projects / lttng-tools.git / blame
| Commit | Line | Data |
|---|---|---|
| 6242251b | 1 | /* |
| ab5be9fa | 2 | * Copyright (C) 2012 Christian Babeux <christian.babeux@efficios.com> |
| 6242251b | 3 | * |
| ab5be9fa | 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 6242251b | 5 | * |
| 6242251b CB |
6 | */ |
| 7 | ||
| 8 | #ifndef NTESTPOINT | |
| 9 | ||
| 6c1c0768 | 10 | #define _LGPL_SOURCE |
| 6242251b CB |
11 | #include <dlfcn.h> /* for dlsym */ |
| 12 | #include <stdlib.h> /* for getenv */ | |
| 13 | #include <string.h> /* for strncmp */ | |
| 14 | ||
| 15 | #include "testpoint.h" | |
| 16 | ||
| 17 | /* Environment variable used to enable the testpoints facilities. */ | |
| 18 | static const char *lttng_testpoint_env_var = "LTTNG_TESTPOINT_ENABLE"; | |
| 19 | ||
| 20 | /* Testpoint toggle flag */ | |
| 21 | int lttng_testpoint_activated; | |
| 22 | ||
| 23 | /* | |
| 24 | * Toggle the support for testpoints on the application startup. | |
| 25 | */ | |
| 26 | static void __attribute__((constructor)) lttng_testpoint_check(void) | |
| 27 | { | |
| 28 | char *testpoint_env_val = NULL; | |
| 29 | ||
| 30 | testpoint_env_val = getenv(lttng_testpoint_env_var); | |
| 31 | if (testpoint_env_val != NULL | |
| 32 | && (strncmp(testpoint_env_val, "1", 1) == 0)) { | |
| 33 | lttng_testpoint_activated = 1; | |
| 34 | } | |
| 35 | } | |
| 36 | ||
| 37 | /* | |
| 38 | * Lookup a symbol by name. | |
| 39 | * | |
| 40 | * Return the address where the symbol is loaded or NULL if the symbol was not | |
| 41 | * found. | |
| 42 | */ | |
| 43 | void *lttng_testpoint_lookup(const char *name) | |
| 44 | { | |
| 45 | if (!name) { | |
| 46 | return NULL; | |
| 47 | } | |
| 48 | ||
| 49 | return dlsym(RTLD_DEFAULT, name); | |
| 50 | } | |
| 51 | ||
| 52 | #endif /* NTESTPOINT */ |