xref: /llvm-project/compiler-rt/lib/profile/InstrProfiling.h (revision f9d07890640434a4be0e7f651dd295478598b36d)
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 // Make sure __LLVM_INSTR_PROFILE_GENERATE is always defined before
16 // including instr_prof_interface.h so the interface functions are
17 // declared correctly for the runtime.
18 // __LLVM_INSTR_PROFILE_GENERATE is always `#undef`ed after the header,
19 // because compiler-rt does not support profiling the profiling runtime itself.
20 #ifndef __LLVM_INSTR_PROFILE_GENERATE
21 #define __LLVM_INSTR_PROFILE_GENERATE
22 #endif
23 #include "profile/instr_prof_interface.h"
24 #undef __LLVM_INSTR_PROFILE_GENERATE
25 
26 #define INSTR_PROF_VISIBILITY COMPILER_RT_VISIBILITY
27 #include "profile/InstrProfData.inc"
28 
29 enum ValueKind {
30 #define VALUE_PROF_KIND(Enumerator, Value, Descr) Enumerator = Value,
31 #include "profile/InstrProfData.inc"
32 };
33 
34 typedef void *IntPtrT;
35 typedef struct COMPILER_RT_ALIGNAS(INSTR_PROF_DATA_ALIGNMENT)
36     __llvm_profile_data {
37 #define INSTR_PROF_DATA(Type, LLVMType, Name, Initializer) Type Name;
38 #include "profile/InstrProfData.inc"
39 } __llvm_profile_data;
40 
41 typedef struct __llvm_profile_header {
42 #define INSTR_PROF_RAW_HEADER(Type, Name, Initializer) Type Name;
43 #include "profile/InstrProfData.inc"
44 } __llvm_profile_header;
45 
46 typedef struct ValueProfNode * PtrToNodeT;
47 typedef struct ValueProfNode {
48 #define INSTR_PROF_VALUE_NODE(Type, LLVMType, Name, Initializer) Type Name;
49 #include "profile/InstrProfData.inc"
50 } ValueProfNode;
51 
52 typedef struct COMPILER_RT_ALIGNAS(INSTR_PROF_DATA_ALIGNMENT) VTableProfData {
53 #define INSTR_PROF_VTABLE_DATA(Type, LLVMType, Name, Initializer) Type Name;
54 #include "profile/InstrProfData.inc"
55 } VTableProfData;
56 
57 typedef struct COMPILER_RT_ALIGNAS(INSTR_PROF_DATA_ALIGNMENT)
58     __llvm_gcov_init_func_struct {
59 #define COVINIT_FUNC(Type, LLVMType, Name, Initializer) Type Name;
60 #include "profile/InstrProfData.inc"
61 } __llvm_gcov_init_func_struct;
62 
63 /*!
64  * \brief Return 1 if profile counters are continuously synced to the raw
65  * profile via an mmap(). This is in contrast to the default mode, in which
66  * the raw profile is written out at program exit time.
67  */
68 int __llvm_profile_is_continuous_mode_enabled(void);
69 
70 /*!
71  * \brief Enable continuous mode.
72  *
73  * See \ref __llvm_profile_is_continuous_mode_enabled. The behavior is undefined
74  * if continuous mode is already enabled, or if it cannot be enable due to
75  * conflicting options.
76  */
77 void __llvm_profile_enable_continuous_mode(void);
78 
79 /*!
80  * \brief Disable continuous mode.
81  *
82  */
83 void __llvm_profile_disable_continuous_mode(void);
84 
85 /*!
86  * \brief Set the page size.
87  *
88  * This is a pre-requisite for enabling continuous mode. The buffer size
89  * calculation code inside of libprofile cannot simply call getpagesize(), as
90  * it is not allowed to depend on libc.
91  */
92 void __llvm_profile_set_page_size(unsigned PageSize);
93 
94 /*!
95  * \brief Get number of bytes necessary to pad the argument to eight
96  * byte boundary.
