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Revert "Simplify handling of '.' and '-' after unbracketed named references."

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This reverts commit bf3e44fe46.

See discussion following
<http://lists.gnu.org/archive/html/bison-patches/2011-01/msg00030.html>.
This commit is contained in:
Joel E. Denny
2011-01-29 10:58:03 -05:00
parent fe3cae17a1
commit 676997e53b
7 changed files with 159 additions and 147 deletions
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182
src/scan-code.l
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@@ -47,9 +47,12 @@ YY_DECL;
#define YY_USER_ACTION location_compute (loc, &loc->end, yytext, yyleng);
static void handle_action_dollar (symbol_list *, char *, unsigned, location);
static void handle_action_at (symbol_list const *, char const *, unsigned,
location);
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;
@@ -79,16 +82,12 @@ tag [^\0\n>]+
white space between the backslash and the newline. */
splice (\\[ \f\t\v]*\n)*
/* A Bison identifier. Keep this synchronized with scan-gram.l "id". */
letter [-.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
id {letter}({letter}|[0-9])*
/* An identifier that can appear unbracketed in a reference.
This happens to be the same as a C-language identifier. */
c_letter [abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
c_id {c_letter}({c_letter}|[0-9])*
ref -?[0-9]+|{c_id}|"["{id}"]"|"$"
/* C style identifier. Must start with letter. Will be used for
named symbol references. Shall be kept synchronized with
scan-gram.l "letter" and "id". */
letter [.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
id -*(-|{letter}({letter}|[-0-9])*)
ref -?[0-9]+|{id}|"["{id}"]"|"$"
%%
@@ -183,11 +182,19 @@ ref -?[0-9]+|{c_id}|"["{id}"]"|"$"
<SC_RULE_ACTION>
{
"$"("<"{tag}">")?{ref} {
handle_action_dollar (self->rule, yytext, yyleng, *loc);
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} {
handle_action_at (self->rule, yytext, yyleng, *loc);
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;
}
"$" {
@@ -331,9 +338,13 @@ typedef struct
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 << 1)
#define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2)
static variant *variant_table = 0;
static unsigned variant_table_size = 0;
@@ -361,25 +372,31 @@ variant_table_free (void)
variant_table_size = variant_count = 0;
}
/* Return TRUE if ID matches the string from CP up to CP_END.
The string does not contain null bytes. */
static bool
identifier_matches (char const *id, char const *cp, char const *cp_end)
static char *
find_prefix_end (const char *prefix, char *begin, char *end)
{
while (cp != cp_end)
if (*id++ != *cp++)
return false;
return !*id;
char *ptr = begin;
for (; *prefix && ptr != end; ++prefix, ++ptr)
if (*prefix != *ptr)
return 0;
if (*prefix)
return 0;
return ptr;
}
/* If scanning ID, return a new variant with that ID, at location
ID_LOC with index SYMBOL_INDEX. Otherwise, return NULL. The
currently scanned identifier starts at CP and ends at CP_END. */
static variant *
variant_add (uniqstr id, location id_loc, unsigned symbol_index,
char const *cp, char const *cp_end)
char *cp, char *cp_end, bool explicit_bracketing)
{
if (identifier_matches (id, cp, cp_end))
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;
@@ -404,15 +421,11 @@ get_at_spec(unsigned symbol_index)
return at_buf;
}
/* Show a subsidiary message for a problem with a grammar rule. TEXT
points to the problematic reference. MIDRULE_RHS_INDEX is the rhs
index (1-origin) in the rule. If IS_WARNING, it is a warning,
otherwise a complaint. Indent the message INDENT spaces. */
static void
show_sub_messages (char const *text, int midrule_rhs_index,
show_sub_messages (const char* cp, bool explicit_bracketing,
int midrule_rhs_index, char dollar_or_at,
bool is_warning, unsigned indent)
{
char dollar_or_at = *text;
unsigned i;
for (i = 0; i < variant_count; ++i)
@@ -432,6 +445,8 @@ show_sub_messages (char const *text, int midrule_rhs_index,
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 :
@@ -445,6 +460,7 @@ show_sub_messages (char const *text, int midrule_rhs_index,
obstack_fgrow1 (&msg_buf, "[%s]", id);
else
obstack_sgrow (&msg_buf, id);
obstack_sgrow (&msg_buf, tail);
if (var->err & VARIANT_HIDDEN)
{
@@ -453,6 +469,7 @@ show_sub_messages (char const *text, int midrule_rhs_index,
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);
@@ -487,22 +504,16 @@ show_sub_messages (char const *text, int midrule_rhs_index,
/* Sub-messages indent. */
#define SUB_INDENT (4)
/* Return the index of a named or positional reference starting at CP
for a rule RULE of length RULE_LENGTH. If MIDRULE_RHS_INDEX is
nonzero, this is a generated midrule whose rhs index (1-origin) is
MIDRULE_RHS_INDEX in the parent rule. The entire semantic value
containing the reference is TEXT, of length TEXTLEN. Its location
is TEXT_LOC.
