cli: Enables using modern hush parser as command line parser

If one defines HUSH_MODERN_PARSER, it is then possible to use modern parser with:
=> cli get
old
=> cli set modern
=> cli get
modern

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Francis Laniel <francis.laniel@amarulasolutions.com>

cmd/Kconfig

@@ -33,6 +33,18 @@ config HUSH_OLD_PARSER
 	  2005.
 
 	  It is actually the default U-Boot shell when decided to use hush as shell.
+
+config HUSH_MODERN_PARSER
+	bool "Use hush modern parser"
+	help
+	  This option enables the new flavor of hush based on hush upstream
+	  Busybox.
+
+	  This parser is experimental and not well tested.
+
+config HUSH_SELECTABLE
+	bool
+	default y if HUSH_OLD_PARSER && HUSH_MODERN_PARSER
 endmenu
 
 config CMDLINE_EDITING

cmd/Makefile

@@ -229,7 +229,7 @@ obj-$(CONFIG_CMD_AVB) += avb.o
 # Foundries.IO SCP03
 obj-$(CONFIG_CMD_SCP03) += scp03.o
 
-obj-$(CONFIG_HUSH_PARSER) += cli.o
+obj-$(CONFIG_HUSH_SELECTABLE) += cli.o
 
 obj-$(CONFIG_ARM) += arm/
 obj-$(CONFIG_RISCV) += riscv/

cmd/cli.c

@@ -12,6 +12,8 @@ static const char *gd_flags_to_parser_name(void)
 {
 	if (gd->flags & GD_FLG_HUSH_OLD_PARSER)
 		return "old";
+	if (gd->flags & GD_FLG_HUSH_MODERN_PARSER)
+		return "modern";
 	return NULL;
 }
 
@@ -34,18 +36,31 @@ static int parser_string_to_gd_flags(const char *parser)
 {
 	if (!strcmp(parser, "old"))
 		return GD_FLG_HUSH_OLD_PARSER;
+	if (!strcmp(parser, "modern"))
+		return GD_FLG_HUSH_MODERN_PARSER;
+	return -1;
+}
+
+static int gd_flags_to_parser_config(int flag)
+{
+	if (gd->flags & GD_FLG_HUSH_OLD_PARSER)
+		return CONFIG_VAL(HUSH_OLD_PARSER);
+	if (gd->flags & GD_FLG_HUSH_MODERN_PARSER)
+		return CONFIG_VAL(HUSH_MODERN_PARSER);
 	return -1;
 }
 
 static void reset_parser_gd_flags(void)
 {
 	gd->flags &= ~GD_FLG_HUSH_OLD_PARSER;
+	gd->flags &= ~GD_FLG_HUSH_MODERN_PARSER;
 }
 
 static int do_cli_set(struct cmd_tbl *cmdtp, int flag, int argc,
 		      char *const argv[])
 {
 	char *parser_name;
+	int parser_config;
 	int parser_flag;
 
 	if (argc < 2)
@@ -59,9 +74,14 @@ static int do_cli_set(struct cmd_tbl *cmdtp, int flag, int argc,
 		return CMD_RET_USAGE;
 	}
 
-	if (parser_flag == GD_FLG_HUSH_OLD_PARSER &&
-		!CONFIG_IS_ENABLED(HUSH_OLD_PARSER)) {
-		printf("Want to set current parser to old, but its code was not compiled!\n");
+	parser_config = gd_flags_to_parser_config(parser_flag);
+	switch (parser_config) {
+	case -1:
+		printf("Bad value for parser flags: %d\n", parser_flag);
+		return CMD_RET_FAILURE;
+	case 0:
+		printf("Want to set current parser to %s, but its code was not compiled!\n",
+			parser_name);
 		return CMD_RET_FAILURE;
 	}
 
@@ -102,7 +122,7 @@ static int do_cli(struct cmd_tbl *cmdtp, int flag, int argc,
 #if CONFIG_IS_ENABLED(SYS_LONGHELP)
 static char cli_help_text[] =
 	"get - print current cli\n"
-	"set - set the current cli, possible value is: old"
+	"set - set the current cli, possible value are: old, modern"
 	;
 #endif
 

common/Makefile

@@ -10,6 +10,7 @@ obj-y += main.o
 obj-y += exports.o
 obj-y += cli_getch.o cli_simple.o cli_readline.o
 obj-$(CONFIG_HUSH_OLD_PARSER) += cli_hush.o
+obj-$(CONFIG_HUSH_MODERN_PARSER) += cli_hush_modern.o
 obj-$(CONFIG_AUTOBOOT) += autoboot.o
 obj-y += version.o
 

common/cli.c

@@ -43,12 +43,15 @@ int run_command(const char *cmd, int flag)
 		return 1;
 
 	return 0;
-#else
+#elif CONFIG_IS_ENABLED(HUSH_OLD_PARSER)
 	int hush_flags = FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP;
 
 	if (flag & CMD_FLAG_ENV)
 		hush_flags |= FLAG_CONT_ON_NEWLINE;
 	return parse_string_outer(cmd, hush_flags);
+#else /* HUSH_MODERN_PARSER */
+	/* Not yet implemented. */
+	return 1;
 #endif
 }
 
