[PATCH v2 20/29] ktap: add compiler(tools/ktap/kp_[lex|parse].[c|h])

[Jovi Zhangwei]

ktap compiler is based on luajit, origin forked from lua.

The compiler use one pass compilation, it is very fast, and
the generated binary is very small.

[root@localhost ktap]# ll -h ktap
-rwxr-xr-x. 1 root root 83K Mar 27 06:09 ktap

The compiler is easy to hack, the code is very easy to understand.

Note that some bytecode in luajit is not used by ktap, it could
be remove in future.

More compiler hack soon:
1). aggregation
	@name[keys] = aggfunction(args)

2). multi-key table
	var s = {}
	s[key1, key2, key3] = value

3). C structure access

Signed-off-by: Jovi Zhangwei <jovi.zhangwei@xxxxxxxxx>
---
 tools/ktap/kp_lex.c   |  552 +++++++++
 tools/ktap/kp_lex.h   |   94 ++
 tools/ktap/kp_parse.c | 3139 +++++++++++++++++++++++++++++++++++++++++++++++++
 tools/ktap/kp_parse.h |    4 +
 4 files changed, 3789 insertions(+)
 create mode 100644 tools/ktap/kp_lex.c
 create mode 100644 tools/ktap/kp_lex.h
 create mode 100644 tools/ktap/kp_parse.c
 create mode 100644 tools/ktap/kp_parse.h

diff --git a/tools/ktap/kp_lex.c b/tools/ktap/kp_lex.c
new file mode 100644
index 0000000..e9597f1
--- /dev/null
+++ b/tools/ktap/kp_lex.c
@@ -0,0 +1,552 @@
+/*
+ * Lexical analyzer.
+ *
+ * This file is part of ktap by Jovi Zhangwei.
+ *
+ * Copyright (C) 2012-2014 Jovi Zhangwei <jovi.zhangwei@xxxxxxxxx>.
+ *
+ * Adapted from luajit and lua interpreter.
+ * Copyright (C) 2005-2014 Mike Pall.
+ * Copyright (C) 1994-2008 Lua.org, PUC-Rio.
+ *
+ * ktap is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * ktap is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "../../include/uapi/ktap/ktap_types.h"
+#include "../../include/uapi/ktap/ktap_err.h"
+#include "kp_util.h"
+#include "kp_lex.h"
+#include "kp_parse.h"
+
+/* lexer token names. */
+static const char *const tokennames[] = {
+#define TKSTR1(name)		#name,
+#define TKSTR2(name, sym)	#sym,
+TKDEF(TKSTR1, TKSTR2)
+#undef TKSTR1
+#undef TKSTR2
+  NULL
+};
+
+/* -- Buffer handling ----------------------------------------------------- */
+
+#define LEX_EOF			(-1)
+#define lex_iseol(ls)		(ls->c == '\n' || ls->c == '\r')
+
+/* Get next character. */
+static inline LexChar lex_next(LexState *ls)
+{
+	return (ls->c = ls->p < ls->pe ? (LexChar)(uint8_t)*ls->p++ : LEX_EOF);
+}
+
+/* Save character. */
+static inline void lex_save(LexState *ls, LexChar c)
+{
+	kp_buf_putb(&ls->sb, c);
+}
+
+/* Save previous character and get next character. */
+static inline LexChar lex_savenext(LexState *ls)
+{
+	lex_save(ls, ls->c);
+	return lex_next(ls);
+}
+
+/* Skip line break. Handles "\n", "\r", "\r\n" or "\n\r". */
+static void lex_newline(LexState *ls)
+{
+	LexChar old = ls->c;
+
+	kp_assert(lex_iseol(ls));
+	lex_next(ls);  /* Skip "\n" or "\r". */
+	if (lex_iseol(ls) && ls->c != old)
+		lex_next(ls);  /* Skip "\n\r" or "\r\n". */
+	if (++ls->linenumber >= KP_MAX_LINE)
+		kp_lex_error(ls, ls->tok, KP_ERR_XLINES);
+}
+
+/* -- Scanner for terminals ----------------------------------------------- */
+
+static int kp_str2d(const char *s, size_t len, ktap_number *result)
+{
+	char *endptr;
+
+	if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
+		return 0;
+	else
+		*result = (long)strtoul(s, &endptr, 0);
+
+	if (endptr == s)
+		return 0;  /* nothing recognized */
+	while (kp_char_isspace((unsigned char)(*endptr)))
+		endptr++;
+	return (endptr == s + len);  /* OK if no trailing characters */
+}
+
+
+/* Parse a number literal. */
+static void lex_number(LexState *ls, ktap_val_t *tv)
+{
+	LexChar c, xp = 'e';
+	ktap_number n = 0;
+
+	kp_assert(kp_char_isdigit(ls->c));
+	if ((c = ls->c) == '0' && (lex_savenext(ls) | 0x20) == 'x')
+		xp = 'p';
+	while (kp_char_isident(ls->c) || ls->c == '.' ||
+		((ls->c == '-' || ls->c == '+') && (c | 0x20) == xp)) {
+		c = ls->c;
+		lex_savenext(ls);
+	}
+	lex_save(ls, '\0');
+	if (!kp_str2d(sbufB(&ls->sb), sbuflen(&ls->sb) - 1, &n))
+			kp_lex_error(ls, ls->tok, KP_ERR_XNUMBER);
+	set_number(tv, n);
+}
+
+/* Skip equal signs for "[=...=[" and "]=...=]" and return their count. */
+static int lex_skipeq(LexState *ls)
+{
+	int count = 0;
+	LexChar s = ls->c;
+
+	kp_assert(s == '[' || s == ']');
+	while (lex_savenext(ls) == '=')
+		count++;
+	return (ls->c == s) ? count : (-count) - 1;
+}
+
+/* Parse a long string or long comment (tv set to NULL). */
+static void lex_longstring(LexState *ls, ktap_val_t *tv, int sep)
+{
+	lex_savenext(ls);  /* Skip second '['. */
+	if (lex_iseol(ls))  /* Skip initial newline. */
+		lex_newline(ls);
+	for (;;) {
+		switch (ls->c) {
+		case LEX_EOF:
+			kp_lex_error(ls, TK_eof,
+					tv ? KP_ERR_XLSTR : KP_ERR_XLCOM);
+			break;
+		case ']':
+			if (lex_skipeq(ls) == sep) {
+				lex_savenext(ls);  /* Skip second ']'. */
+				goto endloop;
+			}
+			break;
+		case '\n':
+		case '\r':
+			lex_save(ls, '\n');
+			lex_newline(ls);
+			if (!tv) /* Don't waste space for comments. */
+				kp_buf_reset(&ls->sb);
+			break;
+		default:
+			lex_savenext(ls);
+			break;
+		}
+	}
+ endloop:
+	if (tv) {
+		ktap_str_t *str = kp_parse_keepstr(ls,
+					sbufB(&ls->sb) + (2 + (int)sep),
+					sbuflen(&ls->sb) - 2*(2 + (int)sep));
+		set_string(tv, str);
+	}
+}
+
+/* Parse a string. */
+static void lex_string(LexState *ls, ktap_val_t *tv)
+{
+	LexChar delim = ls->c;  /* Delimiter is '\'' or '"'. */
+
+	lex_savenext(ls);
+	while (ls->c != delim) {
+		switch (ls->c) {
+		case LEX_EOF:
+			kp_lex_error(ls, TK_eof, KP_ERR_XSTR);
+			continue;
+		case '\n':
+		case '\r':
+			kp_lex_error(ls, TK_string, KP_ERR_XSTR);
+			continue;
+		case '\\': {
+			LexChar c = lex_next(ls);  /* Skip the '\\'. */
+			switch (c) {
+			case 'a': c = '\a'; break;
+			case 'b': c = '\b'; break;
+			case 'f': c = '\f'; break;
+			case 'n': c = '\n'; break;
+			case 'r': c = '\r'; break;
+			case 't': c = '\t'; break;
+			case 'v': c = '\v'; break;
+			case 'x':  /* Hexadecimal escape '\xXX'. */
+				c = (lex_next(ls) & 15u) << 4;
+				if (!kp_char_isdigit(ls->c)) {
+					if (!kp_char_isxdigit(ls->c))
+						goto err_xesc;
+					c += 9 << 4;
+				}
+				c += (lex_next(ls) & 15u);
+				if (!kp_char_isdigit(ls->c)) {
+					if (!kp_char_isxdigit(ls->c))
+						goto err_xesc;
+					c += 9;
+				}
+				break;
+			case 'z':  /* Skip whitespace. */
+				lex_next(ls);
+				while (kp_char_isspace(ls->c))
+					if (lex_iseol(ls))
+						lex_newline(ls);
+					else
+						lex_next(ls);
+					continue;
+			case '\n': case '\r':
+				lex_save(ls, '\n');
+				lex_newline(ls);
+				continue;
+			case '\\': case '\"': case '\'':
+				break;
+			case LEX_EOF:
+				continue;
+			default:
+				if (!kp_char_isdigit(c))
+					goto err_xesc;
+				c -= '0';  /* Decimal escape '\ddd'. */
+				if (kp_char_isdigit(lex_next(ls))) {
+					c = c*10 + (ls->c - '0');
+					if (kp_char_isdigit(lex_next(ls))) {
+						c = c*10 + (ls->c - '0');
+						if (c > 255) {
+ err_xesc:
+							kp_lex_error(ls,
+								TK_string,
+								KP_ERR_XESC);
+						}
+						lex_next(ls);
+					}
+				}
+				lex_save(ls, c);
+				continue;
+			}
+			lex_save(ls, c);
+			lex_next(ls);
+			continue;
+		}
+		default:
+			lex_savenext(ls);
+			break;
+		}
+	}
+	lex_savenext(ls);  /* Skip trailing delimiter. */
+	set_string(tv,
+		kp_parse_keepstr(ls, sbufB(&ls->sb)+1, sbuflen(&ls->sb)-2));
+}
+
+/* lex helper for parse_trace and parse_timer */
+void kp_lex_read_string_until(LexState *ls, int c)
+{
+	ktap_str_t *ts;
+
+	kp_buf_reset(&ls->sb);
+
+	while (ls->c == ' ')
+		lex_next(ls);
+
+	do {
+		lex_savenext(ls);
+	} while (ls->c != c && ls->c != LEX_EOF);
+
+	if (ls->c != c)
+		kp_lex_error(ls, ls->tok, KP_ERR_XTOKEN, c);
+
+	ts = kp_parse_keepstr(ls, sbufB(&ls->sb), sbuflen(&ls->sb));
+	ls->tok = TK_string;
+	set_string(&ls->tokval, ts);
+}
+
+
+/* -- Main lexical scanner ------------------------------------------------ */
+
+/* Get next lexical token. */
+static LexToken lex_scan(LexState *ls, ktap_val_t *tv)
+{
+	kp_buf_reset(&ls->sb);
+	for (;;) {
+		if (kp_char_isident(ls->c)) {
+			ktap_str_t *s;
+			if (kp_char_isdigit(ls->c)) {  /* Numeric literal. */
+				lex_number(ls, tv);
+				return TK_number;
+			}
+			/* Identifier or reserved word. */
+			do {
+				lex_savenext(ls);
+			} while (kp_char_isident(ls->c));
+			s = kp_parse_keepstr(ls, sbufB(&ls->sb),
+						sbuflen(&ls->sb));
+			set_string(tv, s);
+			if (s->reserved > 0)  /* Reserved word? */
+				return TK_OFS + s->reserved;
+			return TK_name;
+		}
+
+		switch (ls->c) {
+		case '\n':
+		case '\r':
+			lex_newline(ls);
+			continue;
+		case ' ':
+		case '\t':
+		case '\v':
+		case '\f':
+			lex_next(ls);
+			continue;
+
+		case '#':
+			while (!lex_iseol(ls) && ls->c != LEX_EOF)
+				lex_next(ls);
+			break;
+		case '-':
+			lex_next(ls);
+			if (ls->c != '-')
+				return '-';
+			lex_next(ls);
+			if (ls->c == '[') { /* Long comment "--[=*[...]=*]". */
+				int sep = lex_skipeq(ls);
+				/* `lex_skipeq' may dirty the buffer */
+				kp_buf_reset(&ls->sb);
+				if (sep >= 0) {
+					lex_longstring(ls, NULL, sep);
+					kp_buf_reset(&ls->sb);
+					continue;
+				}
+			}
+			/* Short comment "--.*\n". */
+			while (!lex_iseol(ls) && ls->c != LEX_EOF)
+				lex_next(ls);
+			continue;
+		case '[': {
+			int sep = lex_skipeq(ls);
+			if (sep >= 0) {
+				lex_longstring(ls, tv, sep);
+				return TK_string;
+			} else if (sep == -1) {
+				return '[';
+			} else {
+				kp_lex_error(ls, TK_string, KP_ERR_XLDELIM);
+				continue;
+			}
+		}
+		case '+': {
+			lex_next(ls);
+			if (ls->c != '=')
+				return '+';
+			else {
+				lex_next(ls);
+				return TK_incr;
+			}
+		}
+		case '=':
+			lex_next(ls);
+			if (ls->c != '=')
+				return '=';
+			else {
+				lex_next(ls);
+				return TK_eq;
+			}
+		case '<':
+			lex_next(ls);
+			if (ls->c != '=')
+				return '<';
+			else {
+				lex_next(ls);
+				return TK_le;
+			}
+		case '>':
+			lex_next(ls);
+			if (ls->c != '=')
+				return '>';
+			else {
+				lex_next(ls);
+				return TK_ge;
+			}
+		case '!':
+      			lex_next(ls);
+			if (ls->c != '=')
+				return TK_not;
+			else {
+				lex_next(ls);
+				return TK_ne;
+			}
+		case ':':
+			lex_next(ls);
+			if (ls->c != ':')
+				return ':';
+			else {
+				lex_next(ls);
+				return TK_label;
+			}
+		case '"':
+		case '\'':
+			lex_string(ls, tv);
+			return TK_string;
+		case '.':
+			if (lex_savenext(ls) == '.') {
+				lex_next(ls);
+				if (ls->c == '.') {
+					lex_next(ls);
+					return TK_dots;   /* ... */
+				}
+				return TK_concat;   /* .. */
+			} else if (!kp_char_isdigit(ls->c)) {
+				return '.';
+			} else {
+				lex_number(ls, tv);
+				return TK_number;
+			}
+		case LEX_EOF:
+			return TK_eof;
+		case '&':
+			lex_next(ls);
+			if (ls->c != '&')
+				return '&';
+			else {
+				lex_next(ls);
+				return TK_and;
+			}
+		case '|':
+			lex_next(ls);
+			if (ls->c != '|')
+				return '|';
+			else {
+				lex_next(ls);
+				return TK_or;
+			}
+		default: {
+			LexChar c = ls->c;
+			lex_next(ls);
+			return c;  /* Single-char tokens (+ - / ...). */
+		}
+		}
+	}
+}
+
+/* -- Lexer API ----------------------------------------------------------- */
+
+/* Setup lexer state. */
+int kp_lex_setup(LexState *ls, const char *str)
+{
+	ls->fs = NULL;
+	ls->pe = ls->p = NULL;
+	ls->p = str;
+	ls->pe = str + strlen(str);
+	ls->vstack = NULL;
+	ls->sizevstack = 0;
+	ls->vtop = 0;
+	ls->bcstack = NULL;
+	ls->sizebcstack = 0;
+	ls->lookahead = TK_eof;  /* No look-ahead token. */
+	ls->linenumber = 1;
+	ls->lastline = 1;
+	lex_next(ls);  /* Read-ahead first char. */
+	if (ls->c == 0xef && ls->p + 2 <= ls->pe &&
+		(uint8_t)ls->p[0] == 0xbb &&
+		(uint8_t)ls->p[1] == 0xbf) {/* Skip UTF-8 BOM (if buffered). */
+		ls->p += 2;
+		lex_next(ls);
+	}
+	if (ls->c == '#') {  /* Skip POSIX #! header line. */
+		do {
+			lex_next(ls);
+			if (ls->c == LEX_EOF)
+				return 0;
+		} while (!lex_iseol(ls));
+		lex_newline(ls);
+	}
+	return 0;
+}
+
+/* Cleanup lexer state. */
+void kp_lex_cleanup(LexState *ls)
+{
+	free(ls->bcstack);
+	free(ls->vstack);
+	kp_buf_free(&ls->sb);
+}
+
+/* Return next lexical token. */
+void kp_lex_next(LexState *ls)
+{
+	ls->lastline = ls->linenumber;
+	if (ls->lookahead == TK_eof) {  /* No lookahead token? */
+		ls->tok = lex_scan(ls, &ls->tokval);  /* Get next token. */
+	} else {  /* Otherwise return lookahead token. */
+		ls->tok = ls->lookahead;
+		ls->lookahead = TK_eof;
+		ls->tokval = ls->lookaheadval;
+	}
+}
+
+/* Look ahead for the next token. */
+LexToken kp_lex_lookahead(LexState *ls)
+{
+	kp_assert(ls->lookahead == TK_eof);
+	ls->lookahead = lex_scan(ls, &ls->lookaheadval);
+	return ls->lookahead;
+}
+
+/* Convert token to string. */
+const char *kp_lex_token2str(LexState *ls, LexToken tok)
+{
+	if (tok > TK_OFS)
+		return tokennames[tok-TK_OFS-1];
+	else if (!kp_char_iscntrl(tok))
+		return kp_sprintf("%c", tok);
+	else
+		return kp_sprintf("char(%d)", tok);
+}
+
+/* Lexer error. */
+void kp_lex_error(LexState *ls, LexToken tok, ErrMsg em, ...)
+{
+	const char *tokstr;
+	va_list argp;
+
+	if (tok == 0) {
+		tokstr = NULL;
+	} else if (tok == TK_name || tok == TK_string || tok == TK_number) {
+		lex_save(ls, '\0');
+		tokstr = sbufB(&ls->sb);
+	} else {
+		tokstr = kp_lex_token2str(ls, tok);
+	}
+
+	va_start(argp, em);
+	kp_err_lex(ls->chunkname, tokstr, ls->linenumber, em, argp);
+	va_end(argp);
+}
+
+/* Initialize strings for reserved words. */
+void kp_lex_init()
+{
+	uint32_t i;
+
+	for (i = 0; i < TK_RESERVED; i++) {
+		ktap_str_t *s = kp_str_newz(tokennames[i]);
+		s->reserved = (uint8_t)(i+1);
+	}
+}
+
diff --git a/tools/ktap/kp_lex.h b/tools/ktap/kp_lex.h
new file mode 100644
index 0000000..d84babd
--- /dev/null
+++ b/tools/ktap/kp_lex.h
@@ -0,0 +1,94 @@
+/*
+ * Lexical analyzer.
