLVMContext**>(Tys);
349 }
350 
351 inline LLVMContextRef *wrap(const LLVMContext **Tys) {
352  return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
353 }
354 
355 } // end namespace llvm
356 
357 #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:64
Extensions to this class implement mechanisms to disable passes and individual optimizations at compi...
Definition: OptBisect.h:31
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:176
F(f)
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:194
Synchronized with respect to signal handlers executing in the same thread.
Definition: LLVMContext.h:55
Synchronized with respect to all concurrently executing threads.
Definition: LLVMContext.h:58
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:68
amdgpu inline
LLVMContextImpl *const pImpl
Definition: LLVMContext.h:70
ValT getOption() const
Query for a debug option&#39;s value.
Definition: LLVMContext.h:315
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:172
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:189
#define I(x, y, z)
Definition: MD5.cpp:58
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:259