Simplify parser implementation

Rather than returning a list of productions and an index,
return the relevant production directly from the rule function.

Also introduce a tag value (replacing production_idx) which tracks
information like command decorations, etc. with more clarity.
This commit is contained in:
ridiculousfish 2015-12-15 14:59:03 -08:00
parent 7188d94c1b
commit 8c707a4e2f
6 changed files with 172 additions and 317 deletions

View file

@ -102,7 +102,9 @@ enum parse_keyword_t
LAST_KEYWORD = parse_keyword_while
} __packed;
/* Statement decorations. This matches the order of productions in decorated_statement */
/* Node tag values */
/* Statement decorations, stored in node tag */
enum parse_statement_decoration_t
{
parse_statement_decoration_none,
@ -111,7 +113,7 @@ enum parse_statement_decoration_t
parse_statement_decoration_exec
};
/* Boolean statement types */
/* Boolean statement types, stored in node tag */
enum parse_bool_statement_type_t
{
parse_bool_and,
@ -119,6 +121,13 @@ enum parse_bool_statement_type_t
parse_bool_not
};
/* Whether a statement is backgrounded */
enum parse_optional_background_t
{
parse_no_background,
parse_background
};
/* Parse error code list */
enum parse_error_code_t
{

View file

@ -320,17 +320,16 @@ parse_execution_result_t parse_execution_context_t::run_if_statement(const parse
{
/* We have an 'else continuation' (either else-if or else) */
const parse_node_t &else_cont = *get_child(*else_clause, 1, symbol_else_continuation);
assert(else_cont.production_idx < 2);
if (else_cont.production_idx == 0)
const parse_node_t *maybe_if_clause = get_child(else_cont, 0);
if (maybe_if_clause && maybe_if_clause->type == symbol_if_clause)
{
/* it's an 'else if', go to the next one */
if_clause = get_child(else_cont, 0, symbol_if_clause);
if_clause = maybe_if_clause;
else_clause = get_child(else_cont, 1, symbol_else_clause);
}
else
{
/* it's the final 'else', we're done */
assert(else_cont.production_idx == 1);
job_list_to_execute = get_child(else_cont, 1, symbol_job_list);
break;
}

