Fixes#20596 by making `Debug` render negative zero with a `-` without affecting the behavior of `Display`.
While I was at it, I also removed some dead code from `float_to_str_bytes_common` (the one from `libcore/fmt/float.rs`, not the function of the same name in `libstd/num/strconv.rs`). It had support for different bases, and for negative numbers, but the function is internal to core and the couple places that call it (all in `libcore/fmt/mod.rs`) never use those features: They pass in `num.abs()` and base 10.
This PR makes `rustc` emit field names for tuple fields in DWARF. Formerly there was no way of directly accessing the fields of a tuple in GDB and LLDB since there is no C/C++ equivalent to this. Now, the debugger sees the name `__{field-index}` for tuple fields. So you can type for example `some_tuple_val.__2` to get the third tuple component.
When pretty printers are used (e.g. via `rust-gdb` or `rust-lldb`) these artificial field names will not clutter tuple rendering (which was the main motivation for not doing this in the past).
Solves #21948.
An actual typeck error is the cause of many failed compilations but an
unrelated bug is being reported instead. It is triggered because a typeck
error is presumably not yet identified during compiler execution, which
would normally bypass an invariant in the presence of other errors. In
this particular situation, we delay the reporting of the bug until
abort_if_errors().
Closes#23827, closes#24356, closes#23041, closes#22897, closes#23966,
closes#24013, and closes#23729
Now that the internals of `format_args!` are unstable, tests that use it
don't compile after pretty-printing (unless they also declare the necessary
feature).
* In `noop_fold_expr`, call `new_span` in these cases:
- `ExprMethodCall`'s identifier
- `ExprField`'s identifier
- `ExprTupField`'s integer
Calling `new_span` for `ExprMethodCall`'s identifier is necessary to print
an acceptable diagnostic for `write!(&2, "")`. We see this error:
```
<std macros>:2:20: 2:66 error: type `&mut _` does not implement any method in scope named `write_fmt`
<std macros>:2 ( & mut * $ dst ) . write_fmt ( format_args ! ( $ ( $ arg ) * ) ) )
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
With this change, we also see a macro expansion backtrace leading to
the `write!(&2, "")` call site.
* After fully expanding a macro, we replace the expansion expression's
span with the original span. Call `fld.new_span` to add a backtrace to
this span. (Note that I'm call `new_span` after `bt.pop()`, so the macro
just expanded isn't on the backtrace.)
The motivating example for this change is `println!("{}")`. The format
string literal is `concat!($fmt, "arg")` and is inside the libstd macro.
We need to see the backtrace to find the `println!` call site.
* Add a backtrace to the `format_args!` format expression span.
r? alexcrichton
Addresses #23459
We provide tools to tell what exact symbols to emit for any fn or static, but
don’t quite check if that won’t cause any issues later on. Some of the issues
include LLVM mangling our names again and our names pointing to wrong locations,
us generating dumb foreign call wrappers, linker errors, extern functions
resolving to different symbols altogether (`extern {fn fail();} fail();` in some
cases calling `fail1()`), etc.
Before the commit we had a function called `note_unique_llvm_symbol`, so it is
clear somebody was aware of the issue at some point, but the function was barely
used, mostly in irrelevant locations.
Along with working on it I took liberty to start refactoring trans/base into
a few smaller modules. The refactoring is incomplete and I hope I will find some
motivation to carry on with it.
This is possibly a [breaking-change] because it makes dumbly written code
properly invalid.
This fixes all those issues about incorrect use of #[no_mangle] being not reported/misreported/ICEd by the compiler.
NB. This PR does not attempt to tackle the parallel codegen issue that was mentioned in https://github.com/rust-lang/rust/pull/22811, but I believe it should be very straightforward in a follow up PR by modifying `trans::declare::get_defined_value` to look at all the contexts.
cc @alexcrichton @huonw @nrc because you commented on the original RFC issue.
EDIT: wow, this became much bigger than I initially intended.
Don't use skolemized parameters but rather fresh variables in coherence. Skolemized parameters wind up preventing unification. Surprised we had no test for this! Fixes#24241.
r? @pnkfelix
Example showing sample inputs, old message, new message:
https://gist.github.com/nikomatsakis/11126784ac678b7eb6ba
Also adds infrastructure for reporting suggestions \"in situ\" and does some (minor) cleanups to `CodeMap`.
r? @brson
Statement macros are now treated somewhat like item macros, in that a statement macro can now expand into a series of statements, rather than just a single statement.
This allows statement macros to be nested inside other kinds of macros and expand properly, where previously the expansion would only work when no nesting was present.
See:
- `src/test/run-pass/macro-stmt_macro_in_expr_macro.rs`
- `src/test/run-pass/macro-nested_stmt_macro.rs`
This changes the interface of the MacResult trait. make_stmt has become make_stmts and now returns a vector, rather than a single item. Plugin writers who were implementing MacResult will have breakage, as well as anyone using MacEager::stmt.
See:
- `src/libsyntax/ext/base.rs`
This also causes a minor difference in behavior to the diagnostics produced by certain malformed macros.
See:
- `src/test/compile-fail/macro-incomplete-parse.rs`
Use `discriminant_value` intrinsic for `derive(PartialOrd)`
[breaking-change]
This is a [breaking-change] because it can change the result of comparison operators when enum discriminants have been explicitly assigned. Notably in a case like:
```rust
#[derive(PartialOrd)]
enum E { A = 2, B = 1}
```
Under the old deriving, `A < B` held, because `A` came before `B` in the order of declaration. But now we use the ordering according to the provided values, and thus `A > B`. (However, this change is very unlikely to break much, if any, code, since the orderings themselves should all remain well-defined, total, etc.)
Fix#15523
This commit series starts out with more official test harness support for rustdoc tests, and then each commit afterwards adds a test (where appropriate). Each commit should also test and finish independently of all others (they're all pretty separable).
I've uploaded a [copy of the documentation](http://people.mozilla.org/~acrichton/doc/std/) generated after all these commits were applied, and a double check on issues being closed would be greatly appreciated! I'll also browse the docs a bit and make sure nothing regressed too horribly.