97  */
98 uint8_t __llvm_profile_get_num_padding_bytes(uint64_t SizeInBytes);
99 
100 /*!
101  * \brief Get required size for profile buffer.
102  */
103 uint64_t __llvm_profile_get_size_for_buffer(void);
104 
105 /*!
106  * \brief Write instrumentation data to the given buffer.
107  *
108  * \pre \c Buffer is the start of a buffer at least as big as \a
109  * __llvm_profile_get_size_for_buffer().
110  */
111 int __llvm_profile_write_buffer(char *Buffer);
112 
113 const __llvm_profile_data *__llvm_profile_begin_data(void);
114 const __llvm_profile_data *__llvm_profile_end_data(void);
115 const char *__llvm_profile_begin_names(void);
116 const char *__llvm_profile_end_names(void);
117 const char *__llvm_profile_begin_vtabnames(void);
118 const char *__llvm_profile_end_vtabnames(void);
119 char *__llvm_profile_begin_counters(void);
120 char *__llvm_profile_end_counters(void);
121 char *__llvm_profile_begin_bitmap(void);
122 char *__llvm_profile_end_bitmap(void);
123 ValueProfNode *__llvm_profile_begin_vnodes(void);
124 ValueProfNode *__llvm_profile_end_vnodes(void);
125 const VTableProfData *__llvm_profile_begin_vtables(void);
126 const VTableProfData *__llvm_profile_end_vtables(void);
127 uint32_t *__llvm_profile_begin_orderfile(void);
128 
129 /*!
130  * \brief Merge profile data from buffer.
131  *
132  * Read profile data from buffer \p Profile and merge with in-process profile
133  * counters and bitmaps. The client is expected to have checked or already
134  * know the profile data in the buffer matches the in-process counter
135  * structure before calling it. Returns 0 (success) if the profile data is
136  * valid. Upon reading invalid/corrupted profile data, returns 1 (failure).
137  */
138 int __llvm_profile_merge_from_buffer(const char *Profile, uint64_t Size);
139 
140 /*! \brief Check if profile in buffer matches the current binary.
141  *
142  *  Returns 0 (success) if the profile data in buffer \p Profile with size
143  *  \p Size was generated by the same binary and therefore matches
144  *  structurally the in-process counters and bitmaps. If the profile data in
145  *  buffer is not compatible, the interface returns 1 (failure).
146  */
147 int __llvm_profile_check_compatibility(const char *Profile,
148                                        uint64_t Size);
149 
150 /*!
151  * \brief Counts the number of times a target value is seen.
152  *
153  * Records the target value for the CounterIndex if not seen before. Otherwise,
154  * increments the counter associated w/ the target value.
155  * void __llvm_profile_instrument_target(uint64_t TargetValue, void *Data,
156  *                                       uint32_t CounterIndex);
157  */
158 void INSTR_PROF_VALUE_PROF_FUNC(
159 #define VALUE_PROF_FUNC_PARAM(ArgType, ArgName, ArgLLVMType) ArgType ArgName
160 #include "profile/InstrProfData.inc"
161     );
162 
163 void __llvm_profile_instrument_target_value(uint64_t TargetValue, void *Data,
164                                             uint32_t CounterIndex,
165                                             uint64_t CounterValue);
166 
167 /*!
168  * \brief Write instrumentation data to the current file.
169  *
170  * Writes to the file with the last name given to \a *
171  * __llvm_profile_set_filename(),
172  * or if it hasn't been called, the \c LLVM_PROFILE_FILE environment variable,
173  * or if that's not set, the last name set to INSTR_PROF_PROFILE_NAME_VAR,
174  * or if that's not set,  \c "default.profraw".
175  */
176 int __llvm_profile_write_file(void);
177 
178 int __llvm_orderfile_write_file(void);
179 
180 /*!
181  * \brief Set the FILE object for writing instrumentation data. Return 0 if set
182  * successfully or return 1 if failed.
