Simplify ModuleEnvironment.

Remove some unneeded functions, and remove the `GlobalInit` special case
for data and elem initializer offsets; implementations that want that
information can provide it for themselves.

lib/wasm/src/environ/dummy.rs

@@ -138,6 +138,15 @@ impl DummyEnvironment {
     pub fn func_env(&self) -> DummyFuncEnvironment {
         DummyFuncEnvironment::new(&self.info, self.return_mode)
     }
+
+    fn get_func_type(&self, func_index: FuncIndex) -> SignatureIndex {
+        self.info.functions[func_index].entity
+    }
+
+    /// Return the number of imported functions within this `DummyEnvironment`.
+    pub fn get_num_func_imports(&self) -> usize {
+        self.info.imported_funcs.len()
+    }
 }
 
 /// The `FuncEnvironment` implementation for use by the `DummyEnvironment`.
@@ -345,10 +354,6 @@ impl<'data> ModuleEnvironment<'data> for DummyEnvironment {
         self.info.signatures.push(sig.clone());
     }
 
-    fn get_signature(&self, sig_index: SignatureIndex) -> &ir::Signature {
-        &self.info.signatures[sig_index]
-    }
-
     fn declare_func_import(
         &mut self,
         sig_index: SignatureIndex,
@@ -366,18 +371,10 @@ impl<'data> ModuleEnvironment<'data> for DummyEnvironment {
             .push((String::from(module), String::from(field)));
     }
 
-    fn get_num_func_imports(&self) -> usize {
-        self.info.imported_funcs.len()
-    }
-
     fn declare_func_type(&mut self, sig_index: SignatureIndex) {
         self.info.functions.push(Exportable::new(sig_index));
     }
 
-    fn get_func_type(&self, func_index: FuncIndex) -> SignatureIndex {
-        self.info.functions[func_index].entity
-    }
-
     fn declare_global(&mut self, global: Global) {
         self.info.globals.push(Exportable::new(global));
     }
@@ -389,10 +386,6 @@ impl<'data> ModuleEnvironment<'data> for DummyEnvironment {
             .push((String::from(module), String::from(field)));
     }
 
-    fn get_global(&self, global_index: GlobalIndex) -> &Global {
-        &self.info.globals[global_index].entity
-    }
-
     fn declare_table(&mut self, table: Table) {
         self.info.tables.push(Exportable::new(table));
     }

lib/wasm/src/environ/spec.rs

@@ -248,9 +248,6 @@ pub trait ModuleEnvironment<'data> {
     /// Declares a function signature to the environment.
     fn declare_signature(&mut self, sig: &ir::Signature);
 
-    /// Return the signature with the given index.
-    fn get_signature(&self, sig_index: SignatureIndex) -> &ir::Signature;
-
     /// Declares a function import to the environment.
     fn declare_func_import(
         &mut self,
@@ -259,24 +256,15 @@ pub trait ModuleEnvironment<'data> {
         field: &'data str,
     );
 
-    /// Return the number of imported funcs.
-    fn get_num_func_imports(&self) -> usize;
-
     /// Declares the type (signature) of a local function in the module.
     fn declare_func_type(&mut self, sig_index: SignatureIndex);
 
-    /// Return the signature index for the given function index.
-    fn get_func_type(&self, func_index: FuncIndex) -> SignatureIndex;
-
     /// Declares a global to the environment.
     fn declare_global(&mut self, global: Global);
 
     /// Declares a global import to the environment.
     fn declare_global_import(&mut self, global: Global, module: &'data str, field: &'data str);
 
-    /// Return the global for the given global index.
-    fn get_global(&self, global_index: GlobalIndex) -> &Global;
-
     /// Declares a table to the environment.
     fn declare_table(&mut self, table: Table);
 
@@ -291,6 +279,7 @@ pub trait ModuleEnvironment<'data> {
         offset: usize,
         elements: Vec<FuncIndex>,
     );
+
     /// Declares a memory to the environment
     fn declare_memory(&mut self, memory: Memory);
 

lib/wasm/src/sections_translator.rs

@@ -244,14 +244,7 @@ pub fn parse_element_section<'data>(
         let mut init_expr_reader = init_expr.get_binary_reader();
         let (base, offset) = match init_expr_reader.read_operator()? {
             Operator::I32Const { value } => (None, value as u32 as usize),
-            Operator::GetGlobal { global_index } => match environ
-                .get_global(GlobalIndex::from_u32(global_index))
-                .initializer
-            {
-                GlobalInit::I32Const(value) => (None, value as u32 as usize),
-                GlobalInit::Import => (Some(GlobalIndex::from_u32(global_index)), 0),
-                _ => panic!("should not happen"),
-            },
+            Operator::GetGlobal { global_index } => (Some(GlobalIndex::from_u32(global_index)), 0),
             ref s => panic!("unsupported init expr in element section: {:?}", s),
         };
         let items_reader = items.get_items_reader()?;
@@ -292,14 +285,7 @@ pub fn parse_data_section<'data>(
         let mut init_expr_reader = init_expr.get_binary_reader();
         let (base, offset) = match init_expr_reader.read_operator()? {
             Operator::I32Const { value } => (None, value as u32 as usize),
-            Operator::GetGlobal { global_index } => match environ
-                .get_global(GlobalIndex::from_u32(global_index))
-                .initializer
-            {
-                GlobalInit::I32Const(value) => (None, value as u32 as usize),
-                GlobalInit::Import => (Some(GlobalIndex::from_u32(global_index)), 0),
-                _ => panic!("should not happen"),
-            },
+            Operator::GetGlobal { global_index } => (Some(GlobalIndex::from_u32(global_index)), 0),
             ref s => panic!("unsupported init expr in data section: {:?}", s),
         };
         environ.declare_data_initialization(

src/wasm.rs

@@ -7,18 +7,16 @@
     allow(too_many_arguments, cyclomatic_complexity)
 )]
 
+use crate::utils::{parse_sets_and_triple, read_to_end};
 use cranelift_codegen::print_errors::{pretty_error, pretty_verifier_error};
 use cranelift_codegen::settings::FlagsOrIsa;
 use cranelift_codegen::timing;
 use cranelift_codegen::Context;
 use cranelift_entity::EntityRef;
-use cranelift_wasm::{
-    translate_module, DummyEnvironment, FuncIndex, ModuleEnvironment, ReturnMode,
-};
+use cranelift_wasm::{translate_module, DummyEnvironment, FuncIndex, ReturnMode};
 use std::path::Path;
 use std::path::PathBuf;
 use term;
-use crate::utils::{parse_sets_and_triple, read_to_end};
 use wabt::wat2wasm;
 
 macro_rules! vprintln {