Preparation for #865, which proposes adding a flag which outputs which
config options are used during formatting.
This PR should not make any difference to functionality. A lot of this
was search-and-replace.
Some areas worthy of review/discussion:
- The method for each config item returns a clone of the underlying
value. We can't simply return an immutable reference, as lots of
places in the code expect to be able to pass the returned value as
`bool` (not `&bool). It would be nice if the `bool` items could
return a copy, but the more complex types a borrowed reference... but
unfortunately, I couldn't get the macro to do this.
- A few places (mostly tests and `src/bin/rustfmt.rs`) were overriding
config items by modifying the fields of the `Config` struct directly.
They now use the existing `override_value()` method, which has been
modified to return a `Result` for use by `src/bin/rustfmt.rs`. This
benefits of this are that the complex `file_lines` and `write_mode`
strings are now parsed in one place (`Config.override_value`) instead
of multiple. The disadvantages are that it moves the compile-time
checks for config names to become run-time checks.
One notable feature is this this adds support for the experimental
`let x = loop { ... break $expr; }` syntax. This also includes a
test for formatting all the break and continue variations.
This commit adds a `codemap` module, and moves the `CodemapSpanUtils`
added in #857 to it. This is preparation for adding more `Codemap`
specific utilities.
Refs #434
The error handling in libsyntax changed to use a `DiagnosticBuilder`
type in the `Err` variant of `PResult`. This type has `emit()` and
`cancel()` methods. Once created, errors must be emitted or canceled; if
not, the `Drop` impl on `DiagnosticBuilder` will panic.
The first syntex_syntax release to include this change was v0.25.0. The
bump from v0.23.0 to v0.29.1 in #847 did not add any `cancel()` calls,
even though at least one was required. There may be others not caught in
this commit.
This commit adds a CodeMapSpanUtils extension trait on CodeMap, and
moves some functions to methods there:
- span_after
- span_after_last
- span_before
This better reflects them being lookup methods on the codemap.
The problem is essentially that if we try to parse a token tree using a
CodeMap different from the one the tree was originally parsed with,
spans become nonsense. Since CodeMaps can't be cloned, we're basically
forced to use the original ParseSess for additional parsing.
Ideally, rustfmt would be a bit more clever and figure out how to parse
macro arguments based on the definition of the macro itself, rather than
just guessing that a particular token sequence looks like an expression,
but this is good enough for now.
Fixes#538.
