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ftdebug.c (14105B)

---

/****************************************************************************
*
* ftdebug.c
*
*   Debugging and logging component (body).
*
* Copyright (C) 1996-2025 by
* David Turner, Robert Wilhelm, and Werner Lemberg.
*
* This file is part of the FreeType project, and may only be used,
* modified, and distributed under the terms of the FreeType project
* license, LICENSE.TXT.  By continuing to use, modify, or distribute
* this file you indicate that you have read the license and
* understand and accept it fully.
*
*/


 /**************************************************************************
  *
  * This component contains various macros and functions used to ease the
  * debugging of the FreeType engine.  Its main purpose is in assertion
  * checking, tracing, and error detection.
  *
  * There are now three debugging modes:
  *
  * - trace mode
  *
  *   Error and trace messages are sent to the log file (which can be the
  *   standard error output).
  *
  * - error mode
  *
  *   Only error messages are generated.
  *
  * - release mode:
  *
  *   No error message is sent or generated.  The code is free from any
  *   debugging parts.
  *
  */


#include <freetype/freetype.h>
#include <freetype/ftlogging.h>
#include <freetype/internal/ftdebug.h>
#include <freetype/internal/ftobjs.h>


#ifdef FT_DEBUG_LOGGING

 /**************************************************************************
  *
  * Variables used to control logging.
  *
  * 1. `ft_default_trace_level` stores the value of trace levels, which are
  *    provided to FreeType using the `FT2_DEBUG` environment variable.
  *
  * 2. `ft_fileptr` stores the `FILE*` handle.
  *
  * 3. `ft_component` is a string that holds the name of `FT_COMPONENT`.
  *
  * 4. The flag `ft_component_flag` prints the name of `FT_COMPONENT` along
  *    with the actual log message if set to true.
  *
  * 5. The flag `ft_timestamp_flag` prints time along with the actual log
  *    message if set to true.
  *
  * 6. `ft_have_newline_char` is used to differentiate between a log
  *    message with and without a trailing newline character.
  *
  * 7. `ft_custom_trace_level` stores the custom trace level value, which
  *    is provided by the user at run-time.
  *
  * We use `static` to avoid 'unused variable' warnings.
  *
  */
 static const char*  ft_default_trace_level = NULL;
 static FILE*        ft_fileptr             = NULL;
 static const char*  ft_component           = NULL;
 static FT_Bool      ft_component_flag      = FALSE;
 static FT_Bool      ft_timestamp_flag      = FALSE;
 static FT_Bool      ft_have_newline_char   = TRUE;
 static const char*  ft_custom_trace_level  = NULL;

 /* declared in ftdebug.h */

 dlg_handler            ft_default_log_handler = NULL;
 FT_Custom_Log_Handler  custom_output_handler  = NULL;

#endif /* FT_DEBUG_LOGGING */


#ifdef FT_DEBUG_LEVEL_ERROR

 /* documentation is in ftdebug.h */

 FT_BASE_DEF( void )
 FT_Message( const char*  fmt,
             ... )
 {
   va_list  ap;


   va_start( ap, fmt );
   vfprintf( stderr, fmt, ap );
   va_end( ap );
 }


 /* documentation is in ftdebug.h */

 FT_BASE_DEF( void )
 FT_Panic( const char*  fmt,
           ... )
 {
   va_list  ap;


   va_start( ap, fmt );
   vfprintf( stderr, fmt, ap );
   va_end( ap );

   exit( EXIT_FAILURE );
 }


 /* documentation is in ftdebug.h */

 FT_BASE_DEF( int )
 FT_Throw( FT_Error     error,
           int          line,
           const char*  file )
 {
#if 0
   /* activating the code in this block makes FreeType very chatty */
   fprintf( stderr,
            "%s:%d: error 0x%02x: %s\n",
            file,
            line,
            error,
            FT_Error_String( error ) );
#else
   FT_UNUSED( error );
   FT_UNUSED( line );
   FT_UNUSED( file );
#endif

   return 0;
 }

#endif /* FT_DEBUG_LEVEL_ERROR */


#ifdef FT_DEBUG_LEVEL_TRACE

 /* array of trace levels, initialized to 0; */
 /* this gets adjusted at run-time           */
 static int  ft_trace_levels_enabled[trace_count];

 /* array of trace levels, always initialized to 0 */
 static int  ft_trace_levels_disabled[trace_count];

 /* a pointer to either `ft_trace_levels_enabled' */
 /* or `ft_trace_levels_disabled'                 */
 int*  ft_trace_levels;

 /* define array of trace toggle names */
#define FT_TRACE_DEF( x )  #x ,

 static const char*  ft_trace_toggles[trace_count + 1] =
 {
#include <freetype/internal/fttrace.h>
   NULL
 };

#undef FT_TRACE_DEF


 /* documentation is in ftdebug.h */

 FT_BASE_DEF( FT_Int )
 FT_Trace_Get_Count( void )
 {
   return trace_count;
 }


 /* documentation is in ftdebug.h */

 FT_BASE_DEF( const char * )
 FT_Trace_Get_Name( FT_Int  idx )
 {
   int  max = FT_Trace_Get_Count();


   if ( idx < max )
     return ft_trace_toggles[idx];
   else
     return NULL;
 }


 /* documentation is in ftdebug.h */

 FT_BASE_DEF( void )
 FT_Trace_Disable( void )
 {
   ft_trace_levels = ft_trace_levels_disabled;
 }


