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"
19 #include "llvm/Support/CBindingWrapping.h"
20 #include "llvm/Support/Options.h"
21 #include <cstdint>
22 #include <memory>
23 #include <string>
24
25 namespace llvm {
26
27 class DiagnosticInfo;
28 enum DiagnosticSeverity : char;
29 class Function;
30 class Instruction;
31 class LLVMContextImpl;
32 class Module;
33 class OptBisect;
34 template <typename T> class SmallVectorImpl;
35 class SMDiagnostic;
36 class StringRef;
37 class Twine;
38
39 namespace yaml {
40 class Output;
41 } // end namespace yaml
42
43 /// This is an important class for using LLVM in a threaded context. It
44 /// (opaquely) owns and manages the core "global" data of LLVM's core
45 /// infrastructure, including the type and constant uniquing tables.
46 /// LLVMContext itself provides no locking guarantees, so you should be careful
47 /// to have one context per thread.
48 class LLVMContext {
49 public:
50 LLVMContextImpl *const pImpl;
51 LLVMContext();
52 LLVMContext(LLVMContext &) = delete;
53 LLVMContext &operator=(const LLVMContext &) = delete;
54 ~LLVMContext();
55
56 // Pinned metadata names, which always have the same value. This is a
57 // compile-time performance optimization, not a correctness optimization.
58 enum {
59 MD_dbg = 0, // "dbg"
60 MD_tbaa = 1, // "tbaa"
61 MD_prof = 2, // "prof"
62 MD_fpmath = 3, // "fpmath"
63 MD_range = 4, // "range"
64 MD_tbaa_struct = 5, // "tbaa.struct"
65 MD_invariant_load = 6, // "invariant.load"
66 MD_alias_scope = 7, // "alias.scope"
67 MD_noalias = 8, // "noalias",
68 MD_nontemporal = 9, // "nontemporal"
69 MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access"
70 MD_nonnull = 11, // "nonnull"
71 MD_dereferenceable = 12, // "dereferenceable"
72 MD_dereferenceable_or_null = 13, // "dereferenceable_or_null"
73 MD_make_implicit = 14, // "make.implicit"
74 MD_unpredictable = 15, // "unpredictable"
75 MD_invariant_group = 16, // "invariant.group"
76 MD_align = 17, // "align"
77 MD_loop = 18, // "llvm.loop"
78 MD_type = 19, // "type"
79 MD_section_prefix = 20, // "section_prefix"
80 MD_absolute_symbol = 21, // "absolute_symbol"
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.
87 enum {
88 OB_deopt = 0, // "deopt"
89 OB_funclet = 1, // "funclet"
90 OB_gc_transition = 2, // "gc-transition"
91 };
92
93 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
94 /// This ID is uniqued across modules in the current LLVMContext.
95 unsigned getMDKindID(StringRef Name) const;
96
97 /// getMDKindNames - Populate client supplied SmallVector with the name for
98 /// custom metadata IDs registered in this LLVMContext.
99 void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;
100
101 /// getOperandBundleTags - Populate client supplied SmallVector with the
102 /// bundle tags registered in this LLVMContext. The bundle tags are ordered
103 /// by increasing bundle IDs.
104 /// \see LLVMContext::getOperandBundleTagID
105 void getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const;
106
107 /// getOperandBundleTagID - Maps a bundle tag to an integer ID. Every bundle
108 /// tag registered with an LLVMContext has an unique ID.
109 uint32_t getOperandBundleTagID(StringRef Tag) const;
110
111 /// Define the GC for a function
112 void setGC(const Function &Fn, std::string GCName);
113
114 /// Return the GC for a function
115 const std::string &getGC(const Function &Fn);
116
117 /// Remove the GC for a function
118 void deleteGC(const Function &Fn);
119
120 /// Return true if the Context runtime configuration is set to discard all
121 /// value names. When true, only GlobalValue names will be available in the
122 /// IR.