+ *
+ * Copyright (C) 2012-2014 Jovi Zhangwei <jovi.zhangwei@xxxxxxxxx>.
+ *
+ * Adapted from luajit and lua interpreter.
+ * Copyright (C) 2005-2014 Mike Pall.
+ * Copyright (C) 1994-2008 Lua.org, PUC-Rio.
+ */
+
+#ifndef _KTAP_LEX_H
+#define _KTAP_LEX_H
+
+#include <stdarg.h>
+#include "../include/err.h"
+#include "../../include/uapi/ktap/ktap_bc.h"
+#include "kp_util.h"
+
+/* ktap lexer tokens. */
+#define TKDEF(_, __) \
+	_(trace) _(trace_end) _(argstr) _(probename) _(ffi) \
+	_(arg0)_(arg1) _(arg2) _(arg3) _(arg4) _(arg5) _(arg6) _(arg7) \
+	_(arg8) _(arg9) _(profile) _(tick) \
+	_(pid) _(tid) _(uid) _(cpu) _(execname) __(incr, +=) \
+	__(and, &&) _(break) _(do) _(else) _(elseif) _(end) _(false) \
+	_(for) _(function) _(goto) _(if) _(in) __(local, var) _(nil) \
+	__(not, !) __(or, ||) \
+	_(repeat) _(return) _(then) _(true) _(until) _(while) \
+	__(concat, ..) __(dots, ...) __(eq, ==) __(ge, >=) __(le, <=) \
+	__(ne, !=) __(label, ::) __(number, <number>) __(name, <name>) \
+	__(string, <string>) __(eof, <eof>)
+
+enum {
+	TK_OFS = 256,
+#define TKENUM1(name)		TK_##name,
+#define TKENUM2(name, sym)	TK_##name,
+	TKDEF(TKENUM1, TKENUM2)
+#undef TKENUM1
+#undef TKENUM2
+	TK_RESERVED = TK_while - TK_OFS
+};
+
+typedef int LexChar;	/* Lexical character. Unsigned ext. from char. */
+typedef int LexToken;	/* Lexical token. */
+
+/* Combined bytecode ins/line. Only used during bytecode generation. */
+typedef struct BCInsLine {
+	BCIns ins;		/* Bytecode instruction. */
+	BCLine line;		/* Line number for this bytecode. */
+} BCInsLine;
+
+/* Info for local variables. Only used during bytecode generation. */
+typedef struct VarInfo {
+	ktap_str_t *name;	/* Local variable name or goto/label name. */
+	BCPos startpc;	/* First point where the local variable is active. */
+	BCPos endpc;	/* First point where the local variable is dead. */
+	uint8_t slot;	/* Variable slot. */
+	uint8_t info;	/* Variable/goto/label info. */
+} VarInfo;
+
+/* lexer state. */
+typedef struct LexState {
+	struct FuncState *fs;	/* Current FuncState. Defined in kp_parse.c. */
+	ktap_val_t tokval;	/* Current token value. */
+	ktap_val_t lookaheadval;/* Lookahead token value. */
+	const char *p;	/* Current position in input buffer. */
+	const char *pe;	/* End of input buffer. */
+	LexChar c;		/* Current character. */
+	LexToken tok;		/* Current token. */
+	LexToken lookahead;	/* Lookahead token. */
+	SBuf sb;		/* String buffer for tokens. */
+	BCLine linenumber;	/* Input line counter. */
+	BCLine lastline;	/* Line of last token. */
+	ktap_str_t *chunkname;/* Current chunk name (interned string). */
+	const char *chunkarg;	/* Chunk name argument. */
+	const char *mode;/* Allow loading bytecode (b) and/or source text (t) */
+	VarInfo *vstack;/* Stack for names and extents of local variables. */
+	int sizevstack;	/* Size of variable stack. */
+	int vtop;	/* Top of variable stack. */
+	BCInsLine *bcstack;/* Stack for bytecode instructions/line numbers. */
+	int sizebcstack;/* Size of bytecode stack. */
+	uint32_t level;	/* Syntactical nesting level. */
+} LexState;
+
+int kp_lex_setup(LexState *ls, const char *str);
+void kp_lex_cleanup(LexState *ls);
+void kp_lex_next(LexState *ls);
+void kp_lex_read_string_until(LexState *ls, int c);
+LexToken kp_lex_lookahead(LexState *ls);
+const char *kp_lex_token2str(LexState *ls, LexToken tok);
+void kp_lex_error(LexState *ls, LexToken tok, ErrMsg em, ...);
+void kp_lex_init(void);
+
+#endif
diff --git a/tools/ktap/kp_parse.c b/tools/ktap/kp_parse.c
new file mode 100644
index 0000000..5c3916c
--- /dev/null
+++ b/tools/ktap/kp_parse.c
@@ -0,0 +1,3139 @@
+/*
+ * ktap parser (source code -> bytecode).
+ *
+ * This file is part of ktap by Jovi Zhangwei.
+ *
+ * Copyright (C) 2012-2014 Jovi Zhangwei <jovi.zhangwei@xxxxxxxxx>.
+ *
+ * Adapted from luajit and lua interpreter.
+ * Copyright (C) 2005-2014 Mike Pall.
+ * Copyright (C) 1994-2008 Lua.org, PUC-Rio.
+ *
+ * ktap is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * ktap is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "../../include/uapi/ktap/ktap_types.h"
+#include "../../include/uapi/ktap/ktap_err.h"
+#include "kp_util.h"
+#include "kp_lex.h"
+
+/* Fixed internal variable names. */
+#define VARNAMEDEF(_) \
+	_(FOR_IDX, "(for index)") \
+	_(FOR_STOP, "(for limit)") \
+	_(FOR_STEP, "(for step)") \
+	_(FOR_GEN, "(for generator)") \
+	_(FOR_STATE, "(for state)") \
+	_(FOR_CTL, "(for control)")
+
+enum {
+	VARNAME_END,
+#define VARNAMEENUM(name, str)  VARNAME_##name,
+	VARNAMEDEF(VARNAMEENUM)
+#undef VARNAMEENUM
+	VARNAME__MAX
+};
+
+/* -- Parser structures and definitions ----------------------------------- */
+
+/* Expression kinds. */
+typedef enum {
+	/* Constant expressions must be first and in this order: */
+	VKNIL,
+	VKFALSE,
+	VKTRUE,
+	VKSTR,	/* sval = string value */
+	VKNUM,	/* nval = number value */
+	VKLAST = VKNUM,
+	VKCDATA, /* nval = cdata value, not treated as a constant expression */
+	/* Non-constant expressions follow: */
+	VLOCAL,	/* info = local register, aux = vstack index */
+	VUPVAL,	/* info = upvalue index, aux = vstack index */
+	VGLOBAL,/* sval = string value */
+	VINDEXED,/* info = table register, aux = index reg/byte/string const */
+	VJMP,	/* info = instruction PC */
+	VRELOCABLE, /* info = instruction PC */
+	VNONRELOC, /* info = result register */
+	VCALL,	/* info = instruction PC, aux = base */
+	VVOID,
+
+	VARGN,
+	VARGSTR,
+	VARGNAME,
+	VPID,
+	VTID,
+	VUID,
+	VCPU,
+	VEXECNAME,
+	VMAX
+} ExpKind;
+
+/* Expression descriptor. */
+typedef struct ExpDesc {
+	union {
+		struct {
+			uint32_t info;	/* Primary info. */
+			uint32_t aux;	/* Secondary info. */
+		} s;
+		ktap_val_t nval;	/* Number value. */
+		ktap_str_t *sval;	/* String value. */
+	} u;
+	ExpKind k;
+	BCPos t;	/* True condition jump list. */
+	BCPos f;	/* False condition jump list. */
+} ExpDesc;
+
+/* Macros for expressions. */
+#define expr_hasjump(e)		((e)->t != (e)->f)
+
+#define expr_isk(e)		((e)->k <= VKLAST)
+#define expr_isk_nojump(e)	(expr_isk(e) && !expr_hasjump(e))
+#define expr_isnumk(e)		((e)->k == VKNUM)
+#define expr_isnumk_nojump(e)	(expr_isnumk(e) && !expr_hasjump(e))
+#define expr_isstrk(e)		((e)->k == VKSTR)
+
+#define expr_numtv(e)		(&(e)->u.nval)
+#define expr_numberV(e)		nvalue(expr_numtv((e)))
+
+/* Initialize expression. */
+static inline void expr_init(ExpDesc *e, ExpKind k, uint32_t info)
+{
+	e->k = k;
+	e->u.s.info = info;
+	e->f = e->t = NO_JMP;
+}
+
+/* Check number constant for +-0. */
+static int expr_numiszero(ExpDesc *e)
+{
+	ktap_val_t *o = expr_numtv(e);
+	return (nvalue(o) == 0);
+}
+
+/* Per-function linked list of scope blocks. */
+typedef struct FuncScope {
+	struct FuncScope *prev;	/* Link to outer scope. */
+	int vstart;		/* Start of block-local variables. */
+	uint8_t nactvar;	/* Number of active vars outside the scope. */
+	uint8_t flags;		/* Scope flags. */
+} FuncScope;
+
+#define FSCOPE_LOOP		0x01	/* Scope is a (breakable) loop. */
+#define FSCOPE_BREAK		0x02	/* Break used in scope. */
+#define FSCOPE_GOLA		0x04	/* Goto or label used in scope. */
+#define FSCOPE_UPVAL		0x08	/* Upvalue in scope. */
+#define FSCOPE_NOCLOSE		0x10	/* Do not close upvalues. */
+
+#define NAME_BREAK		((ktap_str_t *)(uintptr_t)1)
+
+/* Index into variable stack. */
+typedef uint16_t VarIndex;
+#define KP_MAX_VSTACK		(65536 - KP_MAX_UPVAL)
+
+/* Variable/goto/label info. */
+#define VSTACK_VAR_RW		0x01	/* R/W variable. */
+#define VSTACK_GOTO		0x02	/* Pending goto. */
+#define VSTACK_LABEL		0x04	/* Label. */
+
+/* Per-function state. */
+typedef struct FuncState {
+	ktap_tab_t *kt;		/* Hash table for constants. */
+	LexState *ls;		/* Lexer state. */
+	FuncScope *bl;		/* Current scope. */
+	struct FuncState *prev;	/* Enclosing function. */
+	BCPos pc;		/* Next bytecode position. */
+	BCPos lasttarget;	/* Bytecode position of last jump target. */
+	BCPos jpc;		/* Pending jump list to next bytecode. */
+	BCReg freereg;		/* First free register. */
+	BCReg nactvar;		/* Number of active local variables. */
+	BCReg nkn, nkgc;        /* Number of ktap_number/ktap_obj_t constants*/
+	BCLine linedefined;	/* First line of the function definition. */
+	BCInsLine *bcbase;	/* Base of bytecode stack. */
+	BCPos bclim;		/* Limit of bytecode stack. */
+	int vbase;		/* Base of variable stack for this function. */
+	uint8_t flags;		/* Prototype flags. */
+	uint8_t numparams;	/* Number of parameters. */
+	uint8_t framesize;	/* Fixed frame size. */
+	uint8_t nuv;		/* Number of upvalues */
+	VarIndex varmap[KP_MAX_LOCVAR];/* Map from register to variable idx. */
+	VarIndex uvmap[KP_MAX_UPVAL];	/* Map from upvalue to variable idx. */
+	VarIndex uvtmp[KP_MAX_UPVAL];	/* Temporary upvalue map. */
+} FuncState;
+
+/* Binary and unary operators. ORDER OPR */
+typedef enum BinOpr {
+	OPR_ADD, OPR_SUB, OPR_MUL, OPR_DIV, OPR_MOD, OPR_POW, /* ORDER ARITH */
+	OPR_CONCAT,
+	OPR_NE, OPR_EQ,
+	OPR_LT, OPR_GE, OPR_LE, OPR_GT,
+	OPR_AND, OPR_OR,
+	OPR_NOBINOPR
+} BinOpr;
+
+KP_STATIC_ASSERT((int)BC_ISGE-(int)BC_ISLT == (int)OPR_GE-(int)OPR_LT);
+KP_STATIC_ASSERT((int)BC_ISLE-(int)BC_ISLT == (int)OPR_LE-(int)OPR_LT);
+KP_STATIC_ASSERT((int)BC_ISGT-(int)BC_ISLT == (int)OPR_GT-(int)OPR_LT);
+KP_STATIC_ASSERT((int)BC_SUBVV-(int)BC_ADDVV == (int)OPR_SUB-(int)OPR_ADD);
+KP_STATIC_ASSERT((int)BC_MULVV-(int)BC_ADDVV == (int)OPR_MUL-(int)OPR_ADD);
+KP_STATIC_ASSERT((int)BC_DIVVV-(int)BC_ADDVV == (int)OPR_DIV-(int)OPR_ADD);
+KP_STATIC_ASSERT((int)BC_MODVV-(int)BC_ADDVV == (int)OPR_MOD-(int)OPR_ADD);
+
+/* -- Error handling ------------------------------------------------------ */
+
+static void err_syntax(LexState *ls, ErrMsg em)
+{
+	kp_lex_error(ls, ls->tok, em);
+}
+
+static void err_token(LexState *ls, LexToken tok)
+{
+	kp_lex_error(ls, ls->tok, KP_ERR_XTOKEN, kp_lex_token2str(ls, tok));
+}
+
+static void err_limit(FuncState *fs, uint32_t limit, const char *what)
+{
+	if (fs->linedefined == 0)
+		kp_lex_error(fs->ls, 0, KP_ERR_XLIMM, limit, what);
+	else
+		kp_lex_error(fs->ls, 0, KP_ERR_XLIMF, fs->linedefined,
+				limit, what);
+}
+
+#define checklimit(fs, v, l, m)		if ((v) >= (l)) err_limit(fs, l, m)
+#define checklimitgt(fs, v, l, m)	if ((v) > (l)) err_limit(fs, l, m)
+#define checkcond(ls, c, em)		{ if (!(c)) err_syntax(ls, em); }
+
+/* -- Management of constants --------------------------------------------- */
+
+/* Return bytecode encoding for primitive constant. */
+#define const_pri(e)	((e)->k)
+
+#define tvhaskslot(o)	(is_number(o))
+#define tvkslot(o)	(nvalue(o))
+
+/* Add a number constant. */
+static BCReg const_num(FuncState *fs, ExpDesc *e)
+{
+	ktap_val_t *o;
+
+	kp_assert(expr_isnumk(e));
+	o = kp_tab_set(fs->kt, &e->u.nval);
+	if (tvhaskslot(o))
+		return tvkslot(o);
+	set_number(o, fs->nkn);
+	return fs->nkn++;
+}
+
+/* Add a GC object constant. */
+static BCReg const_gc(FuncState *fs, ktap_obj_t *gc, uint32_t itype)
+{
+	ktap_val_t key, *o;
+
+	setitype(&key, itype);
+	key.val.gc = gc;
+	o = kp_tab_set(fs->kt, &key);
+	if (tvhaskslot(o))
+		return tvkslot(o);
+	set_number(o, fs->nkgc);
+	return fs->nkgc++;
+}
+
+/* Add a string constant. */
+static BCReg const_str(FuncState *fs, ExpDesc *e)
+{
+	kp_assert(expr_isstrk(e) || e->k == VGLOBAL);
+	return const_gc(fs, obj2gco(e->u.sval), KTAP_TSTR);
+}
+
+/* Anchor string constant. */
+ktap_str_t *kp_parse_keepstr(LexState *ls, const char *str, size_t len)
+{
+	ktap_val_t v;
+	ktap_str_t *s = kp_str_new(str, len);
+
+	set_string(&v, s);
+	ktap_val_t *tv = kp_tab_set(ls->fs->kt, &v);
+	if (is_nil(tv))
+		set_bool(tv, 1);
+	return s;
+}
+
+/* -- Jump list handling -------------------------------------------------- */
+
+/* Get next element in jump list. */
+static BCPos jmp_next(FuncState *fs, BCPos pc)
+{
+	ptrdiff_t delta = bc_j(fs->bcbase[pc].ins);
+	if ((BCPos)delta == NO_JMP)
+		return NO_JMP;
+	else
+		return (BCPos)(((ptrdiff_t)pc+1)+delta);
+}
+
+/* Check if any of the instructions on the jump list produce no value. */
+static int jmp_novalue(FuncState *fs, BCPos list)
+{
+	for (; list != NO_JMP; list = jmp_next(fs, list)) {
+		BCIns p = fs->bcbase[list >= 1 ? list-1 : list].ins;
+		if (!(bc_op(p) == BC_ISTC || bc_op(p) == BC_ISFC ||
+			bc_a(p) == NO_REG))
+		return 1;
+	}
+	return 0;
+}
+
