[VM] During hot-reload check if .packages was modified, tell IKG to re-load it if so

Change-Id: Ice7bbe0ccd98e450ec9c90a22259ec7b406b2c83
Reviewed-on: https://dart-review.googlesource.com/68360
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>

Author: mkustermann

runtime/vm/isolate_reload.cc

@@ -594,7 +594,7 @@ void IsolateReloadContext::Reload(bool force_reload,
       intptr_t modified_scripts_count = 0;
 
       FindModifiedSources(thread, force_reload, &modified_scripts,
-                          &modified_scripts_count);
+                          &modified_scripts_count, packages_url_);
 
       Dart_KernelCompilationResult retval;
       {
@@ -1014,7 +1014,8 @@ void IsolateReloadContext::FindModifiedSources(
     Thread* thread,
     bool force_reload,
     Dart_SourceFile** modified_sources,
-    intptr_t* count) {
+    intptr_t* count,
+    const char* packages_url) {
   Zone* zone = thread->zone();
   int64_t last_reload = I->last_reload_timestamp();
   GrowableArray<const char*> modified_sources_uris;
@@ -1046,6 +1047,15 @@ void IsolateReloadContext::FindModifiedSources(
     }
   }
 
+  // In addition to all sources, we need to check if the .packages file
+  // contents have been modified.
+  if (packages_url != NULL) {
+    if (file_modified_callback_ == NULL ||
+        (*file_modified_callback_)(packages_url, last_reload)) {
+      modified_sources_uris.Add(packages_url);
+    }
+  }
+
   *count = modified_sources_uris.length();
   if (*count == 0) {
     return;

runtime/vm/isolate_reload.h

@@ -236,7 +236,8 @@ class IsolateReloadContext {
   void FindModifiedSources(Thread* thread,
                            bool force_reload,
                            Dart_SourceFile** modified_sources,
-                           intptr_t* count);
+                           intptr_t* count,
+                           const char* packages_url);
 
   void CheckpointLibraries();