change interfaces to use slices instead of Vec

cranelift/faerie/src/backend.rs

@@ -152,11 +152,11 @@ impl Backend for FaerieBackend {
         ctx: &cranelift_codegen::Context,
         namespace: &ModuleNamespace<Self>,
         total_size: u32,
-    ) -> ModuleResult<(FaerieCompiledFunction, Option<&Vec<TrapSite>>)> {
+    ) -> ModuleResult<(FaerieCompiledFunction, &[TrapSite])> {
         let mut code: Vec<u8> = vec![0; total_size as usize];
         // TODO: Replace this with FaerieStackmapSink once it is implemented.
         let mut stackmap_sink = NullStackmapSink {};
-        let mut traps = None;
+        let mut traps: &[TrapSite] = &[];
 
         // Non-lexical lifetimes would obviate the braces here.
         {
@@ -179,7 +179,7 @@ impl Backend for FaerieBackend {
                         &mut stackmap_sink,
                     )
                 };
-                traps = Some(trap_manifest.add_sink(trap_sink));
+                traps = trap_manifest.add_sink(trap_sink);
             } else {
                 let mut trap_sink = NullTrapSink {};
                 unsafe {
@@ -211,16 +211,16 @@ impl Backend for FaerieBackend {
         bytes: &[u8],
         _namespace: &ModuleNamespace<Self>,
         traps: Vec<TrapSite>,
-    ) -> ModuleResult<(FaerieCompiledFunction, Option<&Vec<TrapSite>>)> {
+    ) -> ModuleResult<(FaerieCompiledFunction, &[TrapSite])> {
         let code_length: u32 = match bytes.len().try_into() {
             Ok(code_length) => code_length,
             _ => Err(ModuleError::FunctionTooLarge(name.to_string()))?,
         };
-        let mut ret_traps = None;
+        let mut ret_traps: &[TrapSite] = &[];
 
         if let Some(ref mut trap_manifest) = self.trap_manifest {
             let trap_sink = FaerieTrapSink::new_with_sites(name, code_length, traps);
-            ret_traps = Some(trap_manifest.add_sink(trap_sink));
+            ret_traps = trap_manifest.add_sink(trap_sink);
         }
 
         self.artifact

cranelift/faerie/src/traps.rs

@@ -59,7 +59,7 @@ impl FaerieTrapManifest {
     }
 
     /// Put a `FaerieTrapSink` into manifest
-    pub fn add_sink(&mut self, sink: FaerieTrapSink) -> &Vec<TrapSite> {
+    pub fn add_sink(&mut self, sink: FaerieTrapSink) -> &[TrapSite] {
         self.sinks.push(sink);
         &self.sinks.last().unwrap().sites
     }

cranelift/module/src/backend.rs

@@ -86,7 +86,7 @@ where
         ctx: &Context,
         namespace: &ModuleNamespace<Self>,
         code_size: u32,
-    ) -> ModuleResult<(Self::CompiledFunction, Option<&Vec<TrapSite>>)>;
+    ) -> ModuleResult<(Self::CompiledFunction, &[TrapSite])>;
 
     /// Define a function, taking the function body from the given `bytes`.
     ///
@@ -98,7 +98,7 @@ where
         bytes: &[u8],
         namespace: &ModuleNamespace<Self>,
         traps: Vec<TrapSite>,
-    ) -> ModuleResult<(Self::CompiledFunction, Option<&Vec<TrapSite>>)>;
+    ) -> ModuleResult<(Self::CompiledFunction, &[TrapSite])>;
 
     /// Define a zero-initialized data object of the given size.
     ///

cranelift/module/src/module.rs

@@ -354,7 +354,7 @@ where
 
 pub struct ModuleCompiledFunction<'a> {
     pub size: binemit::CodeOffset,
-    pub traps: Option<&'a Vec<TrapSite>>,
+    pub traps: &'a [TrapSite],
 }
 
 impl<B> Module<B>

cranelift/object/src/backend.rs

@@ -189,7 +189,7 @@ impl Backend for ObjectBackend {
         ctx: &cranelift_codegen::Context,
         _namespace: &ModuleNamespace<Self>,
         code_size: u32,
-    ) -> ModuleResult<(ObjectCompiledFunction, Option<&Vec<TrapSite>>)> {
+    ) -> ModuleResult<(ObjectCompiledFunction, &[TrapSite])> {
         let mut code: Vec<u8> = vec![0; code_size as usize];
         let mut reloc_sink = ObjectRelocSink::new(self.object.format());
         let mut trap_sink = ObjectTrapSink::default();
@@ -232,7 +232,7 @@ impl Backend for ObjectBackend {
         }
         let trapref = self.traps.index_mut(func_id);
         *trapref = trap_sink.sites;
-        Ok((ObjectCompiledFunction, Some(trapref)))
+        Ok((ObjectCompiledFunction, trapref))
     }
 
     fn define_function_bytes(
@@ -242,7 +242,7 @@ impl Backend for ObjectBackend {
         bytes: &[u8],
         _namespace: &ModuleNamespace<Self>,
         traps: Vec<TrapSite>,
-    ) -> ModuleResult<(ObjectCompiledFunction, Option<&Vec<TrapSite>>)> {
+    ) -> ModuleResult<(ObjectCompiledFunction, &[TrapSite])> {
         let symbol = self.functions[func_id].unwrap();
         let section = self.object.section_id(StandardSection::Text);
         let _offset = self
@@ -250,7 +250,7 @@ impl Backend for ObjectBackend {
             .add_symbol_data(symbol, section, bytes, self.function_alignment);
         let trapref = self.traps.index_mut(func_id);
         *trapref = traps;
-        Ok((ObjectCompiledFunction, Some(trapref)))
+        Ok((ObjectCompiledFunction, trapref))
     }
 
     fn define_data(

cranelift/simplejit/src/backend.rs

@@ -278,7 +278,7 @@ impl<'simple_jit_backend> Backend for SimpleJITBackend {
         ctx: &cranelift_codegen::Context,
         _namespace: &ModuleNamespace<Self>,
         code_size: u32,
-    ) -> ModuleResult<(Self::CompiledFunction, Option<&Vec<TrapSite>>)> {
+    ) -> ModuleResult<(Self::CompiledFunction, &[TrapSite])> {
         let size = code_size as usize;
         let ptr = self
             .memory
@@ -309,7 +309,7 @@ impl<'simple_jit_backend> Backend for SimpleJITBackend {
                 size,
                 relocs: reloc_sink.relocs,
             },
-            None,
+            &[],
         ))
     }
 
@@ -320,7 +320,7 @@ impl<'simple_jit_backend> Backend for SimpleJITBackend {
         bytes: &[u8],
         _namespace: &ModuleNamespace<Self>,
         _traps: Vec<TrapSite>,
-    ) -> ModuleResult<(Self::CompiledFunction, Option<&Vec<TrapSite>>)> {
+    ) -> ModuleResult<(Self::CompiledFunction, &[TrapSite])> {
         let size = bytes.len();
         let ptr = self
             .memory
@@ -340,7 +340,7 @@ impl<'simple_jit_backend> Backend for SimpleJITBackend {
                 size,
                 relocs: vec![],
             },
-            None,
+            &[],
         ))
     }