X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/4521fcdf02e081b691c4a4485dd3441f8cda7c6b..62e5fc6ac9bd59f801ca43e7eb81d19960f3e306:/src/scan-code.l diff --git a/src/scan-code.l b/src/scan-code.l index 235800f8..5bcb5686 100644 --- a/src/scan-code.l +++ b/src/scan-code.l @@ -1,6 +1,6 @@ /* 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. @@ -84,8 +84,8 @@ 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])* +letter [.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_] +id {letter}({letter}|[-0-9])* ref -?[0-9]+|{id}|"["{id}"]"|"$" %% @@ -95,10 +95,10 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" int braces_level = 0; /* Whether a semicolon is probably needed. - The heuristic is that a semicolon is not needed after `{', `}', `;', + 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 `{}'. + 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; @@ -117,7 +117,7 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" %} /*------------------------------------------------------------. - | Scanning a C comment. The initial `/ *' is already eaten. | + | Scanning a C comment. The initial '/ *' is already eaten. | `------------------------------------------------------------*/ @@ -127,7 +127,7 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" /*--------------------------------------------------------------. - | Scanning a line comment. The initial `//' is already eaten. | + | Scanning a line comment. The initial '//' is already eaten. | `--------------------------------------------------------------*/ @@ -197,12 +197,12 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" need_semicolon = true; } "$" { - warn_at (*loc, _("stray `$'")); + warn_at (*loc, _("stray '$'")); obstack_sgrow (&obstack_for_string, "$]["); need_semicolon = true; } "@" { - warn_at (*loc, _("stray `@'")); + warn_at (*loc, _("stray '@'")); obstack_sgrow (&obstack_for_string, "@@"); need_semicolon = true; } @@ -220,16 +220,16 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" "}" { bool outer_brace = --braces_level == 0; - /* As an undocumented Bison extension, append `;' before the last + /* 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 + ';'. 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, ';'); + 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; @@ -238,14 +238,27 @@ ref -?[0-9]+|{id}|"["{id}"]"|"$" /* 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. */ + '#' 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; + [\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; } @@ -306,7 +319,7 @@ contains_dot_or_dash (const char* p) typedef struct { /* Index in symbol list. */ - unsigned index; + unsigned symbol_index; /* Matched symbol id and loc. */ uniqstr id; @@ -375,17 +388,17 @@ find_prefix_end (const char *prefix, char *begin, char *end) static variant * variant_add (uniqstr id, location id_loc, unsigned symbol_index, - char *cp, char *cp_end, bool exact_mode) + 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 || - (!exact_mode && is_dot_or_dash (*prefix_end)))) + (!explicit_bracketing && is_dot_or_dash (*prefix_end)))) { variant *r = variant_table_grow (); - r->index = symbol_index; + r->symbol_index = symbol_index; r->id = id; r->loc = id_loc; r->hidden_by = NULL; @@ -407,14 +420,89 @@ get_at_spec(unsigned 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 ($$) of the current rule. */ + points to LHS ($$) 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 $-n "deep" stack accesses. */ @@ -425,10 +513,10 @@ parse_ref (char *cp, symbol_list *rule, int rule_length, { symbol_list *l; char *cp_end; - bool exact_mode; - bool has_error; - bool has_valid; + bool explicit_bracketing; unsigned i; + unsigned valid_variants = 0; + unsigned valid_variant_index = 0; if ('$' == *cp) return LHS_REF; @@ -454,7 +542,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length, continue; cp_end = p; - exact_mode = true; + explicit_bracketing = true; } else { @@ -470,7 +558,7 @@ parse_ref (char *cp, symbol_list *rule, int rule_length, continue; cp_end = p; - exact_mode = false; + explicit_bracketing = false; } /* Add all relevant variants. */ @@ -485,125 +573,112 @@ parse_ref (char *cp, symbol_list *rule, int rule_length, continue; var = variant_add (l->content.sym->tag, l->sym_loc, - symbol_index, cp, cp_end, exact_mode); + 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, exact_mode); + symbol_index, cp, cp_end, explicit_bracketing); } } /* Check errors. */ - has_error = false; - has_valid = false; for (i = 0; i < variant_count; ++i) { variant *var = &variant_table[i]; - unsigned symbol_index = var->index; + 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; - has_error = true; - } + var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE; /* Check correct bracketing. */ - if (!exact_mode && contains_dot_or_dash (var->id)) - { - var->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 (var->hidden_by) - { - var->err |= VARIANT_HIDDEN; - has_error = true; - } + var->err |= VARIANT_HIDDEN; if (!var->err) - has_valid = true; + { + valid_variant_index = i; + ++valid_variants; + } } - if (variant_count == 1 && has_valid) + switch (valid_variants) { - /* The only "good" case is here. */ - unsigned symbol_index = variant_table[0].index; - if (symbol_index == midrule_rhs_index) - return LHS_REF; - else - return symbol_index; - } - - /* Start complaining. */ - - if (variant_count == 0) - complain_at (text_loc, _("invalid reference: %s, symbol not found"), - quote (text)); - else if (variant_count > 1 && !has_error) - complain_at (text_loc, _("ambiguous reference: %s"), - quote (text)); - else if (variant_count > 1 && has_valid && has_error) - complain_at (text_loc, _("misleading reference: %s"), - quote (text)); - else - complain_at (text_loc, _("invalid reference: %s"), - quote (text)); - - for (i = 0; i < variant_count; ++i) - { - const variant *var = &variant_table[i]; - const char *at_spec = get_at_spec (var->index); - - if (var->err == 0) - 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 $%d", midrule_rhs_index); - - obstack_1grow (&msg_buf, '\0'); - complain_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf)); - obstack_free (&msg_buf, 0); - } + case 0: + { + unsigned len = (explicit_bracketing || !ref_tail_fields) ? + cp_end - cp : ref_tail_fields - cp; + unsigned indent = 0; + + complain_at_indent (text_loc, &indent, _("invalid reference: %s"), + quote (text)); + indent += SUB_INDENT; + if (len == 0) + { + location sym_loc = text_loc; + sym_loc.start.column += 1; + sym_loc.end = sym_loc.start; + const char *format = + _("syntax error after '%c', expecting integer, letter," + " '_', '[', or '$'"); + complain_at_indent (sym_loc, &indent, format, dollar_or_at); + } + else if (midrule_rhs_index) + { + const char *format = + _("symbol not found in production before $%d: %.*s"); + complain_at_indent (rule->location, &indent, format, + midrule_rhs_index, len, cp); + } + else + { + const char *format = + _("symbol not found in production: %.*s"); + complain_at_indent (rule->location, &indent, format, + len, cp); + } + + if (variant_count > 0) + show_sub_messages (cp, explicit_bracketing, midrule_rhs_index, + dollar_or_at, false, indent); + return INVALID_REF; + } + case 1: + { + unsigned indent = 0; + if (variant_count > 1) + { + warn_at_indent (text_loc, &indent, _("misleading reference: %s"), + quote (text)); + show_sub_messages (cp, explicit_bracketing, midrule_rhs_index, + dollar_or_at, true, indent + SUB_INDENT); + } + { + unsigned symbol_index = + variant_table[valid_variant_index].symbol_index; + return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index; + } + } + case 2: + default: + { + unsigned indent = 0; + complain_at_indent (text_loc, &indent, _("ambiguous reference: %s"), + quote (text)); + show_sub_messages (cp, explicit_bracketing, midrule_rhs_index, + dollar_or_at, false, indent + SUB_INDENT); + return INVALID_REF; + } } + /* Not reachable. */ return INVALID_REF; } @@ -614,7 +689,7 @@ int max_left_semantic_context = 0; /*------------------------------------------------------------------. -| TEXT is pointing to a wannabee semantic value (i.e., a `$'). | +| TEXT is pointing to a wannabee semantic value (i.e., a '$'). | | | | Possible inputs: $[]($|integer) | | | @@ -674,23 +749,23 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) 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 = ""; - } + { + if (union_seen | tag_seen) + { + if (rule->midrule_parent_rule) + complain_at (dollar_loc, + _("$$ for the midrule at $%d of %s" + " has no declared type"), + rule->midrule_parent_rhs_index, + quote (effective_rule->content.sym->tag)); + else + complain_at (dollar_loc, _("$$ of %s has no declared type"), + quote (rule->content.sym->tag)); + } + else + untyped_var_seen = true; + type_name = ""; + } obstack_fgrow1 (&obstack_for_string, "]b4_lhs_value([%s])[", type_name); @@ -704,14 +779,14 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) 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, _("$%s of `%s' has no declared type"), - cp, effective_rule->content.sym->tag); - else - untyped_var_seen = true; - type_name = ""; - } + { + if (union_seen | tag_seen) + complain_at (dollar_loc, _("$%s of %s has no declared type"), + cp, quote (effective_rule->content.sym->tag)); + else + untyped_var_seen = true; + type_name = ""; + } obstack_fgrow3 (&obstack_for_string, "]b4_rhs_value(%d, %d, [%s])[", @@ -725,7 +800,7 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) /*------------------------------------------------------. -| TEXT is a location token (i.e., a `@...'). Output to | +| TEXT is a location token (i.e., a '@...'). Output to | | OBSTACK_FOR_STRING a reference to this location. | `------------------------------------------------------*/