For external crates, we must build up a map that goes from
the DefKey to the DefIndex. We do this by iterating over each
index that is found in the metadata and loading the associated
DefKey.
Replace the obligation forest with a graph
In the presence of caching, arbitrary nodes in the obligation forest can be merged, which makes it a general graph. Handle it as such, using cycle-detection algorithms in the processing.
I should do performance measurements sometime.
This was pretty much written as a proof-of-concept. Please help me write this in a less-ugly way. I should also add comments explaining what is going on.
r? @nikomatsakis
Add error description for E0455
r? @GuillaumeGomez.
About this error there is no much thing to explain. The short description says enough to understand. Feel free to review.
Clean up `hir::lowering`
Clean up `hir::lowering`:
- give lowering functions mutable access to the lowering context
- refactor the `lower_*` functions and other functions that take a lowering context into methods
- simplify the API that `hir::lowering` exposes to `driver`
- other miscellaneous cleanups
r? @nrc
Perform name resolution before and during ast->hir lowering
This PR performs name resolution before and during ast->hir lowering instead of in phase 3.
r? @nrc
This commit is an implementation of [RFC 1513] which allows applications to
alter the behavior of panics at compile time. A new compiler flag, `-C panic`,
is added and accepts the values `unwind` or `panic`, with the default being
`unwind`. This model affects how code is generated for the local crate, skipping
generation of landing pads with `-C panic=abort`.
[RFC 1513]: https://github.com/rust-lang/rfcs/blob/master/text/1513-less-unwinding.md
Panic implementations are then provided by crates tagged with
`#![panic_runtime]` and lazily required by crates with
`#![needs_panic_runtime]`. The panic strategy (`-C panic` value) of the panic
runtime must match the final product, and if the panic strategy is not `abort`
then the entire DAG must have the same panic strategy.
With the `-C panic=abort` strategy, users can expect a stable method to disable
generation of landing pads, improving optimization in niche scenarios,
decreasing compile time, and decreasing output binary size. With the `-C
panic=unwind` strategy users can expect the existing ability to isolate failure
in Rust code from the outside world.
Organizationally, this commit dismantles the `sys_common::unwind` module in
favor of some bits moving part of it to `libpanic_unwind` and the rest into the
`panicking` module in libstd. The custom panic runtime support is pretty similar
to the custom allocator support with the only major difference being how the
panic runtime is injected (takes the `-C panic` flag into account).
The extra filename and line was mainly there to keep the indentation
relative to the main snippet; now that this doesn't include
filename/line-number as a prefix, it is distracted.
Add initial version of codegen unit partitioning for incremental compilation.
The task of the partitioning module is to take the complete set of translation items of a crate and produce a set of codegen units from it, where a codegen unit is a named set of (translation-item, linkage) pairs. That is, this module decides which translation item appears in which codegen units with which linkage.
This version only handles the case of partitioning for incremental compilation, not the regular N-codegen units case. In the future the regular case should be handled too, maybe even doing a bit more analysis to intelligently figure out a good partitioning.
One thing that could be improved is the syntax of the codegen unit tests. Right now they still use the compile-fail error specification infrastructure, so everything has to be on one line. Would be nice to be able to format things in a more readable way.
Deduplicate libraries on hash instead of filename.
Removes the need for canonicalization to prevent #12459.
(Now with passing tests!)
Canonicalization breaks certain environments where the libraries are symlinks to files that don't end in .rlib (e.g. /remote/cas/$HASH).
Replace consider_unification_despite_ambiguity with new obligation variant
Is work towards #32730. Addresses part one of #32286. Addresses #24210 and #26046 to some degree.
r? @nikomatsakis
Save/load incremental compilation dep graph
Contains the code to serialize/deserialize the dep graph to disk between executions. We also hash the item contents and compare to the new hashes. Also includes a unit test harness. There are definitely some known limitations, such as https://github.com/rust-lang/rust/issues/32014 and https://github.com/rust-lang/rust/issues/32015, but I am leaving those for follow-up work.
Note that this PR builds on https://github.com/rust-lang/rust/pull/32007, so the overlapping commits can be excluded from review.
r? @michaelwoerister
