src/base/ftdebug.c

/****************************************************************************
 *
 * ftdebug.c
 *
 *   Debugging and logging component (body).
 *
 * Copyright 1996-2018 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 <ft2build.h>
#include FT_FREETYPE_H
#include FT_INTERNAL_DEBUG_H


#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 )
  {
    FT_UNUSED( error );
    FT_UNUSED( line );
    FT_UNUSED( file );

    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 FT_INTERNAL_TRACE_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 = ft_getenv( "FT2_DEBUG" );


    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;

        /* 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 */


/* END */