[lttng-tools.git] / src / lib / lttng-ctl / filter-parser.y

%{
/*
 * filter-parser.y
 *
 * LTTng filter expression parser
 *
 * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License, version 2.1 only,
 * as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * Grammar inspired from http://www.quut.com/c/ANSI-C-grammar-y.html
 */

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include "filter-ast.h"
#include "filter-parser.h"

__attribute__((visibility("protected")))
int yydebug;
int filter_parser_debug = 0;

__attribute__((visibility("protected")))
int yyparse(struct filter_parser_ctx *parser_ctx);
__attribute__((visibility("protected")))
int yylex(union YYSTYPE *yyval, struct filter_parser_ctx *parser_ctx);
__attribute__((visibility("protected")))
int yylex_init_extra(struct filter_parser_ctx *parser_ctx, yyscan_t * ptr_yy_globals);
__attribute__((visibility("protected")))
int yylex_destroy(yyscan_t yyparser_ctx);
__attribute__((visibility("protected")))
void yyrestart(FILE * in_str, yyscan_t parser_ctx);

struct gc_string {
	struct cds_list_head gc;
	size_t alloclen;
	char s[];
};

static const char *node_type_to_str[] = {
	[ NODE_UNKNOWN ] = "NODE_UNKNOWN",
	[ NODE_ROOT ] = "NODE_ROOT",
	[ NODE_EXPRESSION ] = "NODE_EXPRESSION",
	[ NODE_OP ] = "NODE_OP",
	[ NODE_UNARY_OP ] = "NODE_UNARY_OP",
};

__attribute__((visibility("protected")))
const char *node_type(struct filter_node *node)
{
	if (node->type < NR_NODE_TYPES)
		return node_type_to_str[node->type];
	else
		return NULL;
}

static struct gc_string *gc_string_alloc(struct filter_parser_ctx *parser_ctx,
					 size_t len)
{
	struct gc_string *gstr;
	size_t alloclen;

	/* TODO: could be faster with find first bit or glib Gstring */
	/* sizeof long to account for malloc header (int or long ?) */
	for (alloclen = 8; alloclen < sizeof(long) + sizeof(*gstr) + len;
	     alloclen *= 2);

	gstr = malloc(alloclen);
	cds_list_add(&gstr->gc, &parser_ctx->allocated_strings);
	gstr->alloclen = alloclen;
	return gstr;
}

/*
 * note: never use gc_string_append on a string that has external references.
 * gsrc will be garbage collected immediately, and gstr might be.
 * Should only be used to append characters to a string literal or constant.
 */
__attribute__((visibility("protected")))
struct gc_string *gc_string_append(struct filter_parser_ctx *parser_ctx,
				   struct gc_string *gstr,
				   struct gc_string *gsrc)
{
	size_t newlen = strlen(gsrc->s) + strlen(gstr->s) + 1;
	size_t alloclen;

	/* TODO: could be faster with find first bit or glib Gstring */
	/* sizeof long to account for malloc header (int or long ?) */
	for (alloclen = 8; alloclen < sizeof(long) + sizeof(*gstr) + newlen;
	     alloclen *= 2);

	if (alloclen > gstr->alloclen) {
		struct gc_string *newgstr;

		newgstr = gc_string_alloc(parser_ctx, newlen);
		strcpy(newgstr->s, gstr->s);
		strcat(newgstr->s, gsrc->s);
		cds_list_del(&gstr->gc);
		free(gstr);
		gstr = newgstr;
	} else {
		strcat(gstr->s, gsrc->s);
	}
	cds_list_del(&gsrc->gc);
	free(gsrc);
	return gstr;
}

__attribute__((visibility("protected")))
void setstring(struct filter_parser_ctx *parser_ctx, YYSTYPE *lvalp, const char *src)
{
	lvalp->gs = gc_string_alloc(parser_ctx, strlen(src) + 1);
	strcpy(lvalp->gs->s, src);
}

static struct filter_node *make_node(struct filter_parser_ctx *scanner,
				  enum node_type type)
{
	struct filter_ast *ast = filter_parser_get_ast(scanner);
	struct filter_node *node;

	node = malloc(sizeof(*node));
	if (!node)
		return NULL;
	memset(node, 0, sizeof(*node));
	node->type = type;
	cds_list_add(&node->gc, &ast->allocated_nodes);

	switch (type) {
	case NODE_ROOT:
		fprintf(stderr, "[error] %s: trying to create root node\n", __func__);
		break;

	case NODE_EXPRESSION:
		break;
	case NODE_OP:
		break;
	case NODE_UNARY_OP:
		break;

	case NODE_UNKNOWN:
	default:
		fprintf(stderr, "[error] %s: unknown node type %d\n", __func__,
			(int) type);
		break;
	}

	return node;
}

static struct filter_node *make_op_node(struct filter_parser_ctx *scanner,
			enum op_type type,
			struct filter_node *lchild,
			struct filter_node *rchild)
{
	struct filter_ast *ast = filter_parser_get_ast(scanner);
	struct filter_node *node;

	node = malloc(sizeof(*node));
	if (!node)
		return NULL;
	memset(node, 0, sizeof(*node));
	node->type = NODE_OP;
	cds_list_add(&node->gc, &ast->allocated_nodes);
	node->u.op.type = type;
	node->u.op.lchild = lchild;
	node->u.op.rchild = rchild;
	return node;
}

