xpcom/base/nsDebug.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef nsDebug_h___
   8 #define nsDebug_h___
   9
  10 #include "nscore.h"
  11 #include "nsError.h"
  12
  13 #include "nsXPCOM.h"
  14 #include "mozilla/Assertions.h"
  15 #include "mozilla/DbgMacro.h"
  16 #include "mozilla/Likely.h"
  17 #include <stdarg.h>
  18
  19 #ifdef DEBUG
  20 #  include "mozilla/ErrorNames.h"
  21 #  include "mozilla/IntegerPrintfMacros.h"
  22 #  include "mozilla/Printf.h"
  23 #endif
  24
  25 /**
  26  * Warn if the given condition is true. The condition is evaluated in both
  27  * release and debug builds, and the result is an expression which can be
  28  * used in subsequent expressions, such as:
  29  *
  30  * if (NS_WARN_IF(NS_FAILED(rv)) {
  31  *   return rv;
  32  * }
  33  *
  34  * This explicit warning and return is preferred to the NS_ENSURE_* macros
  35  * which hide the warning and the return control flow.
  36  *
  37  * This macro can also be used outside of conditions just to issue a warning,
  38  * like so:
  39  *
  40  *   Unused << NS_WARN_IF(NS_FAILED(FnWithSideEffects());
  41  *
  42  * (The |Unused <<| is necessary because of the [[nodiscard]] annotation.)
  43  *
  44  * However, note that the argument to this macro is evaluated in all builds. If
  45  * you just want a warning assertion, it is better to use NS_WARNING_ASSERTION
  46  * (which evaluates the condition only in debug builds) like so:
  47  *
  48  *   NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "operation failed");
  49  *
  50  * @note This is C++-only
  51  */
  52 #ifdef __cplusplus
  53 #  ifdef DEBUG
  54 [[nodiscard]] inline bool NS_warn_if_impl(bool aCondition, const char* aExpr,
  55                                           const char* aFile, int32_t aLine) {
  56   if (MOZ_UNLIKELY(aCondition)) {
  57     NS_DebugBreak(NS_DEBUG_WARNING, nullptr, aExpr, aFile, aLine);
  58   }
  59   return aCondition;
  60 }
  61 #    define NS_WARN_IF(condition) \
  62       NS_warn_if_impl(condition, #condition, __FILE__, __LINE__)
  63 #  else
  64 #    define NS_WARN_IF(condition) (bool)(condition)
  65 #  endif
  66 #endif
  67
  68 /**
  69  * Test an assertion for truth. If the expression is not true then
  70  * emit a warning.
  71  *
  72  * Program execution continues past the usage of this macro.
  73  *
  74  * Note also that the non-debug version of this macro does <b>not</b>
  75  * evaluate the message argument.
  76  */
  77 #ifdef DEBUG
  78 #  define NS_WARNING_ASSERTION(_expr, _msg)                                \
  79     do {                                                                   \
  80       if (!(_expr)) {                                                      \
  81         NS_DebugBreak(NS_DEBUG_WARNING, _msg, #_expr, __FILE__, __LINE__); \
  82       }                                                                    \
  83     } while (false)
  84 #else
  85 #  define NS_WARNING_ASSERTION(_expr, _msg) \
  86     do { /* nothing */                      \
  87     } while (false)
  88 #endif
  89
  90 /**
  91  * Test an assertion for truth. If the expression is not true then
  92  * trigger a program failure.
  93  *
  94  * Note that the non-debug version of this macro does <b>not</b>
  95  * evaluate the message argument.
  96  */
  97 #ifdef DEBUG
  98 inline void MOZ_PretendNoReturn() MOZ_PRETEND_NORETURN_FOR_STATIC_ANALYSIS {}
  99 #  define NS_ASSERTION(expr, str)                                          \
 100     do {                                                                   \
 101       if (!(expr)) {                                                       \
 102         NS_DebugBreak(NS_DEBUG_ASSERTION, str, #expr, __FILE__, __LINE__); \
 103         MOZ_PretendNoReturn();                                             \
 104       }                                                                    \
 105     } while (0)
 106 #else
 107 #  define NS_ASSERTION(expr, str) \
 108     do { /* nothing */            \
 109     } while (0)
 110 #endif
 111
 112 /**
 113  * Log an error message.
