fix building C

package.cm

@@ -379,10 +379,26 @@ package.get_c_files = function(name, target, exclude_main) {
       push(result, selected)
     }
   })
-  
+
+  // Exclude src/ files (support files, not modules)
+  var sources = package.get_sources(name)
+  if (length(sources) > 0) {
+    result = filter(result, function(f) {
+      return find(sources, function(s) { return s == f }) == null
+    })
+  }
+
   return result
 }
 
+// Get support source files: C files in src/ directories (not modules)
+package.get_sources = function(name) {
+  var files = package.list_files(name)
+  return filter(files, function(f) {
+    return (ends_with(f, '.c') || ends_with(f, '.cpp')) && starts_with(f, 'src/')
+  })
+}
+
 // Get the absolute path for a package
 package.get_dir = function(name) {
   return get_path(name)