frontend: re-organise frontend functionality; add feature and logging switches

bshell/CMakeLists.txt

@@ -24,7 +24,7 @@ add_executable(bshell ${bshell_sources})
 
 target_link_libraries(bshell
 	bshell.core bshell.runtime
-	FX::Runtime FX::Collections)
+	FX::Runtime FX::Collections FX::Cmdline)
 
 if (bshell_interactive)
 	target_link_libraries(bshell FX::Term)

bshell/frontend.c

@@ -0,0 +1,250 @@
+#include "frontend.h"
+
+#include "debug.h"
+
+#include <bshell/ast.h>
+#include <bshell/compile.h>
+#include <bshell/file.h>
+#include <bshell/runtime/runtime.h>
+#include <fx/io/path.h>
+#include <fx/reflection/assembly.h>
+
+#if BSHELL_INTERACTIVE == 1
+#include "line-ed/line-ed.h"
+#endif
+
+#define FRONTEND_FLAG_SET(f, flag)                                             \
+	(((f)->ctx_flags & (FRONTEND_F_##flag)) == (FRONTEND_F_##flag))
+
+enum eval_flags {
+	EVAL_PRINT_RESULT = 0x01u,
+};
+
+extern const fx_assembly *bshell_assembly_get(void);
+extern const fx_assembly *bshell_runtime_assembly_get(void);
+extern const fx_assembly *bshell_core_assembly_get(void);
+
+static void lex_token_scanned(
+	struct bshell_lex_ctx *ctx,
+	struct bshell_lex_token *tok)
+{
+	print_lex_token(tok);
+}
+
+void frontend_init(struct frontend_ctx *ctx, enum frontend_flags flags)
+{
+	memset(ctx, 0x0, sizeof *ctx);
+
+	bshell_assembly_get();
+	bshell_runtime_assembly_get();
+	bshell_core_assembly_get();
+
+	ctx->ctx_flags = flags;
+	ctx->ctx_block = bshell_scriptblock_create();
+	ctx->ctx_rt = bshell_runtime_create();
+}
+
+static enum bshell_status lex_only(
+	struct frontend_ctx *ctx,
+	struct bshell_line_source *linesrc,
+	enum eval_flags flags)
+{
+	while (1) {
+		struct bshell_lex_token *tok
+			= bshell_lex_ctx_peek(&ctx->ctx_lex);
+
+		if (!tok) {
+			break;
+		}
+
+		bshell_lex_ctx_discard(&ctx->ctx_lex);
+	}
+
+	return BSHELL_SUCCESS;
+}
+
+static enum bshell_status parse_only(
+	struct frontend_ctx *ctx,
+	struct bshell_line_source *linesrc,
+	enum eval_flags flags)
+{
+	while (1) {
+		struct bshell_ast_node *node
+			= bshell_parse_ctx_read_node(&ctx->ctx_parse);
+		if (!node) {
+			break;
+		}
+
+		if (FRONTEND_FLAG_SET(ctx, PRINT_AST)) {
+			print_ast_node_recursive(node);
+		}
+
+		bshell_ast_node_destroy(node);
+	}
+
+	return BSHELL_SUCCESS;
+}
+
+static enum bshell_status eval(
+	struct frontend_ctx *ctx,
+	struct bshell_line_source *linesrc,
+	enum eval_flags flags)
+{
+	enum bshell_status status = BSHELL_SUCCESS;
+
+	bshell_lex_ctx_init(&ctx->ctx_lex, 0, linesrc);
+	if (FRONTEND_FLAG_SET(ctx, PRINT_LEX)) {
+		ctx->ctx_lex.lex_token_scanned = lex_token_scanned;
+	}
+
+	if (!FRONTEND_FLAG_SET(ctx, ENABLE_PARSE)) {
+		status = lex_only(ctx, linesrc, flags);
+		bshell_lex_ctx_cleanup(&ctx->ctx_lex);
+		return status;
+	}
+
+	bshell_parse_ctx_init(&ctx->ctx_parse, &ctx->ctx_lex);
+	if (!FRONTEND_FLAG_SET(ctx, ENABLE_EVAL)) {
+		status = parse_only(ctx, linesrc, flags);
+		bshell_parse_ctx_cleanup(&ctx->ctx_parse);
+		bshell_lex_ctx_cleanup(&ctx->ctx_lex);