+/* Patch register of test instructions. */
+static int jmp_patchtestreg(FuncState *fs, BCPos pc, BCReg reg)
+{
+	BCInsLine *ilp = &fs->bcbase[pc >= 1 ? pc-1 : pc];
+	BCOp op = bc_op(ilp->ins);
+
+	if (op == BC_ISTC || op == BC_ISFC) {
+		if (reg != NO_REG && reg != bc_d(ilp->ins)) {
+			setbc_a(&ilp->ins, reg);
+		} else {/* Nothing to store or already in the right register */
+			setbc_op(&ilp->ins, op+(BC_IST-BC_ISTC));
+			setbc_a(&ilp->ins, 0);
+		}
+	} else if (bc_a(ilp->ins) == NO_REG) {
+		if (reg == NO_REG) {
+			ilp->ins =
+				BCINS_AJ(BC_JMP, bc_a(fs->bcbase[pc].ins), 0);
+		} else {
+			setbc_a(&ilp->ins, reg);
+			if (reg >= bc_a(ilp[1].ins))
+				setbc_a(&ilp[1].ins, reg+1);
+		}
+	} else {
+		return 0;  /* Cannot patch other instructions. */
+	}
+	return 1;
+}
+
+/* Drop values for all instructions on jump list. */
+static void jmp_dropval(FuncState *fs, BCPos list)
+{
+	for (; list != NO_JMP; list = jmp_next(fs, list))
+		jmp_patchtestreg(fs, list, NO_REG);
+}
+
+/* Patch jump instruction to target. */
+static void jmp_patchins(FuncState *fs, BCPos pc, BCPos dest)
+{
+	BCIns *jmp = &fs->bcbase[pc].ins;
+	BCPos offset = dest-(pc+1)+BCBIAS_J;
+
+	kp_assert(dest != NO_JMP);
+	if (offset > BCMAX_D)
+		err_syntax(fs->ls, KP_ERR_XJUMP);
+	setbc_d(jmp, offset);
+}
+
+/* Append to jump list. */
+static void jmp_append(FuncState *fs, BCPos *l1, BCPos l2)
+{
+	if (l2 == NO_JMP) {
+		return;
+	} else if (*l1 == NO_JMP) {
+		*l1 = l2;
+	} else {
+		BCPos list = *l1;
+		BCPos next;
+		/* Find last element. */
+		while ((next = jmp_next(fs, list)) != NO_JMP)
+			list = next;
+		jmp_patchins(fs, list, l2);
+	}
+}
+
+/* Patch jump list and preserve produced values. */
+static void jmp_patchval(FuncState *fs, BCPos list, BCPos vtarget,
+			 BCReg reg, BCPos dtarget)
+{
+	while (list != NO_JMP) {
+		BCPos next = jmp_next(fs, list);
+		if (jmp_patchtestreg(fs, list, reg)) {
+			/* Jump to target with value. */
+			jmp_patchins(fs, list, vtarget);
+		} else {
+			/* Jump to default target. */
+			jmp_patchins(fs, list, dtarget);
+		}
+		list = next;
+	}
+}
+
+/* Jump to following instruction. Append to list of pending jumps. */
+static void jmp_tohere(FuncState *fs, BCPos list)
+{
+	fs->lasttarget = fs->pc;
+	jmp_append(fs, &fs->jpc, list);
+}
+
+/* Patch jump list to target. */
+static void jmp_patch(FuncState *fs, BCPos list, BCPos target)
+{
+	if (target == fs->pc) {
+		jmp_tohere(fs, list);
+	} else {
+		kp_assert(target < fs->pc);
+		jmp_patchval(fs, list, target, NO_REG, target);
+	}
+}
+
+/* -- Bytecode register allocator ----------------------------------------- */
+
+/* Bump frame size. */
+static void bcreg_bump(FuncState *fs, BCReg n)
+{
+	BCReg sz = fs->freereg + n;
+
+	if (sz > fs->framesize) {
+		if (sz >= KP_MAX_SLOTS)
+			err_syntax(fs->ls, KP_ERR_XSLOTS);
+		fs->framesize = (uint8_t)sz;
+	}
+}
+
+/* Reserve registers. */
+static void bcreg_reserve(FuncState *fs, BCReg n)
+{
+	bcreg_bump(fs, n);
+	fs->freereg += n;
+}
+
+/* Free register. */
+static void bcreg_free(FuncState *fs, BCReg reg)
+{
+	if (reg >= fs->nactvar) {
+		fs->freereg--;
+		kp_assert(reg == fs->freereg);
+	}
+}
+
+/* Free register for expression. */
+static void expr_free(FuncState *fs, ExpDesc *e)
+{
+	if (e->k == VNONRELOC)
+		bcreg_free(fs, e->u.s.info);
+}
+
+/* -- Bytecode emitter ---------------------------------------------------- */
+
+/* Emit bytecode instruction. */
+static BCPos bcemit_INS(FuncState *fs, BCIns ins)
+{
+	BCPos pc = fs->pc;
+	LexState *ls = fs->ls;
+
+	jmp_patchval(fs, fs->jpc, pc, NO_REG, pc);
+	fs->jpc = NO_JMP;
+	if (pc >= fs->bclim) {
+		ptrdiff_t base = fs->bcbase - ls->bcstack;
+		checklimit(fs, ls->sizebcstack, KP_MAX_BCINS,
+				"bytecode instructions");
+		if (!ls->bcstack) {
+			ls->bcstack = malloc(sizeof(BCInsLine) * 20);
+			ls->sizebcstack = 20;
+		} else {
+			ls->bcstack = realloc(ls->bcstack,
+				ls->sizebcstack * sizeof(BCInsLine) * 2);
+			ls->sizebcstack = ls->sizebcstack * 2;
+		}
+		fs->bclim = (BCPos)(ls->sizebcstack - base);
+		fs->bcbase = ls->bcstack + base;
+	}
+	fs->bcbase[pc].ins = ins;
+	fs->bcbase[pc].line = ls->lastline;
+	fs->pc = pc+1;
+	return pc;
+}
+
+#define bcemit_ABC(fs, o, a, b, c)	bcemit_INS(fs, BCINS_ABC(o, a, b, c))
+#define bcemit_AD(fs, o, a, d)		bcemit_INS(fs, BCINS_AD(o, a, d))
+#define bcemit_AJ(fs, o, a, j)		bcemit_INS(fs, BCINS_AJ(o, a, j))
+
+#define bcptr(fs, e)			(&(fs)->bcbase[(e)->u.s.info].ins)
+
+/* -- Bytecode emitter for expressions ------------------------------------ */
+
+/* Discharge non-constant expression to any register. */
+static void expr_discharge(FuncState *fs, ExpDesc *e)
+{
+	BCIns ins;
+
+	if (e->k == VUPVAL) {
+		ins = BCINS_AD(BC_UGET, 0, e->u.s.info);
+	} else if (e->k == VGLOBAL) {
+		ins = BCINS_AD(BC_GGET, 0, const_str(fs, e));
+	} else if (e->k == VINDEXED) {
+		BCReg rc = e->u.s.aux;
+		if ((int32_t)rc < 0) {
+			ins = BCINS_ABC(BC_TGETS, 0, e->u.s.info, ~rc);
+		} else if (rc > BCMAX_C) {
+			ins = BCINS_ABC(BC_TGETB, 0, e->u.s.info,
+					rc-(BCMAX_C+1));
+		} else {
+			bcreg_free(fs, rc);
+			ins = BCINS_ABC(BC_TGETV, 0, e->u.s.info, rc);
+		}
+		bcreg_free(fs, e->u.s.info);
+	} else if (e->k == VCALL) {
+		e->u.s.info = e->u.s.aux;
+		e->k = VNONRELOC;
+		return;
+	} else if (e->k == VLOCAL) {
+		e->k = VNONRELOC;
+		return;
+	} else {
+		return;
+	}
+
+	e->u.s.info = bcemit_INS(fs, ins);
+	e->k = VRELOCABLE;
+}
+
+/* Emit bytecode to set a range of registers to nil. */
+static void bcemit_nil(FuncState *fs, BCReg from, BCReg n)
+{
+	if (fs->pc > fs->lasttarget) {  /* No jumps to current position? */
+		BCIns *ip = &fs->bcbase[fs->pc-1].ins;
+		BCReg pto, pfrom = bc_a(*ip);
+		/* Try to merge with the previous instruction. */
+		switch (bc_op(*ip)) {
+		case BC_KPRI:
+			if (bc_d(*ip) != ~KTAP_TNIL) break;
+			if (from == pfrom) {
+				if (n == 1)
+					return;
+			} else if (from == pfrom+1) {
+				from = pfrom;
+				n++;
+			} else {
+				break;
+			}
+			/* Replace KPRI. */
+			*ip = BCINS_AD(BC_KNIL, from, from+n-1);
+			return;
+		case BC_KNIL:
+			pto = bc_d(*ip);
+			/* Can we connect both ranges? */
+			if (pfrom <= from && from <= pto+1) {
+				if (from+n-1 > pto) {
+					/* Patch previous instruction range. */
+					setbc_d(ip, from+n-1);
+				}
+				return;
+			}
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* Emit new instruction or replace old instruction. */
+	bcemit_INS(fs, n == 1 ? BCINS_AD(BC_KPRI, from, VKNIL) :
+				BCINS_AD(BC_KNIL, from, from+n-1));
+}
+
+/* Discharge an expression to a specific register. Ignore branches. */
+static void expr_toreg_nobranch(FuncState *fs, ExpDesc *e, BCReg reg)
+{
+	BCIns ins;
+
+	expr_discharge(fs, e);
+	if (e->k == VKSTR) {
+		ins = BCINS_AD(BC_KSTR, reg, const_str(fs, e));
+	} else if (e->k == VKNUM) {
+		ktap_number n = expr_numberV(e);
+		if (n >= 0 && n <= 0xffff) {
+			ins = BCINS_AD(BC_KSHORT, reg, (BCReg)(uint16_t)n);
+		} else
+			ins = BCINS_AD(BC_KNUM, reg, const_num(fs, e));
+	} else if (e->k == VRELOCABLE) {
+		setbc_a(bcptr(fs, e), reg);
+		goto noins;
+	} else if (e->k == VNONRELOC) {
+		if (reg == e->u.s.info)
+			goto noins;
+		ins = BCINS_AD(BC_MOV, reg, e->u.s.info);
+	} else if (e->k == VKNIL) {
+		bcemit_nil(fs, reg, 1);
+		goto noins;
+	} else if (e->k <= VKTRUE) {
+		ins = BCINS_AD(BC_KPRI, reg, const_pri(e));
+	} else if (e->k == VARGN) {
+		ins = BCINS_AD(BC_VARGN, reg, e->u.s.info);
+	} else if (e->k > VARGN && e->k < VMAX) {
+		ins = BCINS_AD(e->k - VARGN + BC_VARGN, reg, 0);
+	} else {
+		kp_assert(e->k == VVOID || e->k == VJMP);
+		return;
+	}
+	bcemit_INS(fs, ins);
+ noins:
+	e->u.s.info = reg;
+	e->k = VNONRELOC;
+}
+
+/* Forward declaration. */
+static BCPos bcemit_jmp(FuncState *fs);
+
+/* Discharge an expression to a specific register. */
+static void expr_toreg(FuncState *fs, ExpDesc *e, BCReg reg)
+{
+	expr_toreg_nobranch(fs, e, reg);
+	if (e->k == VJMP) {
+		/* Add it to the true jump list. */
+		jmp_append(fs, &e->t, e->u.s.info);
+	}
+	if (expr_hasjump(e)) {  /* Discharge expression with branches. */
+		BCPos jend, jfalse = NO_JMP, jtrue = NO_JMP;
+		if (jmp_novalue(fs, e->t) || jmp_novalue(fs, e->f)) {
+			BCPos jval = (e->k == VJMP) ? NO_JMP : bcemit_jmp(fs);
+			jfalse = bcemit_AD(fs, BC_KPRI, reg, VKFALSE);
+			bcemit_AJ(fs, BC_JMP, fs->freereg, 1);
+			jtrue = bcemit_AD(fs, BC_KPRI, reg, VKTRUE);
+			jmp_tohere(fs, jval);
+		}
+		jend = fs->pc;
+		fs->lasttarget = jend;
+		jmp_patchval(fs, e->f, jend, reg, jfalse);
+		jmp_patchval(fs, e->t, jend, reg, jtrue);
+	}
+	e->f = e->t = NO_JMP;
+	e->u.s.info = reg;
+	e->k = VNONRELOC;
+}
+
+/* Discharge an expression to the next free register. */
+static void expr_tonextreg(FuncState *fs, ExpDesc *e)
+{
+	expr_discharge(fs, e);
+	expr_free(fs, e);
+	bcreg_reserve(fs, 1);
+	expr_toreg(fs, e, fs->freereg - 1);
+}
+
+/* Discharge an expression to any register. */
+static BCReg expr_toanyreg(FuncState *fs, ExpDesc *e)
+{
+	expr_discharge(fs, e);
+	if (e->k == VNONRELOC) {
+		if (!expr_hasjump(e))
+			return e->u.s.info;  /* Already in a register. */
+		if (e->u.s.info >= fs->nactvar) {
+			/* Discharge to temp. register. */
+			expr_toreg(fs, e, e->u.s.info);
+			return e->u.s.info;
+		}
+	}
+	expr_tonextreg(fs, e);  /* Discharge to next register. */
+	return e->u.s.info;
+}
+
+/* Partially discharge expression to a value. */
+static void expr_toval(FuncState *fs, ExpDesc *e)
+{
+	if (expr_hasjump(e))
+		expr_toanyreg(fs, e);
+	else
+		expr_discharge(fs, e);
+}
+
+/* Emit store for LHS expression. */
+static void bcemit_store(FuncState *fs, ExpDesc *var, ExpDesc *e)
+{
+	BCIns ins;
+
+	if (var->k == VLOCAL) {
+		fs->ls->vstack[var->u.s.aux].info |= VSTACK_VAR_RW;
+		expr_free(fs, e);
+		expr_toreg(fs, e, var->u.s.info);
+		return;
+	} else if (var->k == VUPVAL) {
+		fs->ls->vstack[var->u.s.aux].info |= VSTACK_VAR_RW;
+		expr_toval(fs, e);
+		if (e->k <= VKTRUE)
+			ins = BCINS_AD(BC_USETP, var->u.s.info, const_pri(e));
+		else if (e->k == VKSTR)
+			ins = BCINS_AD(BC_USETS, var->u.s.info,
+					const_str(fs, e));
+		else if (e->k == VKNUM)
+			ins = BCINS_AD(BC_USETN, var->u.s.info,
+					const_num(fs, e));
+		else
+			ins = BCINS_AD(BC_USETV, var->u.s.info,
+					expr_toanyreg(fs, e));
+	} else if (var->k == VGLOBAL) {
+		BCReg ra = expr_toanyreg(fs, e);
+		ins = BCINS_AD(BC_GSET, ra, const_str(fs, var));
+	} else {
+		BCReg ra, rc;
+		kp_assert(var->k == VINDEXED);
+		ra = expr_toanyreg(fs, e);
+		rc = var->u.s.aux;
+		if ((int32_t)rc < 0) {
+			ins = BCINS_ABC(BC_TSETS, ra, var->u.s.info, ~rc);
+		} else if (rc > BCMAX_C) {
+			ins = BCINS_ABC(BC_TSETB, ra, var->u.s.info,
+				rc-(BCMAX_C+1));
+		} else {
+			/* 
+			 * Free late alloced key reg to avoid assert on
+			 * free of value reg. This can only happen when
+			 * called from expr_table(). 
+			 */
+			kp_assert(e->k != VNONRELOC || ra < fs->nactvar ||
+					rc < ra || (bcreg_free(fs, rc),1));
+			ins = BCINS_ABC(BC_TSETV, ra, var->u.s.info, rc);
+		}
+	}
+	bcemit_INS(fs, ins);
+	expr_free(fs, e);
+}
+
+/* Emit store for '+=' expression. */
+static void bcemit_store_incr(FuncState *fs, ExpDesc *var, ExpDesc *e)
+{
+	BCIns ins;
+
+	if (var->k == VLOCAL) {
+		/* don't need to do like "var a=0; a+=1", just use 'a=a+1' */
+		err_syntax(fs->ls, KP_ERR_XSYMBOL);
+		return;
+	} else if (var->k == VUPVAL) {
+		fs->ls->vstack[var->u.s.aux].info |= VSTACK_VAR_RW;
+		expr_toval(fs, e);
+		if (e->k == VKNUM) {
+			ins = BCINS_AD(BC_UINCN, var->u.s.info,
+					const_num(fs, e));
+		} else if (e->k <= VKTRUE || e->k == VKSTR) {
+			err_syntax(fs->ls, KP_ERR_XSYMBOL);
+			return;
+		} else
+			ins = BCINS_AD(BC_UINCV, var->u.s.info,
+					expr_toanyreg(fs, e));
+	} else if (var->k == VGLOBAL) {
+		BCReg ra = expr_toanyreg(fs, e);
+		ins = BCINS_AD(BC_GINC, ra, const_str(fs, var));
+	} else {
+		BCReg ra, rc;
+		kp_assert(var->k == VINDEXED);
+		ra = expr_toanyreg(fs, e);
+		rc = var->u.s.aux;
+		if ((int32_t)rc < 0) {
+			ins = BCINS_ABC(BC_TINCS, ra, var->u.s.info, ~rc);
+		} else if (rc > BCMAX_C) {
+			ins = BCINS_ABC(BC_TINCB, ra, var->u.s.info,
+				rc-(BCMAX_C+1));
+		} else {
+			/* 
+			 * Free late alloced key reg to avoid assert on
+			 * free of value reg. This can only happen when
+			 * called from expr_table(). 
