Use whisker for Rust

Summary:
Whisker is a replacement for mustache and is largely backward compatible. It brings several quality of life improvements like... error checking.

You can read more about the details [in this post](https://fb.workplace.com/groups/498666380550247/permalink/2051389461944590/).

This diff moves `t_mstch_rust_generator` to use whisker instead of mstch.

This requires some changes to the templates to work around the bugs in mstch that have been previously worked around.

#buildall

Reviewed By: dtolnay

Differential Revision: D67562456

fbshipit-source-id: 832a0d588f3b903a5b8047e68fdbe1de6d9f7ead

thrift/compiler/generate/t_mstch_rust_generator.cc

@@ -619,6 +619,15 @@ class t_mstch_rust_generator : public t_mstch_generator {
  public:
   using t_mstch_generator::t_mstch_generator;
 
+  std::optional<whisker_options> use_whisker() const override {
+    whisker_options opts;
+    opts.allowed_undefined_variables = {
+        "typedef:newtype?",
+        "function:name",
+    };
+    return opts;
+  }
+
   std::string template_prefix() const override { return "rust"; }
 
   void generate_program() override;

thrift/compiler/generate/templates/rust/client.rs.mustache

@@ -45,8 +45,9 @@ pub(crate) use {{program:types}}::services;
 {{#program:interactions}}{{> lib/client}}
 {{/program:interactions}}
 
-{{#program:services}}{{> lib/client}}{{!
-}}{{/program:services}}
+{{#program:services}}
+{{> lib/client}}
+{{/program:services}}
 {{/program:services?}}
 {{^program:services?}}
 #![doc(hidden)]

thrift/compiler/generate/templates/rust/consts.rs.mustache

@@ -22,5 +22,3 @@
 {{#program:has_const_tests?}}
     {{> lib/adapter/const_test}}
 {{/program:has_const_tests?}}
-
-{{!newline}}

thrift/compiler/generate/templates/rust/errors.rs.mustache

@@ -20,8 +20,9 @@
 
 //! Thrift error definitions for `{{program:name}}`.
 
-{{#program:interactions}}{{> lib/errors}}{{!
-}}{{/program:interactions}}{{!
-}}{{#program:services}}{{> lib/errors}}{{!
-}}{{/program:services}}
-{{!newline}}
+{{#program:interactions}}
+{{> lib/errors}}
+{{/program:interactions}}
+{{#program:services}}
+{{> lib/errors}}
+{{/program:services}}

thrift/compiler/generate/templates/rust/lib/adapter/const_test.mustache

@@ -30,4 +30,3 @@ mod tests {
 // This is here to ensure you enable unittests on your Thrift library.
 #[cfg(feature = "thrift_library_unittests_disabled")]
 compile_error!("You are using Rust adapters in a Thrift library that does not have unittests enabled. For safety reasons, this is forbidden. Please enable Rust unittests for this Thrift library.");
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/adapter/default_test.mustache

@@ -35,4 +35,3 @@ mod tests {
 // This is here to ensure you enable unittests on your Thrift library.
 #[cfg(feature = "thrift_library_unittests_disabled")]
 compile_error!("You are using Rust adapters in a Thrift library that does not have unittests enabled. For safety reasons, this is forbidden. Please enable Rust unittests for this Thrift library.");
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/const.mustache

@@ -42,4 +42,3 @@ pub static {{constant:name}}{{!
 {{/constant:lazy?}}
 {{/constant:type}}
 {{/constant:rust}}
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/enum.mustache

@@ -131,7 +131,6 @@ impl ::std::str::FromStr for {{enum:rust_name}} {
 impl ::fbthrift::GetTType for {{enum:rust_name}} {
     const TTYPE: ::fbthrift::TType = ::fbthrift::TType::I32;
 }
-{{!newline}}
 {{#enum:thrift_uri}}
 
 impl ::fbthrift::GetUri for self::{{enum:rust_name}} {
@@ -160,4 +159,3 @@ where
         ::std::result::Result::Ok(Self::from(::anyhow::Context::context(p.read_i32(), "Expected a number indicating enum variant")?))
     }
 }
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/errors.mustache

@@ -450,4 +450,4 @@ pub mod {{service:snake}} {
 #[allow(ambiguous_glob_reexports)]
 pub use self::{{service:snake}}::*;
 
-{{!newline}}
+{{!}}

thrift/compiler/generate/templates/rust/lib/metadata/struct.mustache

@@ -20,7 +20,7 @@
   Annotations on generated patch structs implicitly assume all dependencies
   of `thrift/annotation/patch.thrift` are immediately available in the
   crate, e.g. they require a dependency on `thrift/annotation/cpp.thrift`.
-  
+
   This might be fine in C++, but Rust crates have isolated dependencies, so
   this doesn't work for us. Disable generating annotations on patch structs
   for now.
@@ -29,7 +29,7 @@ impl ::fbthrift::metadata::ThriftAnnotations for {{struct:rust_name}} {
     fn get_structured_annotation<T: Sized + 'static>() -> ::std::option::Option<T> {
         {{! We can't use a match statement as `TypeId::of` must be const, which is blocked by
             https://github.com/rust-lang/rust/issues/77125.
-            
+
             We assume there won't be a large number of annotations, so linear search should
             be fine here.
         }}
@@ -90,4 +90,3 @@ impl ::fbthrift::metadata::ThriftAnnotations for {{struct:rust_name}} {
     }
 }
 {{/struct:generated?}}
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/mod.adapted_types.mustache

@@ -24,4 +24,3 @@ mod adapted_types {{> lib/block}}{{!
 }
 
 pub use self::adapted_types::*;
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/mod.adapters.mustache

@@ -31,4 +31,3 @@ pub mod adapters {
   }};
   {{/program:adapters}}
 }
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/mod.unadapted.mustache

@@ -24,4 +24,3 @@ pub mod unadapted {
   {{/program:adapted_structs}}
 
 }
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/server.mustache

@@ -493,4 +493,3 @@ where
     }
 }
 {{/service:interaction?}}
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/server_ok_type.mustache

@@ -26,5 +26,7 @@
 {{/function:stream_has_first_response?}}
 {{/function:stream?}}
 {{^function:stream?}}{{^function:sink?}}
-{{#function:return_type}}{{> lib/return_type}}{{/function:return_type}}
+{{#function:return_type}}
+{{> lib/return_type}}
+{{/function:return_type}}
 {{/function:sink?}}{{/function:stream?}}

thrift/compiler/generate/templates/rust/lib/server_return_type.mustache

@@ -14,8 +14,8 @@
   See the License for the specific language governing permissions and
   limitations under the License.
 
-}}{{!
-}}::std::result::Result<{{!
+}}
+::std::result::Result<{{!
     }}{{#function:return_type}}{{!
         }}{{#function:creates_interaction?}}{{!
             }}{{#function:stream?}}{{!

thrift/compiler/generate/templates/rust/lib/service.mustache

@@ -309,4 +309,3 @@ pub mod {{service:snake}} {{> lib/block}}{{!
     }
     {{/function:sink?}}{{/function:starts_interaction?}}{{/service:rustFunctions}}
 }
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/struct.mustache

@@ -114,4 +114,3 @@ pub enum {{struct:rust_name}} {{> lib/block}}{{!
     UnknownField(::std::primitive::i32),
 }
 {{/struct:union?}}
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/structimpl.mustache

@@ -82,7 +82,6 @@ impl ::std::panic::UnwindSafe for self::{{struct:rust_name}} {}
 impl ::fbthrift::GetTType for self::{{struct:rust_name}} {
     const TTYPE: ::fbthrift::TType = ::fbthrift::TType::Struct;
 }
-{{!newline}}
 {{#struct:thrift_uri}}
 
 impl ::fbthrift::GetUri for self::{{struct:rust_name}} {
@@ -227,4 +226,3 @@ where
 {{> lib/metadata/struct}}
 {{/program:rust_gen_native_metadata?}}
 {{/struct:union?}}
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/typedef.mustache

@@ -61,4 +61,3 @@ pub struct {{typedef:rust_name}}(pub {{!
   }}{{/typedef:has_adapter?}}{{!
 }});
 {{/typedef:newtype?}}
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/typedefimpl.mustache

@@ -83,4 +83,3 @@ where
 
 {{/typedef:nonstandard?}}
 {{/typedef:newtype?}}
-{{!newline}}

thrift/compiler/generate/templates/rust/lib/unionimpl.mustache

@@ -26,7 +26,6 @@ impl ::std::default::Default for {{struct:rust_name}} {
 impl ::fbthrift::GetTType for {{struct:rust_name}} {
     const TTYPE: ::fbthrift::TType = ::fbthrift::TType::Struct;
 }
-{{!newline}}
 {{#struct:thrift_uri}}
 
 impl ::fbthrift::GetUri for self::{{struct:rust_name}} {
@@ -129,4 +128,3 @@ impl {{struct:rust_name}} {
 {{> lib/metadata/struct}}
 {{/program:rust_gen_native_metadata?}}
 {{/struct:union?}}
-{{!newline}}

thrift/compiler/generate/templates/rust/server.rs.mustache

@@ -16,11 +16,11 @@
 
 }}// @{{!}}generated by Thrift for {{program:autogen_path}}
 // This file is probably not the place you want to edit!
-
 {{#program:include_docs}}
 #![doc = include_str!("{{.}}")]
 {{/program:include_docs}}
 {{#program:services?}}
+
 //! Server definitions for `{{program:name}}`.
 
 {{^program:multifile?}}
@@ -41,7 +41,8 @@ pub mod errors {{> lib/block}}{{#program:services}}
     {{> lib/server_errors}}
 
     {{/program:services}}
-    {{#program:interactions}}    {{> lib/server_errors}}
+    {{#program:interactions}}
+    {{> lib/server_errors}}
 
     {{/program:interactions}}
 }

thrift/compiler/generate/templates/rust/types.rs.mustache

@@ -75,11 +75,15 @@ pub(crate) use {{program:crate}} as types;
     }}{{/struct:has_adapter?}}{{!
 }}{{/program:structs}}{{!
 