+		return status;
+	}
+
+	while (1) {
+		struct bshell_ast_node *node
+			= bshell_parse_ctx_read_node(&ctx->ctx_parse);
+		if (!node) {
+			break;
+		}
+
+		if (FRONTEND_FLAG_SET(ctx, PRINT_AST)) {
+			print_ast_node_recursive(node);
+			printf("----\n");
+		}
+
+		bshell_scriptblock_clear_text(ctx->ctx_block);
+		switch (node->n_type) {
+		case BSHELL_AST_FUNC: {
+			bshell_function *func = NULL;
+			bshell_compile_function(node, &func);
+			if (FRONTEND_FLAG_SET(ctx, PRINT_BYTECODE)) {
+				print_function(func);
+			}
+			bshell_runtime_define_function(ctx->ctx_rt, func);
+			bshell_function_unref(func);
+			break;
+		}
+
+		default: {
+			bshell_compile(node, ctx->ctx_block);
+			if (FRONTEND_FLAG_SET(ctx, PRINT_BYTECODE)) {
+				print_scriptblock(ctx->ctx_block, 0);
+			}
+
+			fx_value result = bshell_runtime_eval_global(
+				ctx->ctx_rt,
+				ctx->ctx_block);
+
+			bool print_result = flags & EVAL_PRINT_RESULT
+			                 && result.v_type != NULL;
+			if (print_result) {
+				bshell_runtime_begin_output(ctx->ctx_rt);
+				bshell_runtime_output_value(
+					ctx->ctx_rt,
+					&result);
+				bshell_runtime_end_output(ctx->ctx_rt);
+			}
+
+			fx_value_unset(&result);
+			break;
+		}
+		}
+
+		bshell_ast_node_destroy(node);
+	}
+
+	bshell_parse_ctx_cleanup(&ctx->ctx_parse);
+	bshell_lex_ctx_cleanup(&ctx->ctx_lex);
+
+	return BSHELL_SUCCESS;
+}
+
+static fx_path *create_path(const char *dir_path, const char *script_path)
+{
+	if (!script_path) {
+		return NULL;
+	}
+
+	fx_path *paths[2] = {0};
+
+	if (dir_path) {
+		paths[0] = fx_path_create_from_cstr(dir_path);
+	}
+
+	if (script_path) {
+		paths[1] = fx_path_create_from_cstr(script_path);
+	}
+
+	if (!dir_path) {
+		return paths[1];
+	}
+
+	fx_path *result = fx_path_join(
+		(const fx_path **)paths,
+		sizeof paths / sizeof paths[0]);
+	fx_path_unref(paths[0]);
+	fx_path_unref(paths[1]);
+
+	return result;
+}
+
+enum bshell_status frontend_eval_file(
+	struct frontend_ctx *ctx,
+	const char *dir_path,
+	const char *script_path)
+{
+	fx_path *path = create_path(dir_path, script_path);
+	if (!path) {
+		return BSHELL_ERR_NO_MEMORY;
+	}
+
+	struct bshell_file *file = NULL;
+	ctx->ctx_status = bshell_file_open(fx_path_ptr(path), &file);
+	fx_path_unref(path);
+
+	if (!FX_OK(ctx->ctx_status)) {
+		return ctx->ctx_status;
+	}
+
+	struct bshell_line_source *linesrc = &file->f_base;
+
+	ctx->ctx_status = eval(ctx, linesrc, 0);
+
+	bshell_file_close(file);
+
+	return ctx->ctx_status;
+}
+
+enum bshell_status frontend_repl(struct frontend_ctx *ctx)
+{
+#if BSHELL_INTERACTIVE
+	struct line_ed *ed = line_ed_create();
+
+	struct bshell_line_source *linesrc = line_ed_to_line_source(ed);
+
+	ctx->ctx_status = eval(ctx, linesrc, EVAL_PRINT_RESULT);
+
+	line_ed_destroy(ed);
+
+	return ctx->ctx_status;
+#else
+	return BSHELL_ERR_NOT_SUPPORTED;
+#endif
+}
+
+void frontend_cleanup(struct frontend_ctx *ctx)
+{
+	bshell_runtime_destroy(ctx->ctx_rt);
+	bshell_scriptblock_unref(ctx->ctx_block);
+}