+			 */
+			kp_assert(e->k != VNONRELOC || ra < fs->nactvar ||
+					rc < ra || (bcreg_free(fs, rc),1));
+			ins = BCINS_ABC(BC_TINCV, ra, var->u.s.info, rc);
+		}
+	}
+	bcemit_INS(fs, ins);
+	expr_free(fs, e);
+}
+
+
+/* Emit method lookup expression. */
+static void bcemit_method(FuncState *fs, ExpDesc *e, ExpDesc *key)
+{
+	BCReg idx, func, obj = expr_toanyreg(fs, e);
+
+	expr_free(fs, e);
+	func = fs->freereg;
+	bcemit_AD(fs, BC_MOV, func+1, obj);/* Copy object to first argument. */
+	kp_assert(expr_isstrk(key));
+	idx = const_str(fs, key);
+	if (idx <= BCMAX_C) {
+		bcreg_reserve(fs, 2);
+		bcemit_ABC(fs, BC_TGETS, func, obj, idx);
+	} else {
+		bcreg_reserve(fs, 3);
+		bcemit_AD(fs, BC_KSTR, func+2, idx);
+		bcemit_ABC(fs, BC_TGETV, func, obj, func+2);
+		fs->freereg--;
+	}
+	e->u.s.info = func;
+	e->k = VNONRELOC;
+}
+
+/* -- Bytecode emitter for branches --------------------------------------- */
+
+/* Emit unconditional branch. */
+static BCPos bcemit_jmp(FuncState *fs)
+{
+	BCPos jpc = fs->jpc;
+	BCPos j = fs->pc - 1;
+	BCIns *ip = &fs->bcbase[j].ins;
+
+	fs->jpc = NO_JMP;
+	if ((int32_t)j >= (int32_t)fs->lasttarget && bc_op(*ip) == BC_UCLO)
+		setbc_j(ip, NO_JMP);
+	else
+		j = bcemit_AJ(fs, BC_JMP, fs->freereg, NO_JMP);
+	jmp_append(fs, &j, jpc);
+	return j;
+}
+
+/* Invert branch condition of bytecode instruction. */
+static void invertcond(FuncState *fs, ExpDesc *e)
+{
+	BCIns *ip = &fs->bcbase[e->u.s.info - 1].ins;
+	setbc_op(ip, bc_op(*ip)^1);
+}
+
+/* Emit conditional branch. */
+static BCPos bcemit_branch(FuncState *fs, ExpDesc *e, int cond)
+{
+	BCPos pc;
+
+	if (e->k == VRELOCABLE) {
+		BCIns *ip = bcptr(fs, e);
+		if (bc_op(*ip) == BC_NOT) {
+			*ip = BCINS_AD(cond ? BC_ISF : BC_IST, 0, bc_d(*ip));
+			return bcemit_jmp(fs);
+		}
+	}
+	if (e->k != VNONRELOC) {
+		bcreg_reserve(fs, 1);
+		expr_toreg_nobranch(fs, e, fs->freereg-1);
+	}
+	bcemit_AD(fs, cond ? BC_ISTC : BC_ISFC, NO_REG, e->u.s.info);
+	pc = bcemit_jmp(fs);
+	expr_free(fs, e);
+	return pc;
+}
+
+/* Emit branch on true condition. */
+static void bcemit_branch_t(FuncState *fs, ExpDesc *e)
+{
+	BCPos pc;
+
+	expr_discharge(fs, e);
+	if (e->k == VKSTR || e->k == VKNUM || e->k == VKTRUE)
+		pc = NO_JMP;  /* Never jump. */
+	else if (e->k == VJMP)
+		invertcond(fs, e), pc = e->u.s.info;
+	else if (e->k == VKFALSE || e->k == VKNIL)
+		expr_toreg_nobranch(fs, e, NO_REG), pc = bcemit_jmp(fs);
+	else
+		pc = bcemit_branch(fs, e, 0);
+	jmp_append(fs, &e->f, pc);
+	jmp_tohere(fs, e->t);
+	e->t = NO_JMP;
+}
+
+/* Emit branch on false condition. */
+static void bcemit_branch_f(FuncState *fs, ExpDesc *e)
+{
+	BCPos pc;
+
+	expr_discharge(fs, e);
+	if (e->k == VKNIL || e->k == VKFALSE)
+		pc = NO_JMP;  /* Never jump. */
+	else if (e->k == VJMP)
+		pc = e->u.s.info;
+	else if (e->k == VKSTR || e->k == VKNUM || e->k == VKTRUE)
+		expr_toreg_nobranch(fs, e, NO_REG), pc = bcemit_jmp(fs);
+	else
+		pc = bcemit_branch(fs, e, 1);
+	jmp_append(fs, &e->t, pc);
+	jmp_tohere(fs, e->f);
+	e->f = NO_JMP;
+}
+
+/* -- Bytecode emitter for operators -------------------------------------- */
+
+static ktap_number number_foldarith(ktap_number x, ktap_number y, int op)
+{
+	switch (op) {
+	case OPR_ADD - OPR_ADD: return x + y;
+	case OPR_SUB - OPR_ADD: return x - y;
+	case OPR_MUL - OPR_ADD: return x * y;
+	case OPR_DIV - OPR_ADD: return x / y;
+	default: return x;
+	}
+}
+
+/* Try constant-folding of arithmetic operators. */
+static int foldarith(BinOpr opr, ExpDesc *e1, ExpDesc *e2)
+{
+	ktap_val_t o;
+	ktap_number n;
+
+	if (!expr_isnumk_nojump(e1) || !expr_isnumk_nojump(e2))
+		return 0;
+
+	if (opr == OPR_DIV && expr_numberV(e2) == 0)
+		return 0; /* do not attempt to divide by 0 */
+
+	if (opr == OPR_MOD)
+		return 0; /* ktap current do not suppor pow arith */
+
+	n = number_foldarith(expr_numberV(e1), expr_numberV(e2),
+				(int)opr-OPR_ADD);
+	set_number(&o, n);
+	set_number(&e1->u.nval, n);
+	return 1;
+}
+
+/* Emit arithmetic operator. */
+static void bcemit_arith(FuncState *fs, BinOpr opr, ExpDesc *e1, ExpDesc *e2)
+{
+	BCReg rb, rc, t;
+	uint32_t op;
+
+	if (foldarith(opr, e1, e2))
+		return;
+	if (opr == OPR_POW) {
+		op = BC_POW;
+		rc = expr_toanyreg(fs, e2);
+		rb = expr_toanyreg(fs, e1);
+	} else {
+		op = opr-OPR_ADD+BC_ADDVV;
+		/*
+		 * Must discharge 2nd operand first since VINDEXED
+		 * might free regs.
+		 */
+		expr_toval(fs, e2);
+		if (expr_isnumk(e2) && (rc = const_num(fs, e2)) <= BCMAX_C)
+			op -= BC_ADDVV-BC_ADDVN;
+		else
+			rc = expr_toanyreg(fs, e2);
+		/* 1st operand discharged by bcemit_binop_left,
+		 * but need KNUM/KSHORT. */
+		kp_assert(expr_isnumk(e1) || e1->k == VNONRELOC);
+		expr_toval(fs, e1);
+		/* Avoid two consts to satisfy bytecode constraints. */
+		if (expr_isnumk(e1) && !expr_isnumk(e2) &&
+			(t = const_num(fs, e1)) <= BCMAX_B) {
+			rb = rc; rc = t; op -= BC_ADDVV-BC_ADDNV;
+		} else {
+			rb = expr_toanyreg(fs, e1);
+		}
+	}
+	/* Using expr_free might cause asserts if the order is wrong. */
+	if (e1->k == VNONRELOC && e1->u.s.info >= fs->nactvar)
+		fs->freereg--;
+	if (e2->k == VNONRELOC && e2->u.s.info >= fs->nactvar)
+		fs->freereg--;
+	e1->u.s.info = bcemit_ABC(fs, op, 0, rb, rc);
+	e1->k = VRELOCABLE;
+}
+
+/* Emit comparison operator. */
+static void bcemit_comp(FuncState *fs, BinOpr opr, ExpDesc *e1, ExpDesc *e2)
+{
+	ExpDesc *eret = e1;
+	BCIns ins;
+
+	expr_toval(fs, e1);
+	if (opr == OPR_EQ || opr == OPR_NE) {
+		BCOp op = opr == OPR_EQ ? BC_ISEQV : BC_ISNEV;
+		BCReg ra;
+
+		if (expr_isk(e1)) { /* Need constant in 2nd arg. */
+			e1 = e2;
+			e2 = eret;
+		}
+		ra = expr_toanyreg(fs, e1);  /* First arg must be in a reg. */
+		expr_toval(fs, e2);
+		switch (e2->k) {
+		case VKNIL: case VKFALSE: case VKTRUE:
+			ins = BCINS_AD(op+(BC_ISEQP-BC_ISEQV), ra,
+					const_pri(e2));
+			break;
+		case VKSTR:
+			ins = BCINS_AD(op+(BC_ISEQS-BC_ISEQV), ra,
+					const_str(fs, e2));
+			break;
+		case VKNUM:
+			ins = BCINS_AD(op+(BC_ISEQN-BC_ISEQV), ra,
+					const_num(fs, e2));
+			break;
+		default:
+			ins = BCINS_AD(op, ra, expr_toanyreg(fs, e2));
+			break;
+		}
+	} else {
+		uint32_t op = opr-OPR_LT+BC_ISLT;
+		BCReg ra, rd;
+		if ((op-BC_ISLT) & 1) {  /* GT -> LT, GE -> LE */
+			e1 = e2; e2 = eret;  /* Swap operands. */
+			op = ((op-BC_ISLT)^3)+BC_ISLT;
+			expr_toval(fs, e1);
+		}
+		rd = expr_toanyreg(fs, e2);
+		ra = expr_toanyreg(fs, e1);
+		ins = BCINS_AD(op, ra, rd);
+	}
+	/* Using expr_free might cause asserts if the order is wrong. */
+	if (e1->k == VNONRELOC && e1->u.s.info >= fs->nactvar)
+		fs->freereg--;
+	if (e2->k == VNONRELOC && e2->u.s.info >= fs->nactvar)
+		fs->freereg--;
+	bcemit_INS(fs, ins);
+	eret->u.s.info = bcemit_jmp(fs);
+	eret->k = VJMP;
+}
+
+/* Fixup left side of binary operator. */
+static void bcemit_binop_left(FuncState *fs, BinOpr op, ExpDesc *e)
+{
+	if (op == OPR_AND) {
+		bcemit_branch_t(fs, e);
+	} else if (op == OPR_OR) {
+		bcemit_branch_f(fs, e);
+	} else if (op == OPR_CONCAT) {
+		expr_tonextreg(fs, e);
+	} else if (op == OPR_EQ || op == OPR_NE) {
+		if (!expr_isk_nojump(e))
+			expr_toanyreg(fs, e);
+	} else {
+		if (!expr_isnumk_nojump(e))
+			expr_toanyreg(fs, e);
+	}
+}
+
+/* Emit binary operator. */
+static void bcemit_binop(FuncState *fs, BinOpr op, ExpDesc *e1, ExpDesc *e2)
+{
+	if (op <= OPR_POW) {
+		bcemit_arith(fs, op, e1, e2);
+	} else if (op == OPR_AND) {
+		kp_assert(e1->t == NO_JMP);  /* List must be closed. */
+		expr_discharge(fs, e2);
+		jmp_append(fs, &e2->f, e1->f);
+		*e1 = *e2;
+	} else if (op == OPR_OR) {
+		kp_assert(e1->f == NO_JMP);  /* List must be closed. */
+		expr_discharge(fs, e2);
+		jmp_append(fs, &e2->t, e1->t);
+		*e1 = *e2;
+	} else if (op == OPR_CONCAT) {
+		expr_toval(fs, e2);
+		if (e2->k == VRELOCABLE && bc_op(*bcptr(fs, e2)) == BC_CAT) {
+			kp_assert(e1->u.s.info == bc_b(*bcptr(fs, e2))-1);
+			expr_free(fs, e1);
+			setbc_b(bcptr(fs, e2), e1->u.s.info);
+			e1->u.s.info = e2->u.s.info;
+		} else {
+			expr_tonextreg(fs, e2);
+			expr_free(fs, e2);
+			expr_free(fs, e1);
+			e1->u.s.info = bcemit_ABC(fs, BC_CAT, 0, e1->u.s.info,
+								 e2->u.s.info);
+		}
+		e1->k = VRELOCABLE;
+	} else {
+		kp_assert(op == OPR_NE || op == OPR_EQ || op == OPR_LT ||
+			  op == OPR_GE || op == OPR_LE || op == OPR_GT);
+		bcemit_comp(fs, op, e1, e2);
+	}
+}
+
+/* Emit unary operator. */
+static void bcemit_unop(FuncState *fs, BCOp op, ExpDesc *e)
+{
+	if (op == BC_NOT) {
+		/* Swap true and false lists. */
+		{ BCPos temp = e->f; e->f = e->t; e->t = temp; }
+		jmp_dropval(fs, e->f);
+		jmp_dropval(fs, e->t);
+		expr_discharge(fs, e);
+		if (e->k == VKNIL || e->k == VKFALSE) {
+			e->k = VKTRUE;
+			return;
+		} else if (expr_isk(e)) {
+			e->k = VKFALSE;
+			return;
+		} else if (e->k == VJMP) {
+			invertcond(fs, e);
+			return;
+		} else if (e->k == VRELOCABLE) {
+			bcreg_reserve(fs, 1);
+			setbc_a(bcptr(fs, e), fs->freereg-1);
+			e->u.s.info = fs->freereg-1;
+			e->k = VNONRELOC;
+		} else {
+			kp_assert(e->k == VNONRELOC);
+		}
+	} else {
+		kp_assert(op == BC_UNM || op == BC_LEN);
+		/* Constant-fold negations. */
+		if (op == BC_UNM && !expr_hasjump(e)) {
+			/* Avoid folding to -0. */
+			if (expr_isnumk(e) && !expr_numiszero(e)) {
+				ktap_val_t *o = expr_numtv(e);
+				if (is_number(o))
+					set_number(o, -nvalue(o));
+				return;
+			}
+		}
+		expr_toanyreg(fs, e);
+	}
+	expr_free(fs, e);
+	e->u.s.info = bcemit_AD(fs, op, 0, e->u.s.info);
+	e->k = VRELOCABLE;
+}
+
+/* -- Lexer support ------------------------------------------------------- */
+
+/* Check and consume optional token. */
+static int lex_opt(LexState *ls, LexToken tok)
+{
+	if (ls->tok == tok) {
+		kp_lex_next(ls);
+		return 1;
+	}
+	return 0;
+}
+
+/* Check and consume token. */
+static void lex_check(LexState *ls, LexToken tok)
+{
+	if (ls->tok != tok)
+		err_token(ls, tok);
+	kp_lex_next(ls);
+}
+
+/* Check for matching token. */
+static void lex_match(LexState *ls, LexToken what, LexToken who, BCLine line)
+{
+	if (!lex_opt(ls, what)) {
+		if (line == ls->linenumber) {
+			err_token(ls, what);
+		} else {
+			const char *swhat = kp_lex_token2str(ls, what);
+			const char *swho = kp_lex_token2str(ls, who);
+			kp_lex_error(ls, ls->tok, KP_ERR_XMATCH, swhat, swho,
+								line);
+		}
+	}
+}
+
+/* Check for string token. */
+static ktap_str_t *lex_str(LexState *ls)
+{
+	ktap_str_t *s;
+
+	if (ls->tok != TK_name)
+		err_token(ls, TK_name);
+	s = rawtsvalue(&ls->tokval);
+	kp_lex_next(ls);
+	return s;
+}
+
+/* -- Variable handling --------------------------------------------------- */
+
+#define var_get(ls, fs, i)	((ls)->vstack[(fs)->varmap[(i)]])
+
+/* Define a new local variable. */
+static void var_new(LexState *ls, BCReg n, ktap_str_t *name)
+{
+	FuncState *fs = ls->fs;
+	int vtop = ls->vtop;
+
+	checklimit(fs, fs->nactvar+n, KP_MAX_LOCVAR, "local variables");
+	if (vtop >= ls->sizevstack) {
+		if (ls->sizevstack >= KP_MAX_VSTACK)
+			kp_lex_error(ls, 0, KP_ERR_XLIMC, KP_MAX_VSTACK);
+		if (!ls->vstack) {
+			ls->vstack = malloc(sizeof(VarInfo) * 20);
+			ls->sizevstack = 20;
+		} else {
+			ls->vstack = realloc(ls->vstack,
+				ls->sizevstack * sizeof(VarInfo) * 2);
+			ls->sizevstack = ls->sizevstack * 2;
+		}
+	}
+	kp_assert((uintptr_t)name < VARNAME__MAX ||
+			kp_tab_getstr(fs->kt, name) != NULL);
+	ls->vstack[vtop].name = name;
+	fs->varmap[fs->nactvar+n] = (uint16_t)vtop;
+	ls->vtop = vtop+1;
+}
+
+#define var_new_lit(ls, n, v) \
+	var_new(ls, (n), kp_parse_keepstr(ls, "" v, sizeof(v)-1))
+
+#define var_new_fixed(ls, n, vn) \
+	var_new(ls, (n), (ktap_str_t *)(uintptr_t)(vn))
+
+/* Add local variables. */
+static void var_add(LexState *ls, BCReg nvars)
+{
+	FuncState *fs = ls->fs;
+	BCReg nactvar = fs->nactvar;
+
+	while (nvars--) {
+		VarInfo *v = &var_get(ls, fs, nactvar);
+		v->startpc = fs->pc;
+		v->slot = nactvar++;
+		v->info = 0;
+	}
+	fs->nactvar = nactvar;
+}
+
+/* Remove local variables. */
+static void var_remove(LexState *ls, BCReg tolevel)
+{
+	FuncState *fs = ls->fs;
+	while (fs->nactvar > tolevel)
+		var_get(ls, fs, --fs->nactvar).endpc = fs->pc;
+}
+
+/* Lookup local variable name. */
+static BCReg var_lookup_local(FuncState *fs, ktap_str_t *n)
+{
+	int i;
+	
+	for (i = fs->nactvar-1; i >= 0; i--) {
+		if (n == var_get(fs->ls, fs, i).name)
+			return (BCReg)i;
+	}
+	return (BCReg)-1;  /* Not found. */
+}
+
+/* Lookup or add upvalue index. */
+static int var_lookup_uv(FuncState *fs, int vidx, ExpDesc *e)
+{
+	int i, n = fs->nuv;
+
+	for (i = 0; i < n; i++)
+		if (fs->uvmap[i] == vidx)
+			return i;  /* Already exists. */
+
+	/* Otherwise create a new one. */
+	checklimit(fs, fs->nuv, KP_MAX_UPVAL, "upvalues");
+	kp_assert(e->k == VLOCAL || e->k == VUPVAL);
+	fs->uvmap[n] = (uint16_t)vidx;
+	fs->uvtmp[n] = (uint16_t)(e->k == VLOCAL ? vidx :
+			KP_MAX_VSTACK+e->u.s.info);
+	fs->nuv = n+1;
+	return n;
+}
+
+/* Forward declaration. */
+static void fscope_uvmark(FuncState *fs, BCReg level);
+
+/* Recursively lookup variables in enclosing functions. */
+static int var_lookup_(FuncState *fs, ktap_str_t *name, ExpDesc *e,
+			 int first)
+{
+	if (fs) {
+		BCReg reg = var_lookup_local(fs, name);
+		if ((int32_t)reg >= 0) {  /* Local in this function? */
+			expr_init(e, VLOCAL, reg);
+			if (!first) {
+				/* Scope now has an upvalue. */
+				fscope_uvmark(fs, reg);
+			}
+			return (int)(e->u.s.aux = (uint32_t)fs->varmap[reg]);
+		} else {
+			/* Var in outer func? */
+			int vidx = var_lookup_(fs->prev, name, e, 0);
+			if ((int32_t)vidx >= 0) {
+				/* Yes, make it an upvalue here. */
+				e->u.s.info =
+					(uint8_t)var_lookup_uv(fs, vidx, e);
+				e->k = VUPVAL;
+				return vidx;
+			}
+		}
+	} else {  /* Not found in any function, must be a global. */
