X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/580b892607e7709b316003f31c825231b7dc6d62..83ea2423f54b6e1d4b69c2972ad7fcdeb7dbb0b2:/src/scan-code.l diff --git a/src/scan-code.l b/src/scan-code.l index 0a338b4e..28a9fe47 100644 --- a/src/scan-code.l +++ b/src/scan-code.l @@ -1,12 +1,12 @@ /* Bison Action Scanner -*- C -*- - Copyright (C) 2006 Free Software Foundation, Inc. + 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 + 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 2 of the License, or + 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, @@ -15,10 +15,7 @@ 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, write to the Free Software - Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - 02110-1301 USA -*/ + along with this program. If not, see . */ %option debug nodefault nounput noyywrap never-interactive %option prefix="code_" outfile="lex.yy.c" @@ -30,19 +27,20 @@ #define code_wrap() 1 #define FLEX_PREFIX(Id) code_ ## Id -#include "flex-scanner.h" +#include -#include "complain.h" -#include "reader.h" -#include "getargs.h" +#include +#include +#include #include #include - -#include "scan-code.h" +#include +#include +#include /* The current calling start condition: SC_RULE_ACTION or SC_SYMBOL_ACTION. */ -# define YY_DECL char *code_lex (int sc_context, symbol_list *rule) +# 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); @@ -50,11 +48,19 @@ YY_DECL; 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 @@ -74,12 +80,31 @@ tag [^\0\n>]+ 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. */ +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. */ @@ -134,10 +159,12 @@ splice (\\[ \f\t\v]*\n)* "'" { STRING_GROW; BEGIN SC_CHARACTER; + need_semicolon = true; } "\"" { STRING_GROW; BEGIN SC_STRING; + need_semicolon = true; } "/"{splice}"*" { STRING_GROW; @@ -151,47 +178,84 @@ splice (\\[ \f\t\v]*\n)* { - "$"("<"{tag}">")?(-?[0-9]+|"$") handle_action_dollar (rule, yytext, *loc); - "@"(-?[0-9]+|"$") handle_action_at (rule, yytext, *loc); - + "$"("<"{tag}">")?{ref} { + ref_tail_fields = 0; + handle_action_dollar (self->rule, yytext, *loc); + if (ref_tail_fields != NULL) { + 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 != NULL) { + 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; + 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; + . STRING_GROW; need_semicolon = true; } { - "$$" obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar["); - "@$" obstack_sgrow (&obstack_for_string, "]b4_at_dollar["); + "$$" { + obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar["); + self->is_value_used = true; + } + "@$" { + obstack_sgrow (&obstack_for_string, "]b4_at_dollar["); + muscle_percent_define_ensure("locations", the_location, true); + } } @@ -215,12 +279,323 @@ splice (\\[ \f\t\v]*\n)* /* End of processing. */ <*><> { - obstack_1grow (&obstack_for_string, '\0'); - return obstack_finish (&obstack_for_string); + STRING_FINISH; + return last_string; } %% + +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) +{ + 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) +{ + return strpbrk(str, ".-") != NULL; +} + +#define VARIANT_HIDDEN (1 << 0) +#define VARIANT_BAD_BRACKETING (1 << 1) +#define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2) + +typedef struct +{ + /* Index in symbol list. */ + long int ind; + + /* Matched symbol id and loc. */ + uniqstr id; + location loc; + + /* Hidding named reference. */ + named_ref* hidden_by; + + /* Error flags. */ + unsigned err; +} variant; + +static variant *variant_table = 0; +static unsigned variant_table_size = 0; +static unsigned variant_count = 0; + +static variant * +variant_table_grow() +{ + ++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 char * +find_prefix_end(const char *prefix, char *begin, char *end) +{ + char *ptr = begin; + + while (*prefix && ptr != end) + { + if (*prefix != *ptr) + return 0; + ++prefix, ++ptr; + } + + if (*prefix) + return 0; + + return ptr; +} + +static variant * +variant_add(uniqstr id, location loc, long int ind, + 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->ind = ind; + r->id = id; + r->loc = loc; + r->hidden_by = NULL; + r->err = 0; + return r; + } + else + return NULL; +} + +#define INVALID_REF (INT_MIN) +#define LHS_REF (INT_MIN + 1) + +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) +{ + symbol_list *l; + char *cp_end; + bool exact_mode; + bool has_error; + bool has_valid; + long int ind, i; + variant* variant; + char* p; + + if ('$' == *cp) + return LHS_REF; + + if (is_digit (*cp) || (*cp == '-' && is_digit (* (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)); + return INVALID_REF; + } + } + + if ('[' == *cp) + { + exact_mode = true; + + /* Ignore the brackets. */ + ++cp; + for (p = cp; *p != ']'; ++p); + cp_end = p; + } + else + { + exact_mode = false; + + /* Take all characters of the name. */ + for (p = cp; *p; ++p) + if (is_dot_or_dash(*p)) + { + ref_tail_fields = p; + break; + } + for (p = cp; *p; ++p); + cp_end = p; + } + + /* 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); + } + + /* Check errors. */ + has_error = false; + has_valid = false; + for (i = 0; i < variant_count; ++i) + { + variant = &variant_table[i]; + ind = variant->ind; + + /* 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; + } + + /* Check correct bracketing. */ + if (!exact_mode && contains_dot_or_dash(variant->id)) + { + variant->err |= VARIANT_BAD_BRACKETING; + has_error = true; + } + + /* Check using of hidden symbols. */ + if (variant->hidden_by != NULL) + { + variant->err |= VARIANT_HIDDEN; + has_error = true; + } + + if (!variant->err) + has_valid = true; + } + + 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) + { + static char at_buf[20]; + + variant = &variant_table[i]; + + if (variant->ind == 0) + strcpy(at_buf, "$$"); + else + snprintf(at_buf, sizeof(at_buf), "$%ld", 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"), (char *) obstack_finish (&msg_buf)); + obstack_free (&msg_buf, 0); + } + } + + return INVALID_REF; +} + /* Keeps track of the maximum number of semantic values to the left of a handle (those referenced by $0, $-1, etc.) are required by the semantic actions of this grammar. */ @@ -238,10 +613,11 @@ int max_left_semantic_context = 0; static void handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) { - const char *type_name = NULL; + char const *type_name = NULL; char *cp = text + 1; + char *gt_ptr = 0; symbol_list *effective_rule; - int effective_rule_length; + int effective_rule_length, n; if (rule->midrule_parent_rule) { @@ -260,15 +636,28 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) type_name = ++cp; while (*cp != '>') ++cp; - *cp = '\0'; + + /* The '>' symbol will be later replaced by '\0'. Original + 'text' is needed for error messages. */ + gt_ptr = cp; ++cp; if (untyped_var_seen) complain_at (dollar_loc, _("explicit type given in untyped grammar")); tag_seen = true; } - if (*cp == '$') + n = parse_named_ref (cp, effective_rule, effective_rule_length, + rule->midrule_parent_rhs_index, text, dollar_loc, '$'); + + if (gt_ptr) + *gt_ptr = '\0'; + + switch (n) { + case INVALID_REF: + break; + + case LHS_REF: if (!type_name) type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0); @@ -293,38 +682,32 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) obstack_fgrow1 (&obstack_for_string, "]b4_lhs_value([%s])[", type_name); - rule->used = true; - } - else - { - long int num = strtol (cp, NULL, 10); - - if (1 - INT_MAX + effective_rule_length <= num - && num <= effective_rule_length) + rule->action_props.is_value_used = true; + break; + + default: + if (max_left_semantic_context < 1 - n) + max_left_semantic_context = 1 - n; + if (!type_name && 0 < n) + type_name = + symbol_list_n_type_name_get (effective_rule, dollar_loc, n); + if (!type_name) { - int n = num; - if (max_left_semantic_context < 1 - n) - max_left_semantic_context = 1 - n; - if (!type_name && 0 < n) - type_name = - symbol_list_n_type_name_get (effective_rule, dollar_loc, n); - if (!type_name) - { - if (union_seen | tag_seen) - complain_at (dollar_loc, _("$%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); - symbol_list_n_used_set (effective_rule, n, true); + if (union_seen | tag_seen) + complain_at (dollar_loc, _("$%s of `%s' has no declared type"), + cp, effective_rule->content.sym->tag); + else + untyped_var_seen = true; + type_name = ""; } - else - complain_at (dollar_loc, _("integer out of range: %s"), quote (text)); + + obstack_fgrow3 (&obstack_for_string, + "]b4_rhs_value(%d, %d, [%s])[", + effective_rule_length, n, type_name); + if (n > 0) + symbol_list_n_get (effective_rule, n)->action_props.is_value_used = + true; + break; } } @@ -338,28 +721,37 @@ static void handle_action_at (symbol_list *rule, char *text, location at_loc) { char *cp = text + 1; - int effective_rule_length = - (rule->midrule_parent_rule - ? rule->midrule_parent_rhs_index - 1 - : symbol_list_length (rule->next)); - - locations_flag = true; + symbol_list *effective_rule; + int effective_rule_length, n; - if (*cp == '$') - obstack_sgrow (&obstack_for_string, "]b4_lhs_location["); + if (rule->midrule_parent_rule) + { + effective_rule = rule->midrule_parent_rule; + effective_rule_length = rule->midrule_parent_rhs_index - 1; + } else { - long int num = strtol (cp, NULL, 10); + effective_rule = rule; + effective_rule_length = symbol_list_length (rule->next); + } - 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)); + muscle_percent_define_ensure("locations", at_loc, true); + + n = parse_named_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; } } @@ -368,12 +760,11 @@ handle_action_at (symbol_list *rule, char *text, location at_loc) | Initialize the scanner. | `-------------------------*/ -/* Translate the dollars and ats in \a a, whose location is \a l. The - translation is for \a rule, in the context \a sc_context +/* 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 (int sc_context, symbol_list *rule, char const *a, location l) +translate_action (code_props *self, int sc_context) { char *res; static bool initialized = false; @@ -384,36 +775,86 @@ translate_action (int sc_context, symbol_list *rule, char const *a, location l) initialized = true; } - loc->start = loc->end = l.start; - yy_switch_to_buffer (yy_scan_string (a)); - res = code_lex (sc_context, rule); + 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; } -char const * -translate_rule_action (symbol_list *rule) +/*------------------------------------------------------------------------. +| Implementation of the public interface as documented in "scan-code.h". | +`------------------------------------------------------------------------*/ + +void +code_props_none_init (code_props *self) { - return translate_action (SC_RULE_ACTION, rule, rule->action, - rule->action_location); + *self = code_props_none; } -char const * -translate_symbol_action (char const *a, location l) +code_props const code_props_none = CODE_PROPS_NONE_INIT; + +void +code_props_plain_init (code_props *self, char const *code, location code_loc) { - return translate_action (SC_SYMBOL_ACTION, NULL, a, l); + self->kind = CODE_PROPS_PLAIN; + self->code = code; + self->location = code_loc; + self->is_value_used = false; + self->rule = NULL; + self->named_ref = NULL; } -char const * -translate_code (char const *a, location l) +void +code_props_symbol_action_init (code_props *self, char const *code, + location code_loc) { - return translate_action (INITIAL, NULL, a, l); + 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; } -/*-----------------------------------------------. -| Free all the memory allocated to the scanner. | -`-----------------------------------------------*/ +void +code_props_rule_action_init (code_props *self, char const *code, + location code_loc, symbol_list *rule, + named_ref *named_ref) +{ + 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; +} + +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)