 /* documentation is in ftdebug.h */

 FT_BASE_DEF( void )
 FT_Trace_Enable( void )
 {
   ft_trace_levels = ft_trace_levels_enabled;
 }


 /**************************************************************************
  *
  * Initialize the tracing sub-system.  This is done by retrieving the
  * value of the `FT2_DEBUG' environment variable.  It must be a list of
  * toggles, separated by spaces, `;', or `,'.  Example:
  *
  *   export FT2_DEBUG="any:3 memory:7 stream:5"
  *
  * This requests that all levels be set to 3, except the trace level for
  * the memory and stream components which are set to 7 and 5,
  * respectively.
  *
  * See the file `include/freetype/internal/fttrace.h' for details of
  * the available toggle names.
  *
  * The level must be between 0 and 7; 0 means quiet (except for serious
  * runtime errors), and 7 means _very_ verbose.
  */
 FT_BASE_DEF( void )
 ft_debug_init( void )
 {
   const char*  ft2_debug = NULL;


#ifdef FT_DEBUG_LOGGING
   if ( ft_custom_trace_level != NULL )
     ft2_debug = ft_custom_trace_level;
   else
     ft2_debug = ft_default_trace_level;
#else
   ft2_debug = ft_getenv( "FT2_DEBUG" );
#endif

   if ( ft2_debug )
   {
     const char*  p = ft2_debug;
     const char*  q;


     for ( ; *p; p++ )
     {
       /* skip leading whitespace and separators */
       if ( *p == ' ' || *p == '\t' || *p == ',' || *p == ';' || *p == '=' )
         continue;

#ifdef FT_DEBUG_LOGGING

       /* check extra arguments for logging */
       if ( *p == '-' )
       {
         const char*  r = ++p;


         if ( *r == 'v' )
         {
           const char*  s = ++r;


           ft_component_flag = TRUE;

           if ( *s == 't' )
           {
             ft_timestamp_flag = TRUE;
             p++;
           }

           p++;
         }

         else if ( *r == 't' )
         {
           const char*  s = ++r;


           ft_timestamp_flag = TRUE;

           if ( *s == 'v' )
           {
             ft_component_flag = TRUE;
             p++;
           }

           p++;
         }
       }

#endif /* FT_DEBUG_LOGGING */

       /* read toggle name, followed by ':' */
       q = p;
       while ( *p && *p != ':' )
         p++;

       if ( !*p )
         break;

       if ( *p == ':' && p > q )
       {
         FT_Int  n, i, len = (FT_Int)( p - q );
         FT_Int  level = -1, found = -1;


         for ( n = 0; n < trace_count; n++ )
         {
           const char*  toggle = ft_trace_toggles[n];


           for ( i = 0; i < len; i++ )
           {
             if ( toggle[i] != q[i] )
               break;
           }

           if ( i == len && toggle[i] == 0 )
           {
             found = n;
             break;
           }
         }

         /* read level */
         p++;
         if ( *p )
         {
           level = *p - '0';
           if ( level < 0 || level > 7 )
             level = -1;
         }

         if ( found >= 0 && level >= 0 )
         {
           if ( found == trace_any )
           {
             /* special case for `any' */
             for ( n = 0; n < trace_count; n++ )
               ft_trace_levels_enabled[n] = level;
           }
           else
             ft_trace_levels_enabled[found] = level;
         }
       }
     }
   }

   ft_trace_levels = ft_trace_levels_enabled;
 }


#else  /* !FT_DEBUG_LEVEL_TRACE */


 FT_BASE_DEF( void )
 ft_debug_init( void )
 {
   /* nothing */
 }


 FT_BASE_DEF( FT_Int )
 FT_Trace_Get_Count( void )
 {
   return 0;
 }


 FT_BASE_DEF( const char * )
 FT_Trace_Get_Name( FT_Int  idx )
 {
   FT_UNUSED( idx );

   return NULL;
 }


 FT_BASE_DEF( void )
 FT_Trace_Disable( void )
 {
   /* nothing */
 }


 /* documentation is in ftdebug.h */

 FT_BASE_DEF( void )
 FT_Trace_Enable( void )
 {
   /* nothing */
 }

#endif /* !FT_DEBUG_LEVEL_TRACE */


#ifdef FT_DEBUG_LOGGING

 /**************************************************************************
  *
  * Initialize and de-initialize 'dlg' library.
  *
  */

 FT_BASE_DEF( void )
 ft_logging_init( void )
 {
   ft_default_log_handler = ft_log_handler;
   ft_default_trace_level = ft_getenv( "FT2_DEBUG" );

   if ( ft_getenv( "FT_LOGGING_FILE" ) )
     ft_fileptr = ft_fopen( ft_getenv( "FT_LOGGING_FILE" ), "w" );
   else
     ft_fileptr = stderr;

   ft_debug_init();

