From 092778750428c0d35378691bb4db94ef5b5ab988 Mon Sep 17 00:00:00 2001
From: Akim Demaille <demaille@gostai.com>
Date: Tue, 19 Aug 2008 21:39:03 +0200
Subject: [PATCH] Make it possible to return a symbol_type from yylex.
* data/lalr1.cc (b4_lex_symbol_if): New.
(parse): When lex_symbol is defined, expected yylex to return the
complete lookahead.
* etc/bench.pl.in (generate_grammar_list): Extend to support this
yylex interface.
(bench_variant_parser): Exercise it.
---
ChangeLog | 10 ++++++
data/lalr1.cc | 15 ++++++---
etc/bench.pl.in | 83 +++++++++++++++++++++++++++++++------------------
3 files changed, 73 insertions(+), 35 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 5e9114d0..fe8e5504 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2008-11-11 Akim Demaille <demaille@gostai.com>
+
+ Make it possible to return a symbol_type from yylex.
+ * data/lalr1.cc (b4_lex_symbol_if): New.
+ (parse): When lex_symbol is defined, expected yylex to return the
+ complete lookahead.
+ * etc/bench.pl.in (generate_grammar_list): Extend to support this
+ yylex interface.
+ (bench_variant_parser): Exercise it.
+
2008-11-11 Akim Demaille <demaille@gostai.com>
Remove useless bench case.
diff --git a/data/lalr1.cc b/data/lalr1.cc
index c286ee08..5a9d5c08 100644
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -53,6 +53,12 @@ b4_variant_if([
]) # b4_variant_if
+# b4_lex_symbol_if([IF-YYLEX-RETURNS-A-COMPLETE-SYMBOL], [IF-NOT])
+# ----------------------------------------------------------------
+m4_define([b4_lex_symbol_if],
+[b4_percent_define_ifdef([[lex_symbol]], [$1], [$2])])
+
+
# b4_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])
# ------------------------------------------------
m4_define([b4_assert_if],
@@ -1144,14 +1150,15 @@ m4_popdef([b4_at_dollar])])dnl
/* Read a lookahead token. */
if (yyempty)
{
- YYCDEBUG << "Reading a token: ";
- yyla.type = yytranslate_ (]b4_c_function_call([yylex], [int],
+ YYCDEBUG << "Reading a token: ";
+]b4_lex_symbol_if(
+[ yyla = yylex();],
+[ yyla.type = yytranslate_ (b4_c_function_call([yylex], [int],
[[YYSTYPE*], [&yyla.value]][]dnl
b4_locations_if([, [[location*], [&yyla.location]]])dnl
-m4_ifdef([b4_lex_param], [, ]b4_lex_param))[);
+m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[
yyempty = false;
}
-
YY_SYMBOL_PRINT ("Next token is", yyla);
/* If the proper action on seeing token YