Lexing converts source text into a token stream. Parsing converts a
token stream into AST fragments. This commit renames several lexing
operations that have "parse" in the name. I think these names have been
subtly confusing me for years.
This is just a `s/parse/lex/` on function names, with one exception:
`parse_stream_from_source_str` becomes `source_str_to_stream`, to make
it consistent with the existing `source_file_to_stream`. The commit also
moves that function's location in the file to be just above
`source_file_to_stream`.
The commit also cleans up a few comments along the way.
Translation of the lint message happens when the actual diagnostic is
created, not when the lint is buffered. Generating the message from
BuiltinLintDiag ensures that all required data to construct the message
is preserved in the LintBuffer, eventually allowing the messages to be
moved to fluent.
Remove the `msg` field from BufferedEarlyLint, it is either generated
from the data in the BuiltinLintDiag or stored inside
BuiltinLintDiag::Normal.
Properly handle emojis as literal prefix in macros
Do not accept the following
```rust
macro_rules! lexes {($($_:tt)*) => {}}
lexes!(🐛"foo");
```
Before, invalid emoji identifiers were gated during parsing instead of lexing in all cases, but this didn't account for macro pre-expansion of literal prefixes.
Fix#123696.
Fix invalid silencing of parsing error
Given
```rust
macro_rules! a {
( ) => {
impl<'b> c for d {
e::<f'g>
}
};
}
```
ensure an error is emitted.
Fix#123079.
Do not accept the following
```rust
macro_rules! lexes {($($_:tt)*) => {}}
lexes!(🐛"foo");
```
Before, invalid emoji identifiers were gated during parsing instead of lexing in all cases, but this didn't account for macro expansion of literal prefixes.
Fix#123696.
`lexer::UnmatchedDelim` struct in `rustc_parse` is unnecessary public
outside of the crate. This commit reduces the visibility to
`pub(crate)`.
Beside, this removes unnecessary field `expected_delim` that causes
warnings after changing the visibility.
Given `'hello world'` and `'1 str', provide a structured suggestion for a valid string literal:
```
error[E0762]: unterminated character literal
--> $DIR/lex-bad-str-literal-as-char-3.rs:2:26
|
LL | println!('hello world');
| ^^^^
|
help: if you meant to write a `str` literal, use double quotes
|
LL | println!("hello world");
| ~ ~
```
```
error[E0762]: unterminated character literal
--> $DIR/lex-bad-str-literal-as-char-1.rs:2:20
|
LL | println!('1 + 1');
| ^^^^
|
help: if you meant to write a `str` literal, use double quotes
|
LL | println!("1 + 1");
| ~ ~
```
Fix#119685.
Existing names for values of this type are `sess`, `parse_sess`,
`parse_session`, and `ps`. `sess` is particularly annoying because
that's also used for `Session` values, which are often co-located, and
it can be difficult to know which type a value named `sess` refers to.
(That annoyance is the main motivation for this change.) `psess` is nice
and short, which is good for a name used this much.
The commit also renames some `parse_sess_created` values as
`psess_created`.
Use `LitKind::Err` for malformed floats
#121120 changed `StringReader::cook_lexer_literal` to return `LitKind::Err` for malformed integer literals. This commit does the same for float literals, for consistency.
r? ``@fmease``
Add newtypes for bool fields/params/return types
Fixed all the cases of this found with some simple searches for `*/ bool` and `bool /*`; probably many more
There are lots of functions that modify a diagnostic. This can be via a
`&mut Diagnostic` or a `&mut DiagnosticBuilder`, because the latter type
wraps the former and impls `DerefMut`.
This commit converts all the `&mut Diagnostic` occurrences to `&mut
DiagnosticBuilder`. This is a step towards greatly simplifying
`Diagnostic`. Some of the relevant function are made generic, because
they deal with both errors and warnings. No function bodies are changed,
because all the modifier methods are available on both `Diagnostic` and
`DiagnosticBuilder`.