__attribute__((visibility("protected")))
void yyerror(struct filter_parser_ctx *parser_ctx, const char *str)
{
	fprintf(stderr, "error %s\n", str);
}
 
__attribute__((visibility("protected")))
int yywrap(void)
{
	return 1;
} 

#define parse_error(parser_ctx, str)				\
do {								\
	yyerror(parser_ctx, YY_("parse error: " str "\n"));	\
	YYERROR;						\
} while (0)

static void free_strings(struct cds_list_head *list)
{
	struct gc_string *gstr, *tmp;

	cds_list_for_each_entry_safe(gstr, tmp, list, gc)
		free(gstr);
}

static struct filter_ast *filter_ast_alloc(void)
{
	struct filter_ast *ast;

	ast = malloc(sizeof(*ast));
	if (!ast)
		return NULL;
	memset(ast, 0, sizeof(*ast));
	CDS_INIT_LIST_HEAD(&ast->allocated_nodes);
	ast->root.type = NODE_ROOT;
	return ast;
}

static void filter_ast_free(struct filter_ast *ast)
{
	struct filter_node *node, *tmp;

	cds_list_for_each_entry_safe(node, tmp, &ast->allocated_nodes, gc)
		free(node);
}

int filter_parser_ctx_append_ast(struct filter_parser_ctx *parser_ctx)
{
	return yyparse(parser_ctx);
}

struct filter_parser_ctx *filter_parser_ctx_alloc(FILE *input)
{
	struct filter_parser_ctx *parser_ctx;
	int ret;

	yydebug = filter_parser_debug;

	parser_ctx = malloc(sizeof(*parser_ctx));
	if (!parser_ctx)
		return NULL;
	memset(parser_ctx, 0, sizeof(*parser_ctx));

	ret = yylex_init_extra(parser_ctx, &parser_ctx->scanner);
	if (ret) {
		fprintf(stderr, "yylex_init error\n");
		goto cleanup_parser_ctx;
	}
	/* Start processing new stream */
	yyrestart(input, parser_ctx->scanner);

	parser_ctx->ast = filter_ast_alloc();
	if (!parser_ctx->ast)
		goto cleanup_lexer;
	CDS_INIT_LIST_HEAD(&parser_ctx->allocated_strings);

	if (yydebug)
		fprintf(stdout, "parser_ctx input is a%s.\n",
			isatty(fileno(input)) ? "n interactive tty" :
						" noninteractive file");

	return parser_ctx;

cleanup_lexer:
	ret = yylex_destroy(parser_ctx->scanner);
	if (!ret)
		fprintf(stderr, "yylex_destroy error\n");
cleanup_parser_ctx:
	free(parser_ctx);
	return NULL;
}

void filter_parser_ctx_free(struct filter_parser_ctx *parser_ctx)
{
	int ret;

	free_strings(&parser_ctx->allocated_strings);
	filter_ast_free(parser_ctx->ast);
	ret = yylex_destroy(parser_ctx->scanner);
	if (ret)
		fprintf(stderr, "yylex_destroy error\n");
	free(parser_ctx);
}

%}

%define api.pure
	/* %locations */
%parse-param {struct filter_parser_ctx *parser_ctx}
%lex-param {struct filter_parser_ctx *parser_ctx}
%start translation_unit
%token CHARACTER_CONSTANT_START SQUOTE STRING_LITERAL_START DQUOTE
%token ESCSEQ CHAR_STRING_TOKEN
%token DECIMAL_CONSTANT OCTAL_CONSTANT HEXADECIMAL_CONSTANT FLOAT_CONSTANT
%token LSBRAC RSBRAC LPAREN RPAREN LBRAC RBRAC RARROW
%token STAR PLUS MINUS
%token MOD_OP DIV_OP RIGHT_OP LEFT_OP
%token EQ_OP NE_OP LE_OP GE_OP LT_OP GT_OP AND_OP OR_OP NOT_OP
%token ASSIGN COLON SEMICOLON DOTDOTDOT DOT EQUAL COMMA
%token XOR_BIN AND_BIN OR_BIN NOT_BIN

%token <gs> IDENTIFIER
%token ERROR
%union
{
	long long ll;
	char c;
	struct gc_string *gs;
	struct filter_node *n;
}

