style: Gracefully handle errors creating shared memory UA style sheets.

We still panic in a debug build, so that developers can notice when they
need to add a new static atom after modifying UA sheets.

We also add telemetry to note when this happens, add an app note to a
crash report, in case any crash later on occurs, and re-up the existing,
expired shared memory sheet telemetry probes so we can look at them
again.

Differential Revision: https://phabricator.services.mozilla.com/D73188
This commit is contained in:
Cameron McCormack 2020-05-11 00:11:45 +00:00 committed by Emilio Cobos Álvarez
parent 709c52fefb
commit 6bae0b99ca
10 changed files with 184 additions and 122 deletions

View file

@ -27,13 +27,23 @@ pub fn derive(mut input: syn::DeriveInput) -> TokenStream {
input.generics.where_clause = where_clause;
let match_body = cg::fmap_match(&input, BindStyle::Ref, |binding| {
quote! {
::std::mem::ManuallyDrop::into_inner(
::to_shmem::ToShmem::to_shmem(#binding, builder)
)
}
});
// Do all of the `to_shmem()?` calls before the `ManuallyDrop::into_inner()`
// calls, so that we don't drop a value in the shared memory buffer if one
// of the `to_shmem`s fails.
let match_body = cg::fmap2_match(
&input,
BindStyle::Ref,
|binding| {
quote! {
::to_shmem::ToShmem::to_shmem(#binding, builder)?
}
},
|binding| {
Some(quote! {
::std::mem::ManuallyDrop::into_inner(#binding)
})
},
);
let name = &input.ident;
let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
@ -44,12 +54,12 @@ pub fn derive(mut input: syn::DeriveInput) -> TokenStream {
fn to_shmem(
&self,
builder: &mut ::to_shmem::SharedMemoryBuilder,
) -> ::std::mem::ManuallyDrop<Self> {
::std::mem::ManuallyDrop::new(
) -> ::to_shmem::Result<Self> {
Ok(::std::mem::ManuallyDrop::new(
match *self {
#match_body
}
)
))
}
}
}