/* Bison Action Scanner -*- C -*-
Copyright (C) 2006, 2007, 2008-2009 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see . */
%option debug nodefault noinput nounput noyywrap never-interactive
%option prefix="code_" outfile="lex.yy.c"
%{
/* Work around a bug in flex 2.5.31. See Debian bug 333231
. */
#undef code_wrap
#define code_wrap() 1
#define FLEX_PREFIX(Id) code_ ## Id
#include "flex-scanner.h"
#include "complain.h"
#include "reader.h"
#include "getargs.h"
#include "scan-code.h"
#include "symlist.h"
#include
#include
#include
/* The current calling start condition: SC_RULE_ACTION or
SC_SYMBOL_ACTION. */
# define YY_DECL static char *code_lex (code_props *self, int sc_context)
YY_DECL;
#define YY_USER_ACTION location_compute (loc, &loc->end, yytext, yyleng);
static void handle_action_dollar (symbol_list *rule, char *cp,
location dollar_loc);
static void handle_action_at (symbol_list *rule, char *cp, location at_loc);
/* A string to be pushed to obstack after dollar/at has been handled. */
static char *ref_tail_fields;
static location the_location;
static location *loc = &the_location;
/* A string representing the most recent translation. */
static char *last_string;
/* True if an untyped $$ or $n was seen. */
static bool untyped_var_seen;
%}
/* C and C++ comments in code. */
%x SC_COMMENT SC_LINE_COMMENT
/* Strings and characters in code. */
%x SC_STRING SC_CHARACTER
/* Whether in a rule or symbol action. Specifies the translation
of $ and @. */
%x SC_RULE_ACTION SC_SYMBOL_ACTION
/* POSIX says that a tag must be both an id and a C union member, but
historically almost any character is allowed in a tag. We disallow
NUL and newline, as this simplifies our implementation. */
tag [^\0\n>]+
/* Zero or more instances of backslash-newline. Following GCC, allow
white space between the backslash and the newline. */
splice (\\[ \f\t\v]*\n)*
/* C style identifier. Must start with letter. Will be used for
named symbol references. Shall be kept synchronized with
scan-gram.l "letter" and "id". */
letter [-.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
id {letter}({letter}|[0-9])*
ref -?[0-9]+|{id}|"["{id}"]"|"$"
%%
%{
/* Nesting level of the current code in braces. */
int braces_level = 0;
/* Whether a semicolon is probably needed.
The heuristic is that a semicolon is not needed after `{', `}', `;',
or a C preprocessor directive, and that whitespaces and comments
do not affect this flag.
Note that `{' does not need a semicolon because of `{}'.
A semicolon may be needed before a cpp direcive, but don't bother. */
bool need_semicolon = false;
/* Whether in a C preprocessor directive. Don't use a start condition
for this because, at the end of strings and comments, we still need
to know whether we're in a directive. */
bool in_cpp = false;
/* This scanner is special: it is invoked only once, henceforth
is expected to return only once. This initialization is
therefore done once per action to translate. */
aver (sc_context == SC_SYMBOL_ACTION
|| sc_context == SC_RULE_ACTION
|| sc_context == INITIAL);
BEGIN sc_context;
%}
/*------------------------------------------------------------.
| Scanning a C comment. The initial `/ *' is already eaten. |
`------------------------------------------------------------*/
{
"*"{splice}"/" STRING_GROW; BEGIN sc_context;
}
/*--------------------------------------------------------------.
| Scanning a line comment. The initial `//' is already eaten. |
`--------------------------------------------------------------*/
{
"\n" STRING_GROW; BEGIN sc_context;
{splice} STRING_GROW;
}
/*--------------------------------------------.