 114  */
 115 #ifdef DEBUG
 116 #  define NS_ERROR(str)                                                    \
 117     do {                                                                   \
 118       NS_DebugBreak(NS_DEBUG_ASSERTION, str, "Error", __FILE__, __LINE__); \
 119       MOZ_PretendNoReturn();                                               \
 120     } while (0)
 121 #else
 122 #  define NS_ERROR(str) \
 123     do { /* nothing */  \
 124     } while (0)
 125 #endif
 126
 127 /**
 128  * Log a warning message.
 129  */
 130 #ifdef DEBUG
 131 #  define NS_WARNING(str) \
 132     NS_DebugBreak(NS_DEBUG_WARNING, str, nullptr, __FILE__, __LINE__)
 133 #else
 134 #  define NS_WARNING(str) \
 135     do { /* nothing */    \
 136     } while (0)
 137 #endif
 138
 139 /**
 140  * Trigger a debugger breakpoint, only in debug builds.
 141  */
 142 #ifdef DEBUG
 143 #  define NS_BREAK()                                                       \
 144     do {                                                                   \
 145       NS_DebugBreak(NS_DEBUG_BREAK, nullptr, nullptr, __FILE__, __LINE__); \
 146       MOZ_PretendNoReturn();                                               \
 147     } while (0)
 148 #else
 149 #  define NS_BREAK()   \
 150     do { /* nothing */ \
 151     } while (0)
 152 #endif
 153
 154 /******************************************************************************
 155 ** Macros for static assertions.  These are used by the sixgill tool.
 156 ** When the tool is not running these macros are no-ops.
 157 ******************************************************************************/
 158
 159 /* Avoid name collision if included with other headers defining annotations. */
 160 #ifndef HAVE_STATIC_ANNOTATIONS
 161 #  define HAVE_STATIC_ANNOTATIONS
 162
 163 #  ifdef XGILL_PLUGIN
 164
 165 #    define STATIC_PRECONDITION(COND) __attribute__((precondition(#    COND)))
 166 #    define STATIC_PRECONDITION_ASSUME(COND) \
 167       __attribute__((precondition_assume(#COND)))
 168 #    define STATIC_POSTCONDITION(COND) __attribute__((postcondition(#    COND)))
 169 #    define STATIC_POSTCONDITION_ASSUME(COND) \
 170       __attribute__((postcondition_assume(#COND)))
 171 #    define STATIC_INVARIANT(COND) __attribute__((invariant(#    COND)))
 172 #    define STATIC_INVARIANT_ASSUME(COND) \
 173       __attribute__((invariant_assume(#COND)))
 174
 175 /* Used to make identifiers for assert/assume annotations in a function. */
 176 #    define STATIC_PASTE2(X, Y) X##Y
 177 #    define STATIC_PASTE1(X, Y) STATIC_PASTE2(X, Y)
 178
 179 #    define STATIC_ASSUME(COND)                                          \
 180       do {                                                               \
 181         __attribute__((assume_static(#COND), unused)) int STATIC_PASTE1( \
 182             assume_static_, __COUNTER__);                                \
 183       } while (false)
 184
 185 #    define STATIC_ASSERT_RUNTIME(COND)                                   \
 186       do {                                                                \
 187         __attribute__((assert_static_runtime(#COND),                      \
 188                        unused)) int STATIC_PASTE1(assert_static_runtime_, \
 189                                                   __COUNTER__);           \
 190       } while (false)
 191
 192 #  else /* XGILL_PLUGIN */
 193
 194 #    define STATIC_PRECONDITION(COND)         /* nothing */
 195 #    define STATIC_PRECONDITION_ASSUME(COND)  /* nothing */
 196 #    define STATIC_POSTCONDITION(COND)        /* nothing */
 197 #    define STATIC_POSTCONDITION_ASSUME(COND) /* nothing */
 198 #    define STATIC_INVARIANT(COND)            /* nothing */
 199 #    define STATIC_INVARIANT_ASSUME(COND)     /* nothing */
 200
 201 #    define STATIC_ASSUME(COND) \
 202       do { /* nothing */        \
 203       } while (false)
 204 #    define STATIC_ASSERT_RUNTIME(COND) \
 205       do { /* nothing */                \
 206       } while (false)
 207
 208 #  endif /* XGILL_PLUGIN */
 209
 210 #  define STATIC_SKIP_INFERENCE STATIC_INVARIANT(skip_inference())
 211
 212 #endif /* HAVE_STATIC_ANNOTATIONS */
 213
 214 /******************************************************************************
 215 ** Macros for terminating execution when an unrecoverable condition is
 216 ** reached.  These need to be compiled regardless of the DEBUG flag.
 217 ******************************************************************************/
 218
 219 /* Macros for checking the trueness of an expression passed in within an
 220  * interface implementation.  These need to be compiled regardless of the
 221  * DEBUG flag. New code should use NS_WARN_IF(condition) instead!
 222  * @status deprecated
 223  */
 224
 225 #define NS_ENSURE_TRUE(x, ret)                     \
 226   do {                                             \
 227     if (MOZ_UNLIKELY(!(x))) {                      \
 228       NS_WARNING("NS_ENSURE_TRUE(" #x ") failed"); \
 229       return ret;                                  \
 230     }                                              \
 231   } while (false)
 232
 233 #define NS_ENSURE_FALSE(x, ret) NS_ENSURE_TRUE(!(x), ret)
 234
 235 #define NS_ENSURE_TRUE_VOID(x)                     \
 236   do {                                             \
 237     if (MOZ_UNLIKELY(!(x))) {                      \
 238       NS_WARNING("NS_ENSURE_TRUE(" #x ") failed"); \
 239       return;                                      \
 240     }                                              \
 241   } while (false)
 242
 243 #define NS_ENSURE_FALSE_VOID(x) NS_ENSURE_TRUE_VOID(!(x))
 244
 245 /******************************************************************************
 246 ** Macros for checking results
 247 ******************************************************************************/
 248
 249 #if defined(DEBUG) && !defined(XPCOM_GLUE_AVOID_NSPR)
 250
 251 #  define NS_ENSURE_SUCCESS_BODY(res, ret)                         \
 252     const char* name = mozilla::GetStaticErrorName(__rv);          \
 253     mozilla::SmprintfPointer msg = mozilla::Smprintf(              \
 254         "NS_ENSURE_SUCCESS(%s, %s) failed with "                   \
 255         "result 0x%" PRIX32 "%s%s%s",                              \
 256         #res, #ret, static_cast<uint32_t>(__rv), name ? " (" : "", \
 257         name ? name : "", name ? ")" : "");                        \
 258     NS_WARNING(msg.get());
 259
 260 #  define NS_ENSURE_SUCCESS_BODY_VOID(res)                                     \
 261     const char* name = mozilla::GetStaticErrorName(__rv);                      \
 262     mozilla::SmprintfPointer msg = mozilla::Smprintf(                          \
 263         "NS_ENSURE_SUCCESS_VOID(%s) failed with "                              \
 264         "result 0x%" PRIX32 "%s%s%s",                                          \
 265         #res, static_cast<uint32_t>(__rv), name ? " (" : "", name ? name : "", \
 266         name ? ")" : "");                                                      \
 267     NS_WARNING(msg.get());
 268
 269 #else
 270
 271 #  define NS_ENSURE_SUCCESS_BODY(res, ret) \
 272     NS_WARNING("NS_ENSURE_SUCCESS(" #res ", " #ret ") failed");
 273
 274 #  define NS_ENSURE_SUCCESS_BODY_VOID(res) \
 275     NS_WARNING("NS_ENSURE_SUCCESS_VOID(" #res ") failed");
 276
 277 #endif
 278
 279 #define NS_ENSURE_SUCCESS(res, ret)                                \
 280   do {                                                             \
 281     nsresult __rv = res; /* Don't evaluate |res| more than once */ \
 282     if (NS_FAILED(__rv)) {                                         \
 283       NS_ENSURE_SUCCESS_BODY(res, ret)                             \
 284       return ret;                                                  \
 285     }                                                              \
 286   } while (false)
 287
 288 #define NS_ENSURE_SUCCESS_VOID(res)    \
 289   do {                                 \
 290     nsresult __rv = res;               \
 291     if (NS_FAILED(__rv)) {             \
 292       NS_ENSURE_SUCCESS_BODY_VOID(res) \
 293       return;                          \
 294     }                                  \
 295   } while (false)
 296
