bshell: re-organise build into three separate components

bshell: the front-end binary
bshell.runtime: contains the parser, compiler, and classes needed to run bshell scripts
bshell.core: contains the builtin commandlets and aliases

bshell.runtime/parse/lex/command.c

@@ -0,0 +1,228 @@
+#include "lex-internal.h"
+
+#include <bshell/parse/token.h>
+
+static bool char_can_continue_word(struct bshell_lex_ctx *ctx, fx_wchar c)
+{
+	if (fx_wchar_is_alnum(c)) {
+		return true;
+	}
+
+	if (fx_wchar_is_space(c)) {
+		return false;
+	}
+
+	if (c == '$') {
+		return true;
+	}
+
+	if (char_can_begin_symbol_in_state(ctx, c, BSHELL_LEX_STATE_WORD)) {
+		return false;
+	}
+
+	return true;
+}
+
+static enum bshell_status command_symbol(struct bshell_lex_ctx *ctx)
+{
+	const struct bshell_lex_token_definition *sym = NULL;
+	enum bshell_status status = read_symbol(ctx, &sym);
+
+	if (status != BSHELL_SUCCESS) {
+		return status;
+	}
+
+	handle_lex_state_transition(ctx, sym->id);
+
+	struct bshell_lex_token *tok = NULL;
+	switch (sym->id) {
+	case BSHELL_SYM_DQUOTE:
+		return BSHELL_SUCCESS;
+	case BSHELL_SYM_SQUOTE:
+		status = read_literal_string(ctx, &tok);
+		if (status != BSHELL_SUCCESS) {
+			return status;
+		}
+		enqueue_token(ctx, tok);
+		return BSHELL_SUCCESS;
+
+	case BSHELL_SYM_HASH:
+		return read_line_comment(ctx);
+	case BSHELL_SYM_DOLLAR:
+		status = read_var(ctx, BSHELL_TOK_VAR, &tok);
+		if (status != BSHELL_SUCCESS) {
+			return status;
+		}
+
+		if (char_can_continue_word(ctx, peek_char(ctx))) {
+			lex_state_push(ctx, BSHELL_LEX_STATE_WORD, 0);
+		}
+
+		enqueue_token(ctx, tok);
+		return status;
+	case BSHELL_SYM_AT:
+		status = read_var(ctx, BSHELL_TOK_VAR_SPLAT, &tok);
+		if (status != BSHELL_SUCCESS) {
+			return status;
+		}
+
+		enqueue_token(ctx, tok);
+		return status;
+	case BSHELL_SYM_DOLLAR_LEFT_BRACE:
+		status = read_braced_var(ctx, BSHELL_TOK_VAR, &tok);
+		if (status != BSHELL_SUCCESS) {
+			return status;
+		}
+
+		if (char_can_continue_word(ctx, peek_char(ctx))) {
+			lex_state_push(ctx, BSHELL_LEX_STATE_WORD, 0);
+		}
+
+		enqueue_token(ctx, tok);
+		return status;
+	default:
+		break;
+	}
+
+	push_symbol(ctx, sym->id);
+
+	return BSHELL_SUCCESS;
+}
+
+static bool string_is_redirection(const char *s)
+{
+	if (!*s) {
+		return false;
+	}
+
+	if (!strcmp(s, ">") || !strcmp(s, ">>")) {
+		return true;
+	}
+
+	long nr_angles = 0;
+	for (size_t i = 0; s[i];) {
+		fx_wchar c = fx_wchar_utf8_codepoint_decode(s);
+		if (fx_wchar_is_number(c)) {
+			if (nr_angles) {
+				return false;
+			}
+		} else if (c == '>') {
+			nr_angles++;
+
+			if (nr_angles > 2) {
+				return false;
+			}
+		} else {
+			return false;
