/* ==========================================================
* MISRA C:2012 Rule 2.x — Unused Code (Edge Cases)
* All rules: 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7
* ========================================================== */
#include <stdio.h>
#include <stdlib.h>
/* ---- Rule 2.1: Unreachable code ---- */
/* Edge: code after return inside nested if-else chain */
int rule_2_1_edge_nested(int a) {
if (a > 0) {
return 1;
} else {
return -1;
}
a = a + 1; /* Line 18: UNREACHABLE — both branches return */
}
/* Edge: code after infinite loop with no break */
void rule_2_1_edge_infinite(void) {
for (;;) {
/* spin forever */
}
printf("never reached\n"); /* Line 26: UNREACHABLE */
}
/* Edge: switch where every case returns */
int rule_2_1_edge_switch(int x) {
switch (x) {
case 0:
return 0;
case 1:
return 1;
default:
return -1;
}
return 99; /* Line 35: UNREACHABLE — all paths return */
}
/* ---- Rule 2.2: Dead code (no side‐effect) ---- */
/* Edge: expression result computed but never stored/used */
void rule_2_2_edge_unused_expr(int a, int b) {
int c = a + b;
a *b; /* Line 43: DEAD CODE — multiplication result discarded */
(void)(c);
}
/* Edge: post-increment with value unused */
void rule_2_2_edge_postinc(void) {
int x = 5;
x++; /* Line 49: actually used (modifies x) — but... */
/* x is never read again — entire modification is dead */
}
/* Edge: assignment to variable that is immediately overwritten */
void rule_2_2_edge_overwrite(int input) {
int result = input * 2; /* Line 55: DEAD — overwritten below */
result = input * 3;
printf("%d\n", result);
}
/* ---- Rule 2.3: Unused type declaration ---- */
/* Edge: typedef inside function scope, never used */
void rule_2_3_edge(void) {
typedef struct { /* Line 63: UNUSED type */
int x;
int y;
} UnusedLocalPoint;
}
/* Edge: typedef at file scope never referenced anywhere */
typedef unsigned long long UnusedFileType; /* Line 69: UNUSED */
/* ---- Rule 2.4: Unused tag declaration ---- */
/* Edge: struct tag declared but only pointer-to-void used */
struct UnusedTag { /* Line 74: UNUSED tag */
float value;
char name[32];
};
/* Edge: enum tag with values that ARE used via #define, but tag itself is not
*/
enum UnusedColorTag { /* Line 80: UNUSED tag */
RED_VAL = 0xFF0000,
GREEN_VAL = 0x00FF00,
BLUE_VAL = 0x0000FF
};
/* ---- Rule 2.5: Unused macro declaration ---- */
#define UNUSED_MACRO_BUFFER_SIZE 1024 /* Line 88: UNUSED macro */
/* Edge: macro defined just before a #undef — never actually expanded */
#define TEMP_MACRO 42 /* Line 91: UNUSED — undef'd immediately */
#undef TEMP_MACRO
/* ---- Rule 2.6: Unused label declaration ---- */
/* Edge: label exists for a goto that was later refactored out */
void rule_2_6_edge(int x) {
if (x > 0) {
printf("positive\n");
}
cleanup: /* Line 100: UNUSED label */
return;
}
/* Edge: multiple labels, only one used */
void rule_2_6_edge_multi(int mode) {
if (mode == 1)
goto used_label;
unused_label: /* Line 107: UNUSED label */
printf("dead path\n");
used_label:
printf("alive\n");
}
/* ---- Rule 2.7: Unused function parameter ---- */
/* Edge: callback signature forces extra params */
int rule_2_7_edge_callback(int used, int unused_a, int unused_b) {
/* Line 115: unused_a, unused_b never referenced */
return used * 2;
}
/* Edge: variadic-like pattern where only first param matters */
void rule_2_7_edge_variadic(int count, int a, int b, int c) {
/* Line 121: a, b, c are never touched */
printf("count = %d\n", count);
}