183  *
184  * Sets the FILE object to be used for subsequent calls to
185  * \a __llvm_profile_write_file(). The profile file name set by environment
186  * variable, command-line option, or calls to \a  __llvm_profile_set_filename
187  * will be ignored.
188  *
189  * \c File will not be closed after a call to \a __llvm_profile_write_file() but
190  * it may be flushed. Passing NULL restores default behavior.
191  *
192  * If \c EnableMerge is nonzero, the runtime will always merge profiling data
193  * with the contents of the profiling file. If EnableMerge is zero, the runtime
194  * may still merge the data if it would have merged for another reason (for
195  * example, because of a %m specifier in the file name).
196  *
197  * Note: There may be multiple copies of the profile runtime (one for each
198  * instrumented image/DSO). This API only modifies the file object within the
199  * copy of the runtime available to the calling image.
200  *
201  * Warning: This is a no-op if EnableMerge is 0 in continuous mode (\ref
202  * __llvm_profile_is_continuous_mode_enabled), because disable merging requires
203  * copying the old profile file to new profile file and this function is usually
204  * used when the proess doesn't have permission to open file.
205  */
206 int __llvm_profile_set_file_object(FILE *File, int EnableMerge);
207 
208 /*! \brief Register to write instrumentation data to file at exit. */
209 int __llvm_profile_register_write_file_atexit(void);
210 
211 /*! \brief Initialize file handling. */
212 void __llvm_profile_initialize_file(void);
213 
214 /*! \brief Initialize the profile runtime. */
215 void __llvm_profile_initialize(void);
216 
217 /*! \brief Initialize the gcov profile runtime. */
218 void __llvm_profile_gcov_initialize(void);
219 
220 /*!
221  * \brief Return path prefix (excluding the base filename) of the profile data.
222  * This is useful for users using \c -fprofile-generate=./path_prefix who do
223  * not care about the default raw profile name. It is also useful to collect
224  * more than more profile data files dumped in the same directory (Online
225  * merge mode is turned on for instrumented programs with shared libs).
226  * Side-effect: this API call will invoke malloc with dynamic memory allocation.
227  */
228 const char *__llvm_profile_get_path_prefix(void);
229 
230 /*!
231  * \brief Return filename (including path) of the profile data. Note that if the
232  * user calls __llvm_profile_set_filename later after invoking this interface,
233  * the actual file name may differ from what is returned here.
234  * Side-effect: this API call will invoke malloc with dynamic memory allocation
235  * (the returned pointer must be passed to `free` to avoid a leak).
236  *
237  * Note: There may be multiple copies of the profile runtime (one for each
238  * instrumented image/DSO). This API only retrieves the filename from the copy
239  * of the runtime available to the calling image.
240  */
241 const char *__llvm_profile_get_filename(void);
242 
243 /*! \brief Get the magic token for the file format. */
244 uint64_t __llvm_profile_get_magic(void);
245 
246 /*! \brief Get the version of the file format. */
247 uint64_t __llvm_profile_get_version(void);
248 
249 /*! \brief Get the number of entries in the profile data section. */
250 uint64_t __llvm_profile_get_num_data(const __llvm_profile_data *Begin,
251                                      const __llvm_profile_data *End);
252 
253 /*! \brief Get the size of the profile data section in bytes. */
254 uint64_t __llvm_profile_get_data_size(const __llvm_profile_data *Begin,
255                                       const __llvm_profile_data *End);
256 
257 /*! \brief Get the size in bytes of a single counter entry. */
258 size_t __llvm_profile_counter_entry_size(void);
259 
260 /*! \brief Get the number of entries in the profile counters section. */
261 uint64_t __llvm_profile_get_num_counters(const char *Begin, const char *End);
262 
263 /*! \brief Get the size of the profile counters section in bytes. */
264 uint64_t __llvm_profile_get_counters_size(const char *Begin, const char *End);
265 
266 /*! \brief Get the number of bytes in the profile bitmap section. */
267 uint64_t __llvm_profile_get_num_bitmap_bytes(const char *Begin,
268                                              const char *End);
269 
270 /*! \brief Get the size of the profile name section in bytes. */
271 uint64_t __llvm_profile_get_name_size(const char *Begin, const char *End);
272 
273 /*! \brief Get the number of virtual table profile data entries */
274 uint64_t __llvm_profile_get_num_vtable(const VTableProfData *Begin,
275                                        const VTableProfData *End);
276 
277 /*! \brief Get the size of virtual table profile data in bytes. */
278 uint64_t __llvm_profile_get_vtable_section_size(const VTableProfData *Begin,
279                                                 const VTableProfData *End);
280 
281 /* ! \brief Given the sizes of the data and counter information, computes the
282  * number of padding bytes before and after the counter section, as well as the
283  * number of padding bytes after other setions in the raw profile.
