GN Build fixes for Flutter + gen_snapshot fix

runtime/bin/gen_snapshot.cc

Index: runtime/bin/gen_snapshot.cc
diff --git a/runtime/bin/gen_snapshot.cc b/runtime/bin/gen_snapshot.cc
index 258b9a72850901574b3a6519cbec3c488849dc25..8dd0515fb7d275c5418613eef199c3acd9f92485 100644
--- a/runtime/bin/gen_snapshot.cc
+++ b/runtime/bin/gen_snapshot.cc
@@ -41,7 +41,6 @@ namespace bin {
 static const char* vm_isolate_snapshot_filename = NULL;
 static const char* isolate_snapshot_filename = NULL;
 static const char* instructions_snapshot_filename = NULL;
-static const char* embedder_entry_points_manifest = NULL;
 static const char* package_root = NULL;
 
 
@@ -54,6 +53,10 @@ static char* app_script_name = NULL;
 // Global state that captures the URL mappings specified on the command line.
 static CommandLineOptions* url_mapping = NULL;
 
+// Global state that captures the entry point manifest files specified on the
+// command line.
+static CommandLineOptions* entry_points_files = NULL;
+
 static bool IsValidFlag(const char* name,
                         const char* prefix,
                         intptr_t prefix_length) {
@@ -105,7 +108,7 @@ static bool ProcessInstructionsSnapshotOption(const char* option) {
 static bool ProcessEmbedderEntryPointsManifestOption(const char* option) {
   const char* name = ProcessOption(option, "--embedder_entry_points_manifest=");
   if (name != NULL) {
-    embedder_entry_points_manifest = name;
+    entry_points_files->AddArgument(name);
     return true;
   }
   return false;
@@ -114,6 +117,9 @@ static bool ProcessEmbedderEntryPointsManifestOption(const char* option) {
 
 static bool ProcessPackageRootOption(const char* option) {
   const char* name = ProcessOption(option, "--package_root=");
+  if (name == NULL) {
+    name = ProcessOption(option, "--package-root=");
+  }
   if (name != NULL) {
     package_root = name;
     return true;
@@ -181,14 +187,14 @@ static int ParseArguments(int argc,
   }
 
   if ((instructions_snapshot_filename != NULL) &&
-      (embedder_entry_points_manifest == NULL)) {
+      (entry_points_files->count() == 0)) {
     Log::PrintErr(
         "Specifying an instructions snapshot filename indicates precompilation"
         ". But no embedder entry points manifest was specified.\n\n");
     return -1;
   }
 
-  if ((embedder_entry_points_manifest != NULL) &&
+  if ((entry_points_files->count() > 0) &&
       (instructions_snapshot_filename == NULL)) {
     Log::PrintErr(
         "Specifying the embedder entry points manifest indicates "
@@ -201,8 +207,8 @@ static int ParseArguments(int argc,
 
 
 static bool IsSnapshottingForPrecompilation(void) {
-  return embedder_entry_points_manifest != NULL &&
-         instructions_snapshot_filename != NULL;
+  return (entry_points_files->count() > 0) &&
+         (instructions_snapshot_filename != NULL);
 }
 
 
@@ -781,31 +787,34 @@ int64_t ParseEntryPointsManifestLines(FILE* file,
 }
 
 
-static Dart_QualifiedFunctionName* ParseEntryPointsManifestFile(
-    const char* path) {
-  if (path == NULL) {
-    return NULL;
-  }
+static Dart_QualifiedFunctionName* ParseEntryPointsManifestFiles() {
+  // Total number of entries across all manifest files.
+  int64_t entry_count = 0;
 
-  FILE* file = fopen(path, "r");
+  // Parse the files once but don't store the results. This is done to first
+  // determine the number of entries in the manifest
+  for (intptr_t i = 0; i < entry_points_files->count(); i++) {
+    const char* path = entry_points_files->GetArgument(i);
 
-  if (file == NULL) {
-    Log::PrintErr("Could not open entry points manifest file\n");
-    return NULL;
-  }
+    FILE* file = fopen(path, "r");
 
-  // Parse the file once but don't store the results. This is done to first
-  // determine the number of entries in the manifest
-  int64_t entry_count = ParseEntryPointsManifestLines(file, NULL);
+    if (file == NULL) {
+      Log::PrintErr("Could not open entry points manifest file `%s`\n", path);
+      return NULL;
+    }
 
-  if (entry_count <= 0) {
-    Log::PrintErr(
-        "Manifest file specified is invalid or contained no entries\n");
+    int64_t entries = ParseEntryPointsManifestLines(file, NULL);
     fclose(file);
-    return NULL;
-  }
 
-  rewind(file);
+    if (entries <= 0) {
+      Log::PrintErr(
+          "Manifest file `%s` specified is invalid or contained no entries\n",
+          path);
+      return NULL;
+    }
+
+    entry_count += entries;
+  }
 
   // Allocate enough storage for the entries in the file plus a termination
   // sentinel and parse it again to populate the allocation
@@ -813,10 +822,16 @@ static Dart_QualifiedFunctionName* ParseEntryPointsManifestFile(
       reinterpret_cast<Dart_QualifiedFunctionName*>(
           calloc(entry_count + 1, sizeof(Dart_QualifiedFunctionName)));
 
-  int64_t parsed_entry_count = ParseEntryPointsManifestLines(file, entries);
-  ASSERT(parsed_entry_count == entry_count);
+  int64_t parsed_entry_count = 0;
+  for (intptr_t i = 0; i < entry_points_files->count(); i++) {
+    const char* path = entry_points_files->GetArgument(i);
+    FILE* file = fopen(path, "r");
+    parsed_entry_count +=
+        ParseEntryPointsManifestLines(file, &entries[parsed_entry_count]);
+    fclose(file);
+  }
 
-  fclose(file);
+  ASSERT(parsed_entry_count == entry_count);
 
   // The entries allocation must be explicitly cleaned up via
   // |CleanupEntryPointsCollection|
@@ -825,8 +840,7 @@ static Dart_QualifiedFunctionName* ParseEntryPointsManifestFile(
 
 
 static Dart_QualifiedFunctionName* ParseEntryPointsManifestIfPresent() {
-  Dart_QualifiedFunctionName* entries =
-      ParseEntryPointsManifestFile(embedder_entry_points_manifest);
+  Dart_QualifiedFunctionName* entries = ParseEntryPointsManifestFiles();
   if ((entries == NULL) && IsSnapshottingForPrecompilation()) {
     Log::PrintErr(
         "Could not find native embedder entry points during precompilation\n");
@@ -998,6 +1012,10 @@ int main(int argc, char** argv) {
   CommandLineOptions url_mapping_array(argc);
   url_mapping = &url_mapping_array;
 
+  // Initialize the entrypoints array.
+  CommandLineOptions entry_points_files_array(argc);
+  entry_points_files = &entry_points_files_array;
+
   // Parse command line arguments.
   if (ParseArguments(argc,
                      argv,