| Scanning user-code characters and strings. |
`--------------------------------------------*/
{
{splice}|\\{splice}. STRING_GROW;
}
{
"'" STRING_GROW; BEGIN sc_context;
}
{
"\"" STRING_GROW; BEGIN sc_context;
}
{
"'" {
STRING_GROW;
BEGIN SC_CHARACTER;
need_semicolon = true;
}
"\"" {
STRING_GROW;
BEGIN SC_STRING;
need_semicolon = true;
}
"/"{splice}"*" {
STRING_GROW;
BEGIN SC_COMMENT;
}
"/"{splice}"/" {
STRING_GROW;
BEGIN SC_LINE_COMMENT;
}
}
{
"$"("<"{tag}">")?{ref} {
ref_tail_fields = 0;
handle_action_dollar (self->rule, yytext, *loc);
if (ref_tail_fields) {
obstack_sgrow (&obstack_for_string, ref_tail_fields);
}
need_semicolon = true;
}
"@"{ref} {
ref_tail_fields = 0;
handle_action_at (self->rule, yytext, *loc);
if (ref_tail_fields) {
obstack_sgrow (&obstack_for_string, ref_tail_fields);
}
need_semicolon = true;
}
"$" {
warn_at (*loc, _("stray `$'"));
obstack_sgrow (&obstack_for_string, "$][");
need_semicolon = true;
}
"@" {
warn_at (*loc, _("stray `@'"));
obstack_sgrow (&obstack_for_string, "@@");
need_semicolon = true;
}
"[" {
obstack_sgrow (&obstack_for_string, "@{");
need_semicolon = true;
}
"]" {
obstack_sgrow (&obstack_for_string, "@}");
need_semicolon = true;
}
";" STRING_GROW; need_semicolon = false;
"{" STRING_GROW; ++braces_level; need_semicolon = false;
"}" {
bool outer_brace = --braces_level == 0;
/* As an undocumented Bison extension, append `;' before the last
brace in braced code, so that the user code can omit trailing
`;'. But do not append `;' if emulating Yacc, since Yacc does
not append one. */
if (outer_brace && !yacc_flag && language_prio == default_prio
&& skeleton_prio == default_prio && need_semicolon && ! in_cpp)
{
warn_at (*loc, _("a `;' might be needed at the end of action code"));
warn_at (*loc, _("future versions of Bison will not add the `;'"));
obstack_1grow (&obstack_for_string, ';');
}
STRING_GROW;
need_semicolon = false;
}
/* Preprocessing directives should only be recognized at the beginning
of lines, allowing whitespace including comments, but in C/C++,
`#' can only be the start of preprocessor directives or within
`#define' directives anyway, so don't bother with begin of line. */
"#" STRING_GROW; in_cpp = true;
{splice} STRING_GROW;
[\n\r] STRING_GROW; if (in_cpp) in_cpp = need_semicolon = false;
[ \t\f] STRING_GROW;
. STRING_GROW; need_semicolon = true;
}
{
"$$" {
obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
self->is_value_used = true;
}
"@$" {
obstack_sgrow (&obstack_for_string, "]b4_at_dollar[");
locations_flag = true;
}
}
/*-----------------------------------------.
| Escape M4 quoting characters in C code. |
`-----------------------------------------*/
<*>
{
\$ obstack_sgrow (&obstack_for_string, "$][");
\@ obstack_sgrow (&obstack_for_string, "@@");
\[ obstack_sgrow (&obstack_for_string, "@{");
\] obstack_sgrow (&obstack_for_string, "@}");
}
/*-----------------------------------------------------.
| By default, grow the string obstack with the input. |
`-----------------------------------------------------*/
<*>.|\n STRING_GROW;
/* End of processing. */
<*><> {
STRING_FINISH;
return last_string;
}
%%
static inline bool
is_dot_or_dash (char ch)
{
return ch == '.' || ch == '-';
}
static inline bool
contains_dot_or_dash (const char* p)
{
for (; *p; ++p)
if (is_dot_or_dash (*p))
return true;
return false;
}
/* Defines a variant of a symbolic name resolution. */
typedef struct
{
/* Index in symbol list. */
unsigned symbol_index;
/* Matched symbol id and loc. */
uniqstr id;
location loc;
/* Hiding named reference. */
named_ref* hidden_by;
/* Error flags. May contain zero (no errors) or
a combination of VARIANT_* values. */
unsigned err;
} variant;
/* Set when the variant refers to a symbol hidden
by an explicit symbol reference. */
#define VARIANT_HIDDEN (1 << 0)
/* Set when the variant refers to a symbol containing
dots or dashes. Will require explicit bracketing. */
#define VARIANT_BAD_BRACKETING (1 << 1)
/* Set when the variant refers to a symbol which is
not visible from current midrule. */
#define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2)
static variant *variant_table = 0;
static unsigned variant_table_size = 0;
static unsigned variant_count = 0;
static variant *
variant_table_grow (void)
{
++variant_count;
if (variant_count > variant_table_size)
{
while (variant_count > variant_table_size)
