3 files changed, 37 insertions, 12 deletions

diff --git a/src/modules.js b/src/modules.js
index dc4a296d..89684411 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -134,7 +134,6 @@ var Types = {
       if (shorter === longer) return;
       if (shorter in this.types) return;
       this.types[shorter] = this.types[longer];
-      delete this.types[longer];
     }, this);
   },
 
diff --git a/src/runtime.js b/src/runtime.js
index 559dd125..06638fa3 100644
--- a/src/runtime.js
+++ b/src/runtime.js
@@ -167,11 +167,17 @@ Runtime = {
   // generateStructInfo(['field1', 'field2'], '%struct.UserStructType');
   // (Note that you will need the full %struct.* name here at compile time,
   // but not at runtime. The reason is that during compilation we cannot simplify
-  // the type names yet.)
-  generateStructInfo: function(struct, typeName) {
+  // the type names yet. At runtime, you can provide either the short or the
+  // full name.)
+  //
+  // When providing a typeName, you can generate information for nested
+  // structs, for example, struct = ['field1', { field2: ['sub1', 'sub2', 'sub3'] }, 'field3']
+  // which repesents a structure whose 2nd field is another structure.
+  generateStructInfo: function(struct, typeName, offset) {
     var type, alignment;
     if (typeName) {
-      type = Types.types[typeName];
+      offset = offset || 0;
+      type = typeof Types === 'undefined' ? Runtime.typeInfo[typeName] : Types.types[typeName];
       if (!type) return null;
       assert(type.fields.length === struct.length, 'Number of named fields must match the type for ' + typeName);
       alignment = type.flatIndexes;
@@ -182,9 +188,22 @@ Runtime = {
     var ret = {
       __size__: type.flatSize
     };
-    struct.forEach(function(item, i) {
-      ret[typeof item === 'string' ? item : item[1]] = alignment[i];
-    });
+    if (typeName) {
+      struct.forEach(function(item, i) {
+        if (typeof item === 'string') {
+          ret[item] = alignment[i] + offset;
+        } else {
+          // embedded struct
+          var key;
+          for (var k in item) key = k;
+          ret[key] = Runtime.generateStructInfo(item[key], type.fields[i], alignment[i]);
+        }
+      });
+    } else {
+      struct.forEach(function(item, i) {
+        ret[item[1]] = alignment[i];
+      });
+    }
     return ret;
   }
 };
diff --git a/tests/runner.py b/tests/runner.py
index d3573d2c..25995c5c 100644
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -2732,12 +2732,17 @@ Child2:9
         struct UserStruct {
           int x;
           char y;
-          void *z;
+          short z;
+        };
+        struct Encloser {
+          short x;
+          UserStruct us;
+          int y;
         };
         int main() {
-          UserStruct u;
-          u.y = 5;
-          printf("*ok:%d*\\n", u.y);
+          Encloser e;
+          e.us.y = 5;
+          printf("*ok:%d*\\n", e.us.y);
           return 0;
         }
       '''
@@ -2748,13 +2753,15 @@ Child2:9
           '''
             if (Runtime.typeInfo) {
               print('|' + Runtime.typeInfo.UserStruct.fields + '|' + Runtime.typeInfo.UserStruct.flatIndexes + '|');
+              var t = Runtime.generateStructInfo(['x', { us: ['x', 'y', 'z'] }, 'y'], 'Encloser')
+              print('|' + [t.x, t.us.x, t.us.y, t.us.z, t.y] + '|');
             } else {
               print('No type info.');
             }
           '''
         )
         open(filename, 'w').write(src)
-      self.do_test(src, '*ok:5*\n|i32,i8,i8*|0,4,8|', post_build=post)
+      self.do_test(src, '*ok:5*\n|i32,i8,i16|0,4,6|\n|0,4,8,10,12|', post_build=post)
 
       # Make sure that without the setting, we don't spam the .js with the type info
       RUNTIME_TYPE_INFO = 0