lib/component: pass extended Libc::Env

Libc::Env is the Genode::Env interface extended to cover access
to the XML content of the 'config' ROM and a VFS instance. This
deduplicates the burden of components to attain and manage
these resources.

Fix #2217
Ref #1987

repos/dde_linux/src/drivers/wifi/main.cc

@@ -254,4 +254,4 @@ struct Main
 };
 
 
-void Libc::Component::construct(Genode::Env &env) { static Main server(env); }
+void Libc::Component::construct(Libc::Env &env) { static Main server(env); }

repos/gems/src/app/backdrop/main.cc

@@ -366,6 +366,6 @@ void Backdrop::Main::handle_sync()
 extern "C" void _sigprocmask() { }
 
 
-void Libc::Component::construct(Genode::Env &env) {
+void Libc::Component::construct(Libc::Env &env) {
 	static Backdrop::Main application(env); }
 

repos/gems/src/app/menu_view/main.cc

@@ -292,5 +292,5 @@ void Menu_view::Main::_handle_frame_timer()
 extern "C" void _sigprocmask() { }
 
 
-void Libc::Component::construct(Genode::Env &env) { static Menu_view::Main main(env); }
+void Libc::Component::construct(Libc::Env &env) { static Menu_view::Main main(env); }
 

repos/gems/src/app/themed_decorator/main.cc

@@ -317,4 +317,4 @@ void Decorator::Main::_handle_pointer_update()
 }
 
 
-void Libc::Component::construct(Genode::Env &env) { static Decorator::Main main(env); }
+void Libc::Component::construct(Libc::Env &env) { static Decorator::Main main(env); }

repos/gems/src/server/http_blk/main.cc

@@ -107,4 +107,4 @@ struct Main
 };
 
 
-void Libc::Component::construct(Genode::Env &env) { static Main m(env); }
+void Libc::Component::construct(Libc::Env &env) { static Main m(env); }

repos/gems/src/server/terminal_mux/main.cc

@@ -721,4 +721,4 @@ struct Main
 };
 
 
-void Libc::Component::construct(Genode::Env &env) { static Main inst(env); }
+void Libc::Component::construct(Libc::Env &env) { static Main inst(env); }

repos/libports/include/libc/component.h

@@ -21,28 +21,51 @@
 #ifndef _INCLUDE__LIBC__COMPONENT_H_
 #define _INCLUDE__LIBC__COMPONENT_H_
 
+#include <vfs/file_system.h>
 #include <base/env.h>
 #include <base/stdint.h>
 
-namespace Genode { struct Env; }
-
 
 /**
  * Interface to be provided by the component implementation
  */
-namespace Libc { namespace Component {
+namespace Libc {
 
-	/**
-	 * Return stack size of the component's initial entrypoint
-	 */
-	Genode::size_t stack_size();
+	class Env : public Genode::Env
+	{
+		private:
 
-	/**
-	 * Construct component
-	 *
-	 * \param env  interface to the component's execution environment
-	 */
-	void construct(Genode::Env &env);
-} }
+			virtual Genode::Xml_node _config_xml() const = 0;
+
+		public:
+
+			/**
+			 * Component configuration
+			 */
+			template <typename FUNC>
+			void config(FUNC const &func) const {
+				func(_config_xml()); }
+
+			/**
+			 * Virtual File System configured for this component
+			 */
+			virtual Vfs::File_system &vfs() = 0;
+	};
+
+	namespace Component {
+
+		/**
+		 * Return stack size of the component's initial entrypoint
+		 */
+		Genode::size_t stack_size();
+
+		/**
+		 * Construct component
+		 *
+		 * \param env  extended interface to the component's execution environment
+		 */
+		void construct(Libc::Env &env);
+	}
+}
 
 #endif /* _INCLUDE__LIBC__COMPONENT_H_ */

repos/libports/lib/mk/libc.mk

@@ -4,7 +4,7 @@
 LIBS   = libc-string libc-locale libc-stdlib libc-stdio libc-gen libc-gdtoa \
          libc-inet libc-stdtime libc-regex libc-compat libc-setjmp libc-mem
 