+		expr_init(e, VGLOBAL, 0);
+		e->u.sval = name;
+	}
+	return (int)-1;  /* Global. */
+}
+
+/* Lookup variable name. */
+#define var_lookup(ls, e) \
+	var_lookup_((ls)->fs, lex_str(ls), (e), 1)
+
+/* -- Goto an label handling ---------------------------------------------- */
+
+/* Add a new goto or label. */
+static int gola_new(LexState *ls, ktap_str_t *name, uint8_t info, BCPos pc)
+{
+	FuncState *fs = ls->fs;
+	int vtop = ls->vtop;
+
+	if (vtop >= ls->sizevstack) {
+		if (ls->sizevstack >= KP_MAX_VSTACK)
+			kp_lex_error(ls, 0, KP_ERR_XLIMC, KP_MAX_VSTACK);
+		if (!ls->vstack) {
+			ls->vstack = malloc(sizeof(VarInfo) * 20);
+			ls->sizevstack = 20;
+		} else {
+			ls->vstack = realloc(ls->vstack,
+					ls->sizevstack * sizeof(VarInfo) * 2);
+			ls->sizevstack = ls->sizevstack * 2;
+		}
+	}
+	kp_assert(name == NAME_BREAK ||
+		  kp_tab_getstr(fs->kt, name) != NULL);
+	ls->vstack[vtop].name = name;
+	ls->vstack[vtop].startpc = pc;
+	ls->vstack[vtop].slot = (uint8_t)fs->nactvar;
+	ls->vstack[vtop].info = info;
+	ls->vtop = vtop+1;
+	return vtop;
+}
+
+#define gola_isgoto(v)		((v)->info & VSTACK_GOTO)
+#define gola_islabel(v)		((v)->info & VSTACK_LABEL)
+#define gola_isgotolabel(v)	((v)->info & (VSTACK_GOTO|VSTACK_LABEL))
+
+/* Patch goto to jump to label. */
+static void gola_patch(LexState *ls, VarInfo *vg, VarInfo *vl)
+{
+	FuncState *fs = ls->fs;
+	BCPos pc = vg->startpc;
+
+	vg->name = NULL; /* Invalidate pending goto. */
+	setbc_a(&fs->bcbase[pc].ins, vl->slot);
+	jmp_patch(fs, pc, vl->startpc);
+}
+
+/* Patch goto to close upvalues. */
+static void gola_close(LexState *ls, VarInfo *vg)
+{
+	FuncState *fs = ls->fs;
+	BCPos pc = vg->startpc;
+	BCIns *ip = &fs->bcbase[pc].ins;
+	kp_assert(gola_isgoto(vg));
+	kp_assert(bc_op(*ip) == BC_JMP || bc_op(*ip) == BC_UCLO);
+	setbc_a(ip, vg->slot);
+	if (bc_op(*ip) == BC_JMP) {
+		BCPos next = jmp_next(fs, pc);
+		if (next != NO_JMP)
+			jmp_patch(fs, next, pc);  /* Jump to UCLO. */
+		setbc_op(ip, BC_UCLO);  /* Turn into UCLO. */
+		setbc_j(ip, NO_JMP);
+	}
+}
+
+/* Resolve pending forward gotos for label. */
+static void gola_resolve(LexState *ls, FuncScope *bl, int idx)
+{
+	VarInfo *vg = ls->vstack + bl->vstart;
+	VarInfo *vl = ls->vstack + idx;
+	for (; vg < vl; vg++)
+		if (vg->name == vl->name && gola_isgoto(vg)) {
+			if (vg->slot < vl->slot) {
+				ktap_str_t *name =
+					var_get(ls, ls->fs, vg->slot).name;
+				kp_assert((uintptr_t)name >= VARNAME__MAX);
+				ls->linenumber =
+					ls->fs->bcbase[vg->startpc].line;
+				kp_assert(vg->name != NAME_BREAK);
+				kp_lex_error(ls, 0, KP_ERR_XGSCOPE,
+				getstr(vg->name), getstr(name));
+			}
+			gola_patch(ls, vg, vl);
+		}
+}
+
+/* Fixup remaining gotos and labels for scope. */
+static void gola_fixup(LexState *ls, FuncScope *bl)
+{
+	VarInfo *v = ls->vstack + bl->vstart;
+	VarInfo *ve = ls->vstack + ls->vtop;
+
+	for (; v < ve; v++) {
+		ktap_str_t *name = v->name;
+		/* Only consider remaining valid gotos/labels. */
+		if (name != NULL) {
+			if (gola_islabel(v)) {
+				VarInfo *vg;
+				/* Invalidate label that goes out of scope. */
+				v->name = NULL;
+				/* Resolve pending backward gotos. */
+				for (vg = v+1; vg < ve; vg++)
+					if (vg->name == name &&
+						gola_isgoto(vg)) {
+						if ((bl->flags&FSCOPE_UPVAL) &&
+							 vg->slot > v->slot)
+							gola_close(ls, vg);
+						gola_patch(ls, vg, v);
+					}
+			} else if (gola_isgoto(v)) {
+				/* Propagate goto or break to outer scope. */
+				if (bl->prev) {
+					bl->prev->flags |= name == NAME_BREAK ? 						FSCOPE_BREAK : FSCOPE_GOLA;
+					v->slot = bl->nactvar;
+					if ((bl->flags & FSCOPE_UPVAL))
+						gola_close(ls, v);
+				} else {
+					ls->linenumber =
+					ls->fs->bcbase[v->startpc].line;
+					if (name == NAME_BREAK)
+						kp_lex_error(ls, 0, KP_ERR_XBREAK);
+					else
+						kp_lex_error(ls, 0, KP_ERR_XLUNDEF, getstr(name));
+				}
+			}
+		}
+	}
+}
+
+/* Find existing label. */
+static VarInfo *gola_findlabel(LexState *ls, ktap_str_t *name)
+{
+	VarInfo *v = ls->vstack + ls->fs->bl->vstart;
+	VarInfo *ve = ls->vstack + ls->vtop;
+
+	for (; v < ve; v++)
+		if (v->name == name && gola_islabel(v))
+			return v;
+	return NULL;
+}
+
+/* -- Scope handling ------------------------------------------------------ */
+
+/* Begin a scope. */
+static void fscope_begin(FuncState *fs, FuncScope *bl, int flags)
+{
+	bl->nactvar = (uint8_t)fs->nactvar;
+	bl->flags = flags;
+	bl->vstart = fs->ls->vtop;
+	bl->prev = fs->bl;
+	fs->bl = bl;
+	kp_assert(fs->freereg == fs->nactvar);
+}
+
+/* End a scope. */
+static void fscope_end(FuncState *fs)
+{
+	FuncScope *bl = fs->bl;
+	LexState *ls = fs->ls;
+
+	fs->bl = bl->prev;
+	var_remove(ls, bl->nactvar);
+	fs->freereg = fs->nactvar;
+	kp_assert(bl->nactvar == fs->nactvar);
+	if ((bl->flags & (FSCOPE_UPVAL|FSCOPE_NOCLOSE)) == FSCOPE_UPVAL)
+		bcemit_AJ(fs, BC_UCLO, bl->nactvar, 0);
+	if ((bl->flags & FSCOPE_BREAK)) {
+		if ((bl->flags & FSCOPE_LOOP)) {
+			int idx = gola_new(ls, NAME_BREAK, VSTACK_LABEL,
+						fs->pc);
+			ls->vtop = idx;  /* Drop break label immediately. */
+			gola_resolve(ls, bl, idx);
+			return;
+		}  /* else: need the fixup step to propagate the breaks. */
+	} else if (!(bl->flags & FSCOPE_GOLA)) {
+		return;
+	}
+	gola_fixup(ls, bl);
+}
+
+/* Mark scope as having an upvalue. */
+static void fscope_uvmark(FuncState *fs, BCReg level)
+{
+	FuncScope *bl;
+
+	for (bl = fs->bl; bl && bl->nactvar > level; bl = bl->prev);
+	if (bl)
+		bl->flags |= FSCOPE_UPVAL;
+}
+
+/* -- Function state management ------------------------------------------- */
+
+/* Fixup bytecode for prototype. */
+static void fs_fixup_bc(FuncState *fs, ktap_proto_t *pt, BCIns *bc, int n)
+{
+	BCInsLine *base = fs->bcbase;
+	int i;
+
+	pt->sizebc = n;
+	bc[0] = BCINS_AD((fs->flags & PROTO_VARARG) ? BC_FUNCV : BC_FUNCF,
+			 fs->framesize, 0);
+	for (i = 1; i < n; i++)
+		bc[i] = base[i].ins;
+}
+
+/* Fixup upvalues for child prototype, step #2. */
+static void fs_fixup_uv2(FuncState *fs, ktap_proto_t *pt)
+{
+	VarInfo *vstack = fs->ls->vstack;
+	uint16_t *uv = pt->uv;
+	int i, n = pt->sizeuv;
+
+	for (i = 0; i < n; i++) {
+		VarIndex vidx = uv[i];
+		if (vidx >= KP_MAX_VSTACK)
+			uv[i] = vidx - KP_MAX_VSTACK;
+		else if ((vstack[vidx].info & VSTACK_VAR_RW))
+			uv[i] = vstack[vidx].slot | PROTO_UV_LOCAL;
+		else
+			uv[i] = vstack[vidx].slot | PROTO_UV_LOCAL |
+					PROTO_UV_IMMUTABLE;
+	}
+}
+
+/* Fixup constants for prototype. */
+static void fs_fixup_k(FuncState *fs, ktap_proto_t *pt, void *kptr)
+{
+	ktap_tab_t *kt;
+	ktap_node_t *node;
+	int i, hmask;
+
+	checklimitgt(fs, fs->nkn, BCMAX_D+1, "constants");
+	checklimitgt(fs, fs->nkgc, BCMAX_D+1, "constants");
+
+	pt->k = kptr;
+	pt->sizekn = fs->nkn;
+	pt->sizekgc = fs->nkgc;
+	kt = fs->kt;
+	node = kt->node;
+	hmask = kt->hmask;
+	for (i = 0; i <= hmask; i++) {
+		ktap_node_t *n = &node[i];
+
+		if (tvhaskslot(&n->val)) {
+			ptrdiff_t kidx = (ptrdiff_t)tvkslot(&n->val);
+			kp_assert(!is_number(&n->key));
+			if (is_number(&n->key)) {
+				ktap_val_t *tv = &((ktap_val_t *)kptr)[kidx];
+				*tv = n->key;
+			} else {
+				ktap_obj_t *o = n->key.val.gc;
+				ktap_obj_t **v = (ktap_obj_t **)kptr;
+				v[~kidx] = o;
+				if (is_proto(&n->key))
+					fs_fixup_uv2(fs, (ktap_proto_t *)o);
+			}
+		}
+	}
+}
+
+/* Fixup upvalues for prototype, step #1. */
+static void fs_fixup_uv1(FuncState *fs, ktap_proto_t *pt, uint16_t *uv)
+{
+	pt->uv = uv;
+	pt->sizeuv = fs->nuv;
+	memcpy(uv, fs->uvtmp, fs->nuv*sizeof(VarIndex));
+}
+
+#ifndef KTAP_DISABLE_LINEINFO
+/* Prepare lineinfo for prototype. */
+static size_t fs_prep_line(FuncState *fs, BCLine numline)
+{
+	return (fs->pc-1) << (numline < 256 ? 0 : numline < 65536 ? 1 : 2);
+}
+
+/* Fixup lineinfo for prototype. */
+static void fs_fixup_line(FuncState *fs, ktap_proto_t *pt,
+			  void *lineinfo, BCLine numline)
+{
+	BCInsLine *base = fs->bcbase + 1;
+	BCLine first = fs->linedefined;
+	int i = 0, n = fs->pc-1;
+
+	pt->firstline = fs->linedefined;
+	pt->numline = numline;
+	pt->lineinfo = lineinfo;
+	if (numline < 256) {
+		uint8_t *li = (uint8_t *)lineinfo;
+		do {
+			BCLine delta = base[i].line - first;
+			kp_assert(delta >= 0 && delta < 256);
+			li[i] = (uint8_t)delta;
+		} while (++i < n);
+	} else if (numline < 65536) {
+		uint16_t *li = (uint16_t *)lineinfo;
+		do {
+			BCLine delta = base[i].line - first;
+			kp_assert(delta >= 0 && delta < 65536);
+			li[i] = (uint16_t)delta;
+		} while (++i < n);
+	} else {
+		uint32_t *li = (uint32_t *)lineinfo;
+		do {
+			BCLine delta = base[i].line - first;
+			kp_assert(delta >= 0);
+			li[i] = (uint32_t)delta;
+		} while (++i < n);
+	}
+}
+
+/* Prepare variable info for prototype. */
+static size_t fs_prep_var(LexState *ls, FuncState *fs, size_t *ofsvar)
+{
+	VarInfo *vs =ls->vstack, *ve;
+	int i, n;
+	BCPos lastpc;
+
+	kp_buf_reset(&ls->sb);  /* Copy to temp. string buffer. */
+	/* Store upvalue names. */
+	for (i = 0, n = fs->nuv; i < n; i++) {
+		ktap_str_t *s = vs[fs->uvmap[i]].name;
+		int len = s->len+1;
+		char *p = kp_buf_more(&ls->sb, len);
+		p = kp_buf_wmem(p, getstr(s), len);
+		setsbufP(&ls->sb, p);
+	}
+
+	*ofsvar = sbuflen(&ls->sb);
+	lastpc = 0;
+	/* Store local variable names and compressed ranges. */
+	for (ve = vs + ls->vtop, vs += fs->vbase; vs < ve; vs++) {
+		if (!gola_isgotolabel(vs)) {
+			ktap_str_t *s = vs->name;
+			BCPos startpc;
+			char *p;
+			if ((uintptr_t)s < VARNAME__MAX) {
+				p = kp_buf_more(&ls->sb, 1 + 2*5);
+				*p++ = (char)(uintptr_t)s;
+			} else {
+				int len = s->len+1;
+				p = kp_buf_more(&ls->sb, len + 2*5);
+				p = kp_buf_wmem(p, getstr(s), len);
+			}
+			startpc = vs->startpc;
+			p = strfmt_wuleb128(p, startpc-lastpc);
+			p = strfmt_wuleb128(p, vs->endpc-startpc);
+			setsbufP(&ls->sb, p);
+			lastpc = startpc;
+		}
+	}
+
+	kp_buf_putb(&ls->sb, '\0');  /* Terminator for varinfo. */
+	return sbuflen(&ls->sb);
+}
+
+/* Fixup variable info for prototype. */
+static void fs_fixup_var(LexState *ls, ktap_proto_t *pt, uint8_t *p,
+			 size_t ofsvar)
+{
+	pt->uvinfo = p;
+	pt->varinfo = (char *)p + ofsvar;
+	/* Copy from temp. buffer. */
+	memcpy(p, sbufB(&ls->sb), sbuflen(&ls->sb));
+}
+#else
+
+/* Initialize with empty debug info, if disabled. */
+#define fs_prep_line(fs, numline)		(UNUSED(numline), 0)
+#define fs_fixup_line(fs, pt, li, numline) \
+  pt->firstline = pt->numline = 0, (pt)->lineinfo = NULL
+#define fs_prep_var(ls, fs, ofsvar)		(UNUSED(ofsvar), 0)
+#define fs_fixup_var(ls, pt, p, ofsvar) \
+  (pt)->uvinfo = NULL, (pt)->varinfo = NULL
+
+#endif
+
+/* Check if bytecode op returns. */
+static int bcopisret(BCOp op)
+{
+	switch (op) {
+	case BC_CALLMT: case BC_CALLT:
+	case BC_RETM: case BC_RET: case BC_RET0: case BC_RET1:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+/* Fixup return instruction for prototype. */
+static void fs_fixup_ret(FuncState *fs)
+{
+	BCPos lastpc = fs->pc;
+
+	if (lastpc <= fs->lasttarget ||
+		!bcopisret(bc_op(fs->bcbase[lastpc-1].ins))) {
+		if ((fs->bl->flags & FSCOPE_UPVAL))
+			bcemit_AJ(fs, BC_UCLO, 0, 0);
+		bcemit_AD(fs, BC_RET0, 0, 1);  /* Need final return. */
+	}
+	fs->bl->flags |= FSCOPE_NOCLOSE;  /* Handled above. */
+	fscope_end(fs);
+	kp_assert(fs->bl == NULL);
+	/* May need to fixup returns encoded before first function
+	 * was created. */
+	if (fs->flags & PROTO_FIXUP_RETURN) {
+		BCPos pc;
+		for (pc = 1; pc < lastpc; pc++) {
+			BCIns ins = fs->bcbase[pc].ins;
+			BCPos offset;
+			switch (bc_op(ins)) {
+			case BC_CALLMT: case BC_CALLT:
+			case BC_RETM: case BC_RET: case BC_RET0: case BC_RET1:
+				/* Copy original instruction. */
+				offset = bcemit_INS(fs, ins);
+				fs->bcbase[offset].line = fs->bcbase[pc].line;
+				offset = offset-(pc+1)+BCBIAS_J;
+				if (offset > BCMAX_D)
+					err_syntax(fs->ls, KP_ERR_XFIXUP);
+				/* Replace with UCLO plus branch. */
+				fs->bcbase[pc].ins = BCINS_AD(BC_UCLO, 0,
+								offset);
+				break;
+			case BC_UCLO:
+				return;  /* We're done. */
+			default:
+				break;
+			}
+		}
+	}
+}
+
+/* Finish a FuncState and return the new prototype. */
+static ktap_proto_t *fs_finish(LexState *ls, BCLine line)
+{
+	FuncState *fs = ls->fs;
+	BCLine numline = line - fs->linedefined;
+	size_t sizept, ofsk, ofsuv, ofsli, ofsdbg, ofsvar;
+	ktap_proto_t *pt;
+
+	/* Apply final fixups. */
+	fs_fixup_ret(fs);
+
+	/* Calculate total size of prototype including all colocated arrays. */
+	sizept = sizeof(ktap_proto_t) + fs->pc*sizeof(BCIns) +
+			fs->nkgc*sizeof(ktap_obj_t *);
+	sizept = (sizept + sizeof(ktap_val_t)-1) & ~(sizeof(ktap_val_t)-1);
+	ofsk = sizept; sizept += fs->nkn*sizeof(ktap_val_t);
+	ofsuv = sizept; sizept += ((fs->nuv+1)&~1)*2;
+	ofsli = sizept; sizept += fs_prep_line(fs, numline);
+	ofsdbg = sizept; sizept += fs_prep_var(ls, fs, &ofsvar);
+
+	/* Allocate prototype and initialize its fields. */
+	pt = (ktap_proto_t *)malloc((int)sizept);
+	pt->gct = ~KTAP_TPROTO;
+	pt->sizept = (int)sizept;
+	pt->flags =
+		(uint8_t)(fs->flags & ~(PROTO_HAS_RETURN|PROTO_FIXUP_RETURN));
+	pt->numparams = fs->numparams;
+	pt->framesize = fs->framesize;
+	pt->chunkname = ls->chunkname;
+
+	/* Close potentially uninitialized gap between bc and kgc. */
+	*(uint32_t *)((char *)pt + ofsk - sizeof(ktap_obj_t *)*(fs->nkgc+1)) = 0;
+	fs_fixup_bc(fs, pt, (BCIns *)((char *)pt + sizeof(ktap_proto_t)), fs->pc);
+	fs_fixup_k(fs, pt, (void *)((char *)pt + ofsk));
+	fs_fixup_uv1(fs, pt, (uint16_t *)((char *)pt + ofsuv));
+	fs_fixup_line(fs, pt, (void *)((char *)pt + ofsli), numline);
+	fs_fixup_var(ls, pt, (uint8_t *)((char *)pt + ofsdbg), ofsvar);
+
+	ls->vtop = fs->vbase;  /* Reset variable stack. */
+	ls->fs = fs->prev;
+	kp_assert(ls->fs != NULL || ls->tok == TK_eof);
+	return pt;
+}
+
