/*
 * Copyright (c) 2019, Vaclav Bubnik
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 *  Frequently used C compiler warning flags:
 *      -std=c90
 *      -pedantic
 *      -Wall
 *      -Wextra
 *
 *  Additional C compiler warning flags with examples:
 *      -Wshadow
 *      -Wconversion
 *      -Wfloat-equal
 *      -Wswitch-default
 *      -Wswitch-enum
 *      -Wcast-align
 *      -Wbad-function-cast
 *      -Wwrite-strings
 *      -Wredundant-decls
 */

int main(void)
{
    return 0;
}

/* -Wshadow, GCC 4.8.4, LLVM 3.5 */
void w_shadow(void)
{
    int i = 1;
    {
        int i = 2; /* declaration shadows a local variable */
        (void)i;
    }
    (void)i;
}

/* -Wsign-conversion, -Wconversion, GCC 4.8.4, LLVM 3.5 */
void w_sign_conversion(void)
{
    int si = 1;
    unsigned int ui;
    ui = si; /* implicit conversion changes signedness: 'int' to 'unsigned int' */

    si = 0x7fffffff;
    ui = 0x7fffffff;

    si = 0x80000000; /* implicit conversion changes signedness: 'unsigned int' to 'int' [-Wsign-conversion] */
    si = 0xffffffff; /* implicit conversion changes signedness: 'unsigned int' to 'int' [-Wsign-conversion] */
    si = 2147483648; /* implicit conversion changes signedness: 'long' to 'int' [-Wsign-conversion] */

    (void)ui;
}

/* -Wfloat-conversion, -Wconversion, GCC 4.8.4, LLVM 3.5 */
void w_float_conversion(void)
{
    double d = 3.14;
    float f;
    f = d; /* implicit conversion loses floating-point precision: 'double' to 'float' */
    (void)f;
}

/* -Wfloat-equal, GCC 4.8.4, LLVM 3.5 */
void w_float_equal(void)
{
    float f = 1.2f;
    if (f == 1.2f) /* comparing floating point with == or != is unsafe */
    {
        /* empty */
    }
}

/* -Wswitch-default, GCC 4.8.4 */
void w_switch_default(int x)
{
    switch (x) /* switch missing default case */
    {
        case 0: break;
    }
}

/* -Wswitch-enum, GCC 4.8.4, LLVM 3.5 */
void w_switch_enum(void)
{
    enum Color { Red, Green, Blue } color = Red;
    switch (color) /* enumeration value 'Blue' not explicitly handled in switch */
    {
        case Red: break;
        case Green: break;
        default: break;
    }
}

/* -Wcast-align, LLVM 3.5 */
void w_cast_align(void)
{
    const char *cstr = "abcd";
    const int *i = (const int *)cstr; /* cast from 'const char *' to 'const int *' increases required alignment from 1 to 4 */
    (void)i;
}

/* -Wbad-function-cast, LLVM 3.5 */
/* -Wpointer-to-int-cast in GCC, default in GCC 4.8.4 */
static const char *getstr(void)
{
    return "abc";
}
void w_bad_function_cast(void)
{
    int i = (int)getstr(); /* cast from function call of type 'const char *' to non-matching type 'int' */
    (void)i;
}

/* -Wwrite-strings, GCC 4.8.4, LLVM 3.5 */
void w_write_strings(void)
{
    char *str = "abc"; /* initializing 'char *' with an expression of type 'const char [4]' discards qualifiers */
    (void)str;
}

/* -Wredundant-decls, GCC 4.8.4 */
void w_redundant_decls(void);
void w_redundant_decls(void); /* redundant redeclaration of '..' */