bshell/frontend.h

@@ -0,0 +1,48 @@
+#ifndef FRONTEND_H_
+#define FRONTEND_H_
+
+#include <bshell/parse/lex.h>
+#include <bshell/parse/parse.h>
+#include <bshell/runtime/script-block.h>
+#include <bshell/status.h>
+
+struct line_ed;
+struct bshell_file;
+struct bshell_runtime;
+
+#define FRONTEND_DEFAULT_FLAGS (FRONTEND_F_ENABLE_EVAL)
+
+enum frontend_flags {
+	FRONTEND_F_ENABLE_LEX = 0x01u,
+	FRONTEND_F_ENABLE_PARSE = 0x03u,
+	FRONTEND_F_ENABLE_EVAL = 0x07u,
+
+	FRONTEND_F_PRINT_LEX = 0x10u,
+	FRONTEND_F_PRINT_AST = 0x20u,
+	FRONTEND_F_PRINT_BYTECODE = 0x40u,
+
+	FRONTEND_F_INTERACTIVE = 0x80u,
+};
+
+struct frontend_ctx {
+	enum bshell_status ctx_status;
+	enum frontend_flags ctx_flags;
+
+	struct bshell_lex_ctx ctx_lex;
+	struct bshell_parse_ctx ctx_parse;
+
+	struct bshell_runtime *ctx_rt;
+	bshell_scriptblock *ctx_block;
+};
+
+extern void frontend_init(struct frontend_ctx *ctx, enum frontend_flags flags);
+
+extern enum bshell_status frontend_eval_file(
+	struct frontend_ctx *ctx,
+	const char *dir_path,
+	const char *script_path);
+extern enum bshell_status frontend_repl(struct frontend_ctx *ctx);
+
+extern void frontend_cleanup(struct frontend_ctx *ctx);
+
+#endif

bshell/main.c

@@ -1,4 +1,4 @@
-#include "debug.h"
+#include "frontend.h"
 
 #include <bshell/ast.h>
 #include <bshell/compile.h>
@@ -7,177 +7,183 @@
 #include <bshell/parse/lex.h>
 #include <bshell/parse/parse.h>
 #include <bshell/parse/token.h>
-#include <bshell/runtime/runtime.h>
 #include <bshell/verb.h>
+#include <fx/cmdline/cmd.h>
 #include <stdio.h>
 
-#if BSHELL_INTERACTIVE == 1
+enum {
-#include "line-ed/line-ed.h"
+	CMD_ROOT,
-#endif
+	OPT_LEX,
+	OPT_PARSE,
+	OPT_EVAL,
+	OPT_PRINT_LEX,
+	OPT_PRINT_AST,
+	OPT_PRINT_BYTECODE,
+	ARG_SCRIPT_FILE,
+};
 
-extern const fx_assembly *bshell_assembly_get(void);
+#define FEATURE_FLAGS                                                          \
-extern const fx_assembly *bshell_runtime_assembly_get(void);
+	(FRONTEND_F_ENABLE_LEX | FRONTEND_F_ENABLE_PARSE                       \
-extern const fx_assembly *bshell_core_assembly_get(void);
+	 | FRONTEND_F_ENABLE_EVAL)
+#define PRINT_FLAGS                                                            \
+	(FRONTEND_F_PRINT_LEX | FRONTEND_F_PRINT_AST                           \
+	 | FRONTEND_F_PRINT_BYTECODE)
 
-static void print_token_queue(fx_queue *q)
+const char *exec_name = NULL;
+
+static enum frontend_flags collect_frontend_flags(const fx_arglist *opt)
 {
-	fx_queue_entry *cur = fx_queue_first(q);
+	enum frontend_flags result = 0;
-	while (cur) {
+#define OPTION_IS_SET(id)                                                      \
-		struct bshell_lex_token *tok
+	fx_arglist_get_count(opt, id, FX_COMMAND_INVALID_ID) > 0
-			= fx_unbox(struct bshell_lex_token, cur, tok_entry);
-		print_lex_token(tok);
-		cur = fx_queue_next(cur);
-	}
-}
 
-static void lex_only(struct bshell_lex_ctx *lex)
+	if (OPTION_IS_SET(OPT_LEX)) {
-{
+		result |= FRONTEND_F_ENABLE_LEX;
-	while (1) {
-		struct bshell_lex_token *tok = bshell_lex_ctx_peek(lex);
-		if (!tok) {
-			break;
 	}
 
