Compile error in Rust 1.36.0

[phiresky]

rusqlite fails to compile on Rust 1.36.0:

   Compiling rusqlite v0.19.0
error[E0277]: `*const libsqlite3_sys::sqlite3_module` cannot be sent between threads safely
  --> /home/tehdog/.cargo/registry/src/github.com-1ecc6299db9ec823/rusqlite-0.19.0/src/vtab/series.rs:21:1
   |
21 | / lazy_static! {
22 | |     static ref SERIES_MODULE: Module<SeriesTab> = eponymous_only_module::<SeriesTab>(1);
23 | | }
   | |_^ `*const libsqlite3_sys::sqlite3_module` cannot be sent between threads safely
   |
   = help: within `vtab::Module<vtab::series::SeriesTab>`, the trait `std::marker::Send` is not implemented for `*const libsqlite3_sys::sqlite3_module`
   = note: required because it appears within the type `libsqlite3_sys::sqlite3_vtab`
   = note: required because it appears within the type `vtab::series::SeriesTab`
   = note: required because it appears within the type `std::marker::PhantomData<vtab::series::SeriesTab>`
   = note: required because it appears within the type `vtab::Module<vtab::series::SeriesTab>`
   = note: required because of the requirements on the impl of `std::marker::Sync` for `spin::once::Once<vtab::Module<vtab::series::SeriesTab>>`
   = note: required because it appears within the type `lazy_static::lazy::Lazy<vtab::Module<vtab::series::SeriesTab>>`
   = note: shared static variables must have a type that implements `Sync`
   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error[E0277]: `*mut i8` cannot be sent between threads safely
  --> /home/tehdog/.cargo/registry/src/github.com-1ecc6299db9ec823/rusqlite-0.19.0/src/vtab/series.rs:21:1
   |
21 | / lazy_static! {
22 | |     static ref SERIES_MODULE: Module<SeriesTab> = eponymous_only_module::<SeriesTab>(1);
23 | | }
   | |_^ `*mut i8` cannot be sent between threads safely
   |
   = help: within `vtab::Module<vtab::series::SeriesTab>`, the trait `std::marker::Send` is not implemented for `*mut i8`
   = note: required because it appears within the type `libsqlite3_sys::sqlite3_vtab`
   = note: required because it appears within the type `vtab::series::SeriesTab`
   = note: required because it appears within the type `std::marker::PhantomData<vtab::series::SeriesTab>`
   = note: required because it appears within the type `vtab::Module<vtab::series::SeriesTab>`
   = note: required because of the requirements on the impl of `std::marker::Sync` for `spin::once::Once<vtab::Module<vtab::series::SeriesTab>>`
   = note: required because it appears within the type `lazy_static::lazy::Lazy<vtab::Module<vtab::series::SeriesTab>>`
   = note: shared static variables must have a type that implements `Sync`
   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.
error: Could not compile `rusqlite`.

To learn more, run the command again with --verbose.

Seems to happen for both 0.19.0 and 0.18.0
Via this error report: phiresky/ripgrep-all#22

[gwenn]

In the original C version, seriesModule is static.
So I guess we can fix this by telling Rust that sqlite3_module is Send and Sync.
I will try to fix and add a test.
Thanks.

[gwenn]

I cannot reproduce the error...
But https://docs.rs/lazy_static/*/lazy_static/:

Any type in them needs to fulfill the Sync trait.

[phiresky]

Uhh, could also be an interaction with some other library? Can you try and see if you get the error if you do cargo install ripgrep_all?

[gwenn]

I tried

$ git clone https://github.com/phiresky/ripgrep-all.git
$ cd ripgrep-all/
$ cargo +stable check 

And your Travis build seems ok.
And https://github.com/jgallagher/rusqlite/blob/master/src/vtab/mod.rs#L70:

unsafe impl<T: VTab> Sync for Module<T> {}

Module is Sync !

[phiresky]

to be honest, I don't know enough about rust to really understand what is happening..

cargo +stable check only started failing for me when I ran cargo upgrade and let it regenerate the lock file (try branch 1.36-weird)

[phiresky]

Oh yeah I should also mention I have vtab and bundled active

[Legogris]

Getting the same when running cargo install riprep_all with Cargo 1.35.0 on a CentOS 7 install with no prior Rust exposure.

[thomcc]

Yeah, I can also repro, but building from the ripgrep-all repo works fine. Wonder if it's a rustc bug or something.

[gwenn]

When we say:

unsafe impl<T: VTab> Sync for Module<T> {}

Rust wants that T is Send ?

[gwenn]

Workaround:
It appears that you are only using the vtab feature for:
rusqlite::vtab::escape_double_quote(&table)
And you are not using it correctly:
"select * from {}",
should be:
"select * from \"{}\"",

Ideally, we would like to use sqlite3_mprintf and "%w" but variadic args are not supported.

I am going to introduce a dedicated series feature.
So you should not have the compile error anymore.

[phiresky]

oh - guess that means an sqlite database do an sql injection on itself with my code 😆

thanks for the effort!

[Br1ght0ne]

@gwenn Can we get a release incorporating this fix? Thanks!

[gwenn]

@filalex77 I would like to merge #549 before.

[Br1ght0ne]

@gwenn Sure, thanks for the reply.

[gwenn]

Should be fixed by release 0.20.