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"
18#include "llvm/IR/DiagnosticHandler.h"
19#include "llvm/Support/CBindingWrapping.h"
20#include <cstdint>
21#include <memory>
22#include <optional>
23#include <string>
24
25namespace llvm {
26
27class DiagnosticInfo;
28enum DiagnosticSeverity : char;
29class Function;
30class Instruction;
31class LLVMContextImpl;
32class Module;
33class OptPassGate;
34template <typename T> class SmallVectorImpl;
35template <typename T> class StringMapEntry;
36class StringRef;
37class Twine;
38class LLVMRemarkStreamer;
39
40namespace remarks {
41class RemarkStreamer;
42}
43
44namespace SyncScope {
45
46typedef uint8_t ID;
47
48/// Known synchronization scope IDs, which always have the same value. All
49/// synchronization scope IDs that LLVM has special knowledge of are listed
50/// here. Additionally, this scheme allows LLVM to efficiently check for
51/// specific synchronization scope ID without comparing strings.
52enum {
53 /// Synchronized with respect to signal handlers executing in the same thread.
54 SingleThread = 0,
55
56 /// Synchronized with respect to all concurrently executing threads.
57 System = 1
58};
59
60} // end namespace SyncScope
61
62/// This is an important class for using LLVM in a threaded context. It
63/// (opaquely) owns and manages the core "global" data of LLVM's core
64/// infrastructure, including the type and constant uniquing tables.
65/// LLVMContext itself provides no locking guarantees, so you should be careful
66/// to have one context per thread.
67class LLVMContext {
68public:
69 LLVMContextImpl *const pImpl;
70 LLVMContext();
71 LLVMContext(const LLVMContext &) = delete;
72 LLVMContext &operator=(const LLVMContext &) = delete;
73 ~LLVMContext();
74
75 // Pinned metadata names, which always have the same value. This is a
76 // compile-time performance optimization, not a correctness optimization.
77 enum : unsigned {
78#define LLVM_FIXED_MD_KIND(EnumID, Name, Value) EnumID = Value,
79#include "llvm/IR/FixedMetadataKinds.def"
80#undef LLVM_FIXED_MD_KIND
81 };
82
83 /// Known operand bundle tag IDs, which always have the same value. All
84 /// operand bundle tags that LLVM has special knowledge of are listed here.
85 /// Additionally, this scheme allows LLVM to efficiently check for specific
86 /// operand bundle tags without comparing strings. Keep this in sync with
87 /// LLVMContext::LLVMContext().
88 enum : unsigned {
89 OB_deopt = 0, // "deopt"
90 OB_funclet = 1, // "funclet"
91 OB_gc_transition = 2, // "gc-transition"
92 OB_cfguardtarget = 3, // "cfguardtarget"
93 OB_preallocated = 4, // "preallocated"
94 OB_gc_live = 5, // "gc-live"
95 OB_clang_arc_attachedcall = 6, // "clang.arc.attachedcall"
96 OB_ptrauth = 7, // "ptrauth"
97 OB_kcfi = 8, // "kcfi"
98 OB_convergencectrl = 9, // "convergencectrl"
99 };
100
101 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
102 /// This ID is uniqued across modules in the current LLVMContext.
103 unsigned getMDKindID(StringRef Name) const;
104
105 /// getMDKindNames - Populate client supplied SmallVector with the name for
106 /// custom metadata IDs registered in this LLVMContext.
107 void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
108
109 /// getOperandBundleTags - Populate client supplied SmallVector with the
110 /// bundle tags registered in this LLVMContext. The bundle tags are ordered
111 /// by increasing bundle IDs.
112 /// \see LLVMContext::getOperandBundleTagID
113 void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;
114
115 /// getOrInsertBundleTag - Returns the Tag to use for an operand bundle of
116 /// name TagName.
117 StringMapEntry<uint32_t> *getOrInsertBundleTag(StringRef TagName) const;
118
119 /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle
120 /// tag registered with an LLVMContext has an unique ID.
121 uint32_t getOperandBundleTagID(StringRef Tag) const;
122
123 /// getOrInsertSyncScopeID - Maps synchronization scope name to
124 /// synchronization scope ID. Every synchronization scope registered with
125 /// LLVMContext has unique ID except pre-defined ones.
126 SyncScope::ID getOrInsertSyncScopeID(StringRef SSN);
127
128 /// getSyncScopeNames - Populates client supplied SmallVector with
129 /// synchronization scope names registered with LLVMContext. Synchronization
130 /// scope names are ordered by increasing synchronization scope IDs.
131 void getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const;
132
133 /// Define the GC for a function
134 void setGC(const Function &Fn, std::string GCName);
135
136 /// Return the GC for a function
137 const std::string &getGC(const Function &Fn);
138
139 /// Remove the GC for a function
140 void deleteGC(const Function &Fn);
141
142 /// Return true if the Context runtime configuration is set to discard all
143 /// value names. When true, only GlobalValue names will be available in the
144 /// IR.
