Merge #687

687: Fix emscripten table assertion panic r=bjfish a=bjfish

Fixes #686 

Co-authored-by: Brandon Fish <[email protected]>

Author: bors[bot]

lib/emscripten-tests/tests/emtests/_common.rs

@@ -42,7 +42,7 @@ macro_rules! assert_emscripten_output {
 
 //        let module = compile(&wasm_bytes[..])
 //            .map_err(|err| format!("Can't create the WebAssembly module: {}", err)).unwrap(); // NOTE: Need to figure what the unwrap is for ??
-        let mut emscripten_globals = EmscriptenGlobals::new(&module);
+        let mut emscripten_globals = EmscriptenGlobals::new(&module).expect("globals are valid");
         let import_object = generate_emscripten_env(&mut emscripten_globals);
 
         let mut instance = module.instantiate(&import_object)

lib/emscripten/src/lib.rs

@@ -436,7 +436,7 @@ pub struct EmscriptenGlobals {
 }
 
 impl EmscriptenGlobals {
-    pub fn new(module: &Module /*, static_bump: u32 */) -> Self {
+    pub fn new(module: &Module /*, static_bump: u32 */) -> Result<Self, String> {
         let mut use_old_abort_on_cannot_grow_memory = false;
         for (
             index,
@@ -458,8 +458,8 @@ impl EmscriptenGlobals {
             }
         }
 
-        let (table_min, table_max) = get_emscripten_table_size(&module);
-        let (memory_min, memory_max, shared) = get_emscripten_memory_size(&module);
+        let (table_min, table_max) = get_emscripten_table_size(&module)?;
+        let (memory_min, memory_max, shared) = get_emscripten_memory_size(&module)?;
 
         // Memory initialization
         let memory_type = MemoryDescriptor {
@@ -530,14 +530,14 @@ impl EmscriptenGlobals {
             }
         }
 
-        Self {
+        Ok(Self {
             data,
             memory,
             table,
             memory_min,
             memory_max,
             null_func_names,
-        }
+        })
     }
 }
 

lib/emscripten/src/utils.rs

@@ -33,22 +33,20 @@ pub fn is_emscripten_module(module: &Module) -> bool {
     false
 }
 
-pub fn get_emscripten_table_size(module: &Module) -> (u32, Option<u32>) {
-    assert!(
-        module.info().imported_tables.len() > 0,
-        "Emscripten requires at least one imported table"
-    );
+pub fn get_emscripten_table_size(module: &Module) -> Result<(u32, Option<u32>), String> {
+    if module.info().imported_tables.len() == 0 {
+        return Err("Emscripten requires at least one imported table".to_string());
+    }
     let (_, table) = &module.info().imported_tables[ImportedTableIndex::new(0)];
-    (table.minimum, table.maximum)
+    Ok((table.minimum, table.maximum))
 }
 
-pub fn get_emscripten_memory_size(module: &Module) -> (Pages, Option<Pages>, bool) {
-    assert!(
-        module.info().imported_tables.len() > 0,
-        "Emscripten requires at least one imported memory"
-    );
+pub fn get_emscripten_memory_size(module: &Module) -> Result<(Pages, Option<Pages>, bool), String> {
+    if module.info().imported_memories.len() == 0 {
+        return Err("Emscripten requires at least one imported memory".to_string());
+    }
     let (_, memory) = &module.info().imported_memories[ImportedMemoryIndex::new(0)];
-    (memory.minimum, memory.maximum, memory.shared)
+    Ok((memory.minimum, memory.maximum, memory.shared))
 }
 
 /// Reads values written by `-s EMIT_EMSCRIPTEN_METADATA=1`

src/bin/wasmer.rs

@@ -544,7 +544,7 @@ fn execute_wasm(options: &Run) -> Result<(), String> {
 
     // TODO: refactor this
     if wasmer_emscripten::is_emscripten_module(&module) {
-        let mut emscripten_globals = wasmer_emscripten::EmscriptenGlobals::new(&module);
+        let mut emscripten_globals = wasmer_emscripten::EmscriptenGlobals::new(&module)?;
         let import_object = wasmer_emscripten::generate_emscripten_env(&mut emscripten_globals);
         let mut instance = module
             .instantiate(&import_object)