pr review: use SecondaryMap for names

Author: data-pup

lucetc/src/decls.rs

@@ -127,8 +127,7 @@ impl<'a> ModuleDecls<'a> {
                 decls
                     .info
                     .function_names
-                    .get(&func_index)
-                    .cloned()
+                    .get(func_index)
                     .map(|s| format!("{}_{}", s, ix))
             }
 
@@ -168,13 +167,9 @@ impl<'a> ModuleDecls<'a> {
                 }
             };
 
-            let custom_info = custom_name_for(ix, func_index, decls);
             let import_info = import_name_for(func_index, decls, bindings)?;
             let export_info = export_name_for(func_index, decls);
 
-            // We don't match on `custom_info` because export and import info are needed to
-            // determine the linkage type, and because we use different values as a fallback for
-            // exported functions and local functions.
             match (import_info, export_info) {
                 (Some(import_sym), _) => {
                     // if a function is only an import, declare the corresponding artifact import.
@@ -192,7 +187,8 @@ impl<'a> ModuleDecls<'a> {
                     // No import or export for this function, which means that it is local. We can
                     // look for a name provided in the custom names section, otherwise we have to
                     // make up a placeholder name for it using its index.
-                    let local_sym = custom_info.unwrap_or_else(|| format!("guest_func_{}", ix));
+                    let local_sym = custom_name_for(ix, func_index, decls)
+                        .unwrap_or_else(|| format!("guest_func_{}", ix));
                     decls.declare_function(clif_module, local_sym, Linkage::Local, func_index)?;
                 }
             }

lucetc/src/module.rs

@@ -1,7 +1,7 @@
 //! Implements ModuleEnvironment for cranelift-wasm. Code derived from cranelift-wasm/environ/dummy.rs
 use crate::error::{LucetcError, LucetcErrorKind};
 use crate::pointer::NATIVE_POINTER;
-use cranelift_codegen::entity::{entity_impl, EntityRef, PrimaryMap};
+use cranelift_codegen::entity::{entity_impl, EntityRef, PrimaryMap, SecondaryMap};
 use cranelift_codegen::ir;
 use cranelift_codegen::isa::TargetFrontendConfig;
 use cranelift_wasm::{
@@ -73,7 +73,7 @@ pub struct ModuleInfo<'a> {
     /// Function signatures: imported and local
     pub functions: PrimaryMap<UniqueFuncIndex, Exportable<'a, SignatureIndex>>,
     /// Function names.
-    pub function_names: HashMap<UniqueFuncIndex, String>,
+    pub function_names: SecondaryMap<UniqueFuncIndex, &'a str>,
     /// Provided by `declare_table`
     pub tables: PrimaryMap<TableIndex, Exportable<'a, Table>>,
     /// Provided by `declare_memory`
@@ -105,7 +105,7 @@ impl<'a> ModuleInfo<'a> {
             imported_memories: PrimaryMap::new(),
             function_mapping: PrimaryMap::new(),
             functions: PrimaryMap::new(),
-            function_names: HashMap::new(),
+            function_names: SecondaryMap::new(),
             tables: PrimaryMap::new(),
             memories: PrimaryMap::new(),
             globals: PrimaryMap::new(),
@@ -410,8 +410,7 @@ impl<'a> ModuleEnvironment<'a> for ModuleInfo<'a> {
             .function_mapping
             .get(func_index)
             .expect("function indices are valid");
-        self.function_names
-            .insert(unique_func_index, name.to_owned());
+        self.function_names[unique_func_index] = name;
         Ok(())
     }
 }