X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/e9071366c3104e4e4a2490c16d53e7eeef670f45..7c0c61812d534683d10234082e6e6adee6eb81a6:/src/scan-code.l?ds=inline diff --git a/src/scan-code.l b/src/scan-code.l index 70b250bc..bf46e2da 100644 --- a/src/scan-code.l +++ b/src/scan-code.l @@ -1,6 +1,6 @@ /* Bison Action Scanner -*- C -*- - Copyright (C) 2006 Free Software Foundation, Inc. + Copyright (C) 2006, 2007 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -31,28 +31,34 @@ #define FLEX_PREFIX(Id) code_ ## Id #include "flex-scanner.h" + +#include "complain.h" #include "reader.h" #include "getargs.h" -#include #include #include #include "scan-code.h" +#include "symlist.h" /* The current calling start condition: SC_RULE_ACTION or SC_SYMBOL_ACTION. */ -# define YY_DECL const char *code_lex (int sc_context) +# 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); -static void handle_action_dollar (char *cp, location loc); -static void handle_action_at (char *cp, location loc); +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); static location the_location; static location *loc = &the_location; -/* The rule being processed. */ -symbol_list *current_rule; +/* 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 @@ -75,12 +81,15 @@ splice (\\[ \f\t\v]*\n)* %% %{ + /* Nesting level of the current code in braces. */ + int braces_level = 0; + /* 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. */ - assert (sc_context == SC_SYMBOL_ACTION - || sc_context == SC_RULE_ACTION - || sc_context == INITIAL); + aver (sc_context == SC_SYMBOL_ACTION + || sc_context == SC_RULE_ACTION + || sc_context == INITIAL); BEGIN sc_context; %} @@ -146,8 +155,12 @@ splice (\\[ \f\t\v]*\n)* { - "$"("<"{tag}">")?(-?[0-9]+|"$") handle_action_dollar (yytext, *loc); - "@"(-?[0-9]+|"$") handle_action_at (yytext, *loc); + "$"("<"{tag}">")?(-?[0-9]+|"$") { + handle_action_dollar (self->rule, yytext, *loc); + } + "@"(-?[0-9]+|"$") { + handle_action_at (self->rule, yytext, *loc); + } "$" { warn_at (*loc, _("stray `$'")); @@ -157,11 +170,38 @@ splice (\\[ \f\t\v]*\n)* warn_at (*loc, _("stray `@'")); obstack_sgrow (&obstack_for_string, "@@"); } + + "{" STRING_GROW; ++braces_level; + "}" { + 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, ';'); + + STRING_GROW; + } } { - "$$" obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar["); + "$$" { + obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar["); + self->is_value_used = true; + } "@$" obstack_sgrow (&obstack_for_string, "]b4_at_dollar["); } @@ -186,8 +226,8 @@ splice (\\[ \f\t\v]*\n)* /* End of processing. */ <*><> { - obstack_1grow (&obstack_for_string, '\0'); - return obstack_finish (&obstack_for_string); + STRING_FINISH; + return last_string; } %% @@ -207,11 +247,23 @@ int max_left_semantic_context = 0; `------------------------------------------------------------------*/ static void -handle_action_dollar (char *text, location loc) +handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) { - const char *type_name = NULL; + char const *type_name = NULL; char *cp = text + 1; - int rule_length = symbol_list_length (current_rule->next); + symbol_list *effective_rule; + int effective_rule_length; + + if (rule->midrule_parent_rule) + { + effective_rule = rule->midrule_parent_rule; + effective_rule_length = rule->midrule_parent_rhs_index - 1; + } + else + { + effective_rule = rule; + effective_rule_length = symbol_list_length (rule->next); + } /* Get the type name if explicit. */ if (*cp == '<') @@ -221,45 +273,70 @@ handle_action_dollar (char *text, location loc) ++cp; *cp = '\0'; ++cp; + if (untyped_var_seen) + complain_at (dollar_loc, _("explicit type given in untyped grammar")); + tag_seen = true; } if (*cp == '$') { if (!type_name) - type_name = symbol_list_n_type_name_get (current_rule, loc, 0); - if (!type_name && typed) - complain_at (loc, _("$$ of `%s' has no declared type"), - current_rule->sym->tag); + type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0); + if (!type_name) - 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 = ""; + } + obstack_fgrow1 (&obstack_for_string, "]b4_lhs_value([%s])[", type_name); - current_rule->used = true; + rule->used = true; } else { - long int num; - set_errno (0); - num = strtol (cp, 0, 10); - if (INT_MIN <= num && num <= rule_length && ! get_errno ()) + long int num = strtol (cp, NULL, 10); + + if (1 - INT_MAX + effective_rule_length <= num + && num <= effective_rule_length) { int n = num; - if (1-n > max_left_semantic_context) - max_left_semantic_context = 1-n; - if (!type_name && n > 0) - type_name = symbol_list_n_type_name_get (current_rule, loc, n); - if (!type_name && typed) - complain_at (loc, _("$%d of `%s' has no declared