Fix importing same types in two modules/crates

This'll hopefully fix fallout from 4f4da74

Author: alexcrichton

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

@@ -24,6 +24,8 @@ pub struct Context<'a> {
     pub typescript: String,
     pub exposed_globals: HashSet<&'static str>,
     pub required_internal_exports: HashSet<&'static str>,
+    pub imported_functions: HashSet<String>,
+    pub imported_statics: HashSet<String>,
     pub config: &'a Bindgen,
     pub module: &'a mut Module,
 
@@ -1884,6 +1886,12 @@ impl<'a, 'b> SubContext<'a, 'b> {
         info: &shared::Import,
         import: &shared::ImportStatic,
     ) -> Result<(), Error> {
+        // The same static can be imported in multiple locations, so only
+        // generate bindings once for it.
+        if !self.cx.imported_statics.insert(import.shim.clone()) {
+            return Ok(())
+        }
+
         // TODO: should support more types to import here
         let obj = self.import_name(info, &import.name)?;
         self.cx.expose_add_heap_object();
@@ -1911,6 +1919,12 @@ impl<'a, 'b> SubContext<'a, 'b> {
             return Ok(());
         }
 
+        // It's possible for the same function to be imported in two locations,
+        // but we only want to generate one.
+        if !self.cx.imported_functions.insert(import.shim.clone()) {
+            return Ok(());
+        }
+
         let descriptor = match self.cx.describe(&import.shim) {
             None => return Ok(()),
             Some(d) => d,

crates/cli-support/src/lib.rs

@@ -201,6 +201,8 @@ impl Bindgen {
                 function_table_needed: false,
                 interpreter: &mut instance,
                 memory_init: None,
+                imported_functions: Default::default(),
+                imported_statics: Default::default(),
             };
             for program in programs.iter() {
                 js::SubContext {