145 bool shouldDiscardValueNames() const;
146
147 /// Set the Context runtime configuration to discard all value name (but
148 /// GlobalValue). Clients can use this flag to save memory and runtime,
149 /// especially in release mode.
150 void setDiscardValueNames(bool Discard);
151
152 /// Whether there is a string map for uniquing debug info
153 /// identifiers across the context. Off by default.
154 bool isODRUniquingDebugTypes() const;
155 void enableDebugTypeODRUniquing();
156 void disableDebugTypeODRUniquing();
157
158 /// Defines the type of a yield callback.
159 /// \see LLVMContext::setYieldCallback.
160 using YieldCallbackTy = void (*)(LLVMContext *Context, void *OpaqueHandle);
161
162 /// setDiagnosticHandlerCallBack - This method sets a handler call back
163 /// that is invoked when the backend needs to report anything to the user.
164 /// The first argument is a function pointer and the second is a context pointer
165 /// that gets passed into the DiagHandler. The third argument should be set to
166 /// true if the handler only expects enabled diagnostics.
167 ///
168 /// LLVMContext doesn't take ownership or interpret either of these
169 /// pointers.
170 void setDiagnosticHandlerCallBack(
171 DiagnosticHandler::DiagnosticHandlerTy DiagHandler,
172 void *DiagContext = nullptr, bool RespectFilters = false);
173
174 /// setDiagnosticHandler - This method sets unique_ptr to object of
175 /// DiagnosticHandler to provide custom diagnostic handling. The first
176 /// argument is unique_ptr of object of type DiagnosticHandler or a derived
177 /// of that. The second argument should be set to true if the handler only
178 /// expects enabled diagnostics.
179 ///
180 /// Ownership of this pointer is moved to LLVMContextImpl.
181 void setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,
182 bool RespectFilters = false);
183
184 /// getDiagnosticHandlerCallBack - Return the diagnostic handler call back set by
185 /// setDiagnosticHandlerCallBack.
186 DiagnosticHandler::DiagnosticHandlerTy getDiagnosticHandlerCallBack() const;
187
188 /// getDiagnosticContext - Return the diagnostic context set by
189 /// setDiagnosticContext.
190 void *getDiagnosticContext() const;
191
192 /// getDiagHandlerPtr - Returns const raw pointer of DiagnosticHandler set by
193 /// setDiagnosticHandler.
194 const DiagnosticHandler *getDiagHandlerPtr() const;
195
196 /// getDiagnosticHandler - transfers ownership of DiagnosticHandler unique_ptr
197 /// to caller.
198 std::unique_ptr<DiagnosticHandler> getDiagnosticHandler();
199
200 /// Return if a code hotness metric should be included in optimization
201 /// diagnostics.
202 bool getDiagnosticsHotnessRequested() const;
203 /// Set if a code hotness metric should be included in optimization
204 /// diagnostics.
205 void setDiagnosticsHotnessRequested(bool Requested);
206
207 bool getMisExpectWarningRequested() const;
208 void setMisExpectWarningRequested(bool Requested);
209 void setDiagnosticsMisExpectTolerance(std::optional<uint32_t> Tolerance);
210 uint32_t getDiagnosticsMisExpectTolerance() const;
211
212 /// Return the minimum hotness value a diagnostic would need in order
213 /// to be included in optimization diagnostics.
214 ///
215 /// Three possible return values:
216 /// 0 - threshold is disabled. Everything will be printed out.
217 /// positive int - threshold is set.
218 /// UINT64_MAX - threshold is not yet set, and needs to be synced from
219 /// profile summary. Note that in case of missing profile
220 /// summary, threshold will be kept at "MAX", effectively
221 /// suppresses all remarks output.
222 uint64_t getDiagnosticsHotnessThreshold() const;
223
224 /// Set the minimum hotness value a diagnostic needs in order to be
225 /// included in optimization diagnostics.
226 void setDiagnosticsHotnessThreshold(std::optional<uint64_t> Threshold);
227
228 /// Return if hotness threshold is requested from PSI.
229 bool isDiagnosticsHotnessThresholdSetFromPSI() const;
230
231 /// The "main remark streamer" used by all the specialized remark streamers.
232 /// This streamer keeps generic remark metadata in memory throughout the life
233 /// of the LLVMContext. This metadata may be emitted in a section in object
234 /// files depending on the format requirements.
235 ///
236 /// All specialized remark streamers should convert remarks to
237 /// llvm::remarks::Remark and emit them through this streamer.