variant_table_size = 2 * variant_table_size + 3;
variant_table = xnrealloc (variant_table, variant_table_size,
sizeof *variant_table);
}
return &variant_table[variant_count - 1];
}
static void
variant_table_free (void)
{
free (variant_table);
variant_table = 0;
variant_table_size = variant_count = 0;
}
static char *
find_prefix_end (const char *prefix, char *begin, char *end)
{
char *ptr = begin;
for (; *prefix && ptr != end; ++prefix, ++ptr)
if (*prefix != *ptr)
return 0;
if (*prefix)
return 0;
return ptr;
}
static variant *
variant_add (uniqstr id, location id_loc, unsigned symbol_index,
char *cp, char *cp_end, bool exact_mode)
{
char *prefix_end;
prefix_end = find_prefix_end (id, cp, cp_end);
if (prefix_end &&
(prefix_end == cp_end ||
(!exact_mode && is_dot_or_dash (*prefix_end))))
{
variant *r = variant_table_grow ();
r->symbol_index = symbol_index;
r->id = id;
r->loc = id_loc;
r->hidden_by = NULL;
r->err = 0;
return r;
}
else
return NULL;
}
static const char *
get_at_spec(unsigned symbol_index)
{
static char at_buf[20];
if (symbol_index == 0)
strcpy (at_buf, "$$");
else
snprintf (at_buf, sizeof at_buf, "$%u", symbol_index);
return at_buf;
}
static void
show_sub_messages (const char* cp, bool exact_mode, int midrule_rhs_index,
char dollar_or_at, bool is_warning)
{
unsigned i;
for (i = 0; i < variant_count; ++i)
{
const variant *var = &variant_table[i];
const char *at_spec = get_at_spec (var->symbol_index);
if (var->err == 0)
{
if (is_warning)
warn_at (var->loc, _(" refers to: %c%s at %s"),
dollar_or_at, var->id, at_spec);
else
complain_at (var->loc, _(" refers to: %c%s at %s"),
dollar_or_at, var->id, at_spec);
}
else
{
static struct obstack msg_buf;
const char *tail = exact_mode ? "" :
cp + strlen (var->id);
const char *id = var->hidden_by ? var->hidden_by->id :
var->id;
location id_loc = var->hidden_by ? var->hidden_by->loc :
var->loc;
/* Create the explanation message. */
obstack_init (&msg_buf);
obstack_fgrow1 (&msg_buf, " possibly meant: %c", dollar_or_at);
if (contains_dot_or_dash (id))
obstack_fgrow1 (&msg_buf, "[%s]", id);
else
obstack_sgrow (&msg_buf, id);
obstack_sgrow (&msg_buf, tail);
if (var->err & VARIANT_HIDDEN)
{
obstack_fgrow1 (&msg_buf, ", hiding %c", dollar_or_at);
if (contains_dot_or_dash (var->id))
obstack_fgrow1 (&msg_buf, "[%s]", var->id);
else
obstack_sgrow (&msg_buf, var->id);
obstack_sgrow (&msg_buf, tail);
}
obstack_fgrow1 (&msg_buf, " at %s", at_spec);
if (var->err & VARIANT_NOT_VISIBLE_FROM_MIDRULE)
obstack_fgrow1 (&msg_buf, ", cannot be accessed from "
"mid-rule action at $%d", midrule_rhs_index);
obstack_1grow (&msg_buf, '\0');
if (is_warning)
warn_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf));
else
complain_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf));
obstack_free (&msg_buf, 0);
}
}
}
/* Returned from "parse_ref" when the reference
is inappropriate. */
#define INVALID_REF (INT_MIN)
/* Returned from "parse_ref" when the reference
points to LHS ($$) of the current rule or midrule. */
#define LHS_REF (INT_MIN + 1)
/* Parse named or positional reference. In case of positional
references, can return negative values for $-n "deep" stack
accesses. */
static long int
parse_ref (char *cp, symbol_list *rule, int rule_length,
int midrule_rhs_index, char *text, location text_loc,
char dollar_or_at)
{
symbol_list *l;
char *cp_end;
bool exact_mode;
unsigned i;
unsigned valid_variants = 0;
unsigned valid_variant_index = 0;
if ('$' == *cp)
return LHS_REF;
if (c_isdigit (*cp) || (*cp == '-' && c_isdigit (* (cp + 1))))
{
long int num = strtol (cp, &cp, 10);
if (1 - INT_MAX + rule_length <= num && num <= rule_length)
return num;
else
{
complain_at (text_loc, _("integer out of range: %s"),
quote (text));
return INVALID_REF;
}
}
if ('[' == *cp)
{
/* Ignore the brackets. */
char *p;
for (p = ++cp; *p != ']'; ++p)
continue;
cp_end = p;
exact_mode = true;
}
else
{
/* Take all characters of the name. */
char* p;
for (p = cp; *p; ++p)
if (is_dot_or_dash (*p))
{
ref_tail_fields = p;
break;
}
for (p = cp; *p; ++p)
continue;
cp_end = p;
exact_mode = false;
}
/* Add all relevant variants. */
{
unsigned symbol_index;
variant_count = 0;
for (symbol_index = 0, l = rule; !symbol_list_null (l);
++symbol_index, l = l->next)
{
variant *var;
if (l->content_type != SYMLIST_SYMBOL)
continue;
var = variant_add (l->content.sym->tag, l->sym_loc,
