Module cargo::core::compiler::future_incompat
source · Expand description
Support for future-incompatible warning reporting.
Here is an overview of how Cargo handles future-incompatible reports.
Receive reports from the compiler
When receiving a compiler message during a build, if it is effectively
a FutureIncompatReport
, Cargo gathers and forwards it as a
Message::FutureIncompatReport
to the main thread.
To have the correct layout of strucutures for deserializing a report
emitted by the compiler, most of structure definitions, for example
FutureIncompatReport
, are copied either partially or entirely from
compiler/rustc_errors/src/json.rs in rust-lang/rust repository.
Persist reports on disk
When a build comes to an end, by calling save_and_display_report
Cargo saves the report on disk, and displays it directly if requested
via command line or configuration. The information of the on-disk file can
be found in FUTURE_INCOMPAT_FILE
.
During the persistent process, Cargo will attempt to query the source of each package emitting the report, for the sake of providing an upgrade information as a solution to fix the incompatibility.
Display reports to users
Users can run cargo report future-incompat
to retrieve a report. This is
done by OnDiskReports::load
. Cargo simply prints reports to the
standard output.
Structs
- A diagnostic emitted by the compiler as a JSON message. We only care about the ‘rendered’ field
- A single future-incompatible warning emitted by rustc.
- The future incompatibility report, emitted by the compiler as a JSON message.
- Structure used for collecting reports in-memory.
- A single report for a given compilation session.
- The structure saved to disk containing the reports.
Constants
- The filename in the top-level
target
directory where we store the report - Max number of reports to save on disk.
- Current version of the on-disk format.
Functions
- Returns a user-readable message explaining which of the packages in
package_ids
have updates available. This is best-effort - if an error occurs,None
will be returned. - Writes a future-incompat report to disk, using the per-package reports gathered during the build. If requested by the user, a message is also displayed in the build output.