238 remarks::RemarkStreamer *getMainRemarkStreamer();
239 const remarks::RemarkStreamer *getMainRemarkStreamer() const;
240 void setMainRemarkStreamer(
241 std::unique_ptr<remarks::RemarkStreamer> MainRemarkStreamer);
242
243 /// The "LLVM remark streamer" used by LLVM to serialize remark diagnostics
244 /// comming from IR and MIR passes.
245 ///
246 /// If it does not exist, diagnostics are not saved in a file but only emitted
247 /// via the diagnostic handler.
248 LLVMRemarkStreamer *getLLVMRemarkStreamer();
249 const LLVMRemarkStreamer *getLLVMRemarkStreamer() const;
250 void
251 setLLVMRemarkStreamer(std::unique_ptr<LLVMRemarkStreamer> RemarkStreamer);
252
253 /// Get the prefix that should be printed in front of a diagnostic of
254 /// the given \p Severity
255 static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
256
257 /// Report a message to the currently installed diagnostic handler.
258 ///
259 /// This function returns, in particular in the case of error reporting
260 /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
261 /// process in a self-consistent state, even though the generated code
262 /// need not be correct.
263 ///
264 /// The diagnostic message will be implicitly prefixed with a severity keyword
265 /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
266 /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
267 void diagnose(const DiagnosticInfo &DI);
268
269 /// Registers a yield callback with the given context.
270 ///
271 /// The yield callback function may be called by LLVM to transfer control back
272 /// to the client that invoked the LLVM compilation. This can be used to yield
273 /// control of the thread, or perform periodic work needed by the client.
274 /// There is no guaranteed frequency at which callbacks must occur; in fact,
275 /// the client is not guaranteed to ever receive this callback. It is at the
276 /// sole discretion of LLVM to do so and only if it can guarantee that
277 /// suspending the thread won't block any forward progress in other LLVM
278 /// contexts in the same process.
279 ///
280 /// At a suspend point, the state of the current LLVM context is intentionally
281 /// undefined. No assumptions about it can or should be made. Only LLVM
282 /// context API calls that explicitly state that they can be used during a
283 /// yield callback are allowed to be used. Any other API calls into the
284 /// context are not supported until the yield callback function returns
285 /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
286 void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
287
288 /// Calls the yield callback (if applicable).
289 ///
290 /// This transfers control of the current thread back to the client, which may
291 /// suspend the current thread. Only call this method when LLVM doesn't hold
292 /// any global mutex or cannot block the execution in another LLVM context.
293 void yield();
294
295 /// emitError - Emit an error message to the currently installed error handler
296 /// with optional location information. This function returns, so code should
297 /// be prepared to drop the erroneous construct on the floor and "not crash".
298 /// The generated code need not be correct. The error message will be
299 /// implicitly prefixed with "error: " and should not end with a ".".
300 void emitError(uint64_t LocCookie, const Twine &ErrorStr);
301 void emitError(const Instruction *I, const Twine &ErrorStr);
302 void emitError(const Twine &ErrorStr);
303
304 /// Access the object which can disable optional passes and individual
305 /// optimizations at compile time.
306 OptPassGate &getOptPassGate() const;
307
308 /// Set the object which can disable optional passes and individual
309 /// optimizations at compile time.
310 ///
311 /// The lifetime of the object must be guaranteed to extend as long as the
312 /// LLVMContext is used by compilation.
313 void setOptPassGate(OptPassGate&);
314
315 /// Set whether opaque pointers are enabled. The method may be called multiple
316 /// times, but only with the same value. Note that creating a pointer type or
317 /// otherwise querying the opaque pointer mode performs an implicit set to
318 /// the default value.
319 [[deprecated("Opaque pointers are always enabled")]]
320 void setOpaquePointers(bool Enable) const;
321
322 /// Whether typed pointers are supported. If false, all pointers are opaque.
323 [[deprecated("Always returns false")]]
324 bool supportsTypedPointers() const;
325
326private:
327 // Module needs access to the add/removeModule methods.
328 friend class Module;
329
330 /// addModule - Register a module as being instantiated in this context. If
331 /// the context is deleted, the module will be deleted as well.
332 void addModule(Module*);
333
334 /// removeModule - Unregister a module from this context.
335 void removeModule(Module*);
336};
337
338// Create wrappers for C Binding types (see CBindingWrapping.h).
339DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef)
340
341/* Specialized opaque context conversions.
342 */
343inline LLVMContext **unwrap(LLVMContextRef* Tys) {
344 return reinterpret_cast<LLVMContext**>(Tys);
345}
346
347inline LLVMContextRef *wrap(const LLVMContext **Tys) {
348 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
349}
350
351} // end namespace llvm
352
353#endif // LLVM_IR_LLVMCONTEXT_H
354

source code of llvm/include/llvm/IR/LLVMContext.h