View file

@ -4,49 +4,37 @@
#include "parse_tree.h"
using namespace parse_productions;
#define NO_PRODUCTION ((production_option_idx_t)(-1))
static bool production_is_empty(const production_t production)
{
return production[0] == token_type_invalid;
}
#define NO_PRODUCTION NULL
/* Empty productions are allowed but must be first. Validate that the given production is in the valid range, i.e. it is either not empty or there is a non-empty production after it */
static bool production_is_valid(const production_options_t production_list, production_option_idx_t which)
{
assert(which >= 0);
if (which >= MAX_PRODUCTIONS)
return false;
/* Herein are encoded the productions for our LL2 fish grammar.
Each symbol (e.g. symbol_job_list) has a corresponding function (e.g. resolve_job_lits).
The function accepts two tokens, representing the first and second lookahead, and returns
returns a production representing the rule, or NULL on error. There is also a tag value
which is returned by reference; the tag is a sort of node annotation.
Productions are generally a static const array, and we return a pointer to the array (yes, really).
*/
bool nonempty_found = false;
for (int i=which; i < MAX_PRODUCTIONS; i++)
{
if (! production_is_empty(production_list[i]))
{
nonempty_found = true;
break;
}
}
return nonempty_found;
}
#define RESOLVE(sym) static const production_t * resolve_##sym (const parse_token_t &token1, const parse_token_t &token2, parse_node_tag_t *out_tag)
#define PRODUCTIONS(sym) static const production_options_t productions_##sym
#define RESOLVE(sym) static production_option_idx_t resolve_##sym (const parse_token_t &token1, const parse_token_t &token2)
#define RESOLVE_ONLY(sym) static production_option_idx_t resolve_##sym (const parse_token_t &input1, const parse_token_t &input2) { return 0; }
/* Hacktastic? */
#define RESOLVE_ONLY(sym) \
extern const production_t sym##_only; \
static const production_t * resolve_##sym (const parse_token_t &token1, const parse_token_t &token2, parse_node_tag_t *out_tag) { return &sym ## _only ; } \
const production_t sym ## _only
#define KEYWORD(x) ((x) + LAST_TOKEN_OR_SYMBOL + 1)
/* Helper macro to define an array */
#define P static const production_t
/* A job_list is a list of jobs, separated by semicolons or newlines */
PRODUCTIONS(job_list) =
{
{},
{symbol_job, symbol_job_list},
{parse_token_type_end, symbol_job_list}
};
RESOLVE(job_list)
{
P list_end = {};
P normal = {symbol_job, symbol_job_list};
P empty_line = {parse_token_type_end, symbol_job_list};
switch (token1.type)
{
case parse_token_type_string:
@ -57,25 +45,24 @@ RESOLVE(job_list)
case parse_keyword_else:
case parse_keyword_case:
// End this job list
return 0;
return &list_end;
default:
// Normal string
return 1;
return &normal;
}
case parse_token_type_pipe:
case parse_token_type_redirection:
case parse_token_type_background:
return 1;
return &normal;
case parse_token_type_end:
// Empty line
return 2;
return &empty_line;
case parse_token_type_terminate:
// no more commands, just transition to empty
return 0;
return &list_end;
default:
return NO_PRODUCTION;
@ -84,42 +71,32 @@ RESOLVE(job_list)
/* A job is a non-empty list of statements, separated by pipes. (Non-empty is useful for cases like if statements, where we require a command). To represent "non-empty", we require a statement, followed by a possibly empty job_continuation */
PRODUCTIONS(job) =
{
{symbol_statement, symbol_job_continuation, symbol_optional_background}
};
RESOLVE_ONLY(job)
RESOLVE_ONLY(job) = {symbol_statement, symbol_job_continuation, symbol_optional_background};
PRODUCTIONS(job_continuation) =
{
{},
{parse_token_type_pipe, symbol_statement, symbol_job_continuation}
};
RESOLVE(job_continuation)
{
P empty = {};
P piped = {parse_token_type_pipe, symbol_statement, symbol_job_continuation};
switch (token1.type)
{
case parse_token_type_pipe:
// Pipe, continuation
return 1;
return &piped;
default:
// Not a pipe, no job continuation
return 0;
return &empty;
}
}
/* A statement is a normal command, or an if / while / and etc */
PRODUCTIONS(statement) =
{
{symbol_boolean_statement},
{symbol_block_statement},
{symbol_if_statement},
{symbol_switch_statement},
{symbol_decorated_statement}
};
RESOLVE(statement)
{