symbol_index, cp, cp_end, exact_mode);
if (var && l->named_ref)
var->hidden_by = l->named_ref;
if (l->named_ref)
variant_add (l->named_ref->id, l->named_ref->loc,
symbol_index, cp, cp_end, exact_mode);
}
}
/* Check errors. */
for (i = 0; i < variant_count; ++i)
{
variant *var = &variant_table[i];
unsigned symbol_index = var->symbol_index;
/* Check visibility from mid-rule actions. */
if (midrule_rhs_index != 0
&& (symbol_index == 0 || midrule_rhs_index < symbol_index))
var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE;
/* Check correct bracketing. */
if (!exact_mode && contains_dot_or_dash (var->id))
var->err |= VARIANT_BAD_BRACKETING;
/* Check using of hidden symbols. */
if (var->hidden_by)
var->err |= VARIANT_HIDDEN;
if (!var->err)
{
valid_variant_index = i;
++valid_variants;
}
}
switch (valid_variants)
{
case 0:
if (variant_count == 0)
complain_at (text_loc, _("invalid reference: %s, symbol not found"),
quote (text));
else
{
complain_at (text_loc, _("invalid reference: %s"),
quote (text));
show_sub_messages (cp, exact_mode, midrule_rhs_index,
dollar_or_at, false);
}
return INVALID_REF;
case 1:
{
if (variant_count > 1)
{
warn_at (text_loc, _("misleading reference: %s"),
quote (text));
show_sub_messages (cp, exact_mode, midrule_rhs_index,
dollar_or_at, true);
}
{
unsigned symbol_index =
variant_table[valid_variant_index].symbol_index;
return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index;
}
}
case 2:
default:
complain_at (text_loc, _("ambiguous reference: %s"),
quote (text));
show_sub_messages (cp, exact_mode, midrule_rhs_index,
dollar_or_at, false);
return INVALID_REF;
}
/* Not reachable. */
return INVALID_REF;
}
/* Keeps track of the maximum number of semantic values to the left of
a handle (those referenced by $0, $-1, etc.) are required by the
semantic actions of this grammar. */
int max_left_semantic_context = 0;
/*------------------------------------------------------------------.
| TEXT is pointing to a wannabee semantic value (i.e., a `$'). |
| |
| Possible inputs: $[]($|integer) |
| |
| Output to OBSTACK_FOR_STRING a reference to this semantic value. |
`------------------------------------------------------------------*/
static void
handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
{
char const *type_name = NULL;
char *cp = text + 1;
char *gt_ptr = 0;
symbol_list *effective_rule;
int effective_rule_length;
int n;
if (rule->midrule_parent_rule)
{
effective_rule = rule->midrule_parent_rule;
effective_rule_length = rule->midrule_parent_rhs_index - 1;
}
else
{
effective_rule = rule;
effective_rule_length = symbol_list_length (rule->next);
}
/* Get the type name if explicit. */
if (*cp == '<')
{
type_name = ++cp;
while (*cp != '>')
++cp;
/* The '>' symbol will be later replaced by '\0'. Original
'text' is needed for error messages. */
gt_ptr = cp;
++cp;
if (untyped_var_seen)
complain_at (dollar_loc, _("explicit type given in untyped grammar"));
tag_seen = true;
}
n = parse_ref (cp, effective_rule, effective_rule_length,
rule->midrule_parent_rhs_index, text, dollar_loc, '$');
if (gt_ptr)
*gt_ptr = '\0';
switch (n)
{
case INVALID_REF:
break;
case LHS_REF:
if (!type_name)
type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0);
if (!type_name)
{
if (union_seen | tag_seen)
{
if (rule->midrule_parent_rule)
complain_at (dollar_loc,
_("$$ for the midrule at $%d of `%s'"
" has no declared type"),
rule->midrule_parent_rhs_index,
effective_rule->content.sym->tag);
else
complain_at (dollar_loc, _("$$ of `%s' has no declared type"),
rule->content.sym->tag);
}
else
untyped_var_seen = true;
type_name = "";
}
obstack_fgrow1 (&obstack_for_string,
"]b4_lhs_value([%s])[", type_name);
rule->action_props.is_value_used = true;
break;
default:
if (max_left_semantic_context < 1 - n)
max_left_semantic_context = 1 - n;
if (!type_name && 0 < n)
type_name =
symbol_list_n_type_name_get (effective_rule, dollar_loc, n);
if (!type_name)
{
if (union_seen | tag_seen)
complain_at (dollar_loc, _("$%s of `%s' has no declared type"),
cp, effective_rule->content.sym->tag);
else
untyped_var_seen = true;
type_name = "";
}
obstack_fgrow3 (&obstack_for_string,
"]b4_rhs_value(%d, %d, [%s])[",
effective_rule_length, n, type_name);
if (n > 0)
symbol_list_n_get (effective_rule, n)->action_props.is_value_used =
true;
break;
}
}
/*------------------------------------------------------.