%type <gs> s_char s_char_sequence c_char c_char_sequence

%type <n> primary_expression
%type <n> postfix_expression
%type <n> unary_expression
%type <n> unary_operator
%type <n> multiplicative_expression
%type <n> additive_expression
%type <n> shift_expression
%type <n> relational_expression
%type <n> equality_expression
%type <n> and_expression
%type <n> exclusive_or_expression
%type <n> inclusive_or_expression
%type <n> logical_and_expression
%type <n> logical_or_expression
%type <n> expression

%%


/* 1.5 Constants */

c_char_sequence:
		c_char
		{	$$ = $1;					}
	|	c_char_sequence c_char
		{	$$ = gc_string_append(parser_ctx, $1, $2);		}
	;

c_char:
		CHAR_STRING_TOKEN
		{	$$ = yylval.gs;					}
	|	ESCSEQ
		{
			parse_error(parser_ctx, "escape sequences not supported yet");
		}
	;

/* 1.6 String literals */

s_char_sequence:
		s_char
		{	$$ = $1;					}
	|	s_char_sequence s_char
		{	$$ = gc_string_append(parser_ctx, $1, $2);		}
	;

s_char:
		CHAR_STRING_TOKEN
		{	$$ = yylval.gs;					}
	|	ESCSEQ
		{
			parse_error(parser_ctx, "escape sequences not supported yet");
		}
	;

primary_expression
	:	IDENTIFIER
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_IDENTIFIER;
			$$->u.expression.u.identifier = yylval.gs->s;
		}
	|	DECIMAL_CONSTANT
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_CONSTANT;
			sscanf(yylval.gs->s, "%" PRIu64,
			       &$$->u.expression.u.constant);
		}
	|	OCTAL_CONSTANT
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_CONSTANT;
			sscanf(yylval.gs->s, "0%" PRIo64,
			       &$$->u.expression.u.constant);
		}
	|	HEXADECIMAL_CONSTANT
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_CONSTANT;
			sscanf(yylval.gs->s, "0x%" PRIx64,
			       &$$->u.expression.u.constant);
		}
	|	FLOAT_CONSTANT
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_FLOAT_CONSTANT;
			sscanf(yylval.gs->s, "%lg",
			       &$$->u.expression.u.float_constant);
		}
	|	STRING_LITERAL_START DQUOTE
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_STRING;
			$$->u.expression.u.string = "";
		}
	|	STRING_LITERAL_START s_char_sequence DQUOTE
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_STRING;
			$$->u.expression.u.string = $2->s;
		}
	|	CHARACTER_CONSTANT_START c_char_sequence SQUOTE
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_STRING;
			$$->u.expression.u.string = $2->s;
		}
	|	LPAREN expression RPAREN
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_NESTED;
			$$->u.expression.u.child = $2;
		}
	;

postfix_expression
	: primary_expression
		{	$$ = $1;					}
	| postfix_expression DOT IDENTIFIER
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_IDENTIFIER;
			$$->u.expression.post_op = AST_LINK_DOT;
			$$->u.expression.u.identifier = $3->s;
			$$->u.expression.prev = $1;
		}
	| postfix_expression RARROW IDENTIFIER
		{
			$$ = make_node(parser_ctx, NODE_EXPRESSION);
			$$->u.expression.type = AST_EXP_IDENTIFIER;
			$$->u.expression.post_op = AST_LINK_RARROW;
			$$->u.expression.u.identifier = $3->s;
			$$->u.expression.prev = $1;
		}
	;

unary_expression
	: postfix_expression
		{	$$ = $1;					}
	| unary_operator unary_expression
		{
			$$ = $1;
			$$->u.unary_op.child = $2;
		}
	;

unary_operator
	: PLUS
		{
			$$ = make_node(parser_ctx, NODE_UNARY_OP);
			$$->u.unary_op.type = AST_UNARY_PLUS;
		}
	| MINUS
		{
			$$ = make_node(parser_ctx, NODE_UNARY_OP);
			$$->u.unary_op.type = AST_UNARY_MINUS;
		}
	| NOT_OP
		{
			$$ = make_node(parser_ctx, NODE_UNARY_OP);
			$$->u.unary_op.type = AST_UNARY_NOT;
		}
	;

multiplicative_expression
	: unary_expression
		{	$$ = $1;					}
	| multiplicative_expression STAR unary_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_MUL, $1, $3);
		}
	| multiplicative_expression DIV_OP unary_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_DIV, $1, $3);
		}
	| multiplicative_expression MOD_OP unary_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_MOD, $1, $3);
		}
	;

additive_expression
	: multiplicative_expression
		{	$$ = $1;					}
	| additive_expression PLUS multiplicative_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_PLUS, $1, $3);
		}
	| additive_expression MINUS multiplicative_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_MINUS, $1, $3);
		}
	;

