errors.h

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/*
 * Utility functions for handling errors.
 *
 * Includes (among others):
 *   return values
 *   better warn
 *   stack trace printing
 *
 *
 * Created by MacBook on 30.10.2024.
 */
 
#ifndef CLIBS_ERRORS_H
#define CLIBS_ERRORS_H
 
/* for this header */
#include "attributes.h"      /* PrintfLike, LibraryDefined */
#include "filenames.h"       /* get_prog_name(), __FILE_NAME__ */
#include "terminal_colors.h" /* COLORs, PrintInColor */
 
#include <errno.h>  /* for WarnUniversal + include */
#include <stddef.h> /* ptrdiff_t */
#include <string.h> /* strerror() */
 
/* for user */
#include <err.h> /* include */
 
 
#define ERRNO_OK 0 /* No error */
 
 
#define RV_EXCEPTION ( -2 ) /* Non-fatal, recoverable error e.g. OOB index */
#define RV_ERROR     ( -1 ) /* Fatal, un-recoverable error */
#define RV_SUCCESS   0      /* Success */
 

LibraryDefined const char *rv_to_string( const int rv )
{
    switch ( rv )
    {
        case RV_SUCCESS:
            return "Success";
        case RV_EXCEPTION:
            return "Exception";
        case RV_ERROR:
            return "Error";
 
        default:
            return "Unknown error";
    }
}
 
 
#define on_fail( func_call )  if ( ( func_call ) != RV_SUCCESS )
#define on_error( func_call ) if ( ( func_call ) == RV_ERROR )

#define return_on_fail( func_call )           \
    do                                        \
    {                                         \
        int func_call_retval = ( func_call ); \
        on_fail ( func_call_retval )          \
        {                                     \
            ( void ) f_stack_trace( NULL );   \
            return func_call_retval;          \
        }                                     \
    }                                         \
    while ( 0 )

#define return_on_error( func_call )          \
    do                                        \
    {                                         \
        int func_call_retval = ( func_call ); \
        on_error ( func_call_retval )         \
        {                                     \
            ( void ) f_stack_trace( 0 );      \
            return func_call_retval;          \
        }                                     \
    }                                         \
    while ( 0 )
 
#define goto_on_fail( GOTO_LABEL, func_call ) \
    do                                        \
    {                                         \
        on_fail ( func_call )                 \
            goto GOTO_LABEL;                  \
    }                                         \
    while ( 0 )
 
#define goto_on_error( GOTO_LABEL, func_call ) \
    do                                         \
    {                                          \
        on_error ( func_call )                 \
            goto GOTO_LABEL;                   \
    }                                          \
    while ( 0 )
 
 
#ifndef COLOR_WARNING
#define COLOR_WARNING FOREGROUND_RED
#endif //COLOR_WARNING
 
LibraryDefined PrintfLike( 7, 8 ) Cold ptrdiff_t
WarnUniversal( bool PrintProgName,
               const char *__restrict FileName,
               const char *__restrict FunctionName,
               int LineNumber,
               int err_no,
               ptrdiff_t return_value,
               const char *__restrict format,
               ... );

ptrdiff_t WarnUniversal( bool PrintProgName,
                         const char *__restrict FileName,
                         const char *__restrict FunctionName,
                         int LineNumber,
                         int err_no,
                         ptrdiff_t return_value,
                         const char *__restrict format,
                         ... )
{
#ifndef SUPPRESS_WARNINGS
    SetTerminalColor( stderr, COLOR_WARNING );
 
    if ( PrintProgName )
        fprintf( stderr, "%s", get_prog_name() );
    if ( FileName != NULL )
        fprintf( stderr, ": %s", FileName );
    if ( FunctionName != NULL )
        fprintf( stderr, ": %s", FunctionName );
    if ( LineNumber > 0 )
        fprintf( stderr, " @ %i", LineNumber );
 
    if ( PrintProgName || FileName != NULL || FunctionName != NULL || LineNumber > 0 )
        fprintf( stderr, ": " );
 
    va_list vaList;
    va_start( vaList, format );
    vfprintf( stderr, format, vaList );
    va_end( vaList );
 
    if ( err_no >= 0 )
        fprintf( stderr, ": %s", strerror( err_no ) );
 
    SetTerminalColor( stderr, COLOR_DEFAULT );
 
    fprintf( stderr, "\n" );
 
#else  // defined( SUPPRESS_WARNINGS )
    ( void ) ( PrintProgName );
    ( void ) ( FileName );
    ( void ) ( FunctionName );
    ( void ) ( LineNumber );
    ( void ) ( err_no );
    ( void ) ( format );
#endif //SUPPRESS_WARNINGS
 
    return return_value;
}

#define f_stack_trace( RETVAL ) \
    WarnUniversal( false, NULL, NULL, -1, -1, ( ptrdiff_t ) RETVAL, "\tin %s", __func__ )

#define ffl_stack_trace( RETVAL )        \
    WarnUniversal( false,                \
                   NULL,                 \
                   NULL,                 \
                   -1,                   \
                   -1,                   \
                   ( ptrdiff_t ) RETVAL, \
                   "\tin %s: %s @ %d",   \
                   __FILE_NAME__,        \
                   __func__,             \
                   __LINE__ )
 

#define warn_ret( RETVAL, ... ) \
    WarnUniversal( true, NULL, NULL, -1, errno, ( ptrdiff_t ) RETVAL, __VA_ARGS__ )
#define warnx_ret( RETVAL, ... ) \
    WarnUniversal( true, NULL, NULL, -1, -1, ( ptrdiff_t ) RETVAL, __VA_ARGS__ )

#define fwarn( ... ) \
    ( void ) WarnUniversal( true, NULL, __func__, -1, errno, -1, __VA_ARGS__ )
#define fwarnx( ... ) \
    ( void ) WarnUniversal( true, NULL, __func__, -1, -1, -1, __VA_ARGS__ )
#define fwarn_ret( RETVAL, ... ) \
    WarnUniversal( true, NULL, __func__, -1, errno, ( ptrdiff_t ) RETVAL, __VA_ARGS__ )
#define fwarnx_ret( RETVAL, ... ) \
    WarnUniversal( true, NULL, __func__, -1, -1, ( ptrdiff_t ) RETVAL, __VA_ARGS__ )
 
#define fflwarn( ... )      \
    ( void ) WarnUniversal( \
            true, __FILE_NAME__, __func__, __LINE__, errno, -1, __VA_ARGS__ )
#define fflwarnx( ... ) \
    ( void ) WarnUniversal( true, __FILE_NAME__, __func__, __LINE__, -1, -1, __VA_ARGS__ )
#define fflwarn_ret( RETVAL, ... )       \
    WarnUniversal( true,                 \
                   __FILE_NAME__,        \
                   __func__,             \
                   __LINE__,             \
                   errno,                \
                   ( ptrdiff_t ) RETVAL, \
                   __VA_ARGS__ )
#define fflwarnx_ret( RETVAL, ... )      \
    WarnUniversal( true,                 \
                   __FILE_NAME__,        \
                   __func__,             \
                   __LINE__,             \
                   -1,                   \
                   ( ptrdiff_t ) RETVAL, \
                   __VA_ARGS__ )
 
 
#endif //CLIBS_ERRORS_H