Add a flag to remove the wasm name section

This commit adds a `--remove-name-section` flag to the `wasm-bindgen`
command which will remove the `name` section of the wasm file, used to
indicate the names of functions typically used in debugging. This flag
is off-by-default and will primarily be controlled by wasm-pack,
typically being passed by default with `wasm-pack build --release`.

Closes #1021

crates/cli-support/src/js/mod.rs

@@ -116,6 +116,7 @@ impl<'a> Context<'a> {
     }
 
     pub fn finalize(&mut self, module_name: &str) -> Result<(String, String), Error> {
+        self.parse_wasm_names();
         self.write_classes()?;
 
         self.bind("__wbindgen_object_clone_ref", &|me| {
@@ -1689,7 +1690,6 @@ impl<'a> Context<'a> {
     }
 
     fn gc(&mut self) {
-        self.parse_wasm_names();
         gc::Config::new()
             .demangle(self.config.demangle)
             .keep_debug(self.config.keep_debug || self.config.debug)
@@ -1700,6 +1700,14 @@ impl<'a> Context<'a> {
         let module = mem::replace(self.module, Module::default());
         let module = module.parse_names().unwrap_or_else(|p| p.1);
         *self.module = module;
+        if self.config.remove_name_section {
+            self.module.sections_mut().retain(|s| {
+                match s {
+                    Section::Name(_) => false,
+                    _ => true,
+                }
+            });
+        }
     }
 
     fn describe(&mut self, name: &str) -> Option<Descriptor> {

crates/cli-support/src/lib.rs

@@ -35,6 +35,7 @@ pub struct Bindgen {
     typescript: bool,
     demangle: bool,
     keep_debug: bool,
+    remove_name_section: bool,
     // Experimental support for `WeakRefGroup`, an upcoming ECMAScript feature.
     // Currently only enable-able through an env var.
     weak_refs: bool,
@@ -62,6 +63,7 @@ impl Bindgen {
             typescript: false,
             demangle: true,
             keep_debug: false,
+            remove_name_section: false,
             weak_refs: env::var("WASM_BINDGEN_WEAKREF").is_ok(),
             threads: threads_config(),
         }
@@ -124,6 +126,11 @@ impl Bindgen {
         self
     }
 
+    pub fn remove_name_section(&mut self, remove: bool) -> &mut Bindgen {
+        self.remove_name_section = remove;
+        self
+    }
+
     pub fn generate<P: AsRef<Path>>(&mut self, path: P) -> Result<(), Error> {
         self._generate(path.as_ref())
     }

crates/cli/src/bin/wasm-bindgen.rs

@@ -37,6 +37,7 @@ Options:
     --debug                  Include otherwise-extraneous debug checks in output
     --no-demangle            Don't demangle Rust symbol names
     --keep-debug             Keep debug sections in wasm files
+    --remove-name-section    Remove the debugging `name` section of the file
     -V --version             Print the version number of wasm-bindgen
 ";
 
@@ -52,6 +53,7 @@ struct Args {
     flag_version: bool,
     flag_no_demangle: bool,
     flag_no_modules_global: Option<String>,
+    flag_remove_name_section: bool,
     flag_keep_debug: bool,
     arg_input: Option<PathBuf>,
 }
@@ -92,6 +94,7 @@ fn rmain(args: &Args) -> Result<(), Error> {
         .debug(args.flag_debug)
         .demangle(!args.flag_no_demangle)
         .keep_debug(args.flag_keep_debug)
+        .remove_name_section(args.flag_remove_name_section)
         .typescript(typescript);
     if let Some(ref name) = args.flag_no_modules_global {
         b.no_modules_global(name);