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1 /*===- InstrProfiling.h- Support library for PGO instrumentation ----------===*\
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 #ifndef PROFILE_INSTRPROFILING_H_
10 #define PROFILE_INSTRPROFILING_H_
11 
12 #include "InstrProfilingPort.h"
13 #include <stdio.h>
14 
15 #define INSTR_PROF_VISIBILITY COMPILER_RT_VISIBILITY
16 #include "profile/InstrProfData.inc"
17 
18 enum ValueKind {
19 #define VALUE_PROF_KIND(Enumerator, Value, Descr) Enumerator = Value,
20 #include "profile/InstrProfData.inc"
21 };
22 
23 typedef void *IntPtrT;
24 typedef struct COMPILER_RT_ALIGNAS(INSTR_PROF_DATA_ALIGNMENT)
25     __llvm_profile_data {
26 #define INSTR_PROF_DATA(Type, LLVMType, Name, Initializer) Type Name;
27 #include "profile/InstrProfData.inc"
28 } __llvm_profile_data;
29 
30 typedef struct __llvm_profile_header {
31 #define INSTR_PROF_RAW_HEADER(Type, Name, Initializer) Type Name;
32 #include "profile/InstrProfData.inc"
33 } __llvm_profile_header;
34 
35 typedef struct ValueProfNode * PtrToNodeT;
36 typedef struct ValueProfNode {
37 #define INSTR_PROF_VALUE_NODE(Type, LLVMType, Name, Initializer) Type Name;
38 #include "profile/InstrProfData.inc"
39 } ValueProfNode;
40 
41 /*!
42  * \brief Return 1 if profile counters are continuously synced to the raw
43  * profile via an mmap(). This is in contrast to the default mode, in which
44  * the raw profile is written out at program exit time.
45  */
46 int __llvm_profile_is_continuous_mode_enabled(void);
47 
48 /*!
49  * \brief Enable continuous mode.
50  *
51  * See \ref __llvm_profile_is_continuous_mode_enabled. The behavior is undefined
52  * if continuous mode is already enabled, or if it cannot be enable due to
53  * conflicting options.
54  */
55 void __llvm_profile_enable_continuous_mode(void);
56 
57 /*!
58  * \brief Set the page size.
59  *
60  * This is a pre-requisite for enabling continuous mode. The buffer size
61  * calculation code inside of libprofile cannot simply call getpagesize(), as
62  * it is not allowed to depend on libc.
63  */
64 void __llvm_profile_set_page_size(unsigned PageSize);
65 
66 /*!
67  * \brief Get number of bytes necessary to pad the argument to eight
68  * byte boundary.
69  */
70 uint8_t __llvm_profile_get_num_padding_bytes(uint64_t SizeInBytes);
71 
72 /*!
73  * \brief Get required size for profile buffer.
74  */
75 uint64_t __llvm_profile_get_size_for_buffer(void);
76 
77 /*!
78  * \brief Write instrumentation data to the given buffer.
79  *
80  * \pre \c Buffer is the start of a buffer at least as big as \a
81  * __llvm_profile_get_size_for_buffer().
82  */
83 int __llvm_profile_write_buffer(char *Buffer);
84 
85 const __llvm_profile_data *__llvm_profile_begin_data(void);
86 const __llvm_profile_data *__llvm_profile_end_data(void);
87 const char *__llvm_profile_begin_names(void);
88 const char *__llvm_profile_end_names(void);
89 uint64_t *__llvm_profile_begin_counters(void);
90 uint64_t *__llvm_profile_end_counters(void);
91 ValueProfNode *__llvm_profile_begin_vnodes();
92 ValueProfNode *__llvm_profile_end_vnodes();
93 uint32_t *__llvm_profile_begin_orderfile();
94 
95 /*!
96  * \brief Clear profile counters to zero.
97  *
98  */
99 void __llvm_profile_reset_counters(void);
100 
101 /*!
102  * \brief Merge profile data from buffer.
103  *
104  * Read profile data form buffer \p Profile  and merge with
105  * in-process profile counters. The client is expected to
106  * have checked or already knows the profile data in the
107  * buffer matches the in-process counter structure before
108  * calling it.
109  */
110 void __llvm_profile_merge_from_buffer(const char *Profile, uint64_t Size);
111 
112 /*! \brief Check if profile in buffer matches the current binary.
113  *
114  *  Returns 0 (success) if the profile data in buffer \p Profile with size
115  *  \p Size was generated by the same binary and therefore matches
116  *  structurally the in-process counters. If the profile data in buffer is
117  *  not compatible, the interface returns 1 (failure).
118  */
119 int __llvm_profile_check_compatibility(const char *Profile,
120                                        uint64_t Size);
121 
122 /*!
123  * \brief Counts the number of times a target value is seen.