123 bool shouldDiscardValueNames() const;
124
125 /// Set the Context runtime configuration to discard all value name (but
126 /// GlobalValue). Clients can use this flag to save memory and runtime,
127 /// especially in release mode.
128 void setDiscardValueNames(bool Discard);
129
130 /// Whether there is a string map for uniquing debug info
131 /// identifiers across the context. Off by default.
132 bool isODRUniquingDebugTypes() const;
133 void enableDebugTypeODRUniquing();
134 void disableDebugTypeODRUniquing();
135
136 typedef void (*InlineAsmDiagHandlerTy)(const SMDiagnostic&, void *Context,
137 unsigned LocCookie);
138
139 /// Defines the type of a diagnostic handler.
140 /// \see LLVMContext::setDiagnosticHandler.
141 /// \see LLVMContext::diagnose.
142 typedef void (*DiagnosticHandlerTy)(const DiagnosticInfo &DI, void *Context);
143
144 /// Defines the type of a yield callback.
145 /// \see LLVMContext::setYieldCallback.
146 typedef void (*YieldCallbackTy)(LLVMContext *Context, void *OpaqueHandle);
147
148 /// setInlineAsmDiagnosticHandler - This method sets a handler that is invoked
149 /// when problems with inline asm are detected by the backend. The first
150 /// argument is a function pointer and the second is a context pointer that
151 /// gets passed into the DiagHandler.
152 ///
153 /// LLVMContext doesn't take ownership or interpret either of these
154 /// pointers.
155 void setInlineAsmDiagnosticHandler(InlineAsmDiagHandlerTy DiagHandler,
156 void *DiagContext = nullptr);
157
158 /// getInlineAsmDiagnosticHandler - Return the diagnostic handler set by
159 /// setInlineAsmDiagnosticHandler.
160 InlineAsmDiagHandlerTy getInlineAsmDiagnosticHandler() const;
161
162 /// getInlineAsmDiagnosticContext - Return the diagnostic context set by
163 /// setInlineAsmDiagnosticHandler.
164 void *getInlineAsmDiagnosticContext() const;
165
166 /// setDiagnosticHandler - This method sets a handler that is invoked
167 /// when the backend needs to report anything to the user. The first
168 /// argument is a function pointer and the second is a context pointer that
169 /// gets passed into the DiagHandler. The third argument should be set to
170 /// true if the handler only expects enabled diagnostics.
171 ///
172 /// LLVMContext doesn't take ownership or interpret either of these
173 /// pointers.
174 void setDiagnosticHandler(DiagnosticHandlerTy DiagHandler,
175 void *DiagContext = nullptr,
176 bool RespectFilters = false);
177
178 /// getDiagnosticHandler - Return the diagnostic handler set by
179 /// setDiagnosticHandler.
180 DiagnosticHandlerTy getDiagnosticHandler() const;
181
182 /// getDiagnosticContext - Return the diagnostic context set by
183 /// setDiagnosticContext.
184 void *getDiagnosticContext() const;
185
186 /// \brief Return if a code hotness metric should be included in optimization
187 /// diagnostics.
188 bool getDiagnosticHotnessRequested() const;
189 /// \brief Set if a code hotness metric should be included in optimization
190 /// diagnostics.
191 void setDiagnosticHotnessRequested(bool Requested);
192
193 /// \brief Return the YAML file used by the backend to save optimization
194 /// diagnostics. If null, diagnostics are not saved in a file but only
195 /// emitted via the diagnostic handler.
196 yaml::Output *getDiagnosticsOutputFile();
197 /// Set the diagnostics output file used for optimization diagnostics.
198 ///
199 /// By default or if invoked with null, diagnostics are not saved in a file
200 /// but only emitted via the diagnostic handler. Even if an output file is
201 /// set, the handler is invoked for each diagnostic message.
202 void setDiagnosticsOutputFile(std::unique_ptr<yaml::Output> F);
203
204 /// \brief Get the prefix that should be printed in front of a diagnostic of
205 /// the given \p Severity
206 static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
207
208 /// \brief Report a message to the currently installed diagnostic handler.
