fix: move stored_procs slice under the feature stored_procs_slice

In picodata, we cannot guarantee that tarantool module will be linked
exactly once due to possible stale versions from various dependencies.
This whole feature is here to disable the distributed slice definition
in all but one instance of this crate; otherwise we'll trigger linkme's
"duplicate distributed slice" check introduced in 0.3.1.

Author: funbringer

examples/all_procs/Cargo.toml

@@ -8,6 +8,7 @@ license = "BSD-2-Clause"
 
 [dependencies.tarantool]
 path = "../../tarantool"
+features = ["stored_procs_slice"]
 
 [lib]
 test = false

tarantool-proc/Cargo.toml

@@ -20,3 +20,6 @@ quote = "^1.0"
 proc-macro2 = "^1.0"
 darling = "0.14.2"
 proc-macro-error = "1"
+
+[features]
+stored_procs_slice = []

tarantool-proc/src/lib.rs

@@ -1186,9 +1186,20 @@ pub fn stored_proc(attr: TokenStream, item: TokenStream) -> TokenStream {
         public = override_public;
     }
 
+    // Only add tarantool::proc-annotated function to the distributed slice
+    // if the `stored_procs_slice` feature is active. We need this to combat
+    // the runtime panics introduced in linkme 0.3.1.
+    let attrs_distributed_slice = if cfg!(feature = "stored_procs_slice") {
+        quote! {
+            #[#linkme::distributed_slice(#section)]
+            #[linkme(crate = #linkme)]
+        }
+    } else {
+        quote! {}
+    };
+
     quote! {
-        #[#linkme::distributed_slice(#section)]
-        #[linkme(crate = #linkme)]
+        #attrs_distributed_slice
         #[cfg(not(test))]
         static #desc_ident: #tarantool::proc::Proc = #tarantool::proc::Proc::new(
             #desc_name,

tarantool/Cargo.toml

@@ -39,7 +39,7 @@ md-5 = "0.10"
 tarantool-proc = { path = "../tarantool-proc", version = "3.1.1" }
 uuid = "0.8.2"
 futures = "0.3.25"
-linkme = "0.3.0"
+linkme = "0.3.29"
 async-trait = "0.1.64"
 tester = { version = "0.7.0", optional = true }
 time = ">=0.3.0, <0.3.18"
@@ -78,7 +78,7 @@ internal_test = ["test", "tlua/internal_test", "pretty_assertions", "tempfile"]
 # in use at the same time is problematic because libdecnumber versions used by both of the
 # options are not exactly the same. Thus deviations in behaviour between them are possible
 standalone_decimal = ["dec"]
-
+stored_procs_slice = ["tarantool-proc/stored_procs_slice"]
 
 [dev-dependencies]
 time-macros = "=0.2.6"

tarantool/src/lib.rs

@@ -115,13 +115,15 @@ pub mod vclock;
 /// automatically added to a global array and can be accessed via
 /// `proc::all_procs` function.
 /// ```no_run
+/// # #[cfg(feature = "stored_procs_slice")] {
 /// use tarantool::proc::all_procs;
 ///
 /// #[tarantool::proc]
 /// fn my_proc() -> i32 { 69 }
 ///
 /// let procs = all_procs();
 /// assert_eq!(procs[0].name(), "my_proc");
+/// # }
 /// ```
 ///
 /// This can be used to generate stored procedure defintions for tarantool's
@@ -154,6 +156,7 @@ pub mod vclock;
 /// you want to override it (e.g. your proc is pub, but you want the flag to be
 /// false) you can specify the `public` attribute.
 /// ```no_run
+/// # #[cfg(feature = "stored_procs_slice")] {
 /// use tarantool::proc::all_procs;
 ///
 /// #[tarantool::proc]
@@ -174,6 +177,7 @@ pub mod vclock;
 ///     if proc.name() == "also_public_proc"  { assert!( proc.is_public()) }
 ///     if proc.name() == "also_private_proc" { assert!(!proc.is_public()) }
 /// }
+/// # }
 /// ```
 ///
 /// # Accepting borrowed arguments

tarantool/src/proc.rs

@@ -24,8 +24,6 @@ macro_rules! unwrap_or_report_err {
 /// Description of a tarantool stored procedure defined using the
 /// `#[`[`tarantool::proc`]`]` macro attribute.
 ///
-/// See also [`all_procs`].
-///
 /// [`tarantool::proc`]: macro@crate::proc
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Proc {
@@ -89,21 +87,33 @@ impl Proc {
     }
 }
 
-// Linkme distributed_slice exports a symbol with the given name, so we must
-// make sure the name is unique, so as not to conflict with distributed slices
-// from other crates or any other global symbols.
-#[doc(hidden)]
-#[::linkme::distributed_slice]
-pub static TARANTOOL_MODULE_STORED_PROCS: [Proc] = [..];
-
-/// Returns a slice of all stored procedures defined using the
-/// `#[`[`tarantool::proc`]`]` macro attribute.
-///
-/// The order of procs in the slice is undefined.
-///
-/// [`tarantool::proc`]: macro@crate::proc
-pub fn all_procs() -> &'static [Proc] {
-    &TARANTOOL_MODULE_STORED_PROCS
+// In picodata, we cannot guarantee that tarantool module will be linked
+// exactly once due to possible stale versions from various dependencies.
+// This whole feature is here to disable the distributed slice definition
+// in all but one instance of this crate; otherwise we'll trigger linkme's
+// "duplicate distributed slice" check introduced in 0.3.1.
+#[cfg(feature = "stored_procs_slice")]
+pub use stored_procs_slice::*;
+#[cfg(feature = "stored_procs_slice")]
+mod stored_procs_slice {
+    use super::*;
+
+    // Linkme distributed_slice exports a symbol with the given name, so we must
+    // make sure the name is unique, so as not to conflict with distributed slices
+    // from other crates or any other global symbols.
+    #[doc(hidden)]
+    #[::linkme::distributed_slice]
+    pub static TARANTOOL_MODULE_STORED_PROCS: [Proc] = [..];
+
+    /// Returns a slice of all stored procedures defined using the
+    /// `#[`[`tarantool::proc`]`]` macro attribute.
+    ///
+    /// The order of procs in the slice is undefined.
+    ///
+    /// [`tarantool::proc`]: macro@crate::proc
+    pub fn all_procs() -> &'static [Proc] {
+        &TARANTOOL_MODULE_STORED_PROCS
+    }
 }
 
 ////////////////////////////////////////////////////////////////////////////////

tests/Cargo.toml

@@ -31,10 +31,11 @@ time-macros = "=0.2.6"
 
 [dependencies.tarantool]
 path = "../tarantool"
-features = ["all", "internal_test"]
+features = ["all", "internal_test", "stored_procs_slice"]
 
 [dependencies.tarantool-proc]
 path = "../tarantool-proc"
+features = ["stored_procs_slice"]
 
 [lib]
 test = false