+/* Initialize a new FuncState. */
+static void fs_init(LexState *ls, FuncState *fs)
+{
+	fs->prev = ls->fs; ls->fs = fs;  /* Append to list. */
+	fs->ls = ls;
+	fs->vbase = ls->vtop;
+	fs->pc = 0;
+	fs->lasttarget = 0;
+	fs->jpc = NO_JMP;
+	fs->freereg = 0;
+	fs->nkgc = 0;
+	fs->nkn = 0;
+	fs->nactvar = 0;
+	fs->nuv = 0;
+	fs->bl = NULL;
+	fs->flags = 0;
+	fs->framesize = 1;  /* Minimum frame size. */
+	fs->kt = kp_tab_new();
+}
+
+/* -- Expressions --------------------------------------------------------- */
+
+/* Forward declaration. */
+static void expr(LexState *ls, ExpDesc *v);
+
+/* Return string expression. */
+static void expr_str(LexState *ls, ExpDesc *e)
+{
+	expr_init(e, VKSTR, 0);
+	e->u.sval = lex_str(ls);
+}
+
+#define checku8(x)     ((x) == (int32_t)(uint8_t)(x))
+
+/* Return index expression. */
+static void expr_index(FuncState *fs, ExpDesc *t, ExpDesc *e)
+{
+	/* Already called: expr_toval(fs, e). */
+	t->k = VINDEXED;
+	if (expr_isnumk(e)) {
+		ktap_number n = expr_numberV(e);
+		int32_t k = (int)n;
+		if (checku8(k) && n == (ktap_number)k) {
+			/* 256..511: const byte key */
+			t->u.s.aux = BCMAX_C+1+(uint32_t)k;
+			return;
+		}
+	} else if (expr_isstrk(e)) {
+		BCReg idx = const_str(fs, e);
+		if (idx <= BCMAX_C) {
+			/* -256..-1: const string key */
+			t->u.s.aux = ~idx;
+			return;
+		}
+	}
+	t->u.s.aux = expr_toanyreg(fs, e);  /* 0..255: register */
+}
+
+/* Parse index expression with named field. */
+static void expr_field(LexState *ls, ExpDesc *v)
+{
+	FuncState *fs = ls->fs;
+	ExpDesc key;
+
+	expr_toanyreg(fs, v);
+	kp_lex_next(ls);  /* Skip dot or colon. */
+	expr_str(ls, &key);
+	expr_index(fs, v, &key);
+}
+
+/* Parse index expression with brackets. */
+static void expr_bracket(LexState *ls, ExpDesc *v)
+{
+	kp_lex_next(ls);  /* Skip '['. */
+	expr(ls, v);
+	expr_toval(ls->fs, v);
+	lex_check(ls, ']');
+}
+
+/* Get value of constant expression. */
+static void expr_kvalue(ktap_val_t *v, ExpDesc *e)
+{
+	if (e->k <= VKTRUE) {
+		setitype(v, ~(uint32_t)e->k);
+	} else if (e->k == VKSTR) {
+		set_string(v, e->u.sval);
+	} else {
+		kp_assert(tvisnumber(expr_numtv(e)));
+		*v = *expr_numtv(e);
+	}
+}
+
+#define FLS(x)       ((uint32_t)(__builtin_clz(x)^31))
+#define hsize2hbits(s) ((s) ? ((s)==1 ? 1 : 1+FLS((uint32_t)((s)-1))) : 0)
+
+
+/* Parse table constructor expression. */
+static void expr_table(LexState *ls, ExpDesc *e)
+{
+	FuncState *fs = ls->fs;
+	BCLine line = ls->linenumber;
+	ktap_tab_t *t = NULL;
+	int vcall = 0, needarr = 0, fixt = 0;
+	uint32_t narr = 1;  /* First array index. */
+	uint32_t nhash = 0;  /* Number of hash entries. */
+	BCReg freg = fs->freereg;
+	BCPos pc = bcemit_AD(fs, BC_TNEW, freg, 0);
+
+	expr_init(e, VNONRELOC, freg);
+	bcreg_reserve(fs, 1);
+	freg++;
+	lex_check(ls, '{');
+	while (ls->tok != '}') {
+		ExpDesc key, val;
+		vcall = 0;
+		if (ls->tok == '[') {
+			expr_bracket(ls, &key);/* Already calls expr_toval. */
+			if (!expr_isk(&key))
+				expr_index(fs, e, &key);
+			if (expr_isnumk(&key) && expr_numiszero(&key))
+				needarr = 1;
+			else
+				nhash++;
+			lex_check(ls, '=');
+		} else if ((ls->tok == TK_name) &&
+				kp_lex_lookahead(ls) == '=') {
+			expr_str(ls, &key);
+			lex_check(ls, '=');
+			nhash++;
+		} else {
+			expr_init(&key, VKNUM, 0);
+			set_number(&key.u.nval, (int)narr);
+			narr++;
+			needarr = vcall = 1;
+		}
+		expr(ls, &val);
+		if (expr_isk(&key) && key.k != VKNIL &&
+			(key.k == VKSTR || expr_isk_nojump(&val))) {
+			ktap_val_t k, *v;
+			if (!t) {  /* Create template table on demand. */
+				BCReg kidx;
+				t = kp_tab_new();
+				kidx = const_gc(fs, obj2gco(t), KTAP_TTAB);
+				fs->bcbase[pc].ins = BCINS_AD(BC_TDUP, freg-1,
+								 kidx);
+			}
+			vcall = 0;
+			expr_kvalue(&k, &key);
+			v = kp_tab_set(t, &k);
+			/* Add const key/value to template table. */
+			if (expr_isk_nojump(&val)) {
+				expr_kvalue(v, &val);
+			} else {
+				/* Otherwise create dummy string key (avoids kp_tab_newkey). */
+				set_table(v, t);  /* Preserve key with table itself as value. */
+				fixt = 1;/* Fix this later, after all resizes. */
+				goto nonconst;
+			}
+		} else {
+ nonconst:
+			if (val.k != VCALL) {
+				expr_toanyreg(fs, &val);
+				vcall = 0;
+			}
+			if (expr_isk(&key))
+				expr_index(fs, e, &key);
+			bcemit_store(fs, e, &val);
+		}
+		fs->freereg = freg;
+		if (!lex_opt(ls, ',') && !lex_opt(ls, ';'))
+			break;
+	}
+	lex_match(ls, '}', '{', line);
+	if (vcall) {
+		BCInsLine *ilp = &fs->bcbase[fs->pc-1];
+		ExpDesc en;
+		kp_assert(bc_a(ilp->ins) == freg &&
+			bc_op(ilp->ins) == (narr > 256 ? BC_TSETV : BC_TSETB));
+		expr_init(&en, VKNUM, 0);
+		set_number(&en.u.nval, narr - 1);
+		if (narr > 256) { fs->pc--; ilp--; }
+		ilp->ins = BCINS_AD(BC_TSETM, freg, const_num(fs, &en));
+		setbc_b(&ilp[-1].ins, 0);
+	}
+	if (pc == fs->pc-1) {  /* Make expr relocable if possible. */
+		e->u.s.info = pc;
+		fs->freereg--;
+		e->k = VRELOCABLE;
+	} else {
+		e->k = VNONRELOC;  /* May have been changed by expr_index. */
+	}
+	if (!t) {  /* Construct TNEW RD: hhhhhaaaaaaaaaaa. */
+		BCIns *ip = &fs->bcbase[pc].ins;
+		if (!needarr) narr = 0;
+		else if (narr < 3) narr = 3;
+		else if (narr > 0x7ff) narr = 0x7ff;
+		setbc_d(ip, narr|(hsize2hbits(nhash)<<11));
+	} else {
+		if (fixt) {  /* Fix value for dummy keys in template table. */
+			ktap_node_t *node = t->node;
+			uint32_t i, hmask = t->hmask;
+			for (i = 0; i <= hmask; i++) {
+				ktap_node_t *n = &node[i];
+				if (is_table(&n->val)) {
+					kp_assert(tabV(&n->val) == t);
+					/* Turn value into nil. */
+					set_nil(&n->val);
+				}
+			}
+		}
+	}
+}
+
+/* Parse function parameters. */
+static BCReg parse_params(LexState *ls, int needself)
+{
+	FuncState *fs = ls->fs;
+	BCReg nparams = 0;
+	lex_check(ls, '(');
+	if (needself)
+		var_new_lit(ls, nparams++, "self");
+	if (ls->tok != ')') {
+		do {
+			if (ls->tok == TK_name) {
+				var_new(ls, nparams++, lex_str(ls));
+			} else if (ls->tok == TK_dots) {
+				kp_lex_next(ls);
+				fs->flags |= PROTO_VARARG;
+				break;
+			} else {
+				err_syntax(ls, KP_ERR_XPARAM);
+			}
+		} while (lex_opt(ls, ','));
+	}
+	var_add(ls, nparams);
+	kp_assert(fs->nactvar == nparams);
+	bcreg_reserve(fs, nparams);
+	lex_check(ls, ')');
+	return nparams;
+}
+
+/* Forward declaration. */
+static void parse_chunk(LexState *ls);
+
+/* Parse body of a function. */
+static void parse_body(LexState *ls, ExpDesc *e, int needself, BCLine line)
+{
+	FuncState fs, *pfs = ls->fs;
+	FuncScope bl;
+	ktap_proto_t *pt;
+	ptrdiff_t oldbase = pfs->bcbase - ls->bcstack;
+
+	fs_init(ls, &fs);
+	fscope_begin(&fs, &bl, 0);
+	fs.linedefined = line;
+	fs.numparams = (uint8_t)parse_params(ls, needself);
+	fs.bcbase = pfs->bcbase + pfs->pc;
+	fs.bclim = pfs->bclim - pfs->pc;
+	bcemit_AD(&fs, BC_FUNCF, 0, 0);  /* Placeholder. */
+	lex_check(ls, '{');
+	parse_chunk(ls);
+	lex_check(ls, '}');
+	pt = fs_finish(ls, (ls->lastline = ls->linenumber));
+	pfs->bcbase = ls->bcstack + oldbase;  /* May have been reallocated. */
+	pfs->bclim = (BCPos)(ls->sizebcstack - oldbase);
+	/* Store new prototype in the constant array of the parent. */
+	expr_init(e, VRELOCABLE,
+		bcemit_AD(pfs, BC_FNEW, 0,
+			  const_gc(pfs, (ktap_obj_t *)pt, KTAP_TPROTO)));
+	if (!(pfs->flags & PROTO_CHILD)) {
+		if (pfs->flags & PROTO_HAS_RETURN)
+			pfs->flags |= PROTO_FIXUP_RETURN;
+		pfs->flags |= PROTO_CHILD;
+	}
+	//kp_lex_next(ls);
+}
+
+/* Parse body of a function, for 'trace/trace_end/profile/tick' closure */
+static void parse_body_no_args(LexState *ls, ExpDesc *e, int needself,
+				BCLine line)
+{
+	FuncState fs, *pfs = ls->fs;
+	FuncScope bl;
+	ktap_proto_t *pt;
+	ptrdiff_t oldbase = pfs->bcbase - ls->bcstack;
+
+	fs_init(ls, &fs);
+	fscope_begin(&fs, &bl, 0);
+	fs.linedefined = line;
+	fs.numparams = 0;
+	fs.bcbase = pfs->bcbase + pfs->pc;
+	fs.bclim = pfs->bclim - pfs->pc;
+	bcemit_AD(&fs, BC_FUNCF, 0, 0);  /* Placeholder. */
+	lex_check(ls, '{');
+	parse_chunk(ls);
+	lex_check(ls, '}');
+	pt = fs_finish(ls, (ls->lastline = ls->linenumber));
+	pfs->bcbase = ls->bcstack + oldbase;  /* May have been reallocated. */
+	pfs->bclim = (BCPos)(ls->sizebcstack - oldbase);
+	/* Store new prototype in the constant array of the parent. */
+	expr_init(e, VRELOCABLE,
+		bcemit_AD(pfs, BC_FNEW, 0,
+			  const_gc(pfs, (ktap_obj_t *)pt, KTAP_TPROTO)));
+	if (!(pfs->flags & PROTO_CHILD)) {
+		if (pfs->flags & PROTO_HAS_RETURN)
+			pfs->flags |= PROTO_FIXUP_RETURN;
+		pfs->flags |= PROTO_CHILD;
+	}
+	//kp_lex_next(ls);
+}
+
+
+/* Parse expression list. Last expression is left open. */
+static BCReg expr_list(LexState *ls, ExpDesc *v)
+{
+	BCReg n = 1;
+
+	expr(ls, v);
+	while (lex_opt(ls, ',')) {
+		expr_tonextreg(ls->fs, v);
+		expr(ls, v);
+		n++;
+	}
+	return n;
+}
+
+/* Parse function argument list. */
+static void parse_args(LexState *ls, ExpDesc *e)
+{
+	FuncState *fs = ls->fs;
+	ExpDesc args;
+	BCIns ins;
+	BCReg base;
+	BCLine line = ls->linenumber;
+
+	if (ls->tok == '(') {
+		if (line != ls->lastline)
+			err_syntax(ls, KP_ERR_XAMBIG);
+		kp_lex_next(ls);
+		if (ls->tok == ')') {  /* f(). */
+			args.k = VVOID;
+		} else {
+			expr_list(ls, &args);
+			/* f(a, b, g()) or f(a, b, ...). */
+			if (args.k == VCALL) {
+				/* Pass on multiple results. */
+				setbc_b(bcptr(fs, &args), 0);
+			}
+		}
+		lex_match(ls, ')', '(', line);
+	} else if (ls->tok == '{') {
+		expr_table(ls, &args);
+	} else if (ls->tok == TK_string) {
+		expr_init(&args, VKSTR, 0);
+		args.u.sval = rawtsvalue(&ls->tokval);
+		kp_lex_next(ls);
+	} else {
+		err_syntax(ls, KP_ERR_XFUNARG);
+		return;  /* Silence compiler. */
+	}
+
+	kp_assert(e->k == VNONRELOC);
+	base = e->u.s.info;  /* Base register for call. */
+	if (args.k == VCALL) {
+		ins = BCINS_ABC(BC_CALLM, base, 2, args.u.s.aux - base - 1);
+	} else {
+		if (args.k != VVOID)
+			expr_tonextreg(fs, &args);
+		ins = BCINS_ABC(BC_CALL, base, 2, fs->freereg - base);
+	}
+	expr_init(e, VCALL, bcemit_INS(fs, ins));
+	e->u.s.aux = base;
+	fs->bcbase[fs->pc - 1].line = line;
+	fs->freereg = base+1;  /* Leave one result by default. */
+}
+
+/* Parse primary expression. */
+static void expr_primary(LexState *ls, ExpDesc *v)
+{
+	FuncState *fs = ls->fs;
+
+	/* Parse prefix expression. */
+	if (ls->tok == '(') {
+		BCLine line = ls->linenumber;
+		kp_lex_next(ls);
+		expr(ls, v);
+		lex_match(ls, ')', '(', line);
+		expr_discharge(ls->fs, v);
+	} else if (ls->tok == TK_name) {
+		var_lookup(ls, v);
+	} else {
+		err_syntax(ls, KP_ERR_XSYMBOL);
+	}
+
+	for (;;) {  /* Parse multiple expression suffixes. */
+		if (ls->tok == '.') {
+			expr_field(ls, v);
+		} else if (ls->tok == '[') {
+			ExpDesc key;
+			expr_toanyreg(fs, v);
+			expr_bracket(ls, &key);
+			expr_index(fs, v, &key);
+		} else if (ls->tok == ':') {
+			ExpDesc key;
+			kp_lex_next(ls);
+			expr_str(ls, &key);
+			bcemit_method(fs, v, &key);
+			parse_args(ls, v);
+		} else if (ls->tok == '(' || ls->tok == TK_string ||
+				ls->tok == '{') {
+			expr_tonextreg(fs, v);
+			parse_args(ls, v);
+		} else {
+			break;
+		}
+	}
+}
+
+/* Parse simple expression. */
+static void expr_simple(LexState *ls, ExpDesc *v)
+{
+	switch (ls->tok) {
+	case TK_number:
+		expr_init(v, VKNUM, 0);
+		set_obj(&v->u.nval, &ls->tokval);
+		break;
+	case TK_string:
+		expr_init(v, VKSTR, 0);
+		v->u.sval = rawtsvalue(&ls->tokval);
+		break;
+	case TK_nil:
+		expr_init(v, VKNIL, 0);
+		break;
+	case TK_true:
+		expr_init(v, VKTRUE, 0);
+		break;
+	case TK_false:
+		expr_init(v, VKFALSE, 0);
+		break;
+	case TK_dots: {  /* Vararg. */
+		FuncState *fs = ls->fs;
+		BCReg base;
+		checkcond(ls, fs->flags & PROTO_VARARG, KP_ERR_XDOTS);
+		bcreg_reserve(fs, 1);
+		base = fs->freereg-1;
+		expr_init(v, VCALL, bcemit_ABC(fs, BC_VARG, base, 2,
+		fs->numparams));
+		v->u.s.aux = base;
+		break;
+	}
+	case '{':  /* Table constructor. */
+		expr_table(ls, v);
+		return;
+	case TK_function:
+		kp_lex_next(ls);
+		parse_body(ls, v, 0, ls->linenumber);
+		return;
+	case TK_argstr:
+		expr_init(v, VARGSTR, 0);
+		break;
+	case TK_probename:
+		expr_init(v, VARGNAME, 0);
+		break;
+	case TK_arg0: case TK_arg1: case TK_arg2: case TK_arg3: case TK_arg4:
+	case TK_arg5: case TK_arg6: case TK_arg7: case TK_arg8: case TK_arg9:
+		expr_init(v, VARGN, ls->tok - TK_arg0);
+		break;
+	case TK_pid:
+		expr_init(v, VPID, 0);
+		break;
+	case TK_tid:
+		expr_init(v, VTID, 0);
+		break;
+	case TK_uid:
+		expr_init(v, VUID, 0);
+		break;
+	case TK_cpu:
+		expr_init(v, VCPU, 0);
+		break;
+	case TK_execname:
+		expr_init(v, VEXECNAME, 0);
+		break;
+	default:
+		expr_primary(ls, v);
+		return;
+	}
+	kp_lex_next(ls);
+}
+
+/* Manage syntactic levels to avoid blowing up the stack. */
+static void synlevel_begin(LexState *ls)
+{
+	if (++ls->level >= KP_MAX_XLEVEL)
+		kp_lex_error(ls, 0, KP_ERR_XLEVELS);
+}
+
+#define synlevel_end(ls)	((ls)->level--)
+
+/* Convert token to binary operator. */
+static BinOpr token2binop(LexToken tok)
+{
+	switch (tok) {
+	case '+':	return OPR_ADD;
+	case '-':	return OPR_SUB;
+	case '*':	return OPR_MUL;
+	case '/':	return OPR_DIV;
+	case '%':	return OPR_MOD;
+	case '^':	return OPR_POW;
+	case TK_concat: return OPR_CONCAT;
+	case TK_ne:	return OPR_NE;
+	case TK_eq:	return OPR_EQ;
+	case '<':	return OPR_LT;
+	case TK_le:	return OPR_LE;
+	case '>':	return OPR_GT;
+	case TK_ge:	return OPR_GE;
+	case TK_and:	return OPR_AND;
+	case TK_or:	return OPR_OR;
+	default:	return OPR_NOBINOPR;
+	}
+}
+
+/* Priorities for each binary operator. ORDER OPR. */
+static const struct {
+	uint8_t left;	/* Left priority. */
+	uint8_t right;	/* Right priority. */
+} priority[] = {
+	{6,6}, {6,6}, {7,7}, {7,7}, {7,7},	/* ADD SUB MUL DIV MOD */
+	{10,9}, {5,4},			/* POW CONCAT (right associative) */