shift_expression
	: additive_expression
		{	$$ = $1;					}
	| shift_expression LEFT_OP additive_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_LSHIFT, $1, $3);
		}
	| shift_expression RIGHT_OP additive_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_RSHIFT, $1, $3);
		}
	;

relational_expression
	: shift_expression
		{	$$ = $1;					}
	| relational_expression LT_OP shift_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_LT, $1, $3);
		}
	| relational_expression GT_OP shift_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_GT, $1, $3);
		}
	| relational_expression LE_OP shift_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_LE, $1, $3);
		}
	| relational_expression GE_OP shift_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_GE, $1, $3);
		}
	;

equality_expression
	: relational_expression
		{	$$ = $1;					}
	| equality_expression EQ_OP relational_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_EQ, $1, $3);
		}
	| equality_expression NE_OP relational_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_NE, $1, $3);
		}
	;

and_expression
	: equality_expression
		{	$$ = $1;					}
	| and_expression AND_BIN equality_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_BIN_AND, $1, $3);
		}
	;

exclusive_or_expression
	: and_expression
		{	$$ = $1;					}
	| exclusive_or_expression XOR_BIN and_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_BIN_XOR, $1, $3);
		}
	;

inclusive_or_expression
	: exclusive_or_expression
		{	$$ = $1;					}
	| inclusive_or_expression OR_BIN exclusive_or_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_BIN_OR, $1, $3);
		}
	;

logical_and_expression
	: inclusive_or_expression
		{	$$ = $1;					}
	| logical_and_expression AND_OP inclusive_or_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_AND, $1, $3);
		}
	;

logical_or_expression
	: logical_and_expression
		{	$$ = $1;					}
	| logical_or_expression OR_OP logical_and_expression
		{
			$$ = make_op_node(parser_ctx, AST_OP_OR, $1, $3);
		}
	;

expression
	: logical_or_expression
		{	$$ = $1;					}
	;