124  *
125  * Records the target value for the CounterIndex if not seen before. Otherwise,
126  * increments the counter associated w/ the target value.
127  * void __llvm_profile_instrument_target(uint64_t TargetValue, void *Data,
128  *                                       uint32_t CounterIndex);
129  */
130 void INSTR_PROF_VALUE_PROF_FUNC(
131 #define VALUE_PROF_FUNC_PARAM(ArgType, ArgName, ArgLLVMType) ArgType ArgName
132 #include "profile/InstrProfData.inc"
133     );
134 
135 void __llvm_profile_instrument_target_value(uint64_t TargetValue, void *Data,
136                                             uint32_t CounterIndex,
137                                             uint64_t CounterValue);
138 
139 /*!
140  * \brief Write instrumentation data to the current file.
141  *
142  * Writes to the file with the last name given to \a *
143  * __llvm_profile_set_filename(),
144  * or if it hasn't been called, the \c LLVM_PROFILE_FILE environment variable,
145  * or if that's not set, the last name set to INSTR_PROF_PROFILE_NAME_VAR,
146  * or if that's not set,  \c "default.profraw".
147  */
148 int __llvm_profile_write_file(void);
149 
150 int __llvm_orderfile_write_file(void);
151 /*!
152  * \brief this is a wrapper interface to \c __llvm_profile_write_file.
153  * After this interface is invoked, a arleady dumped flag will be set
154  * so that profile won't be dumped again during program exit.
155  * Invocation of interface __llvm_profile_reset_counters will clear
156  * the flag. This interface is designed to be used to collect profile
157  * data from user selected hot regions. The use model is
158  *      __llvm_profile_reset_counters();
159  *      ... hot region 1
160  *      __llvm_profile_dump();
161  *      .. some other code
162  *      __llvm_profile_reset_counters();
163  *       ... hot region 2
164  *      __llvm_profile_dump();
165  *
166  *  It is expected that on-line profile merging is on with \c %m specifier
167  *  used in profile filename . If merging is  not turned on, user is expected
168  *  to invoke __llvm_profile_set_filename  to specify different profile names
169  *  for different regions before dumping to avoid profile write clobbering.
170  */
171 int __llvm_profile_dump(void);
172 
173 int __llvm_orderfile_dump(void);
174 
175 /*!
176  * \brief Set the filename for writing instrumentation data.
177  *
178  * Sets the filename to be used for subsequent calls to
179  * \a __llvm_profile_write_file().
180  *
181  * \c Name is not copied, so it must remain valid.  Passing NULL resets the
182  * filename logic to the default behaviour.
183  *
184  * Note: There may be multiple copies of the profile runtime (one for each
185  * instrumented image/DSO). This API only modifies the filename within the
186  * copy of the runtime available to the calling image.
187  *
188  * Warning: This is a no-op if continuous mode (\ref
189  * __llvm_profile_is_continuous_mode_enabled) is on. The reason for this is
190  * that in continuous mode, profile counters are mmap()'d to the profile at
191  * program initialization time. Support for transferring the mmap'd profile
192  * counts to a new file has not been implemented.
193  */
194 void __llvm_profile_set_filename(const char *Name);
195 
196 /*!
197  * \brief Set the FILE object for writing instrumentation data.
198  *
199  * Sets the FILE object to be used for subsequent calls to
200  * \a __llvm_profile_write_file(). The profile file name set by environment
201  * variable, command-line option, or calls to \a  __llvm_profile_set_filename
202  * will be ignored.
203  *
204  * \c File will not be closed after a call to \a __llvm_profile_write_file() but
205  * it may be flushed. Passing NULL restores default behavior.
206  *
207  * If \c EnableMerge is nonzero, the runtime will always merge profiling data
208  * with the contents of the profiling file. If EnableMerge is zero, the runtime
209  * may still merge the data if it would have merged for another reason (for
210  * example, because of a %m specifier in the file name).
211  *
212  * Note: There may be multiple copies of the profile runtime (one for each
213  * instrumented image/DSO). This API only modifies the file object within the
214  * copy of the runtime available to the calling image.
215  *
216  * Warning: This is a no-op if continuous mode (\ref
217  * __llvm_profile_is_continuous_mode_enabled) is on. The reason for this is
218  * that in continuous mode, profile counters are mmap()'d to the profile at
219  * program initialization time. Support for transferring the mmap'd profile
220  * counts to a new file has not been implemented.
221  */
222 void __llvm_profile_set_file_object(FILE *File, int EnableMerge);
223 
224 /*! \brief Register to write instrumentation data to file at exit. */
225 int __llvm_profile_register_write_file_atexit(void);
226 
227 /*! \brief Initialize file handling. */
228 void __llvm_profile_initialize_file(void);
229 
230 /*! \brief Initialize the profile runtime. */
231 void __llvm_profile_initialize(void);
232 
233 /*!
