Support --show-manifest

We want to use this in flathub to avoid all the problems we've having
parsing json manifests via the python parser, which isn't *quite* compatible
with json-glib (differs in comment and multiline string support for instance).

Closes: #307
Approved by: alexlarsson

doc/flatpak-builder.xml

@@ -49,6 +49,12 @@
                 <arg choice="opt" rep="repeat">OPTION</arg>
                 <arg choice="plain">MANIFEST</arg>
             </cmdsynopsis>
+            <cmdsynopsis>
+                <command>flatpak-builder</command>
+                <arg choice="plain">--show-manifest</arg>
+                <arg choice="opt" rep="repeat">OPTION</arg>
+                <arg choice="plain">MANIFEST</arg>
+            </cmdsynopsis>
     </refsynopsisdiv>
 
     <refsect1>
@@ -253,6 +259,23 @@
                 </listitem>
             </varlistentry>
 
+            <varlistentry>
+                <term><option>--show-manifest</option></term>
+
+                <listitem><para>
+                  Loads the manifest, including any included files and prints it in a canonical json format.
+                  This is useful for tools that want to handle manifest files to avoid having to support both
+                  yaml and json, as well as some non-standard json handling that is supported (for example
+                  comments and multiline strings).
+                  </para>
+
+                  <para>
+                  Only the <option>--verbose</option> option can be combined
+                  with this option.
+                  </para>
+                </listitem>
+            </varlistentry>
+
             <varlistentry>
                 <term><option>--download-only</option></term>
 

src/builder-main.c

@@ -47,6 +47,7 @@ static gboolean opt_build_only;
 static gboolean opt_finish_only;
 static gboolean opt_export_only;
 static gboolean opt_show_deps;
+static gboolean opt_show_manifest;
 static gboolean opt_disable_download;
 static gboolean opt_disable_updates;
 static gboolean opt_ccache;
@@ -109,6 +110,7 @@ static GOptionEntry entries[] = {
   { "export-only", 0, 0, G_OPTION_ARG_NONE, &opt_export_only, "Only run export phase", NULL },
   { "allow-missing-runtimes", 0, 0, G_OPTION_ARG_NONE, &opt_allow_missing_runtimes, "Don't fail if runtime and sdk missing", NULL },
   { "show-deps", 0, 0, G_OPTION_ARG_NONE, &opt_show_deps, "List the dependencies of the json file (see --show-deps --help)", NULL },
+  { "show-manifest", 0, 0, G_OPTION_ARG_NONE, &opt_show_manifest, "Print out the manifest file in standard json format (see --show-manifest --help)", NULL },
   { "require-changes", 0, 0, G_OPTION_ARG_NONE, &opt_require_changes, "Don't create app dir or export if no changes", NULL },
   { "keep-build-dirs", 0, 0, G_OPTION_ARG_NONE, &opt_keep_build_dirs, "Don't remove build directories after install", NULL },
   { "delete-build-dirs", 0, 0, G_OPTION_ARG_NONE, &opt_delete_build_dirs, "Always remove build directories, even after build failure", NULL },
@@ -152,7 +154,13 @@ static GOptionEntry run_entries[] = {
 
 static GOptionEntry show_deps_entries[] = {
   { "verbose", 'v', 0, G_OPTION_ARG_NONE, &opt_verbose, "Print debug information during command processing", NULL },
-  { "show-deps", 0, 0, G_OPTION_ARG_NONE, &opt_show_deps, "List the dependencies of the json file (see --show-deps --help)", NULL },
+  { "show-deps", 0, 0, G_OPTION_ARG_NONE, &opt_show_deps, "List the dependencies of the json file", NULL },
+  { NULL }
+};
+
+static GOptionEntry show_manifest_entries[] = {
+  { "verbose", 'v', 0, G_OPTION_ARG_NONE, &opt_verbose, "Print debug information during command processing", NULL },
+  { "show-manifest", 0, 0, G_OPTION_ARG_NONE, &opt_show_manifest, "Print out the manifest file in standard json format", NULL },
   { NULL }
 };
 
@@ -379,6 +387,7 @@ main (int    argc,
   g_autofree char **orig_argv = NULL;
   gboolean is_run = FALSE;
   gboolean is_show_deps = FALSE;
+  gboolean is_show_manifest = FALSE;
   gboolean app_dir_is_empty = FALSE;
   gboolean prune_unused_stages = FALSE;
   g_autoptr(FlatpakContext) arg_context = NULL;
@@ -426,6 +435,8 @@ main (int    argc,
         is_run = TRUE;
       if (strcmp (argv[i], "--show-deps") == 0)
         is_show_deps = TRUE;
+      if (strcmp (argv[i], "--show-manifest") == 0)
+        is_show_manifest = TRUE;
     }
 
   if (is_run)
@@ -443,6 +454,11 @@ main (int    argc,
       context = g_option_context_new ("MANIFEST - Show manifest dependencies");
       g_option_context_add_main_entries (context, show_deps_entries, NULL);
     }
+  else if (is_show_manifest)
+    {
+      context = g_option_context_new ("MANIFEST - Show manifest");
+      g_option_context_add_main_entries (context, show_manifest_entries, NULL);
+    }
   else
     {
       context = g_option_context_new ("DIRECTORY MANIFEST - Build manifest");
@@ -466,7 +482,7 @@ main (int    argc,
 
   argnr = 1;
 
-  if (!is_show_deps)
+  if (!is_show_deps && !is_show_manifest)
     {
       if (argc == argnr)
         return usage (context, "DIRECTORY must be specified");
@@ -574,7 +590,7 @@ main (int    argc,
       if (opt_disable_updates)
         {
           mirror_flags |= FLATPAK_GIT_MIRROR_FLAGS_UPDATE;
-	}
+        }
 
       if (!builder_git_mirror_repo (opt_from_git,
                                     NULL,
@@ -673,6 +689,13 @@ main (int    argc,
       return 0;
     }
 
+  if (is_show_manifest)
+    {
+      g_autofree char *json = builder_manifest_serialize (manifest);
+      g_print ("%s\n", json);
+      return 0;
+    }
+
   if (opt_install_deps_from != NULL)
     {
       if (!builder_manifest_install_deps (manifest, build_context, opt_install_deps_from, opt_user, opt_installation,

src/builder-manifest.c

@@ -1289,7 +1289,7 @@ serializable_iface_init (JsonSerializableIface *serializable_iface)
   serializable_iface->get_property = builder_serializable_get_property;
 }
 
-static char *
+char *
 builder_manifest_serialize (BuilderManifest *self)
 {
   JsonNode *node;

src/builder-manifest.h

@@ -134,6 +134,7 @@ gboolean        builder_manifest_create_platform (BuilderManifest *self,
                                                   BuilderCache    *cache,
                                                   BuilderContext  *context,
                                                   GError         **error);
+char *          builder_manifest_serialize       (BuilderManifest *self);
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (BuilderManifest, g_object_unref)