-LIBS  += base config vfs
+LIBS  += base vfs
 
 #
 # Back end

repos/libports/lib/symbols/libc

@@ -933,7 +933,7 @@ _write T
 _writev T
 
 
-_ZN4Libc9Component9constructERN6Genode3EnvE U
+_ZN4Libc9Component9constructERNS_3EnvE U
 
 #
 # Libc plugin interface

repos/libports/run/ldso.run

@@ -15,9 +15,8 @@ set config {
 		<start name="test-ldso">
 			<resource name="RAM" quantum="2M"/>
 			<config ld_bind_now="no" ld_verbose="no">
-				<libc stdout="/dev/log">
-					<vfs> <dir name="dev"> <log/> </dir> </vfs>
-				</libc>
+				<vfs> <dir name="dev"> <log/> </dir> </vfs>
+				<libc stdout="/dev/log"/>
 			</config>
 		</start>
 	</config>

repos/libports/run/libc.run

@@ -22,9 +22,8 @@ install_config {
 	<start name="test-libc">
 		<resource name="RAM" quantum="4M"/>
 		<config>
-			<libc stdout="/dev/log">
-				<vfs> <dir name="dev"> <log/> </dir> </vfs>
-			</libc>
+			<vfs> <dir name="dev"> <log/> </dir> </vfs>
+			<libc stdout="/dev/log"/>
 		</config>
 	</start>
 </config>

repos/libports/src/app/acpica/os.cc

@@ -307,4 +307,4 @@ ACPI_STATUS AcpiOsInstallInterruptHandler(UINT32 irq, ACPI_OSD_HANDLER handler,
 /* used by normal (no-printf-debug) target */
 void Component::construct(Genode::Env &env) { static Acpica::Main main(env); }
 /* used by debug target (using printf of libc) */
-void Libc::Component::construct(Genode::Env &env) { static Acpica::Main main(env); }
+void Libc::Component::construct(Libc::Env &env) { static Acpica::Main main(env); }

repos/libports/src/app/qt5/qt_avplay/main.cpp

@@ -37,7 +37,7 @@ static inline void load_stylesheet()
 extern int genode_argc;
 extern char **genode_argv;
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	QApplication app(genode_argc, genode_argv);
 

repos/libports/src/app/qt5/qt_launchpad/main.cpp

@@ -57,7 +57,7 @@ struct Qt_launchpad_namespace::Local_env : Genode::Env
 };
 
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	static Qt_launchpad_namespace::Local_env local_env(env);
 

repos/libports/src/lib/libc/task.cc

@@ -13,11 +13,12 @@
 
 /* Genode includes */
 #include <base/component.h>
-#include <base/printf.h>
 #include <base/thread.h>
 #include <base/rpc_server.h>
 #include <base/rpc_client.h>
 #include <base/heap.h>
+#include <base/attached_rom_dataspace.h>
+#include <vfs/dir_file_system.h>
 
 /* libc includes */
 #include <libc/component.h>
@@ -44,7 +45,10 @@
 	} while (0)
 
 
-namespace Libc { class Task; }
+namespace Libc {
+	class Env_implementation;
+	class Task;
+}
 
 
 struct Task_resume
@@ -54,6 +58,102 @@ struct Task_resume
 };
 