In case of positional references, this can return negative values
for $-n "deep" stack accesses. */
/* Parse named or positional reference. In case of positional
references, can return negative values for $-n "deep" stack
accesses. */
static long int
parse_ref (char const *cp, symbol_list const *rule, int rule_length,
int midrule_rhs_index, char const *text, unsigned textlen,
location text_loc)
parse_ref (char *cp, symbol_list *rule, int rule_length,
int midrule_rhs_index, char *text, location text_loc,
char dollar_or_at)
{
symbol_list const *l;
char const *cp_end;
symbol_list *l;
char *cp_end;
bool explicit_bracketing;
unsigned i;
unsigned valid_variants = 0;
@@ -511,9 +522,9 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
if ('$' == *cp)
return LHS_REF;
if (c_isdigit (*cp) || *cp == '-')
if (c_isdigit (*cp) || (*cp == '-' && c_isdigit (* (cp + 1))))
{
long int num = strtol (cp, NULL, 10);
long int num = strtol (cp, &cp, 10);
if (1 - INT_MAX + rule_length <= num && num <= rule_length)
return num;
else
@@ -524,9 +535,32 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
}
}
explicit_bracketing = (*cp == '[');
cp += explicit_bracketing;
cp_end = text + textlen - explicit_bracketing;
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. */
{
@@ -540,13 +574,13 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
continue;
var = variant_add (l->content.sym->tag, l->sym_loc,
symbol_index, cp, cp_end);
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);
symbol_index, cp, cp_end, explicit_bracketing);
}
}
@@ -561,6 +595,10 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
&& (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;
@@ -576,7 +614,8 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
{
case 0:
{
unsigned len = cp_end - cp;
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"),
@@ -590,7 +629,7 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
const char *format =
_("syntax error after `%c', expecting integer, letter,"
" `_', `[', or `$'");
complain_at_indent (sym_loc, &indent, format, *text);
complain_at_indent (sym_loc, &indent, format, dollar_or_at);
}
else if (midrule_rhs_index)
{
@@ -608,7 +647,8 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
}
if (variant_count > 0)
show_sub_messages (text, midrule_rhs_index, false, indent);
show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
dollar_or_at, false, indent);
return INVALID_REF;
}
case 1:
@@ -618,8 +658,8 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
{
warn_at_indent (text_loc, &indent, _("misleading reference: %s"),
quote (text));
show_sub_messages (text, midrule_rhs_index, true,
indent + SUB_INDENT);
show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
dollar_or_at, true, indent + SUB_INDENT);
}
{
unsigned symbol_index =
@@ -633,8 +673,8 @@ parse_ref (char const *cp, symbol_list const *rule, int rule_length,
unsigned indent = 0;
complain_at_indent (text_loc, &indent, _("ambiguous reference: %s"),
quote (text));
show_sub_messages (text, midrule_rhs_index, false,
indent + SUB_INDENT);
show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
dollar_or_at, false, indent + SUB_INDENT);
return INVALID_REF;
}
}
@@ -652,14 +692,13 @@ int max_left_semantic_context = 0;
/*------------------------------------------------------------------.
| TEXT is pointing to a wannabee semantic value (i.e., a `$'). |
| |
| Possible inputs: $(<TYPENAME>|)($|integer|c_id|[id]) |
| Possible inputs: $[<TYPENAME>]($|integer) |
| |
| Output to OBSTACK_FOR_STRING a reference to this semantic value. |
`------------------------------------------------------------------*/
static void
handle_action_dollar (symbol_list *rule, char *text, unsigned textlen,
location dollar_loc)
handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
{
char const *type_name = NULL;
char *cp = text + 1;
@@ -696,7 +735,7 @@ handle_action_dollar (symbol_list *rule, char *text, unsigned textlen,
}
n = parse_ref (cp, effective_rule, effective_rule_length,
rule->midrule_parent_rhs_index, text, textlen, dollar_loc);
rule->midrule_parent_rhs_index, text, dollar_loc, '$');
if (gt_ptr)
*gt_ptr = '\0';
@@ -767,11 +806,10 @@ handle_action_dollar (symbol_list *rule, char *text, unsigned textlen,
`------------------------------------------------------*/
static void
handle_action_at (symbol_list const *rule, char const *text, unsigned textlen,
location at_loc)
handle_action_at (symbol_list *rule, char *text, location at_loc)
{
char const *cp = text + 1;
symbol_list const *effective_rule;
char *cp = text + 1;
symbol_list *effective_rule;
int effective_rule_length;
int n;
@@ -789,7 +827,7 @@ handle_action_at (symbol_list const *rule, char const *text, unsigned textlen,
muscle_percent_define_ensure("locations", at_loc, true);
n = parse_ref (cp, effective_rule, effective_rule_length,
rule->midrule_parent_rhs_index, text, textlen, at_loc);
rule->midrule_parent_rhs_index, text, at_loc, '@');
switch (n)
{
case INVALID_REF: