1 /**************************************************************************** 2 * 3 * ftdebug.h 4 * 5 * Debugging and logging component (specification). 6 * 7 * Copyright (C) 1996-2023 by 8 * David Turner, Robert Wilhelm, and Werner Lemberg. 9 * 10 * This file is part of the FreeType project, and may only be used, 11 * modified, and distributed under the terms of the FreeType project 12 * license, LICENSE.TXT. By continuing to use, modify, or distribute 13 * this file you indicate that you have read the license and 14 * understand and accept it fully. 15 * 16 * 17 * IMPORTANT: A description of FreeType's debugging support can be 18 * found in 'docs/DEBUG.TXT'. Read it if you need to use or 19 * understand this code. 20 * 21 */ 22 23 24 #ifndef FTDEBUG_H_ 25 #define FTDEBUG_H_ 26 27 28 #include <ft2build.h> 29 #include FT_CONFIG_CONFIG_H 30 #include <freetype/freetype.h> 31 32 #include "compiler-macros.h" 33 34 #ifdef FT_DEBUG_LOGGING 35 #define DLG_STATIC 36 #include <dlg/output.h> 37 #include <dlg/dlg.h> 38 39 #include <freetype/ftlogging.h> 40 #endif /* FT_DEBUG_LOGGING */ 41 42 43 FT_BEGIN_HEADER 44 45 /* force the definition of FT_DEBUG_LEVEL_TRACE if FT_DEBUG_LOGGING is */ 46 /* already defined. */ 47 /* */ 48 #ifdef FT_DEBUG_LOGGING 49 #undef FT_DEBUG_LEVEL_TRACE 50 #define FT_DEBUG_LEVEL_TRACE 51 #endif 52 53 /* force the definition of FT_DEBUG_LEVEL_ERROR if FT_DEBUG_LEVEL_TRACE */ 54 /* is already defined; this simplifies the following #ifdefs */ 55 /* */ 56 #ifdef FT_DEBUG_LEVEL_TRACE 57 #undef FT_DEBUG_LEVEL_ERROR 58 #define FT_DEBUG_LEVEL_ERROR 59 #endif 60 61 62 /************************************************************************** 63 * 64 * Define the trace enums as well as the trace levels array when they are 65 * needed. 66 * 67 */ 68 69 #ifdef FT_DEBUG_LEVEL_TRACE 70 71 #define FT_TRACE_DEF( x ) trace_ ## x , 72 73 /* defining the enumeration */ 74 typedef enum FT_Trace_ 75 { 76 #include <freetype/internal/fttrace.h> 77 trace_count 78 79 } FT_Trace; 80 81 82 /* a pointer to the array of trace levels, */ 83 /* provided by `src/base/ftdebug.c' */ 84 extern int* ft_trace_levels; 85 86 #undef FT_TRACE_DEF 87 88 #endif /* FT_DEBUG_LEVEL_TRACE */ 89 90 91 /************************************************************************** 92 * 93 * Define the FT_TRACE macro 94 * 95 * IMPORTANT! 96 * 97 * Each component must define the macro FT_COMPONENT to a valid FT_Trace 98 * value before using any TRACE macro. 99 * 100 * To get consistent logging output, there should be no newline character 101 * (i.e., '\n') or a single trailing one in the message string of 102 * `FT_TRACEx` and `FT_ERROR`. 103 */ 104 105 106 /************************************************************************* 107 * 108 * If FT_DEBUG_LOGGING is enabled, tracing messages are sent to dlg's API. 109 * If FT_DEBUG_LOGGING is disabled, tracing messages are sent to 110 * `FT_Message` (defined in ftdebug.c). 111 */ 112 #ifdef FT_DEBUG_LOGGING 113 114 /* we need two macros to convert the names of `FT_COMPONENT` to a string */ 115 #define FT_LOGGING_TAG( x ) FT_LOGGING_TAG_( x ) 116 #define FT_LOGGING_TAG_( x ) #x 117 118 /* we need two macros to convert the component and the trace level */ 119 /* to a string that combines them */ 120 #define FT_LOGGING_TAGX( x, y ) FT_LOGGING_TAGX_( x, y ) 121 #define FT_LOGGING_TAGX_( x, y ) #x ":" #y 122 123 124 #define FT_LOG( level, varformat ) \ 125 do \ 126 { \ 127 const char* dlg_tag = FT_LOGGING_TAGX( FT_COMPONENT, level ); \ 128 \ 129 \ 130 ft_add_tag( dlg_tag ); \ 131 if ( ft_trace_levels[FT_TRACE_COMP( FT_COMPONENT )] >= level ) \ 132 { \ 133 if ( custom_output_handler != NULL ) \ 134 FT_Logging_Callback varformat; \ 135 else \ 136 dlg_trace varformat; \ 137 } \ 138 ft_remove_tag( dlg_tag ); \ 139 } while( 0 ) 140 141 #else /* !FT_DEBUG_LOGGING */ 142 143 #define FT_LOG( level, varformat ) \ 144 do \ 145 { \ 146 if ( ft_trace_levels[FT_TRACE_COMP( FT_COMPONENT )] >= level ) \ 147 FT_Message varformat; \ 148 } while ( 0 ) 149 150 #endif /* !FT_DEBUG_LOGGING */ 151 152 153 #ifdef FT_DEBUG_LEVEL_TRACE 154 155 /* we need two macros here to make cpp expand `FT_COMPONENT' */ 156 #define FT_TRACE_COMP( x ) FT_TRACE_COMP_( x ) 157 #define FT_TRACE_COMP_( x ) trace_ ## x 158 159 #define FT_TRACE( level, varformat ) FT_LOG( level, varformat ) 160 161 #else /* !FT_DEBUG_LEVEL_TRACE */ 162 163 #define FT_TRACE( level, varformat ) do { } while ( 0 ) /* nothing */ 164 165 #endif /* !FT_DEBUG_LEVEL_TRACE */ 166 167 168 /************************************************************************** 169 * 170 * @function: 171 * FT_Trace_Get_Count 172 * 173 * @description: 174 * Return the number of available trace components. 175 * 176 * @return: 177 * The number of trace components. 0 if FreeType 2 is not built with 178 * FT_DEBUG_LEVEL_TRACE definition. 179 * 180 * @note: 181 * This function may be useful if you want to access elements of the 182 * internal trace levels array by an index. 183 */ 184 FT_BASE( FT_Int ) 185 FT_Trace_Get_Count( void ); 186 187 188 /************************************************************************** 189 * 190 * @function: 191 * FT_Trace_Get_Name 192 * 193 * @description: 194 * Return the name of a trace component. 195 * 196 * @input: 197 * The index of the trace component. 198 * 199 * @return: 200 * The name of the trace component. This is a statically allocated 201 * C~string, so do not free it after use. `NULL` if FreeType is not 202 * built with FT_DEBUG_LEVEL_TRACE definition. 203 * 204 * @note: 205 * Use @FT_Trace_Get_Count to get the number of available trace 206 * components. 207 */ 208 FT_BASE( const char* ) 209 FT_Trace_Get_Name( FT_Int idx ); 210 211 212 /************************************************************************** 213 * 214 * @function: 215 * FT_Trace_Disable 216 * 217 * @description: 218 * Switch off tracing temporarily. It can be activated again with 219 * @FT_Trace_Enable. 220 */ 221 FT_BASE( void ) 222 FT_Trace_Disable( void ); 223 224 225 /************************************************************************** 226 * 227 * @function: 228 * FT_Trace_Enable 229 * 230 * @description: 231 * Activate tracing. Use it after tracing has been switched off with 232 * @FT_Trace_Disable. 233 */ 234 FT_BASE( void ) 235 FT_Trace_Enable( void ); 236 237 238 /************************************************************************** 239 * 240 * You need two opening and closing parentheses! 241 * 242 * Example: FT_TRACE0(( "Value is %i", foo )) 243 * 244 * Output of the FT_TRACEX macros is sent to stderr. 245 * 246 */ 247 248 #define FT_TRACE0( varformat ) FT_TRACE( 0, varformat ) 249 #define FT_TRACE1( varformat ) FT_TRACE( 1, varformat ) 250 #define FT_TRACE2( varformat ) FT_TRACE( 2, varformat ) 251 #define FT_TRACE3( varformat ) FT_TRACE( 3, varformat ) 252 #define FT_TRACE4( varformat ) FT_TRACE( 4, varformat ) 253 #define FT_TRACE5( varformat ) FT_TRACE( 5, varformat ) 254 #define FT_TRACE6( varformat ) FT_TRACE( 6, varformat ) 255 #define FT_TRACE7( varformat ) FT_TRACE( 7, varformat ) 256 257 258 /************************************************************************** 259 * 260 * Define the FT_ERROR macro. 261 * 262 * Output of this macro is sent to stderr. 263 * 264 */ 265 266 #ifdef FT_DEBUG_LEVEL_ERROR 267 268 /************************************************************************** 269 * 270 * If FT_DEBUG_LOGGING is enabled, error messages are sent to dlg's API. 271 * If FT_DEBUG_LOGGING is disabled, error messages are sent to `FT_Message` 272 * (defined in ftdebug.c). 273 * 274 */ 275 #ifdef FT_DEBUG_LOGGING 276 277 #define FT_ERROR( varformat ) \ 278 do \ 279 { \ 280 const char* dlg_tag = FT_LOGGING_TAG( FT_COMPONENT ); \ 281 \ 282 \ 283 ft_add_tag( dlg_tag ); \ 284 dlg_trace varformat; \ 285 ft_remove_tag( dlg_tag ); \ 286 } while ( 0 ) 287 288 #else /* !FT_DEBUG_LOGGING */ 289 290 #define FT_ERROR( varformat ) FT_Message varformat 291 292 #endif /* !FT_DEBUG_LOGGING */ 293 294 295 #else /* !FT_DEBUG_LEVEL_ERROR */ 296 297 #define FT_ERROR( varformat ) do { } while ( 0 ) /* nothing */ 298 299 #endif /* !FT_DEBUG_LEVEL_ERROR */ 300 301 302 /************************************************************************** 303 * 304 * Define the FT_ASSERT and FT_THROW macros. The call to `FT_Throw` makes 305 * it possible to easily set a breakpoint at this function. 306 * 307 */ 308 309 #ifdef FT_DEBUG_LEVEL_ERROR 310 311 #define FT_ASSERT( condition ) \ 312 do \ 313 { \ 314 if ( !( condition ) ) \ 315 FT_Panic( "assertion failed on line %d of file %s\n", \ 316 __LINE__, __FILE__ ); \ 317 } while ( 0 ) 318 319 #define FT_THROW( e ) \ 320 ( FT_Throw( FT_ERR_CAT( FT_ERR_PREFIX, e ), \ 321 __LINE__, \ 322 __FILE__ ) | \ 323 FT_ERR_CAT( FT_ERR_PREFIX, e ) ) 324 325 #else /* !FT_DEBUG_LEVEL_ERROR */ 326 327 #define FT_ASSERT( condition ) do { } while ( 0 ) 328 329 #define FT_THROW( e ) FT_ERR_CAT( FT_ERR_PREFIX, e ) 330 331 #endif /* !FT_DEBUG_LEVEL_ERROR */ 332 333 334 /************************************************************************** 335 * 336 * Define `FT_Message` and `FT_Panic` when needed. 337 * 338 */ 339 340 #ifdef FT_DEBUG_LEVEL_ERROR 341 342 #include "stdio.h" /* for vfprintf() */ 343 344 /* print a message */ 345 FT_BASE( void ) 346 FT_Message( const char* fmt, 347 ... ); 348 349 /* print a message and exit */ 350 FT_BASE( void ) 351 FT_Panic( const char* fmt, 352 ... ); 353 354 /* report file name and line number of an error */ 355 FT_BASE( int ) 356 FT_Throw( FT_Error error, 357 int line, 358 const char* file ); 359 360 #endif /* FT_DEBUG_LEVEL_ERROR */ 361 362 363 FT_BASE( void ) 364 ft_debug_init( void ); 365 366 367 #ifdef FT_DEBUG_LOGGING 368 369 /************************************************************************** 370 * 371 * 'dlg' uses output handlers to control how and where log messages are 372 * printed. Therefore we need to define a default output handler for 373 * FreeType. 374 */ 375 FT_BASE( void ) 376 ft_log_handler( const struct dlg_origin* origin, 377 const char* string, 378 void* data ); 379 380 381 /************************************************************************** 382 * 383 * 1. `ft_default_log_handler` stores the function pointer that is used 384 * internally by FreeType to print logs to a file. 385 * 386 * 2. `custom_output_handler` stores the function pointer to the callback 387 * function provided by the user. 388 * 389 * It is defined in `ftdebug.c`. 390 */ 391 extern dlg_handler ft_default_log_handler; 392 extern FT_Custom_Log_Handler custom_output_handler; 393 394 395 /************************************************************************** 396 * 397 * If FT_DEBUG_LOGGING macro is enabled, FreeType needs to initialize and 398 * un-initialize `FILE*`. 399 * 400 * These functions are defined in `ftdebug.c`. 401 */ 402 FT_BASE( void ) 403 ft_logging_init( void ); 404 405 FT_BASE( void ) 406 ft_logging_deinit( void ); 407 408 409 /************************************************************************** 410 * 411 * For printing the name of `FT_COMPONENT` along with the actual log we 412 * need to add a tag with the name of `FT_COMPONENT`. 413 * 414 * These functions are defined in `ftdebug.c`. 415 */ 416 FT_BASE( void ) 417 ft_add_tag( const char* tag ); 418 419 FT_BASE( void ) 420 ft_remove_tag( const char* tag ); 421 422 423 /************************************************************************** 424 * 425 * A function to print log data using a custom callback logging function 426 * (which is set using `FT_Set_Log_Handler`). 427 * 428 * This function is defined in `ftdebug.c`. 429 */ 430 FT_BASE( void ) 431 FT_Logging_Callback( const char* fmt, 432 ... ); 433 434 #endif /* FT_DEBUG_LOGGING */ 435 436 437 FT_END_HEADER 438 439 #endif /* FTDEBUG_H_ */ 440 441 442 /* END */ 443