Fixes#12350.
Parentheses around assignment statements such as
```rust
let mut a = (0);
a = (1);
a += (2);
```
are not necessary and therefore an unnecessary_parens warning is raised when
statements like this occur.
NOTE: In `let` declarations this does not work as intended. Is it possible that they do not count as assignment expressions (`ExprAssign`)? (edit: this is fixed by now)
Furthermore, there are some cases that I fixed in the rest of the code, where parentheses could potentially enhance readability. Compare these lines:
```rust
a = b == c;
a = (b == c);
```
Thus, after having worked on this I'm not entirely sure, whether we should go through with this patch or not. Probably a matter of debate. ;)
Not all of those messages are covered by tests. I am not sure how to trigger them and where to put those tests.
Also some message patterns in the existing tests are not complete.
For example, i find `error: mismatched types: expected "i32" but found "char" (expected i32 but found char)` a bit repetitive, but as i can see there is no test covering that.
Closes#12366.
Parentheses around assignment statements such as
let mut a = (0);
a = (1);
a += (2);
are not necessary and therefore an unnecessary_parens warning is raised when
statements like this occur.
The warning mechanism was refactored along the way to allow for code reuse
between the routines for checking expressions and statements.
Code had to be adopted throughout the compiler and standard libraries to comply
with this modification of the lint.
This is PR is the beginning of a complete rewrite and ultimate removal of the `std::num::strconv` module (see #6220), and the removal of the `ToStrRadix` trait in favour of using the `std::fmt` functionality directly. This should make for a cleaner API, encourage less allocation, and make the implementation more comprehensible .
The `Formatter::{pad_integral, with_padding}` methods have also been refactored make things easier to understand.
The formatting tests for integers have been moved out of `run-pass/ifmt.rs` in order to provide more immediate feedback when building using `make check-stage2-std NO_REBUILD=1`.
Arbitrary radixes are now easier to use in format strings. For example:
~~~rust
assert_eq!(format!("{:04}", radix(3, 2)), ~"0011");
~~~
The benchmarks have been standardised between `std::num::strconv` and `std::num::fmt` to make it easier to compare the performance of the different implementations.
~~~
type | radix | std::num::strconv | std::num::fmt
======|=======|========================|======================
int | bin | 1748 ns/iter (+/- 150) | 321 ns/iter (+/- 25)
int | oct | 706 ns/iter (+/- 53) | 179 ns/iter (+/- 22)
int | dec | 640 ns/iter (+/- 59) | 207 ns/iter (+/- 10)
int | hex | 637 ns/iter (+/- 77) | 205 ns/iter (+/- 19)
int | 36 | 446 ns/iter (+/- 30) | 309 ns/iter (+/- 20)
------|-------|------------------------|----------------------
uint | bin | 1724 ns/iter (+/- 159) | 322 ns/iter (+/- 13)
uint | oct | 663 ns/iter (+/- 25) | 175 ns/iter (+/- 7)
uint | dec | 613 ns/iter (+/- 30) | 186 ns/iter (+/- 6)
uint | hex | 519 ns/iter (+/- 44) | 207 ns/iter (+/- 20)
uint | 36 | 418 ns/iter (+/- 16) | 308 ns/iter (+/- 32)
~~~
This is in preparation to remove the implementations of ToStrRadix in integers, and to remove the associated logic from `std::num::strconv`.
The parts that still need to be liberated are:
- `std::fmt::Formatter::runplural`
- `num::{bigint, complex, rational}`
Previously an `unsafe` block created by the compiler (like those in the
formatting macros) would be "ignored" if surrounded by `unsafe`, that
is, the internal unsafety would be being legitimised by the external
block:
unsafe { println!("...") } =(expansion)=> unsafe { ... unsafe { ... } }
And the code in the inner block would be using the outer block, making
it considered used (and the inner one considered unused).
This patch forces the compiler to create a new unsafe context for
compiler generated blocks, so that their internal unsafety doesn't
escape to external blocks.
Fixes#12418.
Added allow(non_camel_case_types) to librustc where necesary
Tried to fix problems with non_camel_case_types outside rustc
fixed failing tests
Docs updated
Moved #[allow(non_camel_case_types)] a level higher.
markdown.rs reverted
Fixed timer that was failing tests
Fixed another timer
This "bubble up an error" macro was originally named if_ok! in order to get it
landed, but after the fact it was discovered that this name is not exactly
desirable.
The name `if_ok!` isn't immediately clear that is has much to do with error
handling, and it doesn't look fantastic in all contexts (if if_ok!(...) {}). In
general, the agreed opinion about `if_ok!` is that is came in as subpar.
The name `try!` is more invocative of error handling, it's shorter by 2 letters,
and it looks fitting in almost all circumstances. One concern about the word
`try!` is that it's too invocative of exceptions, but the belief is that this
will be overcome with documentation and examples.
Close#12037
This "bubble up an error" macro was originally named if_ok! in order to get it
landed, but after the fact it was discovered that this name is not exactly
desirable.
The name `if_ok!` isn't immediately clear that is has much to do with error
handling, and it doesn't look fantastic in all contexts (if if_ok!(...) {}). In
general, the agreed opinion about `if_ok!` is that is came in as subpar.
The name `try!` is more invocative of error handling, it's shorter by 2 letters,
and it looks fitting in almost all circumstances. One concern about the word
`try!` is that it's too invocative of exceptions, but the belief is that this
will be overcome with documentation and examples.
Close#12037
Previously an `unsafe` block created by the compiler (like those in the
formatting macros) would be "ignored" if surrounded by `unsafe`, that
is, the internal unsafety would be being legitimised by the external
block:
unsafe { println!("...") } =(expansion)=> unsafe { ... unsafe { ... } }
And the code in the inner block would be using the outer block, making
it considered used (and the inner one considered unused).
This patch forces the compiler to create a new unsafe context for
compiler generated blocks, so that their internal unsafety doesn't
escape to external blocks.
Fixes#12418.
Currently, the format_args! macro and its downstream macros in turn
expand to series of let statements, one for each of its arguments, and
then the invocation of the macro function. If one or more of the
arguments are RefCell's, the enclosing statement for the temporary of
the let is the let itself, which leads to scope problem. This patch
changes let's to a match expression.
Closes#12239.
Function parameters that are to be passed by value but don't fit into a
single register are currently passed by creating a copy on the stack and
passing a pointer to that copy to the callee. Since the copy is made
just for the function call, there are no aliases.
For example, this sometimes allows LLVM to eliminate unnecessary calls
to drop glue. Given
````rust
struct Foo {
a: int,
b: Option<~str>,
}
extern {
fn eat(eat: Option<~str>);
}
pub fn foo(v: Foo) {
match v {
Foo { a: _, b } => unsafe { eat(b) }
}
}
````
LLVM currently can't eliminate the drop call for the string, because it
only sees a _pointer_ to Foo, for which it has to expect an alias. So we
get:
````llvm
; Function Attrs: uwtable
define void @_ZN3foo20h9f32c90ae7201edbxaa4v0.0E(%struct.Foo* nocapture) unnamed_addr #0 {
"_ZN34std..option..Option$LT$$UP$str$GT$9glue_drop17hc39b3015f3b9c69dE.exit":
%1 = getelementptr inbounds %struct.Foo* %0, i64 0, i32 1, i32 0
%2 = load { i64, i64, [0 x i8] }** %1, align 8
store { i64, i64, [0 x i8] }* null, { i64, i64, [0 x i8] }** %1, align 8
%3 = ptrtoint { i64, i64, [0 x i8] }* %2 to i64
%.fca.0.insert = insertvalue { i64 } undef, i64 %3, 0
tail call void @eat({ i64 } %.fca.0.insert)
%4 = load { i64, i64, [0 x i8] }** %1, align 8
%5 = icmp eq { i64, i64, [0 x i8] }* %4, null
br i1 %5, label %_ZN3Foo9glue_drop17hf611996539d3036fE.exit, label %"_ZN8_$UP$str9glue_drop17h15dbdbe2b8897a98E.exit.i.i"
"_ZN8_$UP$str9glue_drop17h15dbdbe2b8897a98E.exit.i.i": ; preds = %"_ZN34std..option..Option$LT$$UP$str$GT$9glue_drop17hc39b3015f3b9c69dE.exit"
%6 = bitcast { i64, i64, [0 x i8] }* %4 to i8*
tail call void @free(i8* %6) #1
br label %_ZN3Foo9glue_drop17hf611996539d3036fE.exit
_ZN3Foo9glue_drop17hf611996539d3036fE.exit: ; preds = %"_ZN34std..option..Option$LT$$UP$str$GT$9glue_drop17hc39b3015f3b9c69dE.exit", %"_ZN8_$UP$str9glue_drop17h15dbdbe2b8897a98E.exit.i.i"
ret void
}
````
But with the `noalias` attribute, it can safely optimize that to:
````llvm
define void @_ZN3foo20hd28431f929f0d6c4xaa4v0.0E(%struct.Foo* noalias nocapture) unnamed_addr #0 {
_ZN3Foo9glue_drop17he9afbc09d4e9c851E.exit:
%1 = getelementptr inbounds %struct.Foo* %0, i64 0, i32 1, i32 0
%2 = load { i64, i64, [0 x i8] }** %1, align 8
store { i64, i64, [0 x i8] }* null, { i64, i64, [0 x i8] }** %1, align 8
%3 = ptrtoint { i64, i64, [0 x i8] }* %2 to i64
%.fca.0.insert = insertvalue { i64 } undef, i64 %3, 0
tail call void @eat({ i64 } %.fca.0.insert)
ret void
}
````
The first setp for #9880 is to add a new `crate` keyword. This PR does exactly that. I took a chance to refactor `parse_item_foreign_mod` and I broke it down into 2 separate methods to isolate each feature.
The next step will be to push a new stage0 snapshot and then get rid of all `extern mod` around the code.
