When items are inlined from extern crates, the filename in the debug info
is taken from the FileMap that's serialized in the rlib metadata.
Currently this is just FileMap.name, which is whatever path is passed to rustc.
Since libcore and libstd are built by invoking rustc with relative paths,
they wind up with relative paths in the rlib, and when linked into a binary
the debug info uses relative paths for the names, but since the compilation
directory for the final binary, tools trying to read source filenames
will wind up with bad paths. We noticed this in Firefox with source
filenames from libcore/libstd having bad paths.
This change stores an absolute path in FileMap.abs_path, and uses that
if available for writing debug info. This is not going to magically make
debuggers able to find the source, but it will at least provide sensible
paths.
Perform `cfg` attribute processing during macro expansion and fix bugs
This PR refactors `cfg` attribute processing and fixes bugs. More specifically:
- It merges gated feature checking for stmt/expr attributes, `cfg_attr` processing, and `cfg` processing into a single fold.
- This allows feature gated `cfg` variables to be used in `cfg_attr` on unconfigured items. All other feature gated attributes can already be used on unconfigured items.
- It performs `cfg` attribute processing during macro expansion instead of after expansion so that macro-expanded items are configured the same as ordinary items. In particular, to match their non-expanded counterparts,
- macro-expanded unconfigured macro invocations are no longer expanded,
- macro-expanded unconfigured macro definitions are no longer usable, and
- feature gated `cfg` variables on macro-expanded macro definitions/invocations are now errors.
This is a [breaking-change]. For example, the following would break:
```rust
macro_rules! m {
() => {
#[cfg(attr)]
macro_rules! foo { () => {} }
foo!(); // This will be an error
macro_rules! bar { () => { fn f() {} } }
#[cfg(attr)] bar!(); // This will no longer be expanded ...
fn g() { f(); } // ... so that `f` will be unresolved.
#[cfg(target_thread_local)] // This will be a gated feature error
macro_rules! baz { () => {} }
}
}
m!();
```
r? @nrc
Major changes:
- Remove old snippet rendering code and use the new stuff.
- Introduce `span_label` method to add a label
- Remove EndSpan mode and replace with a fn to get the last
character of a span.
- Stop using `Option<MultiSpan>` and just use an empty `MultiSpan`
- and probably a bunch of other stuff :)
MultiSpan model is now:
- set of primary spans
- set of span+label pairs
Primary spans render with `^^^`, secondary spans with `---`.
Labels are placed next to the `^^^` or `---` marker as appropriate.
This uncovered a lot of bugs in compiletest and also some shortcomings
of our existing JSON output. We had to add information to the JSON
output, such as suggested text and macro backtraces. We also had to fix
various bugs in the existing tests.
Joint work with jntrnr.
Automated conversion using the untry tool [1] and the following command:
```
$ find -name '*.rs' -type f | xargs untry
```
at the root of the Rust repo.
[1]: https://github.com/japaric/untry
The protocol for `serialize::{En,De}code` doesn't allow for two
integers to be serialized next to each other. This switches the
protocol to serializing `Span`s as a struct. rbml structs don't
have any overhead, so the metadata shouldn't increase in size,
but it allows the json format to be properly generated, albeit
slightly more heavy than when it was just serializing a span as
a u64.
Closes#31025.
s
