/* Bison Action Scanner -*- C -*-
- Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc.
+ Copyright (C) 2006-2012 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
-%option debug nodefault nounput noyywrap never-interactive
+%option debug nodefault noinput nounput noyywrap never-interactive
%option prefix="code_" outfile="lex.yy.c"
%{
#include "complain.h"
#include "reader.h"
#include "getargs.h"
-#include <get-errno.h>
-#include <quote.h>
-
#include "scan-code.h"
#include "symlist.h"
+#include <c-ctype.h>
+#include <get-errno.h>
+#include <quote.h>
+
/* 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)
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;
/* 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
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. */
"'" {
STRING_GROW;
BEGIN SC_CHARACTER;
+ need_semicolon = true;
}
"\"" {
STRING_GROW;
BEGIN SC_STRING;
+ need_semicolon = true;
}
"/"{splice}"*" {
STRING_GROW;
<SC_RULE_ACTION>
{
- "$"("<"{tag}">")?(-?[0-9]+|"$") {
+ "$"("<"{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;
}
- "@"(-?[0-9]+|"$") {
+ "@"{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; ++braces_level;
+ ";" 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.
-
- FIXME: Bison should warn if a semicolon seems to be necessary
- here, and should omit the semicolon if it seems unnecessary
- (e.g., after ';', '{', or '}', each followed by comments or
- white space). Such a warning shouldn't depend on --yacc; it
- should depend on a new --pedantic option, which would cause
- Bison to warn if it detects an extension to POSIX. --pedantic
- should also diagnose other Bison extensions like %yacc.
- Perhaps there should also be a GCC-style --pedantic-errors
- option, so that such warnings are diagnosed as errors. */
- if (outer_brace && ! yacc_flag)
- obstack_1grow (&obstack_for_string, ';');
+ 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;
+
+ /* YYFAIL is undocumented and was formally deprecated in Bison
+ 2.4.2. */
+ YYFAIL {
+ STRING_GROW; need_semicolon = true;
+ warn_at (*loc, _("use of YYFAIL, which is deprecated and will be"
+ " removed"));
}
+
+ /* The sole purpose of this is to make sure identifiers that merely
+ contain YYFAIL don't produce the above warning. */
+ [A-Za-z_][0-9A-Za-z_]* STRING_GROW; need_semicolon = true;
+
+ . STRING_GROW; need_semicolon = true;
}
<SC_SYMBOL_ACTION>
%%
+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 explicit_bracketing)
+{
+ char *prefix_end;
+
+ prefix_end = find_prefix_end (id, cp, cp_end);
+ if (prefix_end &&
+ (prefix_end == cp_end ||
+ (!explicit_bracketing && 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 explicit_bracketing,
+ int midrule_rhs_index, char dollar_or_at,
+ bool is_warning, unsigned indent)
+{
+ 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_indent (var->loc, &indent, _("refers to: %c%s at %s"),
+ dollar_or_at, var->id, at_spec);
+ else
+ complain_at_indent (var->loc, &indent, _("refers to: %c%s at %s"),
+ dollar_or_at, var->id, at_spec);
+ }
+ else
+ {
+ static struct obstack msg_buf;
+ const char *tail = explicit_bracketing ? "" :
+ 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)
+ {
+ const char *format =
+ _(", cannot be accessed from mid-rule action at $%d");
+ obstack_fgrow1 (&msg_buf, format, midrule_rhs_index);
+ }
+
+ obstack_1grow (&msg_buf, '\0');
+ if (is_warning)
+ warn_at_indent (id_loc, &indent, "%s",
+ (char *) obstack_finish (&msg_buf));
+ else
+ complain_at_indent (id_loc, &indent, "%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)
+
+/* Sub-messages indent. */
+#define SUB_INDENT (4)
+
+/* Parse named or positional reference. In case of positional
+ references, can return negative values for $-n "deep" stack
+ accesses. */
+static long int
+parse_ref (char *cp, symbol_list *rule, int rule_length,
+ int midrule_rhs_index, char *text, location text_loc,
+ char dollar_or_at)
+{
+ symbol_list *l;
+ char *cp_end;
+ bool explicit_bracketing;
+ unsigned i;
+ unsigned valid_variants = 0;
+ unsigned valid_variant_index = 0;
+
+ if ('$' == *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;
+
+ explicit_bracketing = 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;
+
+ explicit_bracketing = 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, explicit_bracketing);
+ 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, explicit_bracketing);
+ }
+ }
+
+ /* 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 (!explicit_bracketing && 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:
+ {
+ unsigned len = (explicit_bracketing || !ref_tail_fields) ?
