Rust contains various size checks conditional on target_arch = "x86_64",
but these checks were never intended to apply to
x86_64-unknown-linux-gnux32. Add target_pointer_width = "64" to the
conditions.
...so we can skip serializing `tool_metadata` if it hasn't been set.
This makes the output a bit cleaner, and avoiding having to update a
bunch of unrelated tests.
This allows a build system to indicate a location in its own dependency
specification files (eg Cargo's `Cargo.toml`) which can be reported
along side any unused crate dependency.
This supports several types of location:
- 'json' - provide some json-structured data, which is included in the json diagnostics
in a `tool_metadata` field
- 'raw' - emit the provided string into the output. This also appears as a json string in
`tool_metadata`.
If no `--extern-location` is explicitly provided then a default json entry of the form
`"tool_metadata":{"name":<cratename>,"path":<cratepath>}` is emitted.
The first use case of this detection of regression for trimmed paths
computation, that is in the case of rustc, which should be computed only
in case of errors or warnings.
Our current user of this method is deeply nested, being a side effect
from `Display` formatting on lots of rustc types. So taking only the
caller to the error message is not enough - we should collect the
traceback instead.
