test: run Miri with RUSTFLAGS="-Zrandomize-layout"
#231
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`cordyceps` and `maitake` currently contain code that perform layout-dependent casts (in this case, casting a ptr to struct to a ptr to the struct's first subfield), which would be UB if those structs were not `#[repr(C)]`. the `-Zrandomize-layout` flag tells the Rust compiler to randomize the layout of all `#[repr(Rust)]` structs (see rust-lang/compiler-team#457 for details). if we ever perform a layout-dependent cast on a struct that is not `#[repr(C)]` (or `#[repr(transparent)]`), layout randomization would break that cast. enabling this flag while running the Miri tests will help to catch any bugs introduced by accidentally performing such a cast on a non-layout-dependent type. i also made some changes to the `bin/miri` script. this was primarily to add comments on the individual flags that are added to `$MIRIFLAGS`, so that we can remember what they're doing when we look back at the script. the actual behavior should be identical, but the values added to `$MIRIFLAGS` are now declared in an array so that each flag can have a comment. Closes #229 Signed-off-by: Eliza Weisman <[email protected]>
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`cordyceps` and `maitake` currently contain code that perform layout-dependent casts (in this case, casting a ptr to struct to a ptr to the struct's first subfield), which would be UB if those structs were not `#[repr(C)]`. the `-Zrandomize-layout` flag tells the Rust compiler to randomize the layout of all `#[repr(Rust)]` structs (see rust-lang/compiler-team#457 for details). if we ever perform a layout-dependent cast on a struct that is not `#[repr(C)]` (or `#[repr(transparent)]`), layout randomization would break that cast. enabling this flag while running the Miri tests will help to catch any bugs introduced by accidentally performing such a cast on a non-layout-dependent type. i also made some changes to the `bin/miri` script. this was primarily to add comments on the individual flags that are added to `$MIRIFLAGS`, so that we can remember what they're doing when we look back at the script. the actual behavior should be identical, but the values added to `$MIRIFLAGS` are now declared in an array so that each flag can have a comment. Closes #229 Signed-off-by: Eliza Weisman <[email protected]>
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cordycepsandmaitakecurrently contain code that performlayout-dependent casts (in this case, casting a ptr to struct to a ptr
to the struct's first subfield), which would be UB if those structs
were not
#[repr(C)].the
-Zrandomize-layoutflag tells the Rust compiler to randomize thelayout of all
#[repr(Rust)]structs (see rust-lang/compiler-team#457for details). if we ever perform a layout-dependent cast on a struct
that is not
#[repr(C)](or#[repr(transparent)]), layoutrandomization would break that cast. enabling this flag while running
the Miri tests will help to catch any bugs introduced by accidentally
performing such a cast on a non-layout-dependent type.
i also made some changes to the
bin/miriscript. this was primarily toadd comments on the individual flags that are added to
$MIRIFLAGS, sothat we can remember what they're doing when we look back at the script.
the actual behavior should be identical, but the values added to
$MIRIFLAGSare now declared in an array so that each flag can have acomment.
Closes #229
Signed-off-by: Eliza Weisman [email protected]