   /* Set the default output handler for 'dlg'. */
   dlg_set_handler( ft_default_log_handler, NULL );
 }


 FT_BASE_DEF( void )
 ft_logging_deinit( void )
 {
   if ( ft_fileptr != stderr )
     ft_fclose( ft_fileptr );
 }


 /**************************************************************************
  *
  * An output log handler for FreeType.
  *
  */
 FT_BASE_DEF( void )
 ft_log_handler( const struct dlg_origin*  origin,
                 const char*               string,
                 void*                     data )
 {
   char         features_buf[128];
   char*        bufp = features_buf;

   FT_UNUSED( data );


   if ( ft_have_newline_char )
   {
     const char*  features        = NULL;
     size_t       features_length = 0;


#define FEATURES_TIMESTAMP            "[%h:%m] "
#define FEATURES_COMPONENT            "[%t] "
#define FEATURES_TIMESTAMP_COMPONENT  "[%h:%m %t] "

     if ( ft_timestamp_flag && ft_component_flag )
     {
       features        = FEATURES_TIMESTAMP_COMPONENT;
       features_length = sizeof ( FEATURES_TIMESTAMP_COMPONENT );
     }
     else if ( ft_timestamp_flag )
     {
       features        = FEATURES_TIMESTAMP;
       features_length = sizeof ( FEATURES_TIMESTAMP );
     }
     else if ( ft_component_flag )
     {
       features        = FEATURES_COMPONENT;
       features_length = sizeof ( FEATURES_COMPONENT );
     }

     if ( ft_component_flag || ft_timestamp_flag )
     {
       ft_strncpy( features_buf, features, features_length );
       bufp += features_length - 1;
     }

     if ( ft_component_flag )
     {
       size_t  tag_length = ft_strlen( *origin->tags );
       size_t  i;


       /* To vertically align tracing messages we compensate the */
       /* different FT_COMPONENT string lengths by inserting an  */
       /* appropriate amount of space characters.                */
       for ( i = 0;
             i < FT_MAX_TRACE_LEVEL_LENGTH - tag_length;
             i++ )
         *bufp++ = ' ';
     }
   }

   /* Finally add the format string for the tracing message. */
   *bufp++ = '%';
   *bufp++ = 'c';
   *bufp   = '\0';

   dlg_generic_outputf_stream( ft_fileptr,
                               (const char*)features_buf,
                               origin,
                               string,
                               dlg_default_output_styles,
                               true );

   if ( ft_strrchr( string, '\n' ) )
     ft_have_newline_char = TRUE;
   else
     ft_have_newline_char = FALSE;
 }


 /* documentation is in ftdebug.h */
 FT_BASE_DEF( void )
 ft_add_tag( const char*  tag )
 {
   ft_component = tag;

   dlg_add_tag( tag, NULL );
 }


 /* documentation is in ftdebug.h */
 FT_BASE_DEF( void )
 ft_remove_tag( const char*  tag )
 {
   dlg_remove_tag( tag, NULL );
 }


 /* documentation is in ftlogging.h */

 FT_EXPORT_DEF( void )
 FT_Trace_Set_Level( const char*  level )
 {
   ft_component_flag     = FALSE;
   ft_timestamp_flag     = FALSE;
   ft_custom_trace_level = level;

   ft_debug_init();
 }


 /* documentation is in ftlogging.h */

 FT_EXPORT_DEF( void )
 FT_Trace_Set_Default_Level( void )
 {
   ft_component_flag     = FALSE;
   ft_timestamp_flag     = FALSE;
   ft_custom_trace_level = NULL;

   ft_debug_init();
 }


 /**************************************************************************
  *
  * Functions to handle a custom log handler.
  *
  */

 /* documentation is in ftlogging.h */

 FT_EXPORT_DEF( void )
 FT_Set_Log_Handler( FT_Custom_Log_Handler  handler )
 {
   custom_output_handler = handler;
 }


 /* documentation is in ftlogging.h */

 FT_EXPORT_DEF( void )
 FT_Set_Default_Log_Handler( void )
 {
   custom_output_handler = NULL;
 }


 /* documentation is in ftdebug.h */
 FT_BASE_DEF( void )
 FT_Logging_Callback( const char*  fmt,
                      ... )
 {
   va_list  ap;


   va_start( ap, fmt );
   custom_output_handler( ft_component, fmt, ap );
   va_end( ap );
 }

#else /* !FT_DEBUG_LOGGING */

 FT_EXPORT_DEF( void )
 FT_Trace_Set_Level( const char*  level )
 {
   FT_UNUSED( level );
 }


 FT_EXPORT_DEF( void )
 FT_Trace_Set_Default_Level( void )
 {
   /* nothing */
 }


 FT_EXPORT_DEF( void )
 FT_Set_Log_Handler( FT_Custom_Log_Handler  handler )
 {
   FT_UNUSED( handler );
 }


 FT_EXPORT_DEF( void )
 FT_Set_Default_Log_Handler( void )
 {
   /* nothing */
 }

#endif /* !FT_DEBUG_LOGGING */


/* END */