rust/tests/compile-fail/cyclomatic_complexity.rs
Oliver Schneider 902c7d832b fix cc computation in the presence of diverging calls
CFG treats diverging calls as its completely own path out of the function.
While this makes sense, it should also mean that a panic should increase the cyclomatic
complexity. Instead it decreases it.

Minimal example:

```rust
if a {
    b
} else {
    panic!("cake");
}
d
```

creates the following graph

```dot
digraph G {
  "if a" -> "b"
  "if a" -> "panic!(\"cake\")"
  "b" -> c
}
```

which has a CC of 1 (3 - 4 + 2). A CC of 1 means there is one path through the program.
Obviously that is wrong. There are two paths. One returning normally, and one panicking.
2015-12-14 14:29:20 +01:00

289 lines
6.2 KiB
Rust

#![feature(plugin, custom_attribute)]
#![plugin(clippy)]
#![deny(clippy)]
#![deny(cyclomatic_complexity)]
#![allow(unused)]
fn main() { //~ ERROR: The function has a cyclomatic complexity of 28.
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
if true {
println!("a");
}
}
#[cyclomatic_complexity = "0"]
fn kaboom() { //~ ERROR: The function has a cyclomatic complexity of 8
let n = 0;
'a: for i in 0..20 {
'b: for j in i..20 {
for k in j..20 {
if k == 5 {
break 'b;
}
if j == 3 && k == 6 {
continue 'a;
}
if k == j {
continue;
}
println!("bake");
}
}
println!("cake");
}
}
fn bloo() {
match 42 {
0 => println!("hi"),
1 => println!("hai"),
2 => println!("hey"),
3 => println!("hallo"),
4 => println!("hello"),
5 => println!("salut"),
6 => println!("good morning"),
7 => println!("good evening"),
8 => println!("good afternoon"),
9 => println!("good night"),
10 => println!("bonjour"),
11 => println!("hej"),
12 => println!("hej hej"),
13 => println!("greetings earthling"),
14 => println!("take us to you leader"),
15 | 17 | 19 | 21 | 23 | 25 | 27 | 29 | 31 | 33 => println!("take us to you leader"),
35 | 37 | 39 | 41 | 43 | 45 | 47 | 49 | 51 | 53 => println!("there is no undefined behavior"),
55 | 57 | 59 | 61 | 63 | 65 | 67 | 69 | 71 | 73 => println!("I know borrow-fu"),
_ => println!("bye"),
}
}
#[cyclomatic_complexity = "0"]
fn baa() { //~ ERROR: The function has a cyclomatic complexity of 2
let x = || match 99 {
0 => true,
1 => false,
2 => true,
4 => true,
6 => true,
9 => true,
_ => false,
};
if x() {
println!("x");
} else {
println!("not x");
}
}
#[cyclomatic_complexity = "0"]
fn bar() { //~ ERROR: The function has a cyclomatic complexity of 2
match 99 {
0 => println!("hi"),
_ => println!("bye"),
}
}
#[cyclomatic_complexity = "0"]
fn barr() { //~ ERROR: The function has a cyclomatic complexity of 2
match 99 {
0 => println!("hi"),
1 => println!("bla"),
2 | 3 => println!("blub"),
_ => println!("bye"),
}
}
#[cyclomatic_complexity = "0"]
fn barr2() { //~ ERROR: The function has a cyclomatic complexity of 3
match 99 {
0 => println!("hi"),
1 => println!("bla"),
2 | 3 => println!("blub"),
_ => println!("bye"),
}
match 99 {
0 => println!("hi"),
1 => println!("bla"),
2 | 3 => println!("blub"),
_ => println!("bye"),
}
}
#[cyclomatic_complexity = "0"]
fn barrr() { //~ ERROR: The function has a cyclomatic complexity of 2
match 99 {
0 => println!("hi"),
1 => panic!("bla"),
2 | 3 => println!("blub"),
_ => println!("bye"),
}
}
#[cyclomatic_complexity = "0"]
fn barrr2() { //~ ERROR: The function has a cyclomatic complexity of 3
match 99 {
0 => println!("hi"),
1 => panic!("bla"),
2 | 3 => println!("blub"),
_ => println!("bye"),
}
match 99 {
0 => println!("hi"),
1 => panic!("bla"),
2 | 3 => println!("blub"),
_ => println!("bye"),
}
}
#[cyclomatic_complexity = "0"]
fn barrrr() { //~ ERROR: The function has a cyclomatic complexity of 2
match 99 {
0 => println!("hi"),
1 => println!("bla"),
2 | 3 => panic!("blub"),
_ => println!("bye"),
}
}
#[cyclomatic_complexity = "0"]
fn barrrr2() { //~ ERROR: The function has a cyclomatic complexity of 3
match 99 {
0 => println!("hi"),
1 => println!("bla"),
2 | 3 => panic!("blub"),
_ => println!("bye"),
}
match 99 {
0 => println!("hi"),
1 => println!("bla"),
2 | 3 => panic!("blub"),
_ => println!("bye"),
}
}
#[cyclomatic_complexity = "0"]
fn cake() { //~ ERROR: The function has a cyclomatic complexity of 2
if 4 == 5 {
println!("yea");
} else {
panic!("meh");
}
println!("whee");
}
#[cyclomatic_complexity = "0"]
pub fn read_file(input_path: &str) -> String { //~ ERROR: The function has a cyclomatic complexity of 4
use std::fs::File;
use std::io::{Read, Write};
use std::path::Path;
let mut file = match File::open(&Path::new(input_path)) {
Ok(f) => f,
Err(err) => {
panic!("Can't open {}: {}", input_path, err);
}
};
let mut bytes = Vec::new();
match file.read_to_end(&mut bytes) {
Ok(..) => {},
Err(_) => {
panic!("Can't read {}", input_path);
}
};
match String::from_utf8(bytes) {
Ok(contents) => contents,
Err(_) => {
panic!("{} is not UTF-8 encoded", input_path);
}
}
}
enum Void {}
#[cyclomatic_complexity = "0"]
fn void(void: Void) { //~ ERROR: The function has a cyclomatic complexity of 1
if true {
match void {
}
}
}