209 ///
210 /// This function returns, in particular in the case of error reporting
211 /// (DI.Severity == \a DS_Error), so the caller should leave the compilation
212 /// process in a self-consistent state, even though the generated code
213 /// need not be correct.
214 ///
215 /// The diagnostic message will be implicitly prefixed with a severity keyword
216 /// according to \p DI.getSeverity(), i.e., "error: " for \a DS_Error,
217 /// "warning: " for \a DS_Warning, and "note: " for \a DS_Note.
218 void diagnose(const DiagnosticInfo &DI);
219
220 /// \brief Registers a yield callback with the given context.
221 ///
222 /// The yield callback function may be called by LLVM to transfer control back
223 /// to the client that invoked the LLVM compilation. This can be used to yield
224 /// control of the thread, or perform periodic work needed by the client.
225 /// There is no guaranteed frequency at which callbacks must occur; in fact,
226 /// the client is not guaranteed to ever receive this callback. It is at the
227 /// sole discretion of LLVM to do so and only if it can guarantee that
228 /// suspending the thread won't block any forward progress in other LLVM
229 /// contexts in the same process.
230 ///
231 /// At a suspend point, the state of the current LLVM context is intentionally
232 /// undefined. No assumptions about it can or should be made. Only LLVM
233 /// context API calls that explicitly state that they can be used during a
234 /// yield callback are allowed to be used. Any other API calls into the
235 /// context are not supported until the yield callback function returns
236 /// control to LLVM. Other LLVM contexts are unaffected by this restriction.
237 void setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle);
238
239 /// \brief Calls the yield callback (if applicable).
240 ///
241 /// This transfers control of the current thread back to the client, which may
242 /// suspend the current thread. Only call this method when LLVM doesn't hold
243 /// any global mutex or cannot block the execution in another LLVM context.
244 void yield();
245
246 /// emitError - Emit an error message to the currently installed error handler
247 /// with optional location information. This function returns, so code should
248 /// be prepared to drop the erroneous construct on the floor and "not crash".
249 /// The generated code need not be correct. The error message will be
250 /// implicitly prefixed with "error: " and should not end with a ".".
251 void emitError(unsigned LocCookie, const Twine &ErrorStr);
252 void emitError(const Instruction *I, const Twine &ErrorStr);
253 void emitError(const Twine &ErrorStr);
254
255 /// \brief Query for a debug option's value.
256 ///
257 /// This function returns typed data populated from command line parsing.
258 template <typename ValT, typename Base, ValT(Base::*Mem)>
getOption()259 ValT getOption() const {
260 return OptionRegistry::instance().template get<ValT, Base, Mem>();
261 }
262
263 /// \brief Access the object which manages optimization bisection for failure
264 /// analysis.
265 OptBisect &getOptBisect();
266 private:
267 // Module needs access to the add/removeModule methods.
268 friend class Module;
269
270 /// addModule - Register a module as being instantiated in this context. If
271 /// the context is deleted, the module will be deleted as well.
272 void addModule(Module*);
273
274 /// removeModule - Unregister a module from this context.
275 void removeModule(Module*);
276 };
277
278 // Create wrappers for C Binding types (see CBindingWrapping.h).
DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext,LLVMContextRef)279 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LLVMContext, LLVMContextRef)
280
281 /* Specialized opaque context conversions.
282 */
283 inline LLVMContext **unwrap(LLVMContextRef* Tys) {
284 return reinterpret_cast<LLVMContext**>(Tys);
285 }
286
wrap(const LLVMContext ** Tys)287 inline LLVMContextRef *wrap(const LLVMContext **Tys) {
288 return reinterpret_cast<LLVMContextRef*>(const_cast<LLVMContext**>(Tys));
289 }
290
291 } // end namespace llvm
292
293 #endif // LLVM_IR_LLVMCONTEXT_H
294