P boolean = {symbol_boolean_statement};
P block = {symbol_block_statement};
P ifs = {symbol_if_statement};
P switchs = {symbol_switch_statement};
P decorated = {symbol_decorated_statement};
/* The only block-like builtin that takes any parameters is 'function' So go to decorated statements if the subsequent token looks like '--'.
The logic here is subtle:
If we are 'begin', then we expect to be invoked with no arguments.
@ -133,18 +110,18 @@ RESOLVE(statement)
// Otherwise, if the next token looks like an option (starts with a dash), then parse it as a decorated statement
if (token1.keyword == parse_keyword_function && token2.is_help_argument)
{
return 4;
return &decorated;
}
else if (token1.keyword != parse_keyword_function && token2.has_dash_prefix)
{
return 4;
return &decorated;
}
// Likewise if the next token doesn't look like an argument at all. This corresponds to e.g. a "naked if".
bool naked_invocation_invokes_help = (token1.keyword != parse_keyword_begin && token1.keyword != parse_keyword_end);
if (naked_invocation_invokes_help && (token2.type == parse_token_type_end || token2.type == parse_token_type_terminate))
{
return 4;
return &decorated;
}
}
@ -157,29 +134,29 @@ RESOLVE(statement)
case parse_keyword_and:
case parse_keyword_or:
case parse_keyword_not:
return 0;
return &boolean;
case parse_keyword_for:
case parse_keyword_while:
case parse_keyword_function:
case parse_keyword_begin:
return 1;
return &block;
case parse_keyword_if:
return 2;
return &ifs;
case parse_keyword_else:
return NO_PRODUCTION;
case parse_keyword_switch:
return 3;
return &switchs;
case parse_keyword_end:
return NO_PRODUCTION;
// All other keywords fall through to decorated statement
default:
return 4;
return &decorated;
}
break;
@ -195,294 +172,216 @@ RESOLVE(statement)
}
}
PRODUCTIONS(if_statement) =
{
{symbol_if_clause, symbol_else_clause, symbol_end_command, symbol_arguments_or_redirections_list}
};
RESOLVE_ONLY(if_statement)
RESOLVE_ONLY(if_statement) = {symbol_if_clause, symbol_else_clause, symbol_end_command, symbol_arguments_or_redirections_list};
RESOLVE_ONLY(if_clause) = { KEYWORD(parse_keyword_if), symbol_job, parse_token_type_end, symbol_job_list };
PRODUCTIONS(if_clause) =
{
{ KEYWORD(parse_keyword_if), symbol_job, parse_token_type_end, symbol_job_list }
};
RESOLVE_ONLY(if_clause)
PRODUCTIONS(else_clause) =
{
{ },
{ KEYWORD(parse_keyword_else), symbol_else_continuation }
};
RESOLVE(else_clause)
{
P empty = {};
P else_cont = { KEYWORD(parse_keyword_else), symbol_else_continuation };
switch (token1.keyword)
{
case parse_keyword_else:
return 1;
return &else_cont;
default:
return 0;
return &empty;
}
}
PRODUCTIONS(else_continuation) =
{
{symbol_if_clause, symbol_else_clause},
{parse_token_type_end, symbol_job_list}
};
RESOLVE(else_continuation)
{
P elseif = {symbol_if_clause, symbol_else_clause};
P elseonly = {parse_token_type_end, symbol_job_list};
switch (token1.keyword)
{
case parse_keyword_if:
return 0;
return &elseif;
default:
return 1;
return &elseonly;
}
}
PRODUCTIONS(switch_statement) =
{
{ KEYWORD(parse_keyword_switch), symbol_argument, parse_token_type_end, symbol_case_item_list, symbol_end_command, symbol_arguments_or_redirections_list}
};
RESOLVE_ONLY(switch_statement)
RESOLVE_ONLY(switch_statement) = { KEYWORD(parse_keyword_switch), symbol_argument, parse_token_type_end, symbol_case_item_list, symbol_end_command, symbol_arguments_or_redirections_list};
PRODUCTIONS(case_item_list) =
{
{},
{symbol_case_item, symbol_case_item_list},
{parse_token_type_end, symbol_case_item_list}
};
RESOLVE(case_item_list)
{
if (token1.keyword == parse_keyword_case) return 1;
else if (token1.type == parse_token_type_end) return 2; //empty line
else return 0;
P empty = {};
P case_item = {symbol_case_item, symbol_case_item_list};
P blank_line = {parse_token_type_end, symbol_case_item_list};
if (token1.keyword == parse_keyword_case) return &case_item;
else if (token1.type == parse_token_type_end) return &blank_line;
else return &empty;
}
PRODUCTIONS(case_item) =
{
{KEYWORD(parse_keyword_case), symbol_argument_list, parse_token_type_end, symbol_job_list}
};
RESOLVE_ONLY(case_item)
RESOLVE_ONLY(case_item) = {KEYWORD(parse_keyword_case), symbol_argument_list, parse_token_type_end, symbol_job_list};