type"), - n, current_rule->sym->tag); + if (max_left_semantic_context < 1 - n) + max_left_semantic_context = 1 - n; + if (!type_name && 0 < n) + type_name = + symbol_list_n_type_name_get (effective_rule, dollar_loc, n); if (!type_name) - type_name = ""; + { + if (union_seen | tag_seen) + complain_at (dollar_loc, _("$%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])[", - rule_length, n, type_name); - symbol_list_n_used_set (current_rule, n, true); + effective_rule_length, n, type_name); + if (n > 0) + symbol_list_n_get (effective_rule, n)->used = true; } else - complain_at (loc, _("integer out of range: %s"), quote (text)); + complain_at (dollar_loc, _("integer out of range: %s"), quote (text)); } } @@ -270,28 +347,31 @@ handle_action_dollar (char *text, location loc) `------------------------------------------------------*/ static void -handle_action_at (char *text, location loc) +handle_action_at (symbol_list *rule, char *text, location at_loc) { char *cp = text + 1; - int rule_length = symbol_list_length (current_rule->next); + int effective_rule_length = + (rule->midrule_parent_rule + ? rule->midrule_parent_rhs_index - 1 + : symbol_list_length (rule->next)); + locations_flag = true; if (*cp == '$') obstack_sgrow (&obstack_for_string, "]b4_lhs_location["); else { - long int num; - set_errno (0); - num = strtol (cp, 0, 10); + long int num = strtol (cp, NULL, 10); - if (INT_MIN <= num && num <= rule_length && ! get_errno ()) + 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)[", - rule_length, n); + effective_rule_length, n); } else - complain_at (loc, _("integer out of range: %s"), quote (text)); + complain_at (at_loc, _("integer out of range: %s"), quote (text)); } } @@ -300,59 +380,111 @@ handle_action_at (char *text, location loc) | Initialize the scanner. | `-------------------------*/ -/* Translate the dollars and ats in \a a, whose location is l. - Depending on the \a sc_context (SC_RULE_ACTION, SC_SYMBOL_ACTION, - INITIAL), the processing is different. */ +/* Translate the dollars and ats in \a self, in the context \a sc_context + (SC_RULE_ACTION, SC_SYMBOL_ACTION, INITIAL). */ -static const char * -translate_action (int sc_context, const char *a, location l) +static char const * +translate_action (code_props *self, int sc_context) { - const char *res; + char *res; static bool initialized = false; if (!initialized) { obstack_init (&obstack_for_string); - /* The initial buffer, never used. */ - yy_delete_buffer (YY_CURRENT_BUFFER); yy_flex_debug = 0; initialized = true; } - loc->start = loc->end = l.start; - yy_switch_to_buffer (yy_scan_string (a)); - res = code_lex (sc_context); + 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; } -const char * -translate_rule_action (symbol_list *r, const char *a, location l) +/*------------------------------------------------------------------------. +| Implementation of the public interface as documented in "scan-code.h". | +`------------------------------------------------------------------------*/ + +void +code_props_none_init (code_props *self) +{ + *self = code_props_none; +} + +code_props const code_props_none = CODE_PROPS_NONE_INIT; + +void +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; +} + +void +code_props_symbol_action_init (code_props *self, char const *code, + location code_loc) { - current_rule = r; - return translate_action (SC_RULE_ACTION, a, l); + self->kind = CODE_PROPS_SYMBOL_ACTION; + self->code = code; + self->location = code_loc; + self->is_value_used = false; + self->rule = NULL; } -const char * -translate_symbol_action (const char *a, location l) +void +code_props_rule_action_init (code_props *self, char const *code, + location code_loc, symbol_list *rule) { - return translate_action (SC_SYMBOL_ACTION, a, l); + self->kind = CODE_PROPS_RULE_ACTION; + self->code = code; + self->location = code_loc; + self->is_value_used = false; + self->rule = rule; } -const char * -translate_code (const char *a, location l) +void +code_props_translate_code (code_props *self) { - return translate_action (INITIAL, a, l); + 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; + } } -/*-----------------------------------------------. -| Free all the memory allocated to the scanner. | -`-----------------------------------------------*/ +void +code_scanner_last_string_free (void) +{ + STRING_FREE; +} void code_scanner_free (void) { obstack_free (&obstack_for_string, 0); /* Reclaim Flex's buffers. */ - yy_delete_buffer (YY_CURRENT_BUFFER); + yylex_destroy (); +} + +char const * +translate_rule_action (symbol_list *rule) +{ + code_props cp; + code_props_rule_action_init (&cp, rule->action, rule->action_location, rule); + code_props_translate_code (&cp); + return cp.code; }