+	{3,3}, {3,3},				/* EQ NE */
+	{3,3}, {3,3}, {3,3}, {3,3},		/* LT GE GT LE */
+	{2,2}, {1,1}				/* AND OR */
+};
+
+#define UNARY_PRIORITY		8  /* Priority for unary operators. */
+
+/* Forward declaration. */
+static BinOpr expr_binop(LexState *ls, ExpDesc *v, uint32_t limit);
+
+/* Parse unary expression. */
+static void expr_unop(LexState *ls, ExpDesc *v)
+{
+	BCOp op;
+	if (ls->tok == TK_not) {
+		op = BC_NOT;
+	} else if (ls->tok == '-') {
+		op = BC_UNM;
+#if 0 /* ktap don't support lua length operator '#' */
+	} else if (ls->tok == '#') {
+		op = BC_LEN;
+#endif
+	} else {
+		expr_simple(ls, v);
+		return;
+	}
+	kp_lex_next(ls);
+	expr_binop(ls, v, UNARY_PRIORITY);
+	bcemit_unop(ls->fs, op, v);
+}
+
+/* Parse binary expressions with priority higher than the limit. */
+static BinOpr expr_binop(LexState *ls, ExpDesc *v, uint32_t limit)
+{
+	BinOpr op;
+
+	synlevel_begin(ls);
+	expr_unop(ls, v);
+	op = token2binop(ls->tok);
+	while (op != OPR_NOBINOPR && priority[op].left > limit) {
+		ExpDesc v2;
+		BinOpr nextop;
+		kp_lex_next(ls);
+		bcemit_binop_left(ls->fs, op, v);
+		/* Parse binary expression with higher priority. */
+		nextop = expr_binop(ls, &v2, priority[op].right);
+		bcemit_binop(ls->fs, op, v, &v2);
+		op = nextop;
+	}
+	synlevel_end(ls);
+	return op;  /* Return unconsumed binary operator (if any). */
+}
+
+/* Parse expression. */
+static void expr(LexState *ls, ExpDesc *v)
+{
+	expr_binop(ls, v, 0);  /* Priority 0: parse whole expression. */
+}
+
+/* Assign expression to the next register. */
+static void expr_next(LexState *ls)
+{
+	ExpDesc e;
+	expr(ls, &e);
+	expr_tonextreg(ls->fs, &e);
+}
+
+/* Parse conditional expression. */
+static BCPos expr_cond(LexState *ls)
+{
+	ExpDesc v;
+
+	lex_check(ls, '(');
+	expr(ls, &v);
+	if (v.k == VKNIL)
+		v.k = VKFALSE;
+	bcemit_branch_t(ls->fs, &v);
+	lex_check(ls, ')');
+	return v.f;
+}
+
+/* -- Assignments --------------------------------------------------------- */
+
+/* List of LHS variables. */
+typedef struct LHSVarList {
+	ExpDesc v;			/* LHS variable. */
+	struct LHSVarList *prev;	/* Link to previous LHS variable. */
+} LHSVarList;
+
+/* Eliminate write-after-read hazards for local variable assignment. */
+static void assign_hazard(LexState *ls, LHSVarList *lh, const ExpDesc *v)
+{
+	FuncState *fs = ls->fs;
+	BCReg reg = v->u.s.info; /* Check against this variable. */
+	BCReg tmp = fs->freereg; /* Rename to this temp. register(if needed) */
+	int hazard = 0;
+
+	for (; lh; lh = lh->prev) {
+		if (lh->v.k == VINDEXED) {
+			if (lh->v.u.s.info == reg) {  /* t[i], t = 1, 2 */
+				hazard = 1;
+				lh->v.u.s.info = tmp;
+			}
+			if (lh->v.u.s.aux == reg) {  /* t[i], i = 1, 2 */
+				hazard = 1;
+				lh->v.u.s.aux = tmp;
+			}
+		}
+	}
+	if (hazard) {
+		/* Rename conflicting variable. */
+		bcemit_AD(fs, BC_MOV, tmp, reg);
+		bcreg_reserve(fs, 1);
+	}
+}
+
+/* Adjust LHS/RHS of an assignment. */
+static void assign_adjust(LexState *ls, BCReg nvars, BCReg nexps, ExpDesc *e)
+{
+	FuncState *fs = ls->fs;
+	int32_t extra = (int32_t)nvars - (int32_t)nexps;
+
+	if (e->k == VCALL) {
+		extra++;  /* Compensate for the VCALL itself. */
+		if (extra < 0)
+			extra = 0;
+		setbc_b(bcptr(fs, e), extra+1);  /* Fixup call results. */
+		if (extra > 1)
+			bcreg_reserve(fs, (BCReg)extra-1);
+	} else {
+		if (e->k != VVOID)
+			expr_tonextreg(fs, e);  /* Close last expression. */
+		if (extra > 0) {  /* Leftover LHS are set to nil. */
+			BCReg reg = fs->freereg;
+			bcreg_reserve(fs, (BCReg)extra);
+			bcemit_nil(fs, reg, (BCReg)extra);
+		}
+	}
+}
+
+/* Recursively parse assignment statement. */
+static void parse_assignment(LexState *ls, LHSVarList *lh, BCReg nvars)
+{
+	ExpDesc e;
+
+	checkcond(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
+			KP_ERR_XSYNTAX);
+	if (lex_opt(ls, ',')) {  /* Collect LHS list and recurse upwards. */
+		LHSVarList vl;
+		vl.prev = lh;
+		expr_primary(ls, &vl.v);
+		if (vl.v.k == VLOCAL)
+			assign_hazard(ls, lh, &vl.v);
+		checklimit(ls->fs, ls->level + nvars, KP_MAX_XLEVEL,
+				"variable names");
+		parse_assignment(ls, &vl, nvars+1);
+	} else {  /* Parse RHS. */
+		BCReg nexps;
+		int assign_incr = 1;
+
+		if (lex_opt(ls, '='))
+			assign_incr = 0;
+		else if (lex_opt(ls, TK_incr))
+			assign_incr = 1;
+		else
+			err_syntax(ls, KP_ERR_XSYMBOL);
+
+		nexps = expr_list(ls, &e);
+		if (nexps == nvars) {
+			if (e.k == VCALL) {
+				/* Vararg assignment. */
+				if (bc_op(*bcptr(ls->fs, &e)) == BC_VARG) {
+					ls->fs->freereg--;
+					e.k = VRELOCABLE;
+				} else {  /* Multiple call results. */
+					/* Base of call is not relocatable. */
+					e.u.s.info = e.u.s.aux;
+					e.k = VNONRELOC;
+				}
+			}
+			if (assign_incr == 0)
+				bcemit_store(ls->fs, &lh->v, &e);
+			else
+				bcemit_store_incr(ls->fs, &lh->v, &e);
+			return;
+		}
+		assign_adjust(ls, nvars, nexps, &e);
+		if (nexps > nvars) {
+			/* Drop leftover regs. */
+			ls->fs->freereg -= nexps - nvars;
+		}
+	}
+	/* Assign RHS to LHS and recurse downwards. */
+	expr_init(&e, VNONRELOC, ls->fs->freereg-1);
+	bcemit_store(ls->fs, &lh->v, &e);
+}
+
+/* Parse call statement or assignment. */
+static void parse_call_assign(LexState *ls)
+{
+	FuncState *fs = ls->fs;
+	LHSVarList vl;
+
+	expr_primary(ls, &vl.v);
+	if (vl.v.k == VCALL) {  /* Function call statement. */
+		setbc_b(bcptr(fs, &vl.v), 1);  /* No results. */
+	} else {  /* Start of an assignment. */
+		vl.prev = NULL;
+		parse_assignment(ls, &vl, 1);
+	}
+}
+
+/* Parse 'var'(local in lua) statement. */
+static void parse_local(LexState *ls)
+{
+	if (lex_opt(ls, TK_function)) {  /* Local function declaration. */
+		ExpDesc v, b;
+		FuncState *fs = ls->fs;
+		var_new(ls, 0, lex_str(ls));
+		expr_init(&v, VLOCAL, fs->freereg);
+		v.u.s.aux = fs->varmap[fs->freereg];
+		bcreg_reserve(fs, 1);
+		var_add(ls, 1);
+		parse_body(ls, &b, 0, ls->linenumber);
+		/* bcemit_store(fs, &v, &b) without setting VSTACK_VAR_RW. */
+		expr_free(fs, &b);
+		expr_toreg(fs, &b, v.u.s.info);
+		/* The upvalue is in scope, but the local is only valid 
+		 * after the store. */
+		var_get(ls, fs, fs->nactvar - 1).startpc = fs->pc;
+	} else {  /* Local variable declaration. */
+		ExpDesc e;
+		BCReg nexps, nvars = 0;
+		do {  /* Collect LHS. */
+			var_new(ls, nvars++, lex_str(ls));
+		} while (lex_opt(ls, ','));
+		if (lex_opt(ls, '=')) {  /* Optional RHS. */
+			nexps = expr_list(ls, &e);
+		} else {  /* Or implicitly set to nil. */
+			e.k = VVOID;
+			nexps = 0;
+		}
+		assign_adjust(ls, nvars, nexps, &e);
+		var_add(ls, nvars);
+	}
+}
+
+/* Parse 'function' statement. */
+static void parse_func(LexState *ls, BCLine line)
+{
+	FuncState *fs = ls->fs;
+	ExpDesc v, b;
+
+	kp_lex_next(ls);  /* Skip 'function'. */
+
+	/* function is declared as local */
+#if 1
+	var_new(ls, 0, lex_str(ls));
+	expr_init(&v, VLOCAL, fs->freereg);
+	v.u.s.aux = fs->varmap[fs->freereg];
+	bcreg_reserve(fs, 1);
+	var_add(ls, 1);
+	parse_body(ls, &b, 0, ls->linenumber);
+	/* bcemit_store(fs, &v, &b) without setting VSTACK_VAR_RW. */
+	expr_free(fs, &b);
+	expr_toreg(fs, &b, v.u.s.info);
+	/* The upvalue is in scope, but the local is only valid 
+	 * after the store. */
+	var_get(ls, fs, fs->nactvar - 1).startpc = fs->pc;
+
+#else
+	int needself = 0;
+
+	/* Parse function name. */
+	var_lookup(ls, &v);
+	while (ls->tok == '.')  /* Multiple dot-separated fields. */
+		expr_field(ls, &v);
+	if (ls->tok == ':') {  /* Optional colon to signify method call. */
+		needself = 1;
+		expr_field(ls, &v);
+	}
+	parse_body(ls, &b, needself, line);
+	fs = ls->fs;
+	bcemit_store(fs, &v, &b);
+	fs->bcbase[fs->pc - 1].line = line;  /* Set line for the store. */
+#endif
+}
+
+/* -- Control transfer statements ----------------------------------------- */
+
+/* Check for end of block. */
+static int parse_isend(LexToken tok)
+{
+	switch (tok) {
+	case TK_else: case TK_elseif: case TK_end: case TK_until: case TK_eof:
+	case '}':
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+/* Parse 'return' statement. */
+static void parse_return(LexState *ls)
+{
+	BCIns ins;
+	FuncState *fs = ls->fs;
+
+	kp_lex_next(ls);  /* Skip 'return'. */
+	fs->flags |= PROTO_HAS_RETURN;
+	if (parse_isend(ls->tok) || ls->tok == ';') {  /* Bare return. */
+		ins = BCINS_AD(BC_RET0, 0, 1);
+	} else {  /* Return with one or more values. */
+		ExpDesc e;  /* Receives the _last_ expression in the list. */
+		BCReg nret = expr_list(ls, &e);
+		if (nret == 1) {  /* Return one result. */
+			if (e.k == VCALL) {  /* Check for tail call. */
+				BCIns *ip = bcptr(fs, &e);
+				/* It doesn't pay off to add BC_VARGT just
+				 * for 'return ...'. */
+				if (bc_op(*ip) == BC_VARG)
+					goto notailcall;
+				fs->pc--;
+				ins = BCINS_AD(bc_op(*ip)-BC_CALL+BC_CALLT,
+						bc_a(*ip), bc_c(*ip));
+			} else { /* Can return the result from any register. */
+				ins = BCINS_AD(BC_RET1,
+					expr_toanyreg(fs, &e), 2);
+			}
+		} else {
+			if (e.k == VCALL) {/* Append all results from a call */
+ notailcall:
+				setbc_b(bcptr(fs, &e), 0);
+				ins = BCINS_AD(BC_RETM, fs->nactvar,
+						e.u.s.aux - fs->nactvar);
+			} else {
+				/* Force contiguous registers. */
+				expr_tonextreg(fs, &e);
+				ins = BCINS_AD(BC_RET, fs->nactvar, nret+1);
+			}
+		}
+	}
+	if (fs->flags & PROTO_CHILD) {
+		/* May need to close upvalues first. */
+		bcemit_AJ(fs, BC_UCLO, 0, 0);
+	}
+	bcemit_INS(fs, ins);
+}
+
+/* Parse 'break' statement. */
+static void parse_break(LexState *ls)
+{
+	ls->fs->bl->flags |= FSCOPE_BREAK;
+	gola_new(ls, NAME_BREAK, VSTACK_GOTO, bcemit_jmp(ls->fs));
+}
+
+/* Parse label. */
+static void parse_label(LexState *ls)
+{
+	FuncState *fs = ls->fs;
+	ktap_str_t *name;
+	int idx;
+
+	fs->lasttarget = fs->pc;
+	fs->bl->flags |= FSCOPE_GOLA;
+	kp_lex_next(ls);  /* Skip '::'. */
+	name = lex_str(ls);
+	if (gola_findlabel(ls, name))
+		kp_lex_error(ls, 0, KP_ERR_XLDUP, getstr(name));
+	idx = gola_new(ls, name, VSTACK_LABEL, fs->pc);
+	lex_check(ls, TK_label);
+	/* Recursively parse trailing statements: labels and ';'. */
+	for (;;) {
+		if (ls->tok == TK_label) {
+			synlevel_begin(ls);
+			parse_label(ls);
+			synlevel_end(ls);
+		} else if (ls->tok == ';') {
+			kp_lex_next(ls);
+		} else {
+			break;
+		}
+	}
+	/* Trailing label is considered to be outside of scope. */
+	if (parse_isend(ls->tok) && ls->tok != TK_until)
+		ls->vstack[idx].slot = fs->bl->nactvar;
+	gola_resolve(ls, fs->bl, idx);
+}
+
+/* -- Blocks, loops and conditional statements ---------------------------- */
+
+/* Parse a block. */
+static void parse_block(LexState *ls)
+{
+	FuncState *fs = ls->fs;
+	FuncScope bl;
+
+	fscope_begin(fs, &bl, 0);
+	parse_chunk(ls);
+	fscope_end(fs);
+}
+
+/* Parse 'while' statement. */
+static void parse_while(LexState *ls, BCLine line)
+{
+	FuncState *fs = ls->fs;
+	BCPos start, loop, condexit;
+	FuncScope bl;
+
+	kp_lex_next(ls);  /* Skip 'while'. */
+	start = fs->lasttarget = fs->pc;
+	condexit = expr_cond(ls);
+	fscope_begin(fs, &bl, FSCOPE_LOOP);
+	//lex_check(ls, TK_do);
+	lex_check(ls, '{');
+	loop = bcemit_AD(fs, BC_LOOP, fs->nactvar, 0);
+	parse_block(ls);
+	jmp_patch(fs, bcemit_jmp(fs), start);
+	//lex_match(ls, TK_end, TK_while, line);
+	lex_check(ls, '}');
+	fscope_end(fs);
+	jmp_tohere(fs, condexit);
+	jmp_patchins(fs, loop, fs->pc);
+}
+
+/* Parse 'repeat' statement. */
+static void parse_repeat(LexState *ls, BCLine line)
+{
+	FuncState *fs = ls->fs;
+	BCPos loop = fs->lasttarget = fs->pc;
+	BCPos condexit;
+	FuncScope bl1, bl2;
+
+	fscope_begin(fs, &bl1, FSCOPE_LOOP);  /* Breakable loop scope. */
+	fscope_begin(fs, &bl2, 0);  /* Inner scope. */
+	kp_lex_next(ls);  /* Skip 'repeat'. */
+	bcemit_AD(fs, BC_LOOP, fs->nactvar, 0);
+	parse_chunk(ls);
+	lex_match(ls, TK_until, TK_repeat, line);
+	/* Parse condition (still inside inner scope). */
+	condexit = expr_cond(ls);
+	/* No upvalues? Just end inner scope. */
+	if (!(bl2.flags & FSCOPE_UPVAL)) {
+		fscope_end(fs);
+	} else {
+		/* Otherwise generate: cond: UCLO+JMP out,
+		 * !cond: UCLO+JMP loop. */
+		parse_break(ls);  /* Break from loop and close upvalues. */
+		jmp_tohere(fs, condexit);
+		fscope_end(fs);  /* End inner scope and close upvalues. */
+		condexit = bcemit_jmp(fs);
+	}
+	jmp_patch(fs, condexit, loop);  /* Jump backwards if !cond. */
+	jmp_patchins(fs, loop, fs->pc);
+	fscope_end(fs);  /* End loop scope. */
+}
+
+/* Parse numeric 'for'. */
+static void parse_for_num(LexState *ls, ktap_str_t *varname, BCLine line)
+{
+	FuncState *fs = ls->fs;
+	BCReg base = fs->freereg;
+	FuncScope bl;
+	BCPos loop, loopend;
+
+	/* Hidden control variables. */
+	var_new_fixed(ls, FORL_IDX, VARNAME_FOR_IDX);
+	var_new_fixed(ls, FORL_STOP, VARNAME_FOR_STOP);
+	var_new_fixed(ls, FORL_STEP, VARNAME_FOR_STEP);
+	/* Visible copy of index variable. */
+	var_new(ls, FORL_EXT, varname);
+	lex_check(ls, '=');
+	expr_next(ls);
+	lex_check(ls, ',');
+	expr_next(ls);
+	if (lex_opt(ls, ',')) {
+		expr_next(ls);
+	} else {
+		/* Default step is 1. */
+		bcemit_AD(fs, BC_KSHORT, fs->freereg, 1);
+		bcreg_reserve(fs, 1);
+	}
+	var_add(ls, 3);  /* Hidden control variables. */
+	//lex_check(ls, TK_do);
+	lex_check(ls, ')');
+	lex_check(ls, '{');
+	loop = bcemit_AJ(fs, BC_FORI, base, NO_JMP);
+	fscope_begin(fs, &bl, 0);  /* Scope for visible variables. */
+	var_add(ls, 1);
+	bcreg_reserve(fs, 1);
+	parse_block(ls);
+	fscope_end(fs);
+	/* Perform loop inversion. Loop control instructions are at the end. */
+	loopend = bcemit_AJ(fs, BC_FORL, base, NO_JMP);
+	fs->bcbase[loopend].line = line;  /* Fix line for control ins. */
+	jmp_patchins(fs, loopend, loop+1);
+	jmp_patchins(fs, loop, fs->pc);
+}
+
+/*
+ * Try to predict whether the iterator is next() and specialize the bytecode.