| TEXT is a location token (i.e., a `@...'). Output to |
| OBSTACK_FOR_STRING a reference to this location. |
`------------------------------------------------------*/
static void
handle_action_at (symbol_list *rule, char *text, location at_loc)
{
char *cp = text + 1;
symbol_list *effective_rule;
int effective_rule_length;
int n;
if (rule->midrule_parent_rule)
{
effective_rule = rule->midrule_parent_rule;
effective_rule_length = rule->midrule_parent_rhs_index - 1;
}
else
{
effective_rule = rule;
effective_rule_length = symbol_list_length (rule->next);
}
locations_flag = true;
n = parse_ref (cp, effective_rule, effective_rule_length,
rule->midrule_parent_rhs_index, text, at_loc, '@');
switch (n)
{
case INVALID_REF:
break;
case LHS_REF:
obstack_sgrow (&obstack_for_string, "]b4_lhs_location[");
break;
default:
obstack_fgrow2 (&obstack_for_string, "]b4_rhs_location(%d, %d)[",
effective_rule_length, n);
break;
}
}
/*-------------------------.
| Initialize the scanner. |
`-------------------------*/
/* Translate the dollars and ats in \a self, in the context \a sc_context
(SC_RULE_ACTION, SC_SYMBOL_ACTION, INITIAL). */
static char const *
translate_action (code_props *self, int sc_context)
{
char *res;
static bool initialized = false;
if (!initialized)
{
obstack_init (&obstack_for_string);
yy_flex_debug = 0;
initialized = true;
}
loc->start = loc->end = self->location.start;
yy_switch_to_buffer (yy_scan_string (self->code));
res = code_lex (self, sc_context);
yy_delete_buffer (YY_CURRENT_BUFFER);
return res;
}
/*------------------------------------------------------------------------.
| Implementation of the public interface as documented in "scan-code.h". |
`------------------------------------------------------------------------*/
void
code_props_none_init (code_props *self)
{
*self = code_props_none;
}
code_props const code_props_none = CODE_PROPS_NONE_INIT;
void
code_props_plain_init (code_props *self, char const *code,
location code_loc)
{
self->kind = CODE_PROPS_PLAIN;
self->code = code;
self->location = code_loc;
self->is_value_used = false;
self->rule = NULL;
self->named_ref = NULL;
}
void
code_props_symbol_action_init (code_props *self, char const *code,
location code_loc)
{
self->kind = CODE_PROPS_SYMBOL_ACTION;
self->code = code;
self->location = code_loc;
self->is_value_used = false;
self->rule = NULL;
self->named_ref = NULL;
}
void
code_props_rule_action_init (code_props *self, char const *code,
location code_loc, symbol_list *rule,
named_ref *name)
{
self->kind = CODE_PROPS_RULE_ACTION;
self->code = code;
self->location = code_loc;
self->is_value_used = false;
self->rule = rule;
self->named_ref = name;
}
void
code_props_translate_code (code_props *self)
{
switch (self->kind)
{
case CODE_PROPS_NONE:
break;
case CODE_PROPS_PLAIN:
self->code = translate_action (self, INITIAL);
break;
case CODE_PROPS_SYMBOL_ACTION:
self->code = translate_action (self, SC_SYMBOL_ACTION);
break;
case CODE_PROPS_RULE_ACTION:
self->code = translate_action (self, SC_RULE_ACTION);
break;
}
}
void
code_scanner_last_string_free (void)
{
STRING_FREE;
}
void
code_scanner_free (void)
{
obstack_free (&obstack_for_string, 0);
variant_table_free ();
/* Reclaim Flex's buffers. */
yylex_destroy ();
}