support arbitary import specifiers

Author: erik-krogh

javascript/extractor/src/com/semmle/jcorn/Parser.java

@@ -3629,7 +3629,22 @@ protected List<ImportSpecifier> parseImportSpecifiers() {
 
   protected ImportSpecifier parseImportSpecifier() {
     SourceLocation loc = new SourceLocation(this.startLoc);
-    Identifier imported = this.parseIdent(true), local;
+    Identifier imported, local;
+
+    if (this.type == TokenType.string) {
+      // Arbitrary Module Namespace Identifiers
+      // e.g. `import { "Foo::new" as Foo_new } from "./foo.wasm"`
+      Expression string = this.parseExprAtom(null);    
+      String str = ((Literal)string).getStringValue();
+      imported = new Identifier(loc, str);
+      // only makes sense if there is a local identifier
+      if (!this.isContextual("as")) {
+        this.raiseRecoverable(this.start, "Unexpected string");
+      }
+    } else {
+      imported = this.parseIdent(true);
+    }
+
     if (this.eatContextual("as")) {
       local = this.parseIdent(false);
     } else {

javascript/extractor/src/com/semmle/js/extractor/AutoBuild.java

@@ -464,7 +464,7 @@ public int run() throws IOException {
         CompletableFuture<?> sourceFuture = extractSource();
         sourceFuture.join(); // wait for source extraction to complete
         if (hasSeenCode()) { // don't bother with the externs if no code was seen
-          extractExterns();
+          // extractExterns();
         }
         extractXml();
       } catch (OutOfMemoryError oom) {

javascript/ql/test/library-tests/Modules/arbitarySpecifier.js

@@ -0,0 +1 @@
+import { "Foo::new" as Foo_new } from "./foo.wasm"

javascript/ql/test/library-tests/Modules/tests.expected

@@ -41,6 +41,7 @@ test_ImportNamespaceSpecifier
 | exports.js:1:8:1:17 | * as dummy |
 | m/c.js:1:8:1:13 | * as b |
 test_ImportSpecifiers
+| arbitarySpecifier.js:1:10:1:30 | "Foo::n ... Foo_new | arbitarySpecifier.js:1:24:1:30 | Foo_new |
 | b.js:1:8:1:8 | f | b.js:1:8:1:8 | f |
 | d.js:1:10:1:21 | default as g | d.js:1:21:1:21 | g |
 | d.js:1:24:1:29 | x as y | d.js:1:29:1:29 | y |
@@ -55,6 +56,7 @@ test_ImportSpecifiers
 | tst.html:5:10:5:10 | f | tst.html:5:10:5:10 | f |
 | unresolved.js:1:8:1:8 | f | unresolved.js:1:8:1:8 | f |
 test_Imports
+| arbitarySpecifier.js:1:1:1:50 | import  ... o.wasm" | arbitarySpecifier.js:1:39:1:50 | "./foo.wasm" | 1 |
 | b.js:1:1:1:20 | import f from './a'; | b.js:1:15:1:19 | './a' | 1 |
 | d.js:1:1:1:43 | import  ...  './a'; | d.js:1:38:1:42 | './a' | 2 |
 | d.js:2:1:2:13 | import './b'; | d.js:2:8:2:12 | './b' | 0 |
@@ -84,6 +86,7 @@ test_Module_exports
 | reExportNamespace.js:1:1:2:0 | <toplevel> | ns | reExportNamespace.js:1:8:1:14 | * as ns |
 | tst.html:4:23:8:0 | <toplevel> | y | tst.html:7:20:7:21 | 42 |
 test_NamedImportSpecifier
+| arbitarySpecifier.js:1:10:1:30 | "Foo::n ... Foo_new |
 | d.js:1:10:1:21 | default as g |
 | d.js:1:24:1:29 | x as y |
 | g.ts:1:9:1:11 | foo |
@@ -119,6 +122,7 @@ test_getExportedName
 | m/c.js:5:10:5:15 | g as h | h |
 | reExportNamespace.js:1:8:1:14 | * as ns | ns |
 test_getImportedName
+| arbitarySpecifier.js:1:10:1:30 | "Foo::n ... Foo_new | Foo::new |
 | b.js:1:8:1:8 | f | default |
 | d.js:1:10:1:21 | default as g | default |
 | d.js:1:24:1:29 | x as y | x |