-		bshell_lex_ctx_discard(lex);
+	if (OPTION_IS_SET(OPT_PARSE)) {
+		result |= FRONTEND_F_ENABLE_PARSE;
 	}
+
+	if (OPTION_IS_SET(OPT_EVAL)) {
+		result |= FRONTEND_F_ENABLE_EVAL;
+	}
+
+	if (OPTION_IS_SET(OPT_PRINT_LEX)) {
+		result |= FRONTEND_F_PRINT_LEX;
+	}
+
+	if (OPTION_IS_SET(OPT_PRINT_AST)) {
+		result |= FRONTEND_F_PRINT_AST;
+	}
+
+	if (OPTION_IS_SET(OPT_PRINT_BYTECODE)) {
+		result |= FRONTEND_F_PRINT_BYTECODE;
+	}
+
+	if ((result & PRINT_FLAGS) && !(result & FEATURE_FLAGS)) {
+		result |= FRONTEND_F_ENABLE_EVAL;
+	}
+
+#undef OPTION_IS_SET
+	return result;
 }
 
-static void lex_and_parse(struct bshell_parse_ctx *parse)
+static int bshell(
+	const fx_command *self,
+	const fx_arglist *opt,
+	const fx_array *args)
 {
+	enum frontend_flags flags = collect_frontend_flags(opt);
+	if (flags == 0) {
+		flags = FRONTEND_DEFAULT_FLAGS;
+	}
+
+	struct frontend_ctx ctx;
+	frontend_init(&ctx, flags);
+	enum bshell_status status = BSHELL_SUCCESS;
+
+	size_t nr_input_files = fx_arglist_get_count(
+		opt,
+		FX_COMMAND_INVALID_ID,
+		ARG_SCRIPT_FILE);
+
+	if (nr_input_files == 0) {
+		printf("B Shell " BSHELL_VERSION "\n");
+		frontend_repl(&ctx);
+		frontend_cleanup(&ctx);
+		return 0;
+	}
+
+	fx_arglist_iterator it;
+	fx_arglist_iterator_begin(
+		opt,
+		FX_COMMAND_INVALID_ID,
+		ARG_SCRIPT_FILE,
+		&it);
+
+	while (fx_arglist_iterator_is_valid(&it)) {
+		const char *script_path = it.value->val_str;
+		status = frontend_eval_file(&ctx, NULL, script_path);
+
+		if (status != BSHELL_SUCCESS) {
+			fprintf(stderr,
+			        "%s: cannot open '%s': %s\n",
+			        exec_name,
+			        script_path,
+			        bshell_status_get_description(status));
+		}
+
+		fx_arglist_iterator_next(&it);
+	}
+
+	frontend_cleanup(&ctx);
+	return 0;
 }
 
-#if BSHELL_VERBOSE == 1
+FX_COMMAND(CMD_ROOT, FX_COMMAND_INVALID_ID)
-static void lex_token_scanned(
-	struct bshell_lex_ctx *ctx,
-	struct bshell_lex_token *tok)
 {
-	print_lex_token(tok);
+	FX_COMMAND_NAME("bshell");
-}
+	FX_COMMAND_DESC("B Shell script interpreter.");
-#endif
+	FX_COMMAND_FUNCTION(bshell);
 
-extern int compare_token_types(unsigned int a, unsigned int b);
+	FX_COMMAND_OPTION(OPT_LEX)
+	{
+		FX_OPTION_LONG_NAME("lex");
+		FX_OPTION_SHORT_NAME('l');
+		FX_OPTION_DESC("Enable lexing of shell input.");
+	}
+
+	FX_COMMAND_OPTION(OPT_PARSE)
+	{
+		FX_OPTION_LONG_NAME("parse");
+		FX_OPTION_SHORT_NAME('a');
+		FX_OPTION_DESC(
+			"Enable parsing and ast generation of shell input.");
+	}
+
+	FX_COMMAND_OPTION(OPT_EVAL)
+	{
+		FX_OPTION_LONG_NAME("eval");
+		FX_OPTION_SHORT_NAME('b');
+		FX_OPTION_DESC(
+			"Enable evaluation and bytecode generation of shell "
+			"input. This option is the default if no 'enable' "
+			"flags are specified.");
+	}
+
+	FX_COMMAND_OPTION(OPT_PRINT_LEX)
+	{
+		FX_OPTION_LONG_NAME("print-lex");
+		FX_OPTION_SHORT_NAME('L');
+		FX_OPTION_DESC("Print lex tokens generated from shell input.");
+	}
+
+	FX_COMMAND_OPTION(OPT_PRINT_AST)
+	{
+		FX_OPTION_LONG_NAME("print-ast");
+		FX_OPTION_SHORT_NAME('A');
+		FX_OPTION_DESC("Print ast nodes generated from shell input.");
+	}
+
+	FX_COMMAND_OPTION(OPT_PRINT_BYTECODE)
+	{
+		FX_OPTION_LONG_NAME("print-bytecode");
+		FX_OPTION_SHORT_NAME('B');
+		FX_OPTION_DESC("Print bytecode generated from shell input.");
+	}
+
+	FX_COMMAND_ARG(ARG_SCRIPT_FILE)
+	{
+		FX_ARG_DESC("Script file to evaluate.");
+		FX_ARG_NR_VALUES(FX_ARG_0_OR_MORE_VALUES);
+	}
+
+	FX_COMMAND_HELP_OPTION();
+}
 