PRODUCTIONS(argument_list) =
{
{},
{symbol_argument, symbol_argument_list}
};
RESOLVE(argument_list)
{
P empty = {};
P arg = {symbol_argument, symbol_argument_list};
switch (token1.type)
{
case parse_token_type_string:
return 1;
return &arg;
default:
return 0;
return &empty;
}
}
PRODUCTIONS(freestanding_argument_list) =
{
{},
{symbol_argument, symbol_freestanding_argument_list},
{parse_token_type_end, symbol_freestanding_argument_list},
};
RESOLVE(freestanding_argument_list)
{
P empty = {};
P arg = {symbol_argument, symbol_freestanding_argument_list};
P semicolon = {parse_token_type_end, symbol_freestanding_argument_list};
switch (token1.type)
{
case parse_token_type_string:
return 1;
return &arg;
case parse_token_type_end:
return 2;
return &semicolon;
default:
return 0;
return &empty;
}
}
RESOLVE_ONLY(block_statement) = {symbol_block_header, symbol_job_list, symbol_end_command, symbol_arguments_or_redirections_list};
PRODUCTIONS(block_statement) =
{
{symbol_block_header, symbol_job_list, symbol_end_command, symbol_arguments_or_redirections_list}
};
RESOLVE_ONLY(block_statement)
PRODUCTIONS(block_header) =
{
{symbol_for_header},
{symbol_while_header},
{symbol_function_header},
{symbol_begin_header}
};
RESOLVE(block_header)
{
P forh = {symbol_for_header};
P whileh = {symbol_while_header};
P funch = {symbol_function_header};
P beginh = {symbol_begin_header};
switch (token1.keyword)
{
case parse_keyword_for:
return 0;
return &forh;
case parse_keyword_while:
return 1;
return &whileh;
case parse_keyword_function:
return 2;
return &funch;
case parse_keyword_begin:
return 3;
return &beginh;
default:
return NO_PRODUCTION;
}
}
PRODUCTIONS(for_header) =
{
{KEYWORD(parse_keyword_for), parse_token_type_string, KEYWORD
(parse_keyword_in), symbol_argument_list, parse_token_type_end}
};
RESOLVE_ONLY(for_header)
PRODUCTIONS(while_header) =
{
{KEYWORD(parse_keyword_while), symbol_job, parse_token_type_end}
};
RESOLVE_ONLY(while_header)
PRODUCTIONS(begin_header) =
{
{KEYWORD(parse_keyword_begin)}
};
RESOLVE_ONLY(begin_header)
PRODUCTIONS(function_header) =
{
{KEYWORD(parse_keyword_function), symbol_argument, symbol_argument_list, parse_token_type_end}
};
RESOLVE_ONLY(function_header)
RESOLVE_ONLY(for_header) = {KEYWORD(parse_keyword_for), parse_token_type_string, KEYWORD
(parse_keyword_in), symbol_argument_list, parse_token_type_end};
RESOLVE_ONLY(while_header) = {KEYWORD(parse_keyword_while), symbol_job, parse_token_type_end};
RESOLVE_ONLY(begin_header) = {KEYWORD(parse_keyword_begin)};
RESOLVE_ONLY(function_header) = {KEYWORD(parse_keyword_function), symbol_argument, symbol_argument_list, parse_token_type_end};
/* A boolean statement is AND or OR or NOT */
PRODUCTIONS(boolean_statement) =
{
{KEYWORD(parse_keyword_and), symbol_statement},
{KEYWORD(parse_keyword_or), symbol_statement},
{KEYWORD(parse_keyword_not), symbol_statement}
};
RESOLVE(boolean_statement)
{
P ands = {KEYWORD(parse_keyword_and), symbol_statement};
P ors = {KEYWORD(parse_keyword_or), symbol_statement};
P nots = {KEYWORD(parse_keyword_not), symbol_statement};
switch (token1.keyword)
{
case parse_keyword_and:
return 0;
*out_tag = parse_bool_and;
return &ands;
case parse_keyword_or:
return 1;
*out_tag = parse_bool_or;
return &ors;
case parse_keyword_not:
return 2;
*out_tag = parse_bool_not;
return &nots;
default:
return NO_PRODUCTION;
}
}
PRODUCTIONS(decorated_statement) =
{
{symbol_plain_statement},
{KEYWORD(parse_keyword_command), symbol_plain_statement},
{KEYWORD(parse_keyword_builtin), symbol_plain_statement},
{KEYWORD(parse_keyword_exec), symbol_plain_statement}
};
RESOLVE(decorated_statement)
{
P plains = {symbol_plain_statement};
P cmds = {KEYWORD(parse_keyword_command), symbol_plain_statement};
P builtins = {KEYWORD(parse_keyword_builtin), symbol_plain_statement};
P execs = {KEYWORD(parse_keyword_exec), symbol_plain_statement};
/* If this is e.g. 'command --help' then the command is 'command' and not a decoration. If the second token is not a string, then this is a naked 'command' and we should execute it as undecorated. */
if (token2.type != parse_token_type_string || token2.has_dash_prefix)
{
return 0;
return &plains;
}
switch (token1.keyword)
{
default:
return 0;
*out_tag = parse_statement_decoration_none;
return &plains;
