rust/compiler/rustc_middle
bors 7a58674259 Auto merge of #124255 - RenjiSann:renji/mcdc-nested-expressions, r=Zalathar
MCDC coverage: support nested decision coverage

#123409 provided the initial MCDC coverage implementation.

As referenced in #124144, it does not currently support "nested" decisions, like the following example :

```rust
fn nested_if_in_condition(a: bool, b: bool, c: bool) {
    if a && if b || c { true } else { false } {
        say("yes");
    } else {
        say("no");
    }
}
```

Note that there is an if-expression (`if b || c ...`) embedded inside a boolean expression in the decision of an outer if-expression.

This PR proposes a workaround for this cases, by introducing a Decision context stack, and by handing several `temporary condition bitmaps` instead of just one.
When instrumenting boolean expressions, if the current node is a leaf condition (i.e. not a `||`/`&&` logical operator nor a `!` not operator), we insert a new decision context, such that if there are more boolean expressions inside the condition, they are handled as separate expressions.

On the codegen LLVM side, we allocate as many `temp_cond_bitmap`s as necessary to handle the maximum encountered decision depth.
2024-04-29 11:54:49 +00:00
..
src Auto merge of #124255 - RenjiSann:renji/mcdc-nested-expressions, r=Zalathar 2024-04-29 11:54:49 +00:00
Cargo.toml Fix pretty hir for anon consts in diagnostics 2024-04-15 18:48:12 -04:00
messages.ftl Add a custom panic message for resuming gen blocks after they panicked 2023-10-30 10:23:57 +00:00
README.md

For more information about how rustc works, see the rustc dev guide.