| # 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="" <file> |
| ``` |
| |
| 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 `<crate>.<function>.002-000.analysis.after.mir`. |
| |
| BIR dump is emitted to a `bir_dump` directory. With the following naming scheme: `<crate>.<function>.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 <file> -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 |