+		}
+
+		s += fx_wchar_utf8_codepoint_stride(s);
+	}
+
+	return true;
+}
+
+static enum bshell_status command_word(struct bshell_lex_ctx *ctx)
+{
+	struct bshell_lex_token *word = NULL;
+	enum bshell_status status
+		= read_word(ctx, READ_NO_NUMBER_RECOGNITION, &word);
+	if (status != BSHELL_SUCCESS) {
+		return status;
+	}
+
+	bool continue_word = false;
+
+	fx_wchar c = peek_char(ctx);
+	const char *s = word->tok_str;
+	if (char_can_begin_symbol_in_state(ctx, c, BSHELL_LEX_STATE_WORD)) {
+		continue_word = true;
+	}
+
+	if (char_has_flags(ctx, c, BSHELL_LEX_TOKEN_TERMINATES_WORD)) {
+		continue_word = false;
+	}
+
+	if (string_is_redirection(s)) {
+		continue_word = false;
+	}
+
+	if (continue_word) {
+		lex_state_push(ctx, BSHELL_LEX_STATE_WORD, 0);
+	}
+
+	enqueue_token(ctx, word);
+	return BSHELL_SUCCESS;
+}
+
+enum bshell_status command_pump_token(struct bshell_lex_ctx *ctx)
+{
+	fx_wchar c = peek_char(ctx);
+	bool newline = false;
+
+	set_token_start(ctx);
+	while (fx_wchar_is_space(c)) {
+		if (c == '\n') {
+			newline = true;
+		}
+
+		set_token_end(ctx);
+		advance_char_noread(ctx);
+		c = peek_char_noread(ctx);
+	}
+
+	if (newline) {
+		struct bshell_lex_token *tok
+			= bshell_lex_token_create(BSHELL_TOK_LINEFEED);
+		enqueue_token(ctx, tok);
+		handle_lex_state_transition(ctx, BSHELL_TOK_LINEFEED);
+		return BSHELL_SUCCESS;
+	}
+
+	if (char_can_begin_symbol(ctx, c)) {
+		return command_symbol(ctx);
+	}
+
+	return command_word(ctx);
+}
+
+const struct bshell_lex_state_link links[] = {
+	LINK_PUSH(BSHELL_SYM_DQUOTE, BSHELL_LEX_STATE_STRING, 0),
+	LINK_PUSH(
+		BSHELL_SYM_LEFT_PAREN,
+		BSHELL_LEX_STATE_STATEMENT,
+		STATEMENT_F_DISABLE_KEYWORDS),
+	LINK_PUSH(BSHELL_SYM_DOLLAR_LEFT_PAREN, BSHELL_LEX_STATE_STATEMENT, 0),
+	LINK_POP(BSHELL_SYM_RIGHT_PAREN),
+	LINK_POP(BSHELL_SYM_RIGHT_BRACE),
+	LINK_CHANGE(BSHELL_SYM_SEMICOLON, BSHELL_LEX_STATE_STATEMENT),
+	LINK_PUSH(BSHELL_SYM_AT_LEFT_BRACE, BSHELL_LEX_STATE_HASHTABLE, 0),
+	LINK_CHANGE(BSHELL_TOK_LINEFEED, BSHELL_LEX_STATE_STATEMENT),
+	LINK_END,
+};
+
+static const unsigned int symbols[] = {
+	BSHELL_SYM_DQUOTE,
+	BSHELL_SYM_SQUOTE,
+	BSHELL_SYM_DOLLAR,
+	BSHELL_SYM_DOLLAR_LEFT_PAREN,
+	BSHELL_SYM_DOLLAR_LEFT_BRACE,
+	BSHELL_SYM_AT,
+	BSHELL_SYM_AT_LEFT_BRACE,
+	BSHELL_SYM_AT_LEFT_PAREN,
+	BSHELL_SYM_AMPERSAND,
+	BSHELL_SYM_PIPE,
+	BSHELL_SYM_SEMICOLON,
+	BSHELL_SYM_RIGHT_PAREN,
+	BSHELL_SYM_LEFT_PAREN,
+	BSHELL_SYM_LEFT_BRACE,
+	BSHELL_SYM_RIGHT_BRACE,
+	BSHELL_SYM_NONE,
+};
+
+const struct bshell_lex_state_type lex_command_state = {
+	.s_id = BSHELL_LEX_STATE_COMMAND,
+	.s_pump_token = command_pump_token,
+	.s_links = links,
+	.s_symbols = symbols,
+};