234  * \brief Return path prefix (excluding the base filename) of the profile data.
235  * This is useful for users using \c -fprofile-generate=./path_prefix who do
236  * not care about the default raw profile name. It is also useful to collect
237  * more than more profile data files dumped in the same directory (Online
238  * merge mode is turned on for instrumented programs with shared libs).
239  * Side-effect: this API call will invoke malloc with dynamic memory allocation.
240  */
241 const char *__llvm_profile_get_path_prefix();
242 
243 /*!
244  * \brief Return filename (including path) of the profile data. Note that if the
245  * user calls __llvm_profile_set_filename later after invoking this interface,
246  * the actual file name may differ from what is returned here.
247  * Side-effect: this API call will invoke malloc with dynamic memory allocation
248  * (the returned pointer must be passed to `free` to avoid a leak).
249  *
250  * Note: There may be multiple copies of the profile runtime (one for each
251  * instrumented image/DSO). This API only retrieves the filename from the copy
252  * of the runtime available to the calling image.
253  */
254 const char *__llvm_profile_get_filename();
255 
256 /*! \brief Get the magic token for the file format. */
257 uint64_t __llvm_profile_get_magic(void);
258 
259 /*! \brief Get the version of the file format. */
260 uint64_t __llvm_profile_get_version(void);
261 
262 /*! \brief Get the number of entries in the profile data section. */
263 uint64_t __llvm_profile_get_data_size(const __llvm_profile_data *Begin,
264                                       const __llvm_profile_data *End);
265 
266 /* ! \brief Given the sizes of the data and counter information, return the
267  * number of padding bytes before and after the counters, and after the names,
268  * in the raw profile.
269  *
270  * Note: In this context, "size" means "number of entries", i.e. the first two
271  * arguments must be the result of __llvm_profile_get_data_size() and of
272  * (__llvm_profile_end_counters() - __llvm_profile_begin_counters()) resp.
273  *
274  * Note: When mmap() mode is disabled, no padding bytes before/after counters
275  * are needed. However, in mmap() mode, the counter section in the raw profile
276  * must be page-aligned: this API computes the number of padding bytes
277  * needed to achieve that.
278  */
279 void __llvm_profile_get_padding_sizes_for_counters(
280     uint64_t DataSize, uint64_t CountersSize, uint64_t NamesSize,
281     uint64_t *PaddingBytesBeforeCounters, uint64_t *PaddingBytesAfterCounters,
282     uint64_t *PaddingBytesAfterNames);
283 
284 /*!
285  * \brief Set the flag that profile data has been dumped to the file.
286  * This is useful for users to disable dumping profile data to the file for
287  * certain processes in case the processes don't have permission to write to
288  * the disks, and trying to do so would result in side effects such as crashes.
289  */
290 void __llvm_profile_set_dumped();
291 
292 /*!
293  * This variable is defined in InstrProfilingRuntime.cpp as a hidden
294  * symbol. Its main purpose is to enable profile runtime user to
295  * bypass runtime initialization code -- if the client code explicitly
296  * define this variable, then InstProfileRuntime.o won't be linked in.
297  * Note that this variable's visibility needs to be hidden so that the
298  * definition of this variable in an instrumented shared library won't
299  * affect runtime initialization decision of the main program.
300  *  __llvm_profile_profile_runtime. */
301 COMPILER_RT_VISIBILITY extern int INSTR_PROF_PROFILE_RUNTIME_VAR;
302 
303 /*!
304  * This variable is defined in InstrProfiling.c. Its main purpose is to
305  * encode the raw profile version value and other format related information
306  * such as whether the profile is from IR based instrumentation. The variable
307  * is defined as weak so that compiler can emit an overriding definition
308  * depending on user option.  Since we don't support mixing FE and IR based
309  * data in the same raw profile data file (in other words, shared libs and
310  * main program are expected to be instrumented in the same way), there is
311  * no need for this variable to be hidden.
312  */
313 extern uint64_t INSTR_PROF_RAW_VERSION_VAR; /* __llvm_profile_raw_version */
314 
315 /*!
316  * This variable is a weak symbol defined in InstrProfiling.c. It allows
317  * compiler instrumentation to provide overriding definition with value
318  * from compiler command line. This variable has default visibility.
319  */
320 extern char INSTR_PROF_PROFILE_NAME_VAR[1]; /* __llvm_profile_filename. */
321 
322 /*!
323  * This variable is a weak symbol defined in InstrProfilingBiasVar.c. It
324  * allows compiler instrumentation to provide overriding definition with
325  * value from compiler command line. This variable has hidden visibility.
326  */
327 COMPILER_RT_VISIBILITY extern intptr_t __llvm_profile_counter_bias;
328 
329 #endif /* PROFILE_INSTRPROFILING_H_ */
330