diff --git a/gcc/rust/checks/errors/borrowck/dev-notes.md b/gcc/rust/checks/errors/borrowck/dev-notes.md new file mode 100644 index 000000000000..2e170e761026 --- /dev/null +++ b/gcc/rust/checks/errors/borrowck/dev-notes.md @@ -0,0 +1,40 @@ +# Borrow-checker Development Notes + +## Testing BIR building + +There is no way to test BIR building directly, since it is a dead branch of the compilation pipeline. +The only way to verify its generations is through manual inspection. +The best way to inspect the BIR is to compare it with rustc's MIR. + +The following command will compile a rust file into a library and dump its MIR: + +```shell +rustc --crate-type=lib -A dead_code -A unused -Z dump-mir="" +``` + +The MIR dump directory `mir_dump` contains a dump before and after each MIR pass. +We are interested in the one used for borrow-checking, which is called `..002-000.analysis.after.mir`. + +BIR dump is emitted to a `bir_dump` directory. With the following naming scheme: `..bir.dump`. + +At this point, MIR dump contains helper constructions that BIR does not contain yet (like storage live/dead annotations). To remove them from the MIR dump, run the following command: + +```shell +awk -i inplace '!/^\s*(\/\/|StorageLive|StorageDead|FakeRead)/' mir_dump/* +``` + +To get the BIR dump into a similar format, run the following command: + +```shell +./crab1 -frust-incomplete-and-experimental-compiler-do-not-use -frust-borrowcheck -frust-dump-bir -frust-compile-until=compilation +``` + + +## TODO + +- scope handling, cleanup +- switch coercions to adjustments from typechecking +- operator overloading +- match selection +- let without an initializer +- lifetime parameters \ No newline at end of file