 
+class Libc::Env_implementation : public Libc::Env
+{
+	private:
+
+		Genode::Env &_env;
+
+		Genode::Attached_rom_dataspace _config { _env, "config" };
+
+		Genode::Xml_node _vfs_config()
+		{
+			try { return _config.xml().sub_node("vfs"); }
+			catch (Genode::Xml_node::Nonexistent_sub_node) { }
+			try {
+				Genode::Xml_node node =
+					_config.xml().sub_node("libc").sub_node("vfs");
+				Genode::warning("'<config> <libc> <vfs/>' is deprecated, "
+				                "please move to '<config> <vfs/>'");
+				return node;
+			}
+			catch (Genode::Xml_node::Nonexistent_sub_node) { }
+
+			return Genode::Xml_node("<vfs/>");
+		}
+
+		Vfs::Dir_file_system _vfs;
+
+		Genode::Xml_node _config_xml() const override {
+			return _config.xml(); };
+
+	public:
+
+		Env_implementation(Genode::Env &env, Genode::Allocator &alloc)
+		:
+			_env(env),
+			_vfs(_env, alloc, _vfs_config(),
+			     Vfs::global_file_system_factory())
+		{ }
+
+
+		/*************************
+		 ** Libc::Env interface **
+		 *************************/
+
+		Vfs::File_system &vfs() override {
+			return _vfs; }
+
+
+		/***************************
+		 ** Genode::Env interface **
+		 ***************************/
+
+		Parent &parent() override {
+			return _env.parent(); }
+
+		Ram_session &ram() override {
+			return _env.ram(); }
+
+		Cpu_session &cpu() override {
+			return _env.cpu(); }
+
+		Region_map &rm() override {
+			return _env.rm(); }
+
+		Pd_session &pd() override {
+			return _env.pd(); }
+
+		Entrypoint &ep() override {
+			return _env.ep(); }
+
+		Ram_session_capability ram_session_cap() override {
+			return _env.ram_session_cap(); }
+		Cpu_session_capability cpu_session_cap() override {
+			return _env.cpu_session_cap(); }
+
+		Pd_session_capability pd_session_cap() override {
+			return _env.pd_session_cap(); }
+
+		Id_space<Parent::Client> &id_space() override {
+			return _env.id_space(); }
+
+		Session_capability session(Parent::Service_name const &name,
+	                                   Parent::Client::Id id,
+	                                   Parent::Session_args const &args,
+	                                   Affinity             const &aff) override {
+			return _env.session(name, id, args, aff); }
+
+
+		void upgrade(Parent::Client::Id id,
+		             Parent::Upgrade_args const &args) override {
+			return _env.upgrade(id, args); }
+
+		void close(Parent::Client::Id id) override {
+			return _env.close(id); }
+};
+
+
 /**
  * Libc task
  *
@@ -68,12 +168,10 @@ class Libc::Task : public Genode::Rpc_object<Task_resume, Libc::Task>
 {
 	private:
 
-		Genode::Env &_env;
-
-		/* XXX: this heap is only used by the Vfs_plugin */
-		Genode::Heap _heap { &_env.ram(), &_env.rm() };
-
-		Vfs_plugin   _vfs  { _env, _heap };
+		Genode::Env       &_env;
+		Genode::Heap       _heap { _env.ram(), _env.rm() };
+		Env_implementation _libc_env { _env, _heap };
+		Vfs_plugin         _vfs { _libc_env, _heap };
 
 		/**
 		 * Application context and execution state
@@ -158,9 +256,11 @@ class Libc::Task : public Genode::Rpc_object<Task_resume, Libc::Task>
  ** Libc task implementation **
  ******************************/
 
+extern "C" void wait_for_continue(void);
+
 void Libc::Task::_app_entry(Task *task)
 {
-	Libc::Component::construct(task->_env);
+	Libc::Component::construct(task->_libc_env);
 
 	/* returned from task - switch stack to libc and return to dispatch loop */
 	_longjmp(task->_libc_task, 1);

repos/libports/src/lib/libc/vfs_plugin.cc

@@ -83,14 +83,6 @@ namespace Libc {
 		return Genode::config()->xml_node().sub_node("libc");
 	}
 
-
-	Genode::Xml_node vfs_config() __attribute__((weak));
-	Genode::Xml_node vfs_config()
-	{
-		return Libc::config().sub_node("vfs");
-	}
-
-
 	class Config_attr
 	{
 		private:
@@ -110,38 +102,6 @@ namespace Libc {
 			char const *string() const { return _buf; }
 	};
 
-
-	char const *initial_cwd() __attribute__((weak));
-	char const *initial_cwd()
-	{
-		static Config_attr initial_cwd("cwd", "/");
-		return initial_cwd.string();
-	}
-
-
-	char const *config_stdin() __attribute__((weak));
-	char const *config_stdin()
-	{
-		static Config_attr stdin("stdin", "");
-		return stdin.string();
-	}
-
-
-	char const *config_stdout() __attribute__((weak));
-	char const *config_stdout()
-	{
-		static Config_attr stdout("stdout", "");
-		return stdout.string();
-	}
-
-
-	char const *config_stderr() __attribute__((weak));
-	char const *config_stderr()
-	{
-		static Config_attr stderr("stderr", "");
-		return stderr.string();
-	}
-
 	char const *config_rtc() __attribute__((weak));
 	char const *config_rtc()
 	{

repos/libports/src/lib/libc/vfs_plugin.h

@@ -15,10 +15,7 @@
 #define _LIBC_VFS__PLUGIN_H_
 
 /* Genode includes */
-#include <base/env.h>
-#include <base/printf.h>
-#include <vfs/dir_file_system.h>
-#include <os/config.h>
+#include <libc/component.h>
 
 /* libc includes */
 #include <fcntl.h>
@@ -28,19 +25,6 @@
 #include <libc-plugin/plugin.h>
 #include <libc-plugin/fd_alloc.h>
 
-namespace Libc {
-
-	Genode::Xml_node config();
-	Genode::Xml_node vfs_config();
-
-	char const *initial_cwd();
-	char const *config_stdin();
-	char const *config_stdout();
-	char const *config_stderr();
-
-}
-
-
 namespace Libc { class Vfs_plugin; }
 
 
@@ -50,41 +34,39 @@ class Libc::Vfs_plugin : public Libc::Plugin
 
 		Genode::Allocator &_alloc;
 
-		Vfs::Dir_file_system _root_dir;
+		Vfs::File_system &_root_dir;
 
-		Genode::Xml_node _vfs_config()
+		void _open_stdio(Genode::Xml_node const &node, char const *attr,
+		                 int libc_fd, unsigned flags)
 		{
 			try {
-				return vfs_config();
-			} catch (...) {
-				PINF("no VFS configured");
-				return Genode::Xml_node("<vfs/>");
-			}
-		}
+				Genode::String<Vfs::MAX_PATH_LEN> path;
+				struct stat out_stat;
 
-		void _open_stdio(int libc_fd, char const *path, unsigned flags)
-		{
-			struct stat out_stat;
-			if (::strlen(path) == 0 || stat(path, &out_stat) != 0)
-				return;
+				node.attribute(attr).value(&path);
 
-			Libc::File_descriptor *fd = open(path, flags, libc_fd);
-			if (fd->libc_fd != libc_fd) {
-				PERR("could not allocate fd %d for %s, got fd %d",
-				     libc_fd, path, fd->libc_fd);
-				close(fd);
-				return;
-			}
+				if (stat(path.string(), &out_stat) != 0)
+					return;
 
-			/*
-			 * We need to manually register the path. Normally this is done
-			 * by '_open'. But we call the local 'open' function directly
-			 * because we want to explicitly specify the libc fd ID.
-			 *
-			 * We have to allocate the path from the libc (done via 'strdup')
-			 * such that the path can be freed when an stdio fd is closed.
-			 */
-			fd->fd_path = strdup(path);
+				Libc::File_descriptor *fd = open(path.string(), flags, libc_fd);
+				if (fd->libc_fd != libc_fd) {
+					Genode::error("could not allocate fd ",libc_fd," for ",path,", "
+					              "got fd ",fd->libc_fd);
+					close(fd);
+					return;
+				}
+
+				/*
+				 * We need to manually register the path. Normally this is done
+				 * by '_open'. But we call the local 'open' function directly
+				 * because we want to explicitly specify the libc fd ID.
+				 *
+				 * We have to allocate the path from the libc (done via 'strdup')
+				 * such that the path can be freed when an stdio fd is closed.
+				 */
+				fd->fd_path = strdup(path.string());
+
+			} catch (Xml_node::Nonexistent_attribute) { }
 		}
 
