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Andre Bogus 2015-10-14 12:06:28 +02:00
commit 949c3545ce
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3
README.md
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@ -6,7 +6,7 @@ A collection of lints to catch common mistakes and improve your Rust code.
[Jump to usage instructions](#usage)
##Lints
There are 61 lints included in this crate:
There are 62 lints included in this crate:
name | default | meaning
-------------------------------------------------------------------------------------------------------|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
@ -43,6 +43,7 @@ name
[needless_range_loop](https://github.com/Manishearth/rust-clippy/wiki#needless_range_loop) | warn | for-looping over a range of indices where an iterator over items would do
[needless_return](https://github.com/Manishearth/rust-clippy/wiki#needless_return) | warn | using a return statement like `return expr;` where an expression would suffice
[non_ascii_literal](https://github.com/Manishearth/rust-clippy/wiki#non_ascii_literal) | allow | using any literal non-ASCII chars in a string literal; suggests using the \\u escape instead
[nonsensical_open_options](https://github.com/Manishearth/rust-clippy/wiki#nonsensical_open_options) | warn | nonsensical combination of options for opening a file
[option_unwrap_used](https://github.com/Manishearth/rust-clippy/wiki#option_unwrap_used) | allow | using `Option.unwrap()`, which should at least get a better message using `expect()`
[precedence](https://github.com/Manishearth/rust-clippy/wiki#precedence) | warn | catches operations where precedence may be unclear. See the wiki for a list of cases caught
[ptr_arg](https://github.com/Manishearth/rust-clippy/wiki#ptr_arg) | allow | fn arguments of the type `&Vec<...>` or `&String`, suggesting to use `&[...]` or `&str` instead, respectively

3
src/lib.rs
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@ -48,6 +48,7 @@ pub mod ranges;
pub mod matches;
pub mod precedence;
pub mod zero_div_zero;
pub mod open_options;
mod reexport {
pub use syntax::ast::{Name, Ident, NodeId};
@ -89,6 +90,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
reg.register_late_lint_pass(box matches::MatchPass);
reg.register_late_lint_pass(box misc::PatternPass);
reg.register_late_lint_pass(box minmax::MinMaxPass);
reg.register_late_lint_pass(box open_options::NonSensicalOpenOptions);
reg.register_late_lint_pass(box zero_div_zero::ZeroDivZeroPass);
reg.register_lint_group("clippy_pedantic", vec![
@ -145,6 +147,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
misc::TOPLEVEL_REF_ARG,
mut_reference::UNNECESSARY_MUT_PASSED,
needless_bool::NEEDLESS_BOOL,
open_options::NONSENSICAL_OPEN_OPTIONS,
precedence::PRECEDENCE,
ranges::RANGE_STEP_BY_ZERO,
returns::LET_AND_RETURN,