case parse_keyword_command:
return 1;
*out_tag = parse_statement_decoration_command;
return &cmds;
case parse_keyword_builtin:
return 2;
*out_tag = parse_statement_decoration_builtin;
return &builtins;
case parse_keyword_exec:
return 3;
*out_tag = parse_statement_decoration_exec;
return &execs;
}
}
PRODUCTIONS(plain_statement) =
{
{parse_token_type_string, symbol_arguments_or_redirections_list}
};
RESOLVE_ONLY(plain_statement)
RESOLVE_ONLY(plain_statement) = {parse_token_type_string, symbol_arguments_or_redirections_list};
PRODUCTIONS(arguments_or_redirections_list) =
{
{},
{symbol_argument_or_redirection, symbol_arguments_or_redirections_list}
};
RESOLVE(arguments_or_redirections_list)
{
P empty = {};
P value = {symbol_argument_or_redirection, symbol_arguments_or_redirections_list};
switch (token1.type)
{
case parse_token_type_string:
case parse_token_type_redirection:
return 1;
return &value;
default:
return 0;
return &empty;
}
}
PRODUCTIONS(argument_or_redirection) =
{
{symbol_argument},
{symbol_redirection}
};
RESOLVE(argument_or_redirection)
{
P arg = {symbol_argument};
P redir = {symbol_redirection};
switch (token1.type)
{
case parse_token_type_string:
return 0;
return &arg;
case parse_token_type_redirection:
return 1;
return &redir;
default:
return NO_PRODUCTION;
}
}
PRODUCTIONS(argument) =
{
{parse_token_type_string}
};
RESOLVE_ONLY(argument)
PRODUCTIONS(redirection) =
{
{parse_token_type_redirection, parse_token_type_string}
};
RESOLVE_ONLY(redirection)
PRODUCTIONS(optional_background) =
{
{},
{ parse_token_type_background }
};
RESOLVE_ONLY(argument) = {parse_token_type_string};
RESOLVE_ONLY(redirection) = {parse_token_type_redirection, parse_token_type_string};
RESOLVE(optional_background)
{
P empty = {};
P background = { parse_token_type_background };
switch (token1.type)
{
case parse_token_type_background:
return 1;
*out_tag = parse_background;
return &background;
default:
return 0;
*out_tag = parse_no_background;
return &empty;
}
}
PRODUCTIONS(end_command) =
{
{KEYWORD(parse_keyword_end)}
};
RESOLVE_ONLY(end_command)
RESOLVE_ONLY(end_command) = {KEYWORD(parse_keyword_end)};
#define TEST(sym) case (symbol_##sym): production_list = & productions_ ## sym ; resolver = resolve_ ## sym ; break;
const production_t *parse_productions::production_for_token(parse_token_type_t node_type, const parse_token_t &input1, const parse_token_t &input2, production_option_idx_t *out_which_production, wcstring *out_error_text)
#define TEST(sym) case (symbol_##sym): resolver = resolve_ ## sym ; break;
const production_t *parse_productions::production_for_token(parse_token_type_t node_type, const parse_token_t &input1, const parse_token_t &input2, parse_node_tag_t *out_tag)
{
const bool log_it = false;
if (log_it)
@ -490,9 +389,8 @@ const production_t *parse_productions::production_for_token(parse_token_type_t n
fprintf(stderr, "Resolving production for %ls with input token <%ls>\n", token_type_description(node_type).c_str(), input1.describe().c_str());
}
/* Fetch the list of productions and the function to resolve them */
const production_options_t *production_list = NULL;
production_option_idx_t (*resolver)(const parse_token_t &input1, const parse_token_t &input2) = NULL;
/* Fetch the function to resolve the list of productions */
const production_t * (*resolver)(const parse_token_t &input1, const parse_token_t &input2, parse_node_tag_t *out_tag) = NULL;
switch (node_type)
{
TEST(job_list)
@ -548,32 +446,17 @@ const production_t *parse_productions::production_for_token(parse_token_type_t n
break;
}
PARSE_ASSERT(production_list != NULL);
PARSE_ASSERT(resolver != NULL);
const production_t *result = NULL;
production_option_idx_t which = resolver(input1, input2);
if (log_it)
{
fprintf(stderr, "\tresolved to %u\n", (unsigned)which);
}
if (which == NO_PRODUCTION)
const production_t *result = resolver(input1, input2, out_tag);
if (result == NULL)
{
if (log_it)
{
fprintf(stderr, "Node type '%ls' has no production for input '%ls' (in %s)\n", token_type_description(node_type).c_str(), input1.describe().c_str(), __FUNCTION__);
}
result = NULL;
}
else
{
PARSE_ASSERT(production_is_valid(*production_list, which));
result = &((*production_list)[which]);
}
*out_which_production = which;
return result;
}