translation_unit
	: expression
		{
			parser_ctx->ast->root.u.root.child = $1;
		}
	;
Commit	Line	Data
	1	%{
	2	/*
	3	* filter-parser.y
	4	*
	5	* LTTng filter expression parser
	6	*
	7	* Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	8	*
	9	* This library is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU Lesser General Public License, version 2.1 only,
	11	* as published by the Free Software Foundation.
	12	*
	13	* This library is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public License
	19	* along with this library; if not, write to the Free Software Foundation,
	20	* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	21	*
	22	* Grammar inspired from http://www.quut.com/c/ANSI-C-grammar-y.html
	23	*/
	24
	25	#include <stdio.h>
	26	#include <unistd.h>
	27	#include <string.h>
	28	#include <stdlib.h>
	29	#include <assert.h>
	30	#include <errno.h>
	31	#include <inttypes.h>
	32	#include "filter-ast.h"
	33	#include "filter-parser.h"
	34
	35	__attribute__((visibility("protected")))
	36	int yydebug;
	37	int filter_parser_debug = 0;
	38
	39	__attribute__((visibility("protected")))
	40	int yyparse(struct filter_parser_ctx *parser_ctx);
	41	__attribute__((visibility("protected")))
	42	int yylex(union YYSTYPE yyval, struct filter_parser_ctx parser_ctx);
	43	__attribute__((visibility("protected")))
	44	int yylex_init_extra(struct filter_parser_ctx parser_ctx, yyscan_t ptr_yy_globals);
	45	__attribute__((visibility("protected")))
	46	int yylex_destroy(yyscan_t yyparser_ctx);
	47	__attribute__((visibility("protected")))
	48	void yyrestart(FILE * in_str, yyscan_t parser_ctx);
	49
	50	struct gc_string {
	51	struct cds_list_head gc;
	52	size_t alloclen;
	53	char s[];
	54	};
	55
	56	static const char *node_type_to_str[] = {
	57	[ NODE_UNKNOWN ] = "NODE_UNKNOWN",
	58	[ NODE_ROOT ] = "NODE_ROOT",
	59	[ NODE_EXPRESSION ] = "NODE_EXPRESSION",
	60	[ NODE_OP ] = "NODE_OP",
	61	[ NODE_UNARY_OP ] = "NODE_UNARY_OP",
	62	};
	63
	64	__attribute__((visibility("protected")))
	65	const char node_type(struct filter_node node)
	66	{
	67	if (node->type < NR_NODE_TYPES)
	68	return node_type_to_str[node->type];
	69	else
	70	return NULL;
	71	}
	72
	73	static struct gc_string gc_string_alloc(struct filter_parser_ctx parser_ctx,
	74	size_t len)
	75	{
	76	struct gc_string *gstr;
	77	size_t alloclen;
	78
	79	/* TODO: could be faster with find first bit or glib Gstring */
	80	/* sizeof long to account for malloc header (int or long ?) */
	81	for (alloclen = 8; alloclen < sizeof(long) + sizeof(*gstr) + len;
	82	alloclen *= 2);
	83
	84	gstr = malloc(alloclen);
	85	cds_list_add(&gstr->gc, &parser_ctx->allocated_strings);
	86	gstr->alloclen = alloclen;
	87	return gstr;
	88	}
	89
	90	/*
	91	* note: never use gc_string_append on a string that has external references.
	92	* gsrc will be garbage collected immediately, and gstr might be.
	93	* Should only be used to append characters to a string literal or constant.
	94	*/
	95	__attribute__((visibility("protected")))
	96	struct gc_string gc_string_append(struct filter_parser_ctx parser_ctx,
	97	struct gc_string *gstr,
	98	struct gc_string *gsrc)
	99	{
	100	size_t newlen = strlen(gsrc->s) + strlen(gstr->s) + 1;
	101	size_t alloclen;
	102
	103	/* TODO: could be faster with find first bit or glib Gstring */
	104	/* sizeof long to account for malloc header (int or long ?) */
	105	for (alloclen = 8; alloclen < sizeof(long) + sizeof(*gstr) + newlen;
	106	alloclen *= 2);
	107
	108	if (alloclen > gstr->alloclen) {
	109	struct gc_string *newgstr;
	110
	111	newgstr = gc_string_alloc(parser_ctx, newlen);
	112	strcpy(newgstr->s, gstr->s);
	113	strcat(newgstr->s, gsrc->s);
	114	cds_list_del(&gstr->gc);
	115	free(gstr);
	116	gstr = newgstr;
	117	} else {
	118	strcat(gstr->s, gsrc->s);
	119	}
	120	cds_list_del(&gsrc->gc);
	121	free(gsrc);
	122	return gstr;
	123	}
	124
	125	__attribute__((visibility("protected")))
	126	void setstring(struct filter_parser_ctx parser_ctx, YYSTYPE lvalp, const char *src)
	127	{
	128	lvalp->gs = gc_string_alloc(parser_ctx, strlen(src) + 1);
	129	strcpy(lvalp->gs->s, src);
	130	}
	131
	132	static struct filter_node make_node(struct filter_parser_ctx scanner,
	133	enum node_type type)