-}}{{#program:enums}}{{> lib/enum}}{{/program:enums}}{{!
-
-}}{{#program:typedefs}}{{> lib/typedefimpl}}{{/program:typedefs}}{{!
-
-}}{{#program:structs}}{{^struct:has_adapter?}}{{> lib/structimpl}}{{> lib/unionimpl}}{{/struct:has_adapter?}}{{/program:structs}}{{!
+}}
+{{#program:enums}}
+{{> lib/enum}}
+{{/program:enums}}
+
+{{#program:typedefs}}
+{{> lib/typedefimpl}}
+{{/program:typedefs}}
+{{#program:structs}}{{^struct:has_adapter?}}{{> lib/structimpl}}{{> lib/unionimpl}}{{/struct:has_adapter?}}{{/program:structs}}{{!
 
 }}{{#program:has_adapted_structs?}}{{!
     }}{{> lib/mod.unadapted}}{{!

thrift/compiler/test/fixtures/adapter/out/rust/gen-rust/server.rs

@@ -888,3 +888,4 @@ where
         }
     }
 }
+

thrift/compiler/test/fixtures/adapter/out/rust/gen-rust/services.rs

@@ -96,7 +96,6 @@ pub mod service {
         }
     }
 }
-
 /// Service definitions for `AdapterService`.
 pub mod adapter_service {
     #[derive(Clone, Debug)]

thrift/compiler/test/fixtures/adapter/out/rust/gen-rust/types.rs

@@ -515,6 +515,7 @@ pub struct RenamedStructWithStructAdapterAndFieldAdapter {
     pub _dot_dot_Default_default: self::dot_dot::OtherFields,
 }
 
+
 #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
 pub struct Color(pub ::std::primitive::i32);
 
@@ -647,7 +648,6 @@ where
         ::std::result::Result::Ok(Self::from(::anyhow::Context::context(p.read_i32(), "Expected a number indicating enum variant")?))
     }
 }
-
 #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
 pub struct ThriftAdaptedEnum(pub ::std::primitive::i32);
 

thrift/compiler/test/fixtures/basic-annotations/out/rust/gen-rust/client.rs

@@ -223,6 +223,7 @@ pub type BadInteractionClient = ::std::sync::Arc<BadInteractionDynClient>;
 
 
 
+
 pub trait MyService: ::std::marker::Send {
     fn ping(
         &self,

thrift/compiler/test/fixtures/basic-annotations/out/rust/gen-rust/server.rs

@@ -2340,9 +2340,9 @@ pub mod bad_service {
         fn get_method_metadata(&self) -> &'static [::fbthrift::processor::MethodMetadata] {
             &[
                 // From module.BadInteraction:
-            // Interaction's method names are never queried directly.
-            // They are always queried from the "main" processor.
-        ]
+                // Interaction's method names are never queried directly.
+                // They are always queried from the "main" processor.
+            ]
         }
 
         async fn on_termination(&self) {
@@ -2351,7 +2351,7 @@ pub mod bad_service {
         }
     }
 
-    
+
 }
 
 #[::async_trait::async_trait]
@@ -3322,3 +3322,4 @@ where
         }
     }
 }
+

thrift/compiler/test/fixtures/basic-annotations/out/rust/gen-rust/services.rs

@@ -96,7 +96,6 @@ pub mod bad_interaction {
         }
     }
 }
-
 /// Service definitions for `MyService`.
 pub mod my_service {
     #[derive(Clone, Debug)]
@@ -728,7 +727,6 @@ pub mod my_service {
         }
     }
 }
-
 /// Service definitions for `MyServicePrioParent`.
 pub mod my_service_prio_parent {
     #[derive(Clone, Debug)]
@@ -911,7 +909,6 @@ pub mod my_service_prio_parent {
         }
     }
 }
-
 /// Service definitions for `MyServicePrioChild`.
 pub mod my_service_prio_child {
     #[derive(Clone, Debug)]
@@ -1004,7 +1001,6 @@ pub mod my_service_prio_child {
         }
     }
 }
-
 /// Service definitions for `BadService`.
 pub mod bad_service {
     #[derive(Clone, Debug)]
@@ -1097,7 +1093,6 @@ pub mod bad_service {
         }
     }
 }
-
 /// Service definitions for `FooBarBazService`.
 pub mod foo_bar_baz_service {
     #[derive(Clone, Debug)]

thrift/compiler/test/fixtures/basic-annotations/out/rust/gen-rust/types.rs

@@ -93,6 +93,7 @@ pub struct SecretStruct {
     pub _dot_dot_Default_default: self::dot_dot::OtherFields,
 }
 
+
 #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
 pub struct MyEnum(pub ::std::primitive::i32);
 
@@ -999,6 +1000,7 @@ impl ::fbthrift::metadata::ThriftAnnotations for SecretStruct {
 }
 
 
+
 mod dot_dot {
     #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
     pub struct OtherFields(pub(crate) ());
@@ -1035,3 +1037,4 @@ pub(crate) mod r#impl {
         ::std::result::Result::Ok(value.0)
     }
 }
+