 	public:
@@ -92,19 +74,26 @@ class Libc::Vfs_plugin : public Libc::Plugin
 		/**
 		 * Constructor
 		 */
-		Vfs_plugin(Genode::Env &env, Genode::Allocator &alloc)
+		Vfs_plugin(Libc::Env &env, Genode::Allocator &alloc)
 		:
-			_alloc(alloc),
-			_root_dir(env, _alloc, _vfs_config(),
-			          Vfs::global_file_system_factory())
+			_alloc(alloc), _root_dir(env.vfs())
 		{
-			if (_root_dir.num_dirent("/")) {
-				chdir(initial_cwd());
+			using Genode::Xml_node;
 
-				_open_stdio(0, config_stdin(),  O_RDONLY);
-				_open_stdio(1, config_stdout(), O_WRONLY);
-				_open_stdio(2, config_stderr(), O_WRONLY);
-			}
+			if (_root_dir.num_dirent("/"))
+				env.config([&] (Xml_node const &top) {
+					Xml_node const node = top.sub_node("libc");
+
+					try {
+						Genode::String<Vfs::MAX_PATH_LEN> path;
+						node.attribute("cwd").value(&path);
+						chdir(path.string());
+					} catch (Xml_node::Nonexistent_attribute) { }
+
+					_open_stdio(node, "stdin",  0, O_RDONLY);
+					_open_stdio(node, "stdout", 1, O_WRONLY);
+					_open_stdio(node, "stderr", 2, O_WRONLY);
+				});
 		}
 
 		~Vfs_plugin() { }

repos/libports/src/lib/posix/construct.cc

@@ -26,7 +26,7 @@ extern char **genode_envp;
 extern "C" int main(int argc, char ** argv, char **envp);
 
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	exit(main(genode_argc, genode_argv, genode_envp));
 }

repos/libports/src/server/fuse_fs/fuse_fs_main.cc

@@ -543,7 +543,7 @@ struct File_system::Main
  ** Component **
  ***************/
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	static File_system::Main inst(env.ep());
 }

repos/libports/src/test/ldso/main.cc

@@ -185,7 +185,7 @@ static void test_shared_object_api(Env &env, Allocator &alloc)
 /**
  * Main function of LDSO test
  */
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	static Heap heap(env.ram(), env.rm());
 

repos/libports/src/test/libports/main.cc

@@ -13,4 +13,4 @@
 
 #include <libc/component.h>
 
-void Libc::Component::construct(Genode::Env &) { }
+void Libc::Component::construct(Libc::Env &env) { }

repos/os/src/test/blk/bench/main.cc

@@ -154,7 +154,7 @@ struct Test::Main
 };
 
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	static Test::Main server(env.ep());
 }

repos/ports/src/app/gdb_monitor/main.cc

@@ -33,7 +33,7 @@ extern "C" int gdbserver_main(int argc, const char *argv[]);
 
 extern Genode::Env *genode_env;
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	genode_env = &env;
 

repos/ports/src/app/openvpn/main.cc

@@ -286,7 +286,7 @@ struct Main
  ** Component **
  ***************/
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	static Main server(env.ep());
 }

repos/ports/src/noux/main.cc

@@ -1262,4 +1262,4 @@ void Component::construct(Genode::Env &env)
 /**
  * Support for the noux/net version
  */
-void Libc::Component::construct(Genode::Env &env) { Component::construct(env); }
+void Libc::Component::construct(Libc::Env &env) { Component::construct(env); }

repos/ports/src/virtualbox/frontend/main.cc

@@ -207,7 +207,7 @@ Genode::Env &genode_env()
 }
 
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	/* make Genode environment accessible via the global 'genode_env()' */
 	genode_env_ptr = &env;

repos/ports/src/virtualbox5/frontend/main.cc

@@ -238,7 +238,7 @@ Genode::Env &genode_env()
 }
 
 
-void Libc::Component::construct(Genode::Env &env)
+void Libc::Component::construct(Libc::Env &env)
 {
 	/* make Genode environment accessible via the global 'genode_env()' */
 	genode_env_ptr = &env;