Struct rustc_middle::dep_graph::WorkProduct
source · pub struct WorkProduct {
pub cgu_name: String,
pub saved_files: HashMap<String, String, BuildHasherDefault<FxHasher>>,
}
Expand description
A “work product” is an intermediate result that we save into the incremental directory for later re-use. The primary example are the object files that we save for each partition at code generation time.
Each work product is associated with a dep-node, representing the
process that produced the work-product. If that dep-node is found
to be dirty when we load up, then we will delete the work-product
at load time. If the work-product is found to be clean, then we
will keep a record in the previous_work_products
list.
In addition, work products have an associated hash. This hash is an extra hash that can be used to decide if the work-product from a previous compilation can be re-used (in addition to the dirty edges check).
As the primary example, consider the object files we generate for
each partition. In the first run, we create partitions based on
the symbols that need to be compiled. For each partition P, we
hash the symbols in P and create a WorkProduct
record associated
with DepNode::CodegenUnit(P)
; the hash is the set of symbols
in P.
The next time we compile, if the DepNode::CodegenUnit(P)
is
judged to be clean (which means none of the things we read to
generate the partition were found to be dirty), it will be loaded
into previous work products. We will then regenerate the set of
symbols in the partition P and hash them (note that new symbols
may be added – for example, new monomorphizations – even if
nothing in P changed!). We will compare that hash against the
previous hash. If it matches up, we can reuse the object file.
Fields§
§cgu_name: String
§saved_files: HashMap<String, String, BuildHasherDefault<FxHasher>>
Saved files associated with this CGU. In each key/value pair, the value is the path to the saved file and the key is some identifier for the type of file being saved.
By convention, file extensions are currently used as identifiers, i.e. the key “o” maps to the object file’s path, and “dwo” to the dwarf object file’s path.
Auto Trait Implementations§
impl RefUnwindSafe for WorkProduct
impl Send for WorkProduct
impl Sync for WorkProduct
impl Unpin for WorkProduct
impl UnwindSafe for WorkProduct
Blanket Implementations§
source§impl<T, R> InternIteratorElement<T, R> for T
impl<T, R> InternIteratorElement<T, R> for T
type Output = R
fn intern_with<I, F>(iter: I, f: F) -> <T as InternIteratorElement<T, R>>::Outputwhere
I: Iterator<Item = T>,
F: FnOnce(&[T]) -> R,
source§impl<T> MaybeResult<T> for T
impl<T> MaybeResult<T> for T
source§impl<'tcx, T> ToPredicate<'tcx, T> for T
impl<'tcx, T> ToPredicate<'tcx, T> for T
fn to_predicate(self, _tcx: TyCtxt<'tcx>) -> T
source§impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
default fn from_cycle_error(tcx: Tcx, _: &[QueryInfo]) -> T
Layout§
Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...)
attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.
Size: 56 bytes