+ * Detecting next() and pairs() by name is simplistic, but quite effective.
+ * The interpreter backs off if the check for the closure fails at runtime.
+ */
+static int predict_next(LexState *ls, FuncState *fs, BCPos pc)
+{
+	BCIns ins = fs->bcbase[pc].ins;
+	ktap_str_t *name;
+	const ktap_val_t *o;
+
+	switch (bc_op(ins)) {
+	case BC_MOV:
+		name = var_get(ls, fs, bc_d(ins)).name;
+		break;
+	case BC_UGET:
+		name = ls->vstack[fs->uvmap[bc_d(ins)]].name;
+		break;
+	case BC_GGET:
+		/* There's no inverse index (yet), so lookup the strings. */
+		o = kp_tab_getstr(fs->kt, kp_str_newz("pairs"));
+		if (o && tvhaskslot(o) && tvkslot(o) == bc_d(ins))
+			return 1;
+		o = kp_tab_getstr(fs->kt, kp_str_newz("next"));
+		if (o && tvhaskslot(o) && tvkslot(o) == bc_d(ins))
+			return 1;
+		return 0;
+	default:
+		return 0;
+	}
+
+	return (name->len == 5 && !strcmp(getstr(name), "pairs")) ||
+		(name->len == 4 && !strcmp(getstr(name), "next"));
+}
+
+/* Parse 'for' iterator. */
+static void parse_for_iter(LexState *ls, ktap_str_t *indexname)
+{
+	FuncState *fs = ls->fs;
+	ExpDesc e;
+	BCReg nvars = 0;
+	BCLine line;
+	BCReg base = fs->freereg + 3;
+	BCPos loop, loopend, exprpc = fs->pc;
+	FuncScope bl;
+	int isnext;
+
+	/* Hidden control variables. */
+	var_new_fixed(ls, nvars++, VARNAME_FOR_GEN);
+	var_new_fixed(ls, nvars++, VARNAME_FOR_STATE);
+	var_new_fixed(ls, nvars++, VARNAME_FOR_CTL);
+
+	/* Visible variables returned from iterator. */
+	var_new(ls, nvars++, indexname);
+	while (lex_opt(ls, ','))
+		var_new(ls, nvars++, lex_str(ls));
+	lex_check(ls, TK_in);
+	line = ls->linenumber;
+	assign_adjust(ls, 3, expr_list(ls, &e), &e);
+	/* The iterator needs another 3 slots (func + 2 args). */
+	bcreg_bump(fs, 3);
+	isnext = (nvars <= 5 && predict_next(ls, fs, exprpc));
+	var_add(ls, 3);  /* Hidden control variables. */
+	//lex_check(ls, TK_do);
+	lex_check(ls, ')');
+	lex_check(ls, '{');
+	loop = bcemit_AJ(fs, isnext ? BC_ISNEXT : BC_JMP, base, NO_JMP);
+	fscope_begin(fs, &bl, 0);  /* Scope for visible variables. */
+	var_add(ls, nvars-3);
+	bcreg_reserve(fs, nvars-3);
+	parse_block(ls);
+	fscope_end(fs);
+	/* Perform loop inversion. Loop control instructions are at the end. */
+	jmp_patchins(fs, loop, fs->pc);
+	bcemit_ABC(fs, isnext ? BC_ITERN : BC_ITERC, base, nvars-3+1, 2+1);
+	loopend = bcemit_AJ(fs, BC_ITERL, base, NO_JMP);
+	fs->bcbase[loopend-1].line = line;  /* Fix line for control ins. */
+	fs->bcbase[loopend].line = line;
+	jmp_patchins(fs, loopend, loop+1);
+}
+
+/* Parse 'for' statement. */
+static void parse_for(LexState *ls, BCLine line)
+{
+	FuncState *fs = ls->fs;
+	ktap_str_t *varname;
+	FuncScope bl;
+
+	fscope_begin(fs, &bl, FSCOPE_LOOP);
+	kp_lex_next(ls);  /* Skip 'for'. */
+	lex_check(ls, '(');
+	varname = lex_str(ls);  /* Get first variable name. */
+	if (ls->tok == '=')
+		parse_for_num(ls, varname, line);
+	else if (ls->tok == ',' || ls->tok == TK_in)
+		parse_for_iter(ls, varname);
+	else
+		err_syntax(ls, KP_ERR_XFOR);
+	//lex_check(ls, '}');
+	//lex_match(ls, TK_end, TK_for, line);
+	lex_match(ls, '}', TK_for, line);
+	fscope_end(fs);  /* Resolve break list. */
+}
+
+/* Parse condition and 'then' block. */
+static BCPos parse_then(LexState *ls)
+{
+	BCPos condexit;
+	kp_lex_next(ls);  /* Skip 'if' or 'elseif'. */
+	condexit = expr_cond(ls);
+	lex_check(ls, '{');
+	parse_block(ls);
+	lex_check(ls, '}');
+	return condexit;
+}
+
+/* Parse 'if' statement. */
+static void parse_if(LexState *ls, BCLine line)
+{
+	FuncState *fs = ls->fs;
+	BCPos flist;
+	BCPos escapelist = NO_JMP;
+	flist = parse_then(ls);
+	while (ls->tok == TK_elseif) {  /* Parse multiple 'elseif' blocks. */
+		jmp_append(fs, &escapelist, bcemit_jmp(fs));
+		jmp_tohere(fs, flist);
+		flist = parse_then(ls);
+	}
+	if (ls->tok == TK_else) {  /* Parse optional 'else' block. */
+		jmp_append(fs, &escapelist, bcemit_jmp(fs));
+		jmp_tohere(fs, flist);
+		kp_lex_next(ls);  /* Skip 'else'. */
+		lex_check(ls, '{');
+		parse_block(ls);
+		lex_check(ls, '}');
+	} else {
+		jmp_append(fs, &escapelist, flist);
+	}
+	jmp_tohere(fs, escapelist);
+	//lex_match(ls, TK_end, TK_if, line);
+}
+
+/* Parse 'trace' and 'trace_end' statement. */
+static void parse_trace(LexState *ls)
+{
+	ExpDesc v, key, args;
+	ktap_str_t *kdebug_str = kp_str_newz("kdebug");
+	ktap_str_t *probe_str = kp_str_newz("trace_by_id");
+	ktap_str_t *probe_end_str = kp_str_newz("trace_end");
+	FuncState *fs = ls->fs;
+	int token = ls->tok;
+	BCIns ins;
+	BCReg base;
+	BCLine line = ls->linenumber;
+
+	if (token == TK_trace)
+		kp_lex_read_string_until(ls, '{');
+	else
+		kp_lex_next(ls);  /* skip "trace_end" keyword */
+
+	/* kdebug */
+	expr_init(&v, VGLOBAL, 0);
+	v.u.sval = kdebug_str;
+	expr_toanyreg(fs, &v);
+
+	/* fieldsel: kdebug.probe */
+	expr_init(&key, VKSTR, 0);
+	key.u.sval = token == TK_trace ? probe_str : probe_end_str;
+	expr_index(fs, &v, &key);
+
+	/* funcargs*/
+	expr_tonextreg(fs, &v);
+
+	if (token == TK_trace) {
+		ktap_eventdesc_t *evdef_info;
+		const char *str;
+
+		/* argument: EVENTDEF string */
+		lex_check(ls, TK_string);
+		str = svalue(&ls->tokval);
+		evdef_info = kp_parse_events(str);
+		if (!evdef_info)
+			kp_lex_error(ls, 0, KP_ERR_XEVENTDEF, str);
+
+
+		/* pass a userspace pointer to kernel */
+		expr_init(&args, VKNUM, 0);
+		set_number(&args.u.nval, (ktap_number)evdef_info);
+
+		expr_tonextreg(fs, &args);
+	}
+
+	/* argument: callback function */
+	parse_body_no_args(ls, &args, 0, ls->linenumber);
+
+	expr_tonextreg(fs, &args);
+
+	base = v.u.s.info;  /* base register for call */
+	ins = BCINS_ABC(BC_CALL, base, 2, fs->freereg - base);
+
+	expr_init(&v, VCALL, bcemit_INS(fs, ins));
+	v.u.s.aux = base;
+	fs->bcbase[fs->pc - 1].line = line;
+	fs->freereg = base+1;  /* Leave one result by default. */
+
+	setbc_b(bcptr(fs, &v), 1);  /* No results. */
+}
+
+
+/* Parse 'profile' and 'tick' statement. */
+static void parse_timer(LexState *ls)
+{
+	FuncState *fs = ls->fs;
+	ExpDesc v, key, args;
+	ktap_str_t *token_str = rawtsvalue(&ls->tokval);
+	ktap_str_t *interval_str;
+	BCLine line = ls->linenumber;
+	BCIns ins;
+	BCReg base;
+
+	kp_lex_next(ls);  /* skip '-' */
+
+	kp_lex_read_string_until(ls, '{');
+	interval_str = rawtsvalue(&ls->tokval);
+	lex_check(ls, TK_string);
+
+	/* timer */
+	expr_init(&v, VGLOBAL, 0);
+	v.u.sval = kp_str_newz("timer");
+	expr_toanyreg(fs, &v);
+
+	/* fieldsel: timer.profile, timer.tick */
+	expr_init(&key, VKSTR, 0);
+	key.u.sval = token_str;
+	expr_index(fs, &v, &key);
+
+	/* funcargs*/
+	expr_tonextreg(fs, &v);
+
+	/* argument: interval string */
+	expr_init(&args, VKSTR, 0);
+	args.u.sval = interval_str;
+
+	expr_tonextreg(fs, &args);
+
+	/* argument: callback function */
+	parse_body_no_args(ls, &args, 0, ls->linenumber);
+
+	expr_tonextreg(fs, &args);
+
+	base = v.u.s.info;  /* base register for call */
+	ins = BCINS_ABC(BC_CALL, base, 2, fs->freereg - base);
+
+	expr_init(&v, VCALL, bcemit_INS(fs, ins));
+	v.u.s.aux = base;
+	fs->bcbase[fs->pc - 1].line = line;
+	fs->freereg = base+1;  /* Leave one result by default. */
+
+	setbc_b(bcptr(fs, &v), 1);  /* No results. */
+}
+
+/* -- Parse statements ---------------------------------------------------- */
+
+/* Parse a statement. Returns 1 if it must be the last one in a chunk. */
+static int parse_stmt(LexState *ls)
+{
+	BCLine line = ls->linenumber;
+	switch (ls->tok) {
+	case TK_if:
+		parse_if(ls, line);
+		break;
+	case TK_while:
+		parse_while(ls, line);
+		break;
+	case TK_do:
+		kp_lex_next(ls);
+		parse_block(ls);
+		lex_match(ls, TK_end, TK_do, line);
+		break;
+	case TK_for:
+		parse_for(ls, line);
+		break;
+	case TK_repeat:
+		parse_repeat(ls, line);
+		break;
+	case TK_function:
+		parse_func(ls, line);
+		break;
+	case TK_local:
+		kp_lex_next(ls);
+		parse_local(ls);
+		break;
+	case TK_return:
+		parse_return(ls);
+		return 1;  /* Must be last. */
+	case TK_break:
+		kp_lex_next(ls);
+		parse_break(ls);
+		return 0;  /* Must be last. */
+	case ';':
+		kp_lex_next(ls);
+		break;
+	case TK_label:
+		parse_label(ls);
+		break;
+	case TK_trace:
+	case TK_trace_end:
+		parse_trace(ls);
+		break;
+	case TK_profile:
+	case TK_tick:
+		parse_timer(ls);
+		break;
+	default:
+		parse_call_assign(ls);
+		break;
+	}
+	return 0;
+}
+
+/* A chunk is a list of statements optionally separated by semicolons. */
+static void parse_chunk(LexState *ls)
+{
+	int islast = 0;
+
+	synlevel_begin(ls);
+	while (!islast && !parse_isend(ls->tok)) {
+		islast = parse_stmt(ls);
+		lex_opt(ls, ';');
+		kp_assert(ls->fs->framesize >= ls->fs->freereg &&
+			ls->fs->freereg >= ls->fs->nactvar);
+		/* Free registers after each stmt. */
+		ls->fs->freereg = ls->fs->nactvar;
+	}
+	synlevel_end(ls);
+}
+
+/* Entry point of bytecode parser. */
+ktap_proto_t *kp_parse(LexState *ls)
+{
+	FuncState fs;
+	FuncScope bl;
+	ktap_proto_t *pt;
+
+	ls->chunkname = kp_str_newz(ls->chunkarg);
+	ls->level = 0;
+	fs_init(ls, &fs);
+	fs.linedefined = 0;
+	fs.numparams = 0;
+	fs.bcbase = NULL;
+	fs.bclim = 0;
+	fs.flags |= PROTO_VARARG;  /* Main chunk is always a vararg func. */
+	fscope_begin(&fs, &bl, 0);
+	bcemit_AD(&fs, BC_FUNCV, 0, 0);  /* Placeholder. */
+	kp_lex_next(ls);  /* Read-ahead first token. */
+	parse_chunk(ls);
+	if (ls->tok != TK_eof)
+		err_token(ls, TK_eof);
+	pt = fs_finish(ls, ls->linenumber);
+	kp_assert(fs.prev == NULL);
+	kp_assert(ls->fs == NULL);
+	kp_assert(pt->sizeuv == 0);
+	return pt;
+}
+
diff --git a/tools/ktap/kp_parse.h b/tools/ktap/kp_parse.h
new file mode 100644
index 0000000..90d27cb
--- /dev/null
+++ b/tools/ktap/kp_parse.h
@@ -0,0 +1,4 @@
+
+ktap_proto_t *kp_parse(LexState *ls);
+ktap_str_t *kp_parse_keepstr(LexState *ls, const char *str, size_t l);
+
-- 
1.8.1.4

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