	134	{
	135	struct filter_ast *ast = filter_parser_get_ast(scanner);
	136	struct filter_node *node;
	137
	138	node = malloc(sizeof(*node));
	139	if (!node)
	140	return NULL;
	141	memset(node, 0, sizeof(*node));
	142	node->type = type;
	143	cds_list_add(&node->gc, &ast->allocated_nodes);
	144
	145	switch (type) {
	146	case NODE_ROOT:
	147	fprintf(stderr, "[error] %s: trying to create root node\n", __func__);
	148	break;
	149
	150	case NODE_EXPRESSION:
	151	break;
	152	case NODE_OP:
	153	break;
	154	case NODE_UNARY_OP:
	155	break;
	156
	157	case NODE_UNKNOWN:
	158	default:
	159	fprintf(stderr, "[error] %s: unknown node type %d\n", __func__,
	160	(int) type);
	161	break;
	162	}
	163
	164	return node;
	165	}
	166
	167	static struct filter_node make_op_node(struct filter_parser_ctx scanner,
	168	enum op_type type,
	169	struct filter_node *lchild,
	170	struct filter_node *rchild)
	171	{
	172	struct filter_ast *ast = filter_parser_get_ast(scanner);
	173	struct filter_node *node;
	174
	175	node = malloc(sizeof(*node));
	176	if (!node)
	177	return NULL;
	178	memset(node, 0, sizeof(*node));
	179	node->type = NODE_OP;
	180	cds_list_add(&node->gc, &ast->allocated_nodes);
	181	node->u.op.type = type;
	182	node->u.op.lchild = lchild;
	183	node->u.op.rchild = rchild;
	184	return node;
	185	}
	186
	187	__attribute__((visibility("protected")))
	188	void yyerror(struct filter_parser_ctx parser_ctx, const char str)
	189	{
	190	fprintf(stderr, "error %s\n", str);
	191	}
	192
	193	__attribute__((visibility("protected")))
	194	int yywrap(void)
	195	{
	196	return 1;
	197	}
	198
	199	#define parse_error(parser_ctx, str) \
	200	do { \
	201	yyerror(parser_ctx, YY_("parse error: " str "\n")); \
	202	YYERROR; \
	203	} while (0)
	204
	205	static void free_strings(struct cds_list_head *list)
	206	{
	207	struct gc_string gstr, tmp;
	208
	209	cds_list_for_each_entry_safe(gstr, tmp, list, gc)
	210	free(gstr);
	211	}
	212
	213	static struct filter_ast *filter_ast_alloc(void)
	214	{
	215	struct filter_ast *ast;
	216
	217	ast = malloc(sizeof(*ast));
	218	if (!ast)
	219	return NULL;
	220	memset(ast, 0, sizeof(*ast));
	221	CDS_INIT_LIST_HEAD(&ast->allocated_nodes);
	222	ast->root.type = NODE_ROOT;
	223	return ast;
	224	}
	225
	226	static void filter_ast_free(struct filter_ast *ast)
	227	{
	228	struct filter_node node, tmp;
	229
	230	cds_list_for_each_entry_safe(node, tmp, &ast->allocated_nodes, gc)
	231	free(node);
	232	}
	233
	234	int filter_parser_ctx_append_ast(struct filter_parser_ctx *parser_ctx)
	235	{
	236	return yyparse(parser_ctx);
	237	}
	238
	239	struct filter_parser_ctx filter_parser_ctx_alloc(FILE input)
	240	{
	241	struct filter_parser_ctx *parser_ctx;
	242	int ret;
	243
	244	yydebug = filter_parser_debug;
	245
	246	parser_ctx = malloc(sizeof(*parser_ctx));
	247	if (!parser_ctx)
	248	return NULL;
	249	memset(parser_ctx, 0, sizeof(*parser_ctx));
	250
	251	ret = yylex_init_extra(parser_ctx, &parser_ctx->scanner);
	252	if (ret) {
	253	fprintf(stderr, "yylex_init error\n");
	254	goto cleanup_parser_ctx;
	255	}
	256	/* Start processing new stream */
	257	yyrestart(input, parser_ctx->scanner);
	258
	259	parser_ctx->ast = filter_ast_alloc();
	260	if (!parser_ctx->ast)
	261	goto cleanup_lexer;
	262	CDS_INIT_LIST_HEAD(&parser_ctx->allocated_strings);
	263
	264	if (yydebug)
	265	fprintf(stdout, "parser_ctx input is a%s.\n",
	266	isatty(fileno(input)) ? "n interactive tty" :
	267	" noninteractive file");
	268
	269	return parser_ctx;
	270
	271	cleanup_lexer:
	272	ret = yylex_destroy(parser_ctx->scanner);
	273	if (!ret)
	274	fprintf(stderr, "yylex_destroy error\n");
	275	cleanup_parser_ctx:
	276	free(parser_ctx);
	277	return NULL;
	278	}
	279
	280	void filter_parser_ctx_free(struct filter_parser_ctx *parser_ctx)
	281	{
	282	int ret;
	283
	284	free_strings(&parser_ctx->allocated_strings);
	285	filter_ast_free(parser_ctx->ast);
	286	ret = yylex_destroy(parser_ctx->scanner);
	287	if (ret)
	288	fprintf(stderr, "yylex_destroy error\n");
	289	free(parser_ctx);
	290	}
	291
	292	%}
	293
	294	%define api.pure
	295	/* %locations */
	296	%parse-param {struct filter_parser_ctx *parser_ctx}
	297	%lex-param {struct filter_parser_ctx *parser_ctx}
	298	%start translation_unit