@@ -108,7 +111,12 @@ int run_command_list(const char *cmd, int len, int flag)
 		buff[len] = '\0';
 	}
 #ifdef CONFIG_HUSH_PARSER
+#if CONFIG_IS_ENABLED(HUSH_OLD_PARSER)
 	rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
+#else /* HUSH_MODERN_PARSER */
+	/* Not yet implemented. */
+	rcode = 1;
+#endif
 #else
 	/*
 	 * This function will overwrite any \n it sees with a \0, which
@@ -254,8 +262,13 @@ err:
 void cli_loop(void)
 {
 	bootstage_mark(BOOTSTAGE_ID_ENTER_CLI_LOOP);
-#ifdef CONFIG_HUSH_PARSER
-	parse_file_outer();
+#if CONFIG_IS_ENABLED(HUSH_PARSER)
+	if (gd->flags & GD_FLG_HUSH_MODERN_PARSER)
+		parse_and_run_file();
+	else if (gd->flags & GD_FLG_HUSH_OLD_PARSER)
+		parse_file_outer();
+
+	printf("Problem\n");
 	/* This point is never reached */
 	for (;;);
 #elif defined(CONFIG_CMDLINE)
@@ -268,10 +281,23 @@ void cli_loop(void)
 void cli_init(void)
 {
 #ifdef CONFIG_HUSH_PARSER
+	/* This if block is used to initialize hush parser gd flag. */
 	if (!(gd->flags & GD_FLG_HUSH_OLD_PARSER)
-		&& CONFIG_IS_ENABLED(HUSH_OLD_PARSER))
-		gd->flags |= GD_FLG_HUSH_OLD_PARSER;
-	u_boot_hush_start();
+		&& !(gd->flags & GD_FLG_HUSH_MODERN_PARSER)) {
+		if (CONFIG_IS_ENABLED(HUSH_OLD_PARSER))
+			gd->flags |= GD_FLG_HUSH_OLD_PARSER;
+		else if (CONFIG_IS_ENABLED(HUSH_MODERN_PARSER))
+			gd->flags |= GD_FLG_HUSH_MODERN_PARSER;
+	}
+
+	if (gd->flags & GD_FLG_HUSH_OLD_PARSER) {
+		u_boot_hush_start();
+	} else if (gd->flags & GD_FLG_HUSH_MODERN_PARSER) {
+		u_boot_hush_start_modern();
+	} else {
+		printf("No valid hush parser to use, cli will not initialized!\n");
+		return;
+	}
 #endif
 
 #if defined(CONFIG_HUSH_INIT_VAR)

common/cli_hush_modern.c

@@ -221,6 +221,9 @@ static uint8_t xfunc_error_retval;
 static const char defifsvar[] __aligned(1) = "IFS= \t\n";
 #define defifs (defifsvar + 4)
 
+/* This define is used to check if exit command was called. */
+#define EXIT_RET_CODE -2
+
 /*
  * This define is used for changes that need be done directly in the upstream
  * sources still. Ideally, its use should be minimized as much as possible.

common/cli_hush_upstream.c

@@ -7913,7 +7913,17 @@ static void parse_and_run_stream(struct in_str *inp, int end_trigger)
 		}
 		debug_print_tree(pipe_list, 0);
 		debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
+#ifndef __U_BOOT__
 		run_and_free_list(pipe_list);
+#else /* __U_BOOT__ */
+		int rcode = run_and_free_list(pipe_list);
+		/*
+		 * We reset input string to not run the following command, so running
+		 * 'exit; echo foo' does not print foo.
+		 */
+		if (rcode <= EXIT_RET_CODE)
+			setup_file_in_str(inp);
+#endif /* __U_BOOT__ */
 		empty = 0;
 		if (G_flag_return_in_progress == 1)
 			break;
@@ -10368,13 +10378,39 @@ static int run_list(struct pipe *pi)
 #endif /* !__U_BOOT__ */
 		rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
 #ifdef __U_BOOT__
-		if (r == -2) {
-			/* -2 indicates exit was called, so we need to quit now. */
-			G.last_exitcode = rcode;
+		if (r <= EXIT_RET_CODE) {
+			int previous_rcode = G.last_exitcode;
+			/*
+			 * This magic is to get the exit code given by the user.
+			 * Contrary to old shell code, we use + EXIT_RET_CODE as EXIT_RET_CODE
+			 * equals -2.
+			 */
+			G.last_exitcode = -r + EXIT_RET_CODE;
 
