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 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  MD_dbg = 0, // "dbg"
76  MD_tbaa = 1, // "tbaa"
77  MD_prof = 2, // "prof"
78  MD_fpmath = 3, // "fpmath"
79  MD_range = 4, // "range"
80  MD_tbaa_struct = 5, // "tbaa.struct"
81  MD_invariant_load = 6, // "invariant.load"
82  MD_alias_scope = 7, // "alias.scope"
83  MD_noalias = 8, // "noalias",
84  MD_nontemporal = 9, // "nontemporal"
85  MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access"
86  MD_nonnull = 11, // "nonnull"
87  MD_dereferenceable = 12, // "dereferenceable"
88  MD_dereferenceable_or_null = 13, // "dereferenceable_or_null"
89  MD_make_implicit = 14, // "make.implicit"
90  MD_unpredictable = 15, // "unpredictable"
91  MD_invariant_group = 16, // "invariant.group"
92  MD_align = 17, // "align"
93  MD_loop = 18, // "llvm.loop"
94  MD_type = 19, // "type"
95  MD_section_prefix = 20, // "section_prefix"
96  MD_absolute_symbol = 21, // "absolute_symbol"
97  MD_associated = 22, // "associated"
98  MD_callees = 23, // "callees"
99  MD_irr_loop = 24, // "irr_loop"
100  MD_access_group = 25, // "llvm.access.group"
101  MD_callback = 26, // "callback"
102  MD_preserve_access_index = 27, // "llvm.preserve.*.access.index"
103  };
104 
105  /// Known operand bundle tag IDs, which always have the same value. All
106  /// operand bundle tags that LLVM has special knowledge of are listed here.
107  /// Additionally, this scheme allows LLVM to efficiently check for specific
108  /// operand bundle tags without comparing strings.
109  enum : unsigned {
110  OB_deopt = 0, // "deopt"
111  OB_funclet = 1, // "funclet"
112  OB_gc_transition = 2, // "gc-transition"
113  };
114 
115  /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
116  /// This ID is uniqued across modules in the current LLVMContext.
117  unsigned getMDKindID(StringRef Name) const;
118 
119  /// getMDKindNames - Populate client supplied SmallVector with the name for
120  /// custom metadata IDs registered in this LLVMContext.
121  void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
122 
123  /// getOperandBundleTags - Populate client supplied SmallVector with the
124  /// bundle tags registered in this LLVMContext. The bundle tags are ordered
125  /// by increasing bundle IDs.
126  /// \see LLVMContext::getOperandBundleTagID
127  void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;
128 
129  /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle
130  /// tag registered with an LLVMContext has an unique ID.
131  uint32_t getOperandBundleTagID(StringRef Tag) const;
132 
133  /// getOrInsertSyncScopeID - Maps synchronization scope name to
134  /// synchronization scope ID. Every synchronization scope registered with
135  /// LLVMContext has unique ID except pre-defined ones.
136  SyncScope::ID getOrInsertSyncScopeID(StringRef SSN);
137 
138  /// getSyncScopeNames - Populates client supplied SmallVector with
139  /// synchronization scope names registered with LLVMContext. Synchronization
140  /// scope names are ordered by increasing synchronization scope IDs.
141  void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const;
142 
143  /// Define the GC for a function
144  void setGC(const Function &Fn, std::string GCName);
145 
146  /// Return the GC for a function
147  const std::string &getGC(const Function &Fn);
148 
149  /// Remove the GC for a function
150  void deleteGC(const Function &Fn);
151 
152  /// Return true if the Context runtime configuration is set to discard all
153  /// value names. When true, only GlobalValue names will be available in the
154  /// IR.
155  bool shouldDiscardValueNames() const;
156 
157  /// Set the Context runtime configuration to discard all value name (but
158  /// GlobalValue). Clients can use this flag to save memory and runtime,
159  /// especially in release mode.
160  void setDiscardValueNames(bool Discard);
161 
162  /// Whether there is a string map for uniquing debug info
163  /// identifiers across the context. Off by default.
