X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/b9f1d9a47a49c40e8f0a5006b492daba53f25b20..575619af5e1f61a5f78fb3910bee424ead5fe5a6:/src/scan-code.l?ds=sidebyside diff --git a/src/scan-code.l b/src/scan-code.l index 4c91fd1a..a5f570d7 100644 --- a/src/scan-code.l +++ b/src/scan-code.l @@ -1,6 +1,6 @@ /* Bison Action Scanner -*- C -*- - Copyright (C) 2006, 2007, 2008, 2009 Free Software Foundation, Inc. + Copyright (C) 2006-2011 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License along with this program. If not, see . */ -%option debug nodefault nounput noyywrap never-interactive +%option debug nodefault noinput nounput noyywrap never-interactive %option prefix="code_" outfile="lex.yy.c" %{ @@ -32,12 +32,14 @@ #include #include #include -#include -#include #include #include #include +#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) @@ -49,7 +51,7 @@ 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 */ +/* A string to be pushed to obstack after dollar/at has been handled. */ static char *ref_tail_fields; static location the_location; @@ -81,7 +83,8 @@ tag [^\0\n>]+ splice (\\[ \f\t\v]*\n)* /* C style identifier. Must start with letter. Will be used for - named symbol references. */ + 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}"]"|"$" @@ -181,7 +184,7 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" "$"("<"{tag}">")?{ref} { ref_tail_fields = 0; handle_action_dollar (self->rule, yytext, *loc); - if (ref_tail_fields != NULL) { + if (ref_tail_fields) { obstack_sgrow (&obstack_for_string, ref_tail_fields); } need_semicolon = true; @@ -189,7 +192,7 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" "@"{ref} { ref_tail_fields = 0; handle_action_at (self->rule, yytext, *loc); - if (ref_tail_fields != NULL) { + if (ref_tail_fields) { obstack_sgrow (&obstack_for_string, ref_tail_fields); } need_semicolon = true; @@ -243,7 +246,20 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" {splice} STRING_GROW; [\n\r] STRING_GROW; if (in_cpp) in_cpp = need_semicolon = false; [ \t\f] STRING_GROW; - . STRING_GROW; need_semicolon = true; + + /* YYFAIL is undocumented and was formally deprecated in Bison + 2.4.2. */ + YYFAIL { + STRING_GROW; need_semicolon = true; + warn_at (*loc, _("use of YYFAIL, which is deprecated and will be" + " removed")); + } + + /* The sole purpose of this is to make sure identifiers that merely + contain YYFAIL don't produce the above warning. */ + [A-Za-z_][0-9A-Za-z_]* STRING_GROW; need_semicolon = true; + + . STRING_GROW; need_semicolon = true; } @@ -285,60 +301,57 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" %% - static inline bool -symbol_list_null(symbol_list *l) -{ - if (l && !(l->content_type == SYMLIST_SYMBOL && l->content.sym == NULL)) - return false; - else - return true; -} - -static inline bool -is_dot_or_dash(char ch) +is_dot_or_dash (char ch) { return ch == '.' || ch == '-'; } static inline bool -is_digit(char ch) -{ - return '0' <= ch && ch <= '9'; -} - -static inline bool -contains_dot_or_dash(const char* str) +contains_dot_or_dash (const char* p) { - return strpbrk(str, ".-") != NULL; + for (; *p; ++p) + if (is_dot_or_dash (*p)) + return true; + return false; } -#define VARIANT_HIDDEN (1 << 0) -#define VARIANT_BAD_BRACKETING (1 << 1) -#define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2) - +/* Defines a variant of a symbolic name resolution. */ typedef struct { /* Index in symbol list. */ - long int ind; + unsigned symbol_index; /* Matched symbol id and loc. */ uniqstr id; location loc; - /* Hidding named reference. */ + /* Hiding named reference. */ named_ref* hidden_by; - /* Error flags. */ + /* 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() +variant_table_grow (void) { ++variant_count; if (variant_count > variant_table_size) @@ -351,17 +364,22 @@ variant_table_grow() 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) +find_prefix_end (const char *prefix, char *begin, char *end) { char *ptr = begin; - while (*prefix && ptr != end) - { - if (*prefix != *ptr) - return 0; - ++prefix, ++ptr; - } + for (; *prefix && ptr != end; ++prefix, ++ptr) + if (*prefix != *ptr) + return 0; if (*prefix) return 0; @@ -370,20 +388,20 @@ find_prefix_end(const char *prefix, char *begin, char *end) } static variant * -variant_add(uniqstr id, location