-			break;
+			/*
+			 * This case deals with the following:
+			 * => setenv inner 'echo entry inner; exit; echo inner done'
+			 * => setenv outer 'echo entry outer; run inner; echo outer done'
+			 * => run outer
+			 * So, if we are in inner, we need to break and not run the other
+			 * commands.
+			 * Otherwise, we just continue in outer.
+			 * As return code are propagated, we use the previous value to check if
+			 * exit was just called or was propagated.
+			 */
+			if (previous_rcode != r) {
+				/*
+				 * If run from run_command, run_command_flags will be set, so we check
+				 * this to know if we are in main input shell.
+				 */
+				if (!G.run_command_flags)
+					printf("exit not allowed from main input shell.\n");
+
+				break;
+			}
+			continue;
 		}
-#endif
+#endif /* __U_BOOT__ */
 		if (r != -1) {
 			/* We ran a builtin, function, or group.
 			 * rcode is already known

doc/usage/cmd/cli.rst

@@ -26,7 +26,7 @@ cli set
 
 It permits setting the value of the parser used by the CLI.
 
-Possible values are old and 2021.
+Possible values are old and modern.
 Note that, to use a specific parser its code should have been compiled, that
 is to say you need to enable the corresponding CONFIG_HUSH*.
 Otherwise, an error message is printed.
@@ -41,7 +41,14 @@ Get the current parser::
 
 Change the current parser::
 
+    => cli get
+    old
+    => cli set modern
+    => cli get
+    modern
     => cli set old
+    => cli get
+    old
 
 Trying to set the current parser to an unknown value::
 
@@ -51,7 +58,15 @@ Trying to set the current parser to an unknown value::
 
     Usage:
     cli get - print current cli
-    set - set the current cli, possible value is: old
+    set - set the current cli, possible values are: old, modern
+
+Trying to set the current parser to a correct value but its code was not
+compiled::
+
+    => cli get
+    modern
+    => cli set old
+    Want to set current parser to old, but its code was not compiled!
 
 Return value
 ------------

include/asm-generic/global_data.h

@@ -701,6 +701,10 @@ enum gd_flags {
 	 * @GD_FLG_HUSH_OLD_PARSER: Use hush old parser.
 	 */
 	GD_FLG_HUSH_OLD_PARSER = 0x1000000,
+	/**
+	 * @GD_FLG_HUSH_MODERN_PARSER: Use hush 2021 parser.
+	 */
+	GD_FLG_HUSH_MODERN_PARSER = 0x2000000,
 };
 
 #endif /* __ASSEMBLY__ */

include/cli_hush.h

@@ -12,11 +12,58 @@
 #define FLAG_REPARSING       (1 << 2)	  /* >=2nd pass */
 #define FLAG_CONT_ON_NEWLINE (1 << 3)	  /* continue when we see \n */
 
+#if CONFIG_IS_ENABLED(HUSH_OLD_PARSER)
 extern int u_boot_hush_start(void);
-extern int parse_string_outer(const char *, int);
+extern int parse_string_outer(const char *str, int flag);
 extern int parse_file_outer(void);
-
 int set_local_var(const char *s, int flg_export);
+#else
+static inline int u_boot_hush_start(void)
+{
+	return 0;
+}
+
+static inline int parse_string_outer(const char *str, int flag)
+{
+	return 1;
+}
+
+static inline int parse_file_outer(void)
+{
+	return 0;
+}
+
+static inline int set_local_var(const char *s, int flg_export)
+{
+	return 0;
+}
+#endif
+#if CONFIG_IS_ENABLED(HUSH_MODERN_PARSER)
+extern int u_boot_hush_start_modern(void);
+extern int parse_string_outer_modern(const char *str, int flag);
+extern void parse_and_run_file(void);
+int set_local_var_modern(char *s, int flg_export);
+#else
+static inline int u_boot_hush_start_modern(void)
+{
+	return 0;
+}
+
+static inline int parse_string_outer_modern(const char *str, int flag)
+{
+	return 1;
+}
+
+static inline void parse_and_run_file(void)
+{
+}
+
+static inline int set_local_var_modern(char *s, int flg_export)
+{
+	return 0;
+}
+#endif
+
 void unset_local_var(const char *name);
 char *get_local_var(const char *s);