This mostly works well, and eliminates a couple of delayed bugs.
One annoying thing is that we should really also add an
`ErrorGuaranteed` to `proc_macro::bridge::LitKind::Err`. But that's
difficult because `proc_macro` doesn't have access to `ErrorGuaranteed`,
so we have to fake it.
`cook_lexer_literal` can emit an error about an invalid int literal but
then return a non-`Err` token. And then `integer_lit` has to account for
this to avoid printing a redundant error message.
This commit changes `cook_lexer_literal` to return `Err` in that case.
Then `integer_lit` doesn't need the special case, and
`LitError::LexerError` can be removed.
Error codes are integers, but `String` is used everywhere to represent
them. Gross!
This commit introduces `ErrCode`, an integral newtype for error codes,
replacing `String`. It also introduces a constant for every error code,
e.g. `E0123`, and removes the `error_code!` macro. The constants are
imported wherever used with `use rustc_errors::codes::*`.
With the old code, we have three different ways to specify an error code
at a use point:
```
error_code!(E0123) // macro call
struct_span_code_err!(dcx, span, E0123, "msg"); // bare ident arg to macro call
\#[diag(name, code = "E0123")] // string
struct Diag;
```
With the new code, they all use the `E0123` constant.
```
E0123 // constant
struct_span_code_err!(dcx, span, E0123, "msg"); // constant
\#[diag(name, code = E0123)] // constant
struct Diag;
```
The commit also changes the structure of the error code definitions:
- `rustc_error_codes` now just defines a higher-order macro listing the
used error codes and nothing else.
- Because that's now the only thing in the `rustc_error_codes` crate, I
moved it into the `lib.rs` file and removed the `error_codes.rs` file.
- `rustc_errors` uses that macro to define everything, e.g. the error
code constants and the `DIAGNOSTIC_TABLES`. This is in its new
`codes.rs` file.
They can't contain `\x` escapes, which means they can't contain high
bytes, which means we can used `unescape_unicode` instead of
`unescape_mixed` to unescape them. This avoids unnecessary used of
`MixedUnit`.
`unescape_literal` becomes `unescape_unicode`, and `unescape_c_string`
becomes `unescape_mixed`. Because rfc3349 will mean that C string
literals will no longer be the only mixed utf8 literals.
By making it an `EscapeError` instead of a `LitError`. This makes it
like the other errors produced when checking string literals contents,
e.g. for invalid escape sequences or bare CR chars.
NOTE: this means these errors are issued earlier, before expansion,
which changes behaviour. It will be possible to move the check back to
the later point if desired. If that happens, it's likely that all the
string literal contents checks will be delayed together.
One nice thing about this: the old approach had some code in
`report_lit_error` to calculate the span of the nul char from a range.
This code used a hardwired `+2` to account for the `c"` at the start of
a C string literal, but this should have changed to a `+3` for raw C
string literals to account for the `cr"`, which meant that the caret in
`cr"` nul error messages was one short of where it should have been. The
new approach doesn't need any of this and avoids the off-by-one error.
One consequence is that errors returned by
`maybe_new_parser_from_source_str` now must be consumed, so a bunch of
places that previously ignored those errors now cancel them. (Most of
them explicitly dropped the errors before. I guess that was to indicate
"we are explicitly ignoring these", though I'm not 100% sure.)
Two different lifetimes are conflated. This doesn't matter right now,
but needs to be fixed for the next commit to work. And the more
descriptive lifetime names make the code easier to read.
In #119606 I added them and used a `_mv` suffix, but that wasn't great.
A `with_` prefix has three different existing uses.
- Constructors, e.g. `Vec::with_capacity`.
- Wrappers that provide an environment to execute some code, e.g.
`with_session_globals`.
- Consuming chaining methods, e.g. `Span::with_{lo,hi,ctxt}`.
The third case is exactly what we want, so this commit changes
`DiagnosticBuilder::foo_mv` to `DiagnosticBuilder::with_foo`.