164  bool isODRUniquingDebugTypes() const;
165  void enableDebugTypeODRUniquing();
166  void disableDebugTypeODRUniquing();
167 
168  using InlineAsmDiagHandlerTy = void (*)(const SMDiagnostic&, void *Context,
169  unsigned LocCookie);
170 
171  /// Defines the type of a yield callback.
172  /// \see LLVMContext::setYieldCallback.
173  using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle);
174 
175  /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
176  /// when problems with inline asm are detected by the backend. The first
177  /// argument is a function pointer and the second is a context pointer that
178  /// gets passed into the DiagHandler.
179  ///
180  /// LLVMContext doesn't take ownership or interpret either of these
181  /// pointers.
182  void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
183  void *DiagContext = nullptr);
184 
185  /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
186  /// setInlineAsmDiagnosticHandler.
187  InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const;
188 
189  /// getInlineAsmDiagnosticContext - Return the diagnostic context set by
190  /// setInlineAsmDiagnosticHandler.
191  void *getInlineAsmDiagnosticContext() const;
192 
193  /// setDiagnosticHandlerCallBack - This method sets a handler call back
194  /// that is invoked when the backend needs to report anything to the user.
195  /// The first argument is a function pointer and the second is a context pointer
196  /// that gets passed into the DiagHandler. The third argument should be set to
197  /// true if the handler only expects enabled diagnostics.
198  ///
199  /// LLVMContext doesn't take ownership or interpret either of these
200  /// pointers.
201  void setDiagnosticHandlerCallBack(
203  void *DiagContext = nullptr, bool RespectFilters = false);
204 
205  /// setDiagnosticHandler - This method sets unique_ptr to object of DiagnosticHandler
206  /// to provide custom diagnostic handling. The first argument is unique_ptr of object
207  /// of type DiagnosticHandler or a derived of that. The third argument should be
208  /// set to true if the handler only expects enabled diagnostics.
209  ///
210  /// Ownership of this pointer is moved to LLVMContextImpl.
211  void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,
212  bool RespectFilters = false);
213 
214  /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by
215  /// setDiagnosticHandlerCallBack.
216  DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const;
217 
218  /// getDiagnosticContext - Return the diagnostic context set by
219  /// setDiagnosticContext.
220  void *getDiagnosticContext() const;
221 
222  /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by
223  /// setDiagnosticHandler.
224  const DiagnosticHandler *getDiagHandlerPtr() const;
225 
226  /// getDiagnosticHandler - transfers owenership of DiagnosticHandler unique_ptr
227  /// to caller.
228  std::unique_ptr<DiagnosticHandler> getDiagnosticHandler();
229 
230  /// Return if a code hotness metric should be included in optimization
231  /// diagnostics.
232  bool getDiagnosticsHotnessRequested() const;
233  /// Set if a code hotness metric should be included in optimization
234  /// diagnostics.
235  void setDiagnosticsHotnessRequested(bool Requested);
236 
237  /// Return the minimum hotness value a diagnostic would need in order
238  /// to be included in optimization diagnostics. If there is no minimum, this
239  /// returns None.
240  uint64_t getDiagnosticsHotnessThreshold() const;
241 
242  /// Set the minimum hotness value a diagnostic needs in order to be
243  /// included in optimization diagnostics.
244  void setDiagnosticsHotnessThreshold(uint64_t Threshold);
245 
246  /// Return the streamer used by the backend to save remark diagnostics. If it
247  /// does not exist, diagnostics are not saved in a file but only emitted via
248  /// the diagnostic handler.
249  RemarkStreamer *getRemarkStreamer();
250  const RemarkStreamer *getRemarkStreamer() const;
251 
252  /// Set the diagnostics output used for optimization diagnostics.
253  /// This filename may be embedded in a section for tools to find the
254  /// diagnostics whenever they're needed.
255  ///
256  /// If a remark streamer is already set, it will be replaced with
257  /// \p RemarkStreamer.