loc, long int ind, - char *cp, char *cp_end, bool exact_mode) +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); + prefix_end = find_prefix_end (id, cp, cp_end); if (prefix_end && (prefix_end == cp_end || - (!exact_mode && is_dot_or_dash(*prefix_end)))) + (!explicit_bracketing && is_dot_or_dash (*prefix_end)))) { - variant *r = variant_table_grow(); - r->ind = ind; + variant *r = variant_table_grow (); + r->symbol_index = symbol_index; r->id = id; - r->loc = loc; + r->loc = id_loc; r->hidden_by = NULL; r->err = 0; return r; @@ -392,207 +410,266 @@ variant_add(uniqstr id, location loc, long int ind, 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 $-n "deep" stack + accesses. */ static long int -parse_named_ref(char *cp, symbol_list *rule, int rule_length, - int midrule_rhs_index, char *text, location loc, - char dollar_or_at) +parse_ref (char *cp, symbol_list *rule, int rule_length, + int midrule_rhs_index, char *text, location text_loc, + char dollar_or_at) { symbol_list *l; char *cp_end; - bool exact_mode; - bool has_error; - bool has_valid; - long int ind, i; - variant* variant; - char* p; + bool explicit_bracketing; + unsigned i; + unsigned valid_variants = 0; + unsigned valid_variant_index = 0; if ('$' == *cp) return LHS_REF; - if (is_digit (*cp) || (*cp == '-' && is_digit (* (cp + 1)))) + 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 (loc, _("integer out of range: %s"), quote (text)); + complain_at (text_loc, _("integer out of range: %s"), + quote (text)); return INVALID_REF; } } if ('[' == *cp) { - exact_mode = true; - /* Ignore the brackets. */ - ++cp; - for (p = cp; *p != ']'; ++p); + char *p; + for (p = ++cp; *p != ']'; ++p) + continue; cp_end = p; + + explicit_bracketing = true; } else { - exact_mode = false; - /* Take all characters of the name. */ + char* p; for (p = cp; *p; ++p) - if (is_dot_or_dash(*p)) + if (is_dot_or_dash (*p)) { ref_tail_fields = p; break; } - for (p = cp; *p; ++p); + for (p = cp; *p; ++p) + continue; cp_end = p; + + explicit_bracketing = false; } /* Add all relevant variants. */ - variant_count = 0; - for (ind = 0, l = rule; !symbol_list_null(l); ++ind, l = l->next) - { - if (l->content_type != SYMLIST_SYMBOL) - continue; - - variant = variant_add(l->content.sym->tag, l->sym_loc, ind, - cp, cp_end, exact_mode); - - if (variant && l->named_ref) - variant->hidden_by = l->named_ref; - - if (l->named_ref) - variant_add(l->named_ref->id, l->named_ref->loc, ind, - cp, cp_end, exact_mode); - } + { + 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. */ - has_error = false; - has_valid = false; for (i = 0; i < variant_count; ++i) { - variant = &variant_table[i]; - ind = variant->ind; + variant *var = &variant_table[i]; + unsigned symbol_index = var->symbol_index; /* Check visibility from mid-rule actions. */ - if (midrule_rhs_index != 0 && - (ind == 0 || ind > midrule_rhs_index)) - { - variant->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE; - has_error = true; - } + 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(variant->id)) - { - variant->err |= VARIANT_BAD_BRACKETING; - has_error = true; - } + if (!explicit_bracketing && contains_dot_or_dash (var->id)) + var->err |= VARIANT_BAD_BRACKETING; /* Check using of hidden symbols. */ - if (variant->hidden_by != NULL) - { - variant->err |= VARIANT_HIDDEN; - has_error = true; - } - - if (!variant->err) - has_valid = true; + if (var->hidden_by) + var->err |= VARIANT_HIDDEN; + + if (!var->err) + { + valid_variant_index = i; + ++valid_variants; + } } - if (variant_count == 1 && has_valid) - { - /* The only "good" case is here. */ - ind = variant_table[0].ind; - if (ind == midrule_rhs_index) - return LHS_REF; - else - return ind; - } - - /* Start complaining. */ - - if (variant_count == 0) - complain_at (loc, _("reference is invalid: %s, symbol not found"), - quote (text)); - else if (variant_count > 1 && !has_error) - complain_at (loc, _("reference is ambiguous: %s"), - quote (text)); - else if (variant_count > 1 && has_valid && has_error) - complain_at (loc, _("reference is misleading: %s"), - quote (text)); - else - complain_at (loc, _("reference is invalid: %s"), - quote (text)); - - for (i = 0; i < variant_count; ++i) + switch (valid_variants) { - static char at_buf[20]; - - variant = &variant_table[i]; - - if (variant->ind == 0) - strcpy(at_buf, "$$"); - else - snprintf(at_buf, sizeof(at_buf), "$%d", variant->ind); - - if (variant->err == 0) - complain_at (variant->loc, _(" refers to: %c%s at %s"), - dollar_or_at, variant->id, at_buf); - else - { - static struct obstack msg_buf; - const char *tail = ""; - const char *id; - location loc; - - if (!exact_mode) - tail = cp + strlen(variant->id); - - if (variant->hidden_by) - { - id = variant->hidden_by->id; - loc = variant->hidden_by->loc; - } - else - { - id = variant->id; - loc = variant->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 (variant->err & VARIANT_HIDDEN) - { - obstack_fgrow1 (&msg_buf, ", hiding %c", dollar_or_at); - if (contains_dot_or_dash (variant->id)) - obstack_fgrow1 (&msg_buf, "[%s]", variant->id); - else - obstack_sgrow (&msg_buf, variant->id); - obstack_sgrow (&msg_buf, tail); - } - - obstack_fgrow1 (&msg_buf, " at %s", at_buf); - - if (variant->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'); - complain_at (loc, _("%s"), obstack_finish (&msg_buf)); - obstack_free (&msg_buf, 0); - } + 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 (midrule_rhs_index) + { + const char *format = + _("symbol not found in production before $%d: %.*s"); + complain_at_indent (rule->location, &indent, format, + midrule_rhs_index, len, cp); + } + else + { + const char *format = + _("symbol not found in production: %.*s"); + complain_at_indent (rule->location, &indent, format, + len, cp); + } + + if (variant_count > 0) + show_sub_messages (cp, explicit_bracketing, midrule_rhs_index, + dollar_or_at, false, indent); + return INVALID_REF; + } + case 1: + { + unsigned indent = 0; + if (variant_count > 1) + { + warn_at_indent (text_loc, &indent, _("misleading reference: %s"), + quote (text)); + show_sub_messages (cp, explicit_bracketing, midrule_rhs_index, + dollar_or_at, true, indent + SUB_INDENT); + } + { + unsigned symbol_index = + variant_table[valid_variant_index].symbol_index; + return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index; + } + } + case 2: + default: + { + unsigned indent = 0; + complain_at_indent (text_loc, &indent, _("ambiguous reference: %s"), + quote (text)); + show_sub_messages (cp, explicit_bracketing, midrule_rhs_index, + dollar_or_at, false, indent + SUB_INDENT); + return INVALID_REF; + } } + /* Not reachable. */ return INVALID_REF; } @@ -617,7 +694,8 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) char *cp = text + 1; char *gt_ptr = 0; symbol_list *effective_rule; - int effective_rule_length, n; + int effective_rule_length; + int n; if (rule->midrule_parent_rule) { @@ -646,8 +724,8 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) tag_seen = true; } - n = parse_named_ref (cp, effective_rule, effective_rule_length, - rule->midrule_parent_rhs_index, text, dollar_loc, '$'); + n = parse_ref (cp, effective_rule, effective_rule_length, + rule->midrule_parent_rhs_index, text, dollar_loc, '$'); if (gt_ptr) *gt_ptr = '\0'; @@ -722,7 +800,8 @@ handle_action_at (symbol_list *rule, char *text, location at_loc) { char *cp = text + 1; symbol_list *effective_rule; - int effective_rule_length, n; + int effective_rule_length; + int n; if (rule->midrule_parent_rule) { @@ -737,7 +816,7 @@ handle_action_at (symbol_list *rule, char *text, location at_loc) muscle_percent_define_ensure("locations", at_loc, true); - n = parse_named_ref (cp, effective_rule, effective_rule_length, + n = parse_ref (cp, effective_rule, effective_rule_length, rule->midrule_parent_rhs_index, text, at_loc, '@'); switch (n) { @@ -796,7 +875,8 @@ code_props_none_init (code_props *self) 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; @@ -821,14 +901,15 @@ code_props_symbol_action_init (code_props *self, char const *code, void code_props_rule_action_init (code_props *self, char const *code, location code_loc, symbol_list *rule, - named_ref *named_ref) + named_ref *name, bool is_predicate) { self->kind = CODE_PROPS_RULE_ACTION; self->code = code; self->location = code_loc; self->is_value_used = false; self->rule = rule; - self->named_ref = named_ref; + self->named_ref = name; + self->is_predicate = is_predicate; } void @@ -860,6 +941,8 @@ void code_scanner_free (void) { obstack_free (&obstack_for_string, 0); + variant_table_free (); + /* Reclaim Flex's buffers. */ yylex_destroy (); }