View file

@ -15,23 +15,12 @@ struct parse_token_t;
namespace parse_productions
{
#define MAX_PRODUCTIONS 5
#define MAX_SYMBOLS_PER_PRODUCTION 6
typedef uint32_t production_tag_t;
/* A production is an array of unsigned char. Symbols are encoded directly as their symbol value. Keywords are encoded with an offset of LAST_TOKEN_OR_SYMBOL + 1. So essentially we glom together keywords and symbols. */
typedef uint8_t production_element_t;
/* An index into a production option list */
typedef uint8_t production_option_idx_t;
/* A production is an array of production elements */
typedef production_element_t const production_t[MAX_SYMBOLS_PER_PRODUCTION];
/* A production options is an array of (possible) productions */
typedef production_t production_options_t[MAX_PRODUCTIONS];
/* Resolve the type from a production element */
inline parse_token_type_t production_element_type(production_element_t elem)
{
@ -65,8 +54,8 @@ inline bool production_element_is_valid(production_element_t elem)
return elem != token_type_invalid;
}
/* Fetch a production. We are passed two input tokens. The first input token is guaranteed to not be invalid; the second token may be invalid if there's no more tokens. */
const production_t *production_for_token(parse_token_type_t node_type, const parse_token_t &input1, const parse_token_t &input2, production_option_idx_t *out_which_production, wcstring *out_error_text);
/* Fetch a production. We are passed two input tokens. The first input token is guaranteed to not be invalid; the second token may be invalid if there's no more tokens. We may also set flags. */
const production_t *production_for_token(parse_token_type_t node_type, const parse_token_t &input1, const parse_token_t &input2, uint8_t *out_tag);
}