Thanks to @compiler-errors for the suggestion.
The existing uses are replaced in one of three ways.
- In a function that also has calls to `emit`, just rearrange the code
so that exactly one of `delay_as_bug` or `emit` is called on every
path.
- In a function returning a `DiagnosticBuilder`, use
`downgrade_to_delayed_bug`. That's good enough because it will get
emitted later anyway.
- In `unclosed_delim_err`, one set of errors is being replaced with
another set, so just cancel the original errors.
This works for most of its call sites. This is nice, because `emit` very
much makes sense as a consuming operation -- indeed,
`DiagnosticBuilderState` exists to ensure no diagnostic is emitted
twice, but it uses runtime checks.
For the small number of call sites where a consuming emit doesn't work,
the commit adds `DiagnosticBuilder::emit_without_consuming`. (This will
be removed in subsequent commits.)
Likewise, `emit_unless` becomes consuming. And `delay_as_bug` becomes
consuming, while `delay_as_bug_without_consuming` is added (which will
also be removed in subsequent commits.)
All this requires significant changes to `DiagnosticBuilder`'s chaining
methods. Currently `DiagnosticBuilder` method chaining uses a
non-consuming `&mut self -> &mut Self` style, which allows chaining to
be used when the chain ends in `emit()`, like so:
```
struct_err(msg).span(span).emit();
```
But it doesn't work when producing a `DiagnosticBuilder` value,
requiring this:
```
let mut err = self.struct_err(msg);
err.span(span);
err
```
This style of chaining won't work with consuming `emit` though. For
that, we need to use to a `self -> Self` style. That also would allow
`DiagnosticBuilder` production to be chained, e.g.:
```
self.struct_err(msg).span(span)
```
However, removing the `&mut self -> &mut Self` style would require that
individual modifications of a `DiagnosticBuilder` go from this:
```
err.span(span);
```
to this:
```
err = err.span(span);
```
There are *many* such places. I have a high tolerance for tedious
refactorings, but even I gave up after a long time trying to convert
them all.
Instead, this commit has it both ways: the existing `&mut self -> Self`
chaining methods are kept, and new `self -> Self` chaining methods are
added, all of which have a `_mv` suffix (short for "move"). Changes to
the existing `forward!` macro lets this happen with very little
additional boilerplate code. I chose to add the suffix to the new
chaining methods rather than the existing ones, because the number of
changes required is much smaller that way.
This doubled chainging is a bit clumsy, but I think it is worthwhile
because it allows a *lot* of good things to subsequently happen. In this
commit, there are many `mut` qualifiers removed in places where
diagnostics are emitted without being modified. In subsequent commits:
- chaining can be used more, making the code more concise;
- more use of chaining also permits the removal of redundant diagnostic
APIs like `struct_err_with_code`, which can be replaced easily with
`struct_err` + `code_mv`;
- `emit_without_diagnostic` can be removed, which simplifies a lot of
machinery, removing the need for `DiagnosticBuilderState`.
`Diagnostic` has 40 methods that return `&mut Self` and could be
considered setters. Four of them have a `set_` prefix. This doesn't seem
necessary for a type that implements the builder pattern. This commit
removes the `set_` prefixes on those four methods.
This lets different error levels share the same return type from
`emit_*`.
- A lot of inconsistencies in the `DiagCtxt` API are removed.
- `Noted` is removed.
- `FatalAbort` is introduced for fatal errors (abort via `raise`),
replacing the `EmissionGuarantee` impl for `!`.
- `Bug` is renamed `BugAbort` (to avoid clashing with `Level::Bug` and
to mirror `FatalAbort`), and modified to work in the new way with bug
errors (abort via panic).
- Various diagnostic creators and emitters updated to the new, better
signatures. Note that `DiagCtxt::bug` no longer needs to call
`panic_any`, because `emit` handles that.
Also shorten the obnoxiously long
`diagnostic_builder_emit_producing_guarantee` name.