 297 /******************************************************************************
 298 ** Macros for checking state and arguments upon entering interface boundaries
 299 ******************************************************************************/
 300
 301 #define NS_ENSURE_ARG(arg) NS_ENSURE_TRUE(arg, NS_ERROR_INVALID_ARG)
 302
 303 #define NS_ENSURE_ARG_POINTER(arg) NS_ENSURE_TRUE(arg, NS_ERROR_INVALID_POINTER)
 304
 305 #define NS_ENSURE_ARG_MIN(arg, min) \
 306   NS_ENSURE_TRUE((arg) >= min, NS_ERROR_INVALID_ARG)
 307
 308 #define NS_ENSURE_ARG_MAX(arg, max) \
 309   NS_ENSURE_TRUE((arg) <= max, NS_ERROR_INVALID_ARG)
 310
 311 #define NS_ENSURE_ARG_RANGE(arg, min, max) \
 312   NS_ENSURE_TRUE(((arg) >= min) && ((arg) <= max), NS_ERROR_INVALID_ARG)
 313
 314 #define NS_ENSURE_STATE(state) NS_ENSURE_TRUE(state, NS_ERROR_UNEXPECTED)
 315
 316 #define NS_ENSURE_NO_AGGREGATION(outer) \
 317   NS_ENSURE_FALSE(outer, NS_ERROR_NO_AGGREGATION)
 318
 319 /*****************************************************************************/
 320
 321 #if (defined(DEBUG) || (defined(NIGHTLY_BUILD) && !defined(MOZ_PROFILING))) && \
 322     !defined(XPCOM_GLUE_AVOID_NSPR)
 323 #  define MOZ_THREAD_SAFETY_OWNERSHIP_CHECKS_SUPPORTED 1
 324 #endif
 325
 326 #ifdef MOZILLA_INTERNAL_API
 327 void NS_ABORT_OOM(size_t aSize);
 328 #else
 329 inline void NS_ABORT_OOM(size_t) { MOZ_CRASH(); }
 330 #endif
 331
 332 /* When compiling the XPCOM Glue on Windows, we pretend that it's going to
 333  * be linked with a static CRT (-MT) even when it's not. This means that we
 334  * cannot link to data exports from the CRT, only function exports. So,
 335  * instead of referencing "stderr" directly, use fdopen.
 336  */
 337 #ifdef __cplusplus
 338 extern "C" {
 339 #endif
 340
 341 /**
 342  * printf_stderr(...) is much like fprintf(stderr, ...), except that:
 343  *  - on Android and Firefox OS, *instead* of printing to stderr, it
 344  *    prints to logcat.  (Newlines in the string lead to multiple lines
 345  *    of logcat, but each function call implicitly completes a line even
 346  *    if the string does not end with a newline.)
 347  *  - on Windows, if a debugger is present, it calls OutputDebugString
 348  *    in *addition* to writing to stderr
 349  */
 350 void printf_stderr(const char* aFmt, ...) MOZ_FORMAT_PRINTF(1, 2);
 351
 352 /**
 353  * Same as printf_stderr, but taking va_list instead of varargs
 354  */
 355 void vprintf_stderr(const char* aFmt, va_list aArgs) MOZ_FORMAT_PRINTF(1, 0);
 356
 357 /**
 358  * fprintf_stderr is like fprintf, except that if its file argument
 359  * is stderr, it invokes printf_stderr instead.
 360  *
 361  * This is useful for general debugging code that logs information to a
 362  * file, but that you would like to be useful on Android and Firefox OS.
 363  * If you use fprintf_stderr instead of fprintf in such debugging code,
 364  * then callers can pass stderr to get logging that works on Android and
 365  * Firefox OS (and also the other side-effects of using printf_stderr).
 366  *
 367  * Code that is structured this way needs to be careful not to split a
 368  * line of output across multiple calls to fprintf_stderr, since doing
 369  * so will cause it to appear in multiple lines in logcat output.
 370  * (Producing multiple lines at once is fine.)
 371  */
 372 void fprintf_stderr(FILE* aFile, const char* aFmt, ...) MOZ_FORMAT_PRINTF(2, 3);
 373
 374 /*
 375  * print_stderr and fprint_stderr are like printf_stderr and fprintf_stderr,
 376  * except they deal with Android logcat line length limitations. They do this
 377  * by printing individual lines out of the provided stringstream using separate
 378  * calls to logcat.
 379  */
 380 void print_stderr(std::stringstream& aStr);
 381 void fprint_stderr(FILE* aFile, std::stringstream& aStr);
 382
 383 #ifdef __cplusplus
 384 }
 385 #endif
 386
 387 #endif /* nsDebug_h___ */