View file

@ -327,11 +327,7 @@ static wcstring block_type_user_presentable_description(parse_token_type_t type)
/** Returns a string description of the given parse node */
wcstring parse_node_t::describe() const
{
wcstring result = token_type_description(type);
if (type < FIRST_TERMINAL_TYPE)
{
append_format(result, L" (prod %d)", this->production_idx);
}
wcstring result = token_type_description(this->type);
return result;
}
@ -1151,7 +1147,7 @@ void parse_ll_t::accept_tokens(parse_token_t token1, parse_token_t token2)
// Get the production for the top of the stack
parse_stack_element_t &stack_elem = symbol_stack.back();
parse_node_t &node = nodes.at(stack_elem.node_idx);
const production_t *production = production_for_token(stack_elem.type, token1, token2, &node.production_idx, NULL /* error text */);
const production_t *production = production_for_token(stack_elem.type, token1, token2, &node.tag);
if (production == NULL)
{
parse_error_failed_production(stack_elem, token1);
@ -1544,13 +1540,9 @@ bool parse_node_tree_t::argument_list_is_root(const parse_node_t &node) const
enum parse_statement_decoration_t parse_node_tree_t::decoration_for_plain_statement(const parse_node_t &node) const
{
assert(node.type == symbol_plain_statement);
enum parse_statement_decoration_t decoration = parse_statement_decoration_none;
const parse_node_t *decorated_statement = this->get_parent(node, symbol_decorated_statement);
if (decorated_statement != NULL)
{
decoration = static_cast<enum parse_statement_decoration_t>(decorated_statement->production_idx);
}
return decoration;
const parse_node_t *decorated_statement = this->get_parent(node, symbol_decorated_statement);
parse_node_tag_t tag = decorated_statement ? decorated_statement->tag : parse_statement_decoration_none;
return static_cast<parse_statement_decoration_t>(tag);
}
bool parse_node_tree_t::command_for_plain_statement(const parse_node_t &node, const wcstring &src, wcstring *out_cmd) const
@ -1683,39 +1675,15 @@ parse_node_tree_t::parse_node_list_t parse_node_tree_t::comment_nodes_for_node(c
enum parse_bool_statement_type_t parse_node_tree_t::statement_boolean_type(const parse_node_t &node)
{
assert(node.type == symbol_boolean_statement);
switch (node.production_idx)
{
// These magic numbers correspond to productions for boolean_statement
case 0:
return parse_bool_and;
case 1:
return parse_bool_or;
case 2:
return parse_bool_not;
default:
{
fprintf(stderr, "Unexpected production in boolean statement\n");
PARSER_DIE();
return (enum parse_bool_statement_type_t)(-1);
}
}
return static_cast<parse_bool_statement_type_t>(node.tag);
}
bool parse_node_tree_t::job_should_be_backgrounded(const parse_node_t &job) const
{
assert(job.type == symbol_job);
assert(job.production_idx == 0);
bool result = false;
const parse_node_t *opt_background = get_child(job, 2, symbol_optional_background);
if (opt_background != NULL)
{
// We may get the value -1 if the node is not yet materialized (i.e. an incomplete parse tree)
assert(opt_background->production_idx == uint8_t(-1) || opt_background->production_idx <= 1);
result = (opt_background->production_idx == 1);
}
result = opt_background != NULL && opt_background->tag == parse_background;
return result;
}

View file

@ -66,13 +66,17 @@ wcstring parse_dump_tree(const parse_node_tree_t &tree, const wcstring &src);
wcstring token_type_description(parse_token_type_t type);
wcstring keyword_description(parse_keyword_t type);
/* Node flags */
enum
{
/* Flag indicating that the node has associated comment nodes */
parse_node_flag_has_comments = 1 << 0
parse_node_flag_has_comments = 1 << 0,
};
typedef uint8_t parse_node_flags_t;
/* Node-type specific tag value */
typedef uint8_t parse_node_tag_t;
/** Class for nodes of a parse tree. Since there's a lot of these, the size and order of the fields is important. */
class parse_node_t
{
@ -92,20 +96,23 @@ public:
/* Number of children */
uint8_t child_count;
/* Which production was used */
uint8_t production_idx;
/* Type of the node */
enum parse_token_type_t type;
/* Keyword associated with node */
enum parse_keyword_t keyword;
/* Node flags */
parse_node_flags_t flags;
/* This is used to store e.g. the statement decoration. */
parse_node_tag_t tag;
/* Description */
wcstring describe(void) const;
/* Constructor */
explicit parse_node_t(parse_token_type_t ty) : source_start(SOURCE_OFFSET_INVALID), source_length(0), parent(NODE_OFFSET_INVALID), child_start(0), child_count(0), production_idx(-1), type(ty), flags(0)
explicit parse_node_t(parse_token_type_t ty) : source_start(SOURCE_OFFSET_INVALID), source_length(0), parent(NODE_OFFSET_INVALID), child_start(0), child_count(0), type(ty), flags(0), tag(0)
{
}