+ cp_end - cp : ref_tail_fields - cp;
+ unsigned indent = 0;
+
+ complain_at_indent (text_loc, &indent, _("invalid reference: %s"),
+ quote (text));
+ indent += SUB_INDENT;
+ if (len == 0)
+ {
+ location sym_loc = text_loc;
+ sym_loc.start.column += 1;
+ sym_loc.end = sym_loc.start;
+ const char *format =
+ _("syntax error after `%c', expecting integer, letter,"
+ " `_', `[', or `$'");
+ complain_at_indent (sym_loc, &indent, format, dollar_or_at);
+ }
+ else if (midrule_rhs_index)
+ {
+ const char *format =
+ _("symbol not found in production before $%d: %.*s");
+ complain_at_indent (rule->location, &indent, format,
+ midrule_rhs_index, len, cp);
+ }
+ else
+ {
+ const char *format =
+ _("symbol not found in production: %.*s");
+ complain_at_indent (rule->location, &indent, format,
+ len, cp);
+ }
+
+ if (variant_count > 0)
+ show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+ dollar_or_at, false, indent);
+ return INVALID_REF;
+ }
+ case 1:
+ {
+ unsigned indent = 0;
+ if (variant_count > 1)
+ {
+ warn_at_indent (text_loc, &indent, _("misleading reference: %s"),
+ quote (text));
+ show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+ dollar_or_at, true, indent + SUB_INDENT);
+ }
+ {
+ unsigned symbol_index =
+ variant_table[valid_variant_index].symbol_index;
+ return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index;
+ }
+ }
+ case 2:
+ default:
+ {
+ unsigned indent = 0;
+ complain_at_indent (text_loc, &indent, _("ambiguous reference: %s"),
+ quote (text));
+ show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
+ dollar_or_at, false, indent + SUB_INDENT);
+ 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, $-1, etc.) are required by the
semantic actions of this grammar. */
{
char const *type_name = NULL;
char *cp = text + 1;
+ char *gt_ptr = 0;
symbol_list *effective_rule;
int effective_rule_length;
+ int n;
if (rule->midrule_parent_rule)
{
type_name = ++cp;
while (*cp != '>')
++cp;
- *cp = '\0';
+
+ /* The '>' symbol will be later replaced by '\0'. Original
+ 'text' is needed for error messages. */
+ gt_ptr = cp;
++cp;
if (untyped_var_seen)
complain_at (dollar_loc, _("explicit type given in untyped grammar"));
tag_seen = true;
}
- if (*cp == '$')
+ n = parse_ref (cp, effective_rule, effective_rule_length,
+ rule->midrule_parent_rhs_index, text, dollar_loc, '$');
+
+ if (gt_ptr)
+ *gt_ptr = '\0';
+
+ switch (n)
{
+ case INVALID_REF:
+ break;
+
+ case LHS_REF:
if (!type_name)
type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0);
obstack_fgrow1 (&obstack_for_string,
"]b4_lhs_value([%s])[", type_name);
rule->action_props.is_value_used = true;
- }
- else
- {
- long int num = strtol (cp, NULL, 10);
-
- if (1 - INT_MAX + effective_rule_length <= num
- && num <= effective_rule_length)
+ break;
+
+ default:
+ if (max_left_semantic_context < 1 - n)
+ max_left_semantic_context = 1 - n;
+ if (!type_name && 0 < n)
+ type_name =
+ symbol_list_n_type_name_get (effective_rule, dollar_loc, n);
+ if (!type_name)
{
- int n = num;
- if (max_left_semantic_context < 1 - n)
- max_left_semantic_context = 1 - n;
- if (!type_name && 0 < n)
- type_name =
- symbol_list_n_type_name_get (effective_rule, dollar_loc, n);
- if (!type_name)
- {
- if (union_seen | tag_seen)
- complain_at (dollar_loc, _("$%d of `%s' has no declared type"),
- n, 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;
+ if (union_seen | tag_seen)
+ complain_at (dollar_loc, _("$%s of `%s' has no declared type"),
+ cp, effective_rule->content.sym->tag);
+ else
+ untyped_var_seen = true;
+ type_name = "";
}
- else
- complain_at (dollar_loc, _("integer out of range: %s"), quote (text));
+
+ obstack_fgrow3 (&obstack_for_string,
+ "]b4_rhs_value(%d, %d, [%s])[",
+ effective_rule_length, n, type_name);
+ if (n > 0)
+ symbol_list_n_get (effective_rule, n)->action_props.is_value_used =
+ true;
+ break;
}
}
handle_action_at (symbol_list *rule, char *text, location at_loc)
{
char *cp = text + 1;
- int effective_rule_length =
- (rule->midrule_parent_rule
- ? rule->midrule_parent_rhs_index - 1
- : symbol_list_length (rule->next));
+ symbol_list *effective_rule;
+ int effective_rule_length;
+ int n;
+
+ if (rule->midrule_parent_rule)
+ {
+ effective_rule = rule->midrule_parent_rule;
+ effective_rule_length = rule->midrule_parent_rhs_index - 1;
+ }
+ else
+ {
+ effective_rule = rule;
+ effective_rule_length = symbol_list_length (rule->next);
+ }
locations_flag = true;
- if (*cp == '$')
- obstack_sgrow (&obstack_for_string, "]b4_lhs_location[");
- else
+ n = parse_ref (cp, effective_rule, effective_rule_length,
+ rule->midrule_parent_rhs_index, text, at_loc, '@');
+ switch (n)
{
- long int num = strtol (cp, NULL, 10);
+ case INVALID_REF:
+ break;
- if (1 - INT_MAX + effective_rule_length <= num
- && num <= effective_rule_length)
- {
- int n = num;
- obstack_fgrow2 (&obstack_for_string, "]b4_rhs_location(%d, %d)[",
- effective_rule_length, n);
- }
- else
- complain_at (at_loc, _("integer out of range: %s"), quote (text));
+ 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;
}
}
code_props const code_props_none = CODE_PROPS_NONE_INIT;
void
-code_props_plain_init (code_props *self, char const *code, location code_loc)
+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
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)
+ 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_scanner_free (void)
{
obstack_free (&obstack_for_string, 0);
+ variant_table_free ();
+
/* Reclaim Flex's buffers. */
yylex_destroy ();
}
projects / bison.git / blobdiff