139
src/open_options.rs Normal file
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@ -0,0 +1,139 @@
use rustc::lint::*;
use rustc_front::hir::{Expr, ExprMethodCall, ExprLit};
use utils::{walk_ptrs_ty_depth, match_type, span_lint, OPEN_OPTIONS_PATH};
use syntax::codemap::{Span, Spanned};
use syntax::ast::Lit_::LitBool;
declare_lint! {
pub NONSENSICAL_OPEN_OPTIONS,
Warn,
"nonsensical combination of options for opening a file"
}
#[derive(Copy,Clone)]
pub struct NonSensicalOpenOptions;
impl LintPass for NonSensicalOpenOptions {
fn get_lints(&self) -> LintArray {
lint_array!(NONSENSICAL_OPEN_OPTIONS)
}
}
impl LateLintPass for NonSensicalOpenOptions {
fn check_expr(&mut self, cx: &LateContext, e: &Expr) {
if let ExprMethodCall(ref name, _, ref arguments) = e.node {
let (obj_ty, _) = walk_ptrs_ty_depth(cx.tcx.expr_ty(&arguments[0]));
if name.node.as_str() == "open" && match_type(cx, obj_ty, &OPEN_OPTIONS_PATH){
let mut options = Vec::new();
get_open_options(cx, &arguments[0], &mut options);
check_open_options(cx, &options, e.span);
}
}
}
}
#[derive(Debug)]
enum Argument {
True,
False,
Unknown
}
#[derive(Debug)]
enum OpenOption {
Write,
Read,
Truncate,
Create,
Append
}
fn get_open_options(cx: &LateContext, argument: &Expr, options: &mut Vec<(OpenOption, Argument)>) {
if let ExprMethodCall(ref name, _, ref arguments) = argument.node {
let (obj_ty, _) = walk_ptrs_ty_depth(cx.tcx.expr_ty(&arguments[0]));
// Only proceed if this is a call on some object of type std::fs::OpenOptions
if match_type(cx, obj_ty, &OPEN_OPTIONS_PATH) && arguments.len() >= 2 {
let argument_option = match arguments[1].node {
ExprLit(ref span) => {
if let Spanned {node: LitBool(lit), span: _} = **span {
if lit {Argument::True} else {Argument::False}
} else {
return; // The function is called with a literal
// which is not a boolean literal. This is theoretically
// possible, but not very likely.
}
},
_ => {
Argument::Unknown
}
};
match &*name.node.as_str() {
"create" => {
options.push((OpenOption::Create, argument_option));
},
"append" => {
options.push((OpenOption::Append, argument_option));
},
"truncate" => {
options.push((OpenOption::Truncate, argument_option));
},
"read" => {
options.push((OpenOption::Read, argument_option));
},
"write" => {
options.push((OpenOption::Write, argument_option));
},
_ => {}
}
get_open_options(cx, &arguments[0], options);
}
}
}
fn check_for_duplicates(cx: &LateContext, options: &[(OpenOption, Argument)], span: Span) {
// This code is almost duplicated (oh, the irony), but I haven't found a way to unify it.
if options.iter().filter(|o| if let (OpenOption::Create, _) = **o {true} else {false}).count() > 1 {
span_lint(cx, NONSENSICAL_OPEN_OPTIONS, span, "The method \"create\" \
is called more than once");
}
if options.iter().filter(|o| if let (OpenOption::Append, _) = **o {true} else {false}).count() > 1 {
span_lint(cx, NONSENSICAL_OPEN_OPTIONS, span, "The method \"append\" \
is called more than once");
}
if options.iter().filter(|o| if let (OpenOption::Truncate, _) = **o {true} else {false}).count() > 1 {
span_lint(cx, NONSENSICAL_OPEN_OPTIONS, span, "The method \"truncate\" \
is called more than once");
}
if options.iter().filter(|o| if let (OpenOption::Read, _) = **o {true} else {false}).count() > 1 {
span_lint(cx, NONSENSICAL_OPEN_OPTIONS, span, "The method \"read\" \
is called more than once");
}
if options.iter().filter(|o| if let (OpenOption::Write, _) = **o {true} else {false}).count() > 1 {
span_lint(cx, NONSENSICAL_OPEN_OPTIONS, span, "The method \"write\" \
is called more than once");
}
}
fn check_for_inconsistencies(cx: &LateContext, options: &[(OpenOption, Argument)], span: Span) {
// Truncate + read makes no sense.
if options.iter().filter(|o| if let (OpenOption::Read, Argument::True) = **o {true} else {false}).count() > 0 &&
options.iter().filter(|o| if let (OpenOption::Truncate, Argument::True) = **o {true} else {false}).count() > 0 {
span_lint(cx, NONSENSICAL_OPEN_OPTIONS, span, "File opened with \"truncate\" and \"read\"");
}
// Append + truncate makes no sense.
if options.iter().filter(|o| if let (OpenOption::Append, Argument::True) = **o {true} else {false}).count() > 0 &&
options.iter().filter(|o| if let (OpenOption::Truncate, Argument::True) = **o {true} else {false}).count() > 0 {
span_lint(cx, NONSENSICAL_OPEN_OPTIONS, span, "File opened with \"append\" and \"truncate\"");
}
}
fn check_open_options(cx: &LateContext, options: &[(OpenOption, Argument)], span: Span) {
check_for_duplicates(cx, options, span);
check_for_inconsistencies(cx, options, span);
}

1
src/utils.rs
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@ -15,6 +15,7 @@ pub const RESULT_PATH: [&'static str; 3] = ["core", "result", "Result"];
pub const STRING_PATH: [&'static str; 3] = ["collections", "string", "String"];
pub const VEC_PATH: [&'static str; 3] = ["collections", "vec", "Vec"];
pub const LL_PATH: [&'static str; 3] = ["collections", "linked_list", "LinkedList"];
pub const OPEN_OPTIONS_PATH: [&'static str; 3] = ["std", "fs", "OpenOptions"];
/// Produce a nested chain of if-lets and ifs from the patterns:
///

16
tests/compile-fail/open_options.rs Normal file
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@ -0,0 +1,16 @@
#![feature(plugin)]
#![plugin(clippy)]
use std::fs::OpenOptions;
#[allow(unused_must_use)]
#[deny(nonsensical_open_options)]
fn main() {
OpenOptions::new().read(true).truncate(true).open("foo.txt"); //~ERROR File opened with "truncate" and "read"
OpenOptions::new().append(true).truncate(true).open("foo.txt"); //~ERROR File opened with "append" and "truncate"
OpenOptions::new().read(true).read(false).open("foo.txt"); //~ERROR The method "read" is called more than once
OpenOptions::new().create(true).create(false).open("foo.txt"); //~ERROR The method "create" is called more than once
OpenOptions::new().write(true).write(false).open("foo.txt"); //~ERROR The method "write" is called more than once
OpenOptions::new().append(true).append(false).open("foo.txt"); //~ERROR The method "append" is called more than once
OpenOptions::new().truncate(true).truncate(false).open("foo.txt"); //~ERROR The method "truncate" is called more than once
}