 int main(int argc, const char **argv)
 {
-	bshell_assembly_get();
+	exec_name = argv[0];
-	bshell_runtime_assembly_get();
+	return fx_command_dispatch(CMD_ROOT, argc, argv);
-	bshell_core_assembly_get();
-
-	bshell_init_all_verbs();
-	bshell_table_init();
-
-	struct bshell_file *file = NULL;
-	struct line_ed *ed = NULL;
-	struct bshell_line_source *linesrc = NULL;
-
-	enum bshell_status status = BSHELL_SUCCESS;
-	bool interactive = true;
-
-	if (argc > 1) {
-		status = bshell_file_open(argv[1], &file);
-		linesrc = &file->f_base;
-		interactive = false;
-
-		if (!FX_OK(status)) {
-			fprintf(stderr,
-			        "%s: cannot open '%s': %s\n",
-			        argv[0],
-			        argv[1],
-			        bshell_status_get_description(status));
-			return -1;
-		}
-	} else {
-#if BSHELL_INTERACTIVE == 1
-		ed = line_ed_create();
-		linesrc = line_ed_to_line_source(ed);
-#else
-		fprintf(stderr, "Interactive mode is not supported.\n");
-		return -1;
-#endif
-	}
-
-	struct bshell_lex_ctx lex = {0};
-	bshell_lex_ctx_init(&lex, 0, linesrc);
-#if BSHELL_VERBOSE == 1
-	lex.lex_token_scanned = lex_token_scanned;
-#endif
-	struct bshell_parse_ctx parse = {0};
-	bshell_parse_ctx_init(&parse, &lex);
-
-#if 0
-	lex_only(&lex);
-	return 0;
-#endif
-
-	if (interactive) {
-		printf("B Shell " BSHELL_VERSION "\n");
-	}
-
-	bshell_scriptblock *block = bshell_scriptblock_create();
-	struct bshell_runtime *rt = bshell_runtime_create();
-
-	while (1) {
-		struct bshell_ast_node *node
-			= bshell_parse_ctx_read_node(&parse);
-		if (!node) {
-			break;
-		}
-
-#if BSHELL_VERBOSE == 1
-		print_ast_node_recursive(node);
-		printf("----\n");
-#endif
-
-		bshell_scriptblock_clear_text(block);
-		switch (node->n_type) {
-		case BSHELL_AST_FUNC: {
-			bshell_function *func = NULL;
-			bshell_compile_function(node, &func);
-#if BSHELL_VERBOSE == 1
-			print_function(func);
-#endif
-			bshell_runtime_define_function(rt, func);
-			bshell_function_unref(func);
-			break;
-		}
-
-		default: {
-			bshell_compile(node, block);
-#if BSHELL_VERBOSE == 1
-			print_scriptblock(block, 0);
-#endif
-
-			fx_value result = bshell_runtime_eval_global(rt, block);
-
-			if (interactive && result.v_type != NULL) {
-				format_value_default(&result, fx_stdout);
-			}
-
-			fx_value_unset(&result);
-			break;
-		}
-		}
-
-		bshell_ast_node_destroy(node);
-	}
-
-	bshell_runtime_destroy(rt);
-	bshell_scriptblock_unref(block);
-
-	bshell_parse_ctx_cleanup(&parse);
-	bshell_lex_ctx_cleanup(&lex);
-
-#if BSHELL_INTERACTIVE == 1
-	if (ed) {
-		line_ed_destroy(ed);
-	}
-#endif
-
-	if (file) {
-		bshell_file_close(file);
-	}
-
-	bshell_cleanup_all_verbs();
-
-	return 0;
 }