284  * Returns -1 upon errors and 0 upon success. Output parameters should be used
285  * iff return value is 0.
286  *
287  * Note: When mmap() mode is disabled, no padding bytes before/after counters
288  * are needed. However, in mmap() mode, the counter section in the raw profile
289  * must be page-aligned: this API computes the number of padding bytes
290  * needed to achieve that.
291  */
292 int __llvm_profile_get_padding_sizes_for_counters(
293     uint64_t DataSize, uint64_t CountersSize, uint64_t NumBitmapBytes,
294     uint64_t NamesSize, uint64_t VTableSize, uint64_t VNameSize,
295     uint64_t *PaddingBytesBeforeCounters, uint64_t *PaddingBytesAfterCounters,
296     uint64_t *PaddingBytesAfterBitmap, uint64_t *PaddingBytesAfterNames,
297     uint64_t *PaddingBytesAfterVTable, uint64_t *PaddingBytesAfterVNames);
298 
299 /*!
300  * \brief Set the flag that profile data has been dumped to the file.
301  * This is useful for users to disable dumping profile data to the file for
302  * certain processes in case the processes don't have permission to write to
303  * the disks, and trying to do so would result in side effects such as crashes.
304  */
305 void __llvm_profile_set_dumped(void);
306 
307 /*!
308  * This variable is defined in InstrProfilingRuntime.cpp as a hidden
309  * symbol. Its main purpose is to enable profile runtime user to
310  * bypass runtime initialization code -- if the client code explicitly
311  * define this variable, then InstProfileRuntime.o won't be linked in.
312  * Note that this variable's visibility needs to be hidden so that the
313  * definition of this variable in an instrumented shared library won't
314  * affect runtime initialization decision of the main program.
315  *  __llvm_profile_profile_runtime. */
316 COMPILER_RT_VISIBILITY extern int INSTR_PROF_PROFILE_RUNTIME_VAR;
317 
318 /*!
319  * This variable is defined in InstrProfilingVersionVar.c as a hidden symbol
320  * (except on Apple platforms where this symbol is checked by TAPI).  Its main
321  * purpose is to encode the raw profile version value and other format related
322  * information such as whether the profile is from IR based instrumentation. The
323  * variable is defined as weak so that compiler can emit an overriding
324  * definition depending on user option.
325  */
326 COMPILER_RT_VISIBILITY extern uint64_t
327     INSTR_PROF_RAW_VERSION_VAR; /* __llvm_profile_raw_version */
328 
329 /*!
330  * This variable is a weak symbol defined in InstrProfiling.c. It allows
331  * compiler instrumentation to provide overriding definition with value
332  * from compiler command line. This variable has default visibility.
333  */
334 extern char INSTR_PROF_PROFILE_NAME_VAR[1]; /* __llvm_profile_filename. */
335 
336 const __llvm_gcov_init_func_struct *__llvm_profile_begin_covinit();
337 const __llvm_gcov_init_func_struct *__llvm_profile_end_covinit();
338 #endif /* PROFILE_INSTRPROFILING_H_ */
339