258  ///
259  /// By default, diagnostics are not saved in a file but only emitted via the
260  /// diagnostic handler. Even if an output file is set, the handler is invoked
261  /// for each diagnostic message.
262  void setRemarkStreamer(std::unique_ptr<RemarkStreamer> RemarkStreamer);
263 
264  /// Get the prefix that should be printed in front of a diagnostic of
265  /// the given \p Severity
266  static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
267 
268  /// Report a message to the currently installed diagnostic handler.
269  ///
270  /// This function returns, in particular in the case of error reporting
271  /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
272  /// process in a self-consistent state, even though the generated code
273  /// need not be correct.
274  ///
275  /// The diagnostic message will be implicitly prefixed with a severity keyword
276  /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
277  /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
278  void diagnose(const DiagnosticInfo &DI);
279 
280  /// Registers a yield callback with the given context.
281  ///
282  /// The yield callback function may be called by LLVM to transfer control back
283  /// to the client that invoked the LLVM compilation. This can be used to yield
284  /// control of the thread, or perform periodic work needed by the client.
285  /// There is no guaranteed frequency at which callbacks must occur; in fact,
286  /// the client is not guaranteed to ever receive this callback. It is at the
287  /// sole discretion of LLVM to do so and only if it can guarantee that
288  /// suspending the thread won't block any forward progress in other LLVM
289  /// contexts in the same process.
290  ///
291  /// At a suspend point, the state of the current LLVM context is intentionally
292  /// undefined. No assumptions about it can or should be made. Only LLVM
293  /// context API calls that explicitly state that they can be used during a
294  /// yield callback are allowed to be used. Any other API calls into the
295  /// context are not supported until the yield callback function returns
296  /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
297  void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
298 
299  /// Calls the yield callback (if applicable).
300  ///
301  /// This transfers control of the current thread back to the client, which may
302  /// suspend the current thread. Only call this method when LLVM doesn't hold
303  /// any global mutex or cannot block the execution in another LLVM context.
304  void yield();
305 
306  /// emitError - Emit an error message to the currently installed error handler
307  /// with optional location information. This function returns, so code should
308  /// be prepared to drop the erroneous construct on the floor and "not crash".
309  /// The generated code need not be correct. The error message will be
310  /// implicitly prefixed with "error: " and should not end with a ".".
311  void emitError(unsigned LocCookie, const Twine &ErrorStr);
312  void emitError(const Instruction *I, const Twine &ErrorStr);
313  void emitError(const Twine &ErrorStr);
314 
315  /// Query for a debug option's value.
316  ///
317  /// This function returns typed data populated from command line parsing.
318  template <typename ValT, typename Base, ValT(Base::*Mem)>
319  ValT getOption() const {
320  return OptionRegistry::instance().template get<ValT, Base, Mem>();
321  }
322 
323  /// Access the object which can disable optional passes and individual
324  /// optimizations at compile time.
325  OptPassGate &getOptPassGate() const;
326 
327  /// Set the object which can disable optional passes and individual
328  /// optimizations at compile time.
329  ///
330  /// The lifetime of the object must be guaranteed to extend as long as the
331  /// LLVMContext is used by compilation.
332  void setOptPassGate(OptPassGate&);
333 
334 private:
335  // Module needs access to the add/removeModule methods.
336  friend class Module;
337 
338  /// addModule - Register a module as being instantiated in this context. If
339  /// the context is deleted, the module will be deleted as well.
340  void addModule(Module*);
341 
342  /// removeModule - Unregister a module from this context.
343  void removeModule(Module*);
344 };
345 
346 // Create wrappers for C Binding types (see CBindingWrapping.h).
348 
349 /* Specialized opaque context conversions.
350  */
352  return reinterpret_cast<LLVMContext**>(Tys);
353 }
354 
355 inline LLVMContextRef *wrap(const LLVMContext **Tys) {
356  return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
357 }
358 
359 } // end namespace llvm
360 
361 #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:173
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:203
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
Synchronized with respect to all concurrently executing threads.
Definition: LLVMContext.h:54
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:319
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:169
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:198
#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