	299	%token CHARACTER_CONSTANT_START SQUOTE STRING_LITERAL_START DQUOTE
	300	%token ESCSEQ CHAR_STRING_TOKEN
	301	%token DECIMAL_CONSTANT OCTAL_CONSTANT HEXADECIMAL_CONSTANT FLOAT_CONSTANT
	302	%token LSBRAC RSBRAC LPAREN RPAREN LBRAC RBRAC RARROW
	303	%token STAR PLUS MINUS
	304	%token MOD_OP DIV_OP RIGHT_OP LEFT_OP
	305	%token EQ_OP NE_OP LE_OP GE_OP LT_OP GT_OP AND_OP OR_OP NOT_OP
	306	%token ASSIGN COLON SEMICOLON DOTDOTDOT DOT EQUAL COMMA
	307	%token XOR_BIN AND_BIN OR_BIN NOT_BIN
	308
	309	%token <gs> IDENTIFIER
	310	%token ERROR
	311	%union
	312	{
	313	long long ll;
	314	char c;
	315	struct gc_string *gs;
	316	struct filter_node *n;
	317	}
	318
	319	%type <gs> s_char s_char_sequence c_char c_char_sequence
	320
	321	%type <n> primary_expression
	322	%type <n> postfix_expression
	323	%type <n> unary_expression
	324	%type <n> unary_operator
	325	%type <n> multiplicative_expression
	326	%type <n> additive_expression
	327	%type <n> shift_expression
	328	%type <n> relational_expression
	329	%type <n> equality_expression
	330	%type <n> and_expression
	331	%type <n> exclusive_or_expression
	332	%type <n> inclusive_or_expression
	333	%type <n> logical_and_expression
	334	%type <n> logical_or_expression
	335	%type <n> expression
	336
	337	%%
	338
	339
	340	/* 1.5 Constants */
	341
	342	c_char_sequence:
	343	c_char
	344	{ $$ = $1; }
	345	\| c_char_sequence c_char
	346	{ $$ = gc_string_append(parser_ctx, $1, $2); }
	347	;
	348
	349	c_char:
	350	CHAR_STRING_TOKEN
	351	{ $$ = yylval.gs; }
	352	\| ESCSEQ
	353	{
	354	parse_error(parser_ctx, "escape sequences not supported yet");
	355	}
	356	;
	357
	358	/* 1.6 String literals */
	359
	360	s_char_sequence:
	361	s_char
	362	{ $$ = $1; }
	363	\| s_char_sequence s_char
	364	{ $$ = gc_string_append(parser_ctx, $1, $2); }
	365	;
	366
	367	s_char:
	368	CHAR_STRING_TOKEN
	369	{ $$ = yylval.gs; }
	370	\| ESCSEQ
	371	{
	372	parse_error(parser_ctx, "escape sequences not supported yet");
	373	}
	374	;
	375
	376	primary_expression
	377	: IDENTIFIER
	378	{
	379	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	380	$$->u.expression.type = AST_EXP_IDENTIFIER;
	381	$$->u.expression.u.identifier = yylval.gs->s;
	382	}
	383	\| DECIMAL_CONSTANT
	384	{
	385	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	386	$$->u.expression.type = AST_EXP_CONSTANT;
	387	sscanf(yylval.gs->s, "%" PRIu64,
	388	&$$->u.expression.u.constant);
	389	}
	390	\| OCTAL_CONSTANT
	391	{
	392	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	393	$$->u.expression.type = AST_EXP_CONSTANT;
	394	sscanf(yylval.gs->s, "0%" PRIo64,
	395	&$$->u.expression.u.constant);
	396	}
	397	\| HEXADECIMAL_CONSTANT
	398	{
	399	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	400	$$->u.expression.type = AST_EXP_CONSTANT;
	401	sscanf(yylval.gs->s, "0x%" PRIx64,
	402	&$$->u.expression.u.constant);
	403	}
	404	\| FLOAT_CONSTANT
	405	{
	406	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	407	$$->u.expression.type = AST_EXP_FLOAT_CONSTANT;
	408	sscanf(yylval.gs->s, "%lg",
	409	&$$->u.expression.u.float_constant);
	410	}
	411	\| STRING_LITERAL_START DQUOTE
	412	{
	413	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	414	$$->u.expression.type = AST_EXP_STRING;
	415	$$->u.expression.u.string = "";
	416	}
	417	\| STRING_LITERAL_START s_char_sequence DQUOTE
	418	{
	419	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	420	$$->u.expression.type = AST_EXP_STRING;
	421	$$->u.expression.u.string = $2->s;
	422	}
	423	\| CHARACTER_CONSTANT_START c_char_sequence SQUOTE
	424	{
	425	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	426	$$->u.expression.type = AST_EXP_STRING;
	427	$$->u.expression.u.string = $2->s;
	428	}
	429	\| LPAREN expression RPAREN
	430	{
	431	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	432	$$->u.expression.type = AST_EXP_NESTED;
	433	$$->u.expression.u.child = $2;
	434	}
	435	;
	436
	437	postfix_expression
	438	: primary_expression
	439	{ $$ = $1; }
	440	\| postfix_expression DOT IDENTIFIER
	441	{
	442	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	443	$$->u.expression.type = AST_EXP_IDENTIFIER;
	444	$$->u.expression.post_op = AST_LINK_DOT;
	445	$$->u.expression.u.identifier = $3->s;
	446	$$->u.expression.prev = $1;
	447	}
	448	\| postfix_expression RARROW IDENTIFIER
	449	{
	450	$$ = make_node(parser_ctx, NODE_EXPRESSION);
	451	$$->u.expression.type = AST_EXP_IDENTIFIER;
	452	$$->u.expression.post_op = AST_LINK_RARROW;
	453	$$->u.expression.u.identifier = $3->s;
	454	$$->u.expression.prev = $1;
	455	}
	456	;
	457
	458	unary_expression
	459	: postfix_expression
	460	{ $$ = $1; }
	461	\| unary_operator unary_expression
	462	{
	463	$$ = $1;
	464	$$->u.unary_op.child = $2;
	465	}
	466	;
	467
	468	unary_operator
	469	: PLUS
	470	{
	471	$$ = make_node(parser_ctx, NODE_UNARY_OP);
	472	$$->u.unary_op.type = AST_UNARY_PLUS;
	473	}
	474	\| MINUS
	475	{
	476	$$ = make_node(parser_ctx, NODE_UNARY_OP);
	477	$$->u.unary_op.type = AST_UNARY_MINUS;
	478	}
	479	\| NOT_OP
	480	{
	481	$$ = make_node(parser_ctx, NODE_UNARY_OP);
	482	$$->u.unary_op.type = AST_UNARY_NOT;
	483	}
	484	;
	485
	486	multiplicative_expression
	487	: unary_expression
	488	{ $$ = $1; }
	489	\| multiplicative_expression STAR unary_expression
	490	{
	491	$$ = make_op_node(parser_ctx, AST_OP_MUL, $1, $3);
	492	}
	493	\| multiplicative_expression DIV_OP unary_expression
	494	{
	495	$$ = make_op_node(parser_ctx, AST_OP_DIV, $1, $3);
	496	}
	497	\| multiplicative_expression MOD_OP unary_expression
	498	{
	499	$$ = make_op_node(parser_ctx, AST_OP_MOD, $1, $3);
	500	}
	501	;
	502
	503	additive_expression
	504	: multiplicative_expression
	505	{ $$ = $1; }
	506	\| additive_expression PLUS multiplicative_expression
	507	{
	508	$$ = make_op_node(parser_ctx, AST_OP_PLUS, $1, $3);
	509	}
	510	\| additive_expression MINUS multiplicative_expression
	511	{
	512	$$ = make_op_node(parser_ctx, AST_OP_MINUS, $1, $3);
	513	}
	514	;
	515
	516	shift_expression
	517	: additive_expression
	518	{ $$ = $1; }
	519	\| shift_expression LEFT_OP additive_expression
	520	{
	521	$$ = make_op_node(parser_ctx, AST_OP_LSHIFT, $1, $3);
	522	}
	523	\| shift_expression RIGHT_OP additive_expression
	524	{
	525	$$ = make_op_node(parser_ctx, AST_OP_RSHIFT, $1, $3);
	526	}
	527	;
	528
	529	relational_expression
	530	: shift_expression
	531	{ $$ = $1; }
	532	\| relational_expression LT_OP shift_expression
	533	{
	534	$$ = make_op_node(parser_ctx, AST_OP_LT, $1, $3);
	535	}
	536	\| relational_expression GT_OP shift_expression
	537	{
	538	$$ = make_op_node(parser_ctx, AST_OP_GT, $1, $3);
	539	}
	540	\| relational_expression LE_OP shift_expression
	541	{
	542	$$ = make_op_node(parser_ctx, AST_OP_LE, $1, $3);
	543	}
	544	\| relational_expression GE_OP shift_expression
	545	{
	546	$$ = make_op_node(parser_ctx, AST_OP_GE, $1, $3);
	547	}
	548	;
	549
	550	equality_expression
	551	: relational_expression
	552	{ $$ = $1; }
	553	\| equality_expression EQ_OP relational_expression
	554	{
	555	$$ = make_op_node(parser_ctx, AST_OP_EQ, $1, $3);
	556	}
	557	\| equality_expression NE_OP relational_expression
	558	{
	559	$$ = make_op_node(parser_ctx, AST_OP_NE, $1, $3);
	560	}
	561	;
	562
	563	and_expression
	564	: equality_expression
	565	{ $$ = $1; }
	566	\| and_expression AND_BIN equality_expression
	567	{
	568	$$ = make_op_node(parser_ctx, AST_OP_BIN_AND, $1, $3);
	569	}
	570	;
	571
	572	exclusive_or_expression
	573	: and_expression
	574	{ $$ = $1; }
	575	\| exclusive_or_expression XOR_BIN and_expression
	576	{
	577	$$ = make_op_node(parser_ctx, AST_OP_BIN_XOR, $1, $3);
	578	}
	579	;
	580
	581	inclusive_or_expression
	582	: exclusive_or_expression
	583	{ $$ = $1; }
	584	\| inclusive_or_expression OR_BIN exclusive_or_expression
	585	{
	586	$$ = make_op_node(parser_ctx, AST_OP_BIN_OR, $1, $3);
	587	}
	588	;
	589
	590	logical_and_expression
	591	: inclusive_or_expression
	592	{ $$ = $1; }
	593	\| logical_and_expression AND_OP inclusive_or_expression
	594	{
	595	$$ = make_op_node(parser_ctx, AST_OP_AND, $1, $3);
	596	}
	597	;
	598
	599	logical_or_expression
	600	: logical_and_expression
	601	{ $$ = $1; }
	602	\| logical_or_expression OR_OP logical_and_expression
	603	{
	604	$$ = make_op_node(parser_ctx, AST_OP_OR, $1, $3);
	605	}
	606	;
	607
	608	expression
	609	: logical_or_expression
	610	{ $$ = $1; }
	611	;
	612
	613	translation_unit
	614	: expression
	615	{
	616	parser_ctx->ast->root.u.root.child = $1;
	617	}
	618	;