common.h

/**
 * Copyright © 2019 Andrey Nevolin, https://github.com/AndreyNevolin
 * Twitter: @Andrey_Nevolin
 * LinkedIn: https://www.linkedin.com/in/andrey-nevolin-76387328
 *
 * Common tools that can be used by all modules:
 *      - assertions
 *      - debugging
 *      - logging
 */

#ifndef _PEF_COMMON_H_
#define _PEF_COMMON_H_

#ifdef PEF_DEBUG
#include <execinfo.h>
#include <cstdio>
#include <cstdlib>
#endif

#include "errno.h"
#include "string.h"

/**
 * Maximum size of error messages generated by PEF. This value is used when declaring
 * (or allocating memory for) a buffer intended for storing an error message
 */
#define PEF_ERR_MSG_SIZE 500

/*
 * Macro that evaluates to 1 if PEF should use non-negative return values. In the
 * opposite case the macro evaluates to -1.
 * PEF takes care of its return values' sign to avoid interference with reserved error
 * codes. Only one such 'reserved code' is relevant for now. Namely, PTHREAD_CANCELED
 */
#define PEF_RET_SIGN ((long)PTHREAD_CANCELED < 0 ? 1 : -1)
/* Return value that indicates generic error */
#define PEF_RET_GENERIC_ERR (PEF_RET_SIGN * 1)

#ifdef PEF_DEBUG
/**
 * Print stack dump
 */
static inline void pef_PrintStack()
{
    void *frames[100];
    size_t stack_depth;
    char **calls; 

    fprintf( stderr, "Stack trace: \n");
    stack_depth = backtrace( frames, 100);
    calls = backtrace_symbols( frames, stack_depth);

    for ( size_t i = 0; i < stack_depth; i++ )
    {
        printf ("\t[%2lu] %s\n", stack_depth - i - 1, calls[i]);
    }

    free( calls); 
}

#define PEF_ABORT                                                                   \
    fprintf( stderr, "\n"),                                                         \
    fprintf( stderr, "Internal error: file \"%s\", line %u\n", __FILE__, __LINE__), \
    fprintf( stderr, "\n"),                                                         \
    fflush( NULL),                                                                  \
    pef_PrintStack(),                                                               \
    abort()
#endif /* PEF_DEBUG */

#ifdef PEF_DEBUG
#    define PEF_ASSERT( condition_) ((condition_) || (PEF_ABORT, 0))
#else
#    define PEF_ASSERT( condition_)
#endif

#define PEF_OUT( format_, ...) \
    fprintf( stdout, format_, ##__VA_ARGS__), \
    fprintf( stdout, "\n")

#define PEF_EMIT_ERR_MSG( format_, ...)      \
    fprintf( stderr, format_, ##__VA_ARGS__), \
    fprintf( stderr, "\n")                    \

#define PEF_ERROR( ...)             \
    PEF_EMIT_ERR_MSG( __VA_ARGS__), \
    exit( EXIT_FAILURE)

/**
 * Print formatted error message to the specified buffer
 * Just a shortcut to make error-processing code more compact
 */
#define PEF_BUFF_MSG( buff_, buff_size_, format_, ...)             \
    if ( buff_ )                                                   \
    {                                                              \
        snprintf( buff_, buff_size_, format_, ##__VA_ARGS__);      \
        /* Precaution in case the string doesn't fit the buffer */ \
        buff_[buff_size_ - 1] = '\0';                              \
    }

/**
 * Wrapper around "strerror_r()" aimed at making calls to
 * "strerror_r()" more compact and manageable
 */
static inline char *PEF_STRERROR_R( char *buff, size_t size)
{
    PEF_ASSERT( buff);

    return strerror_r( errno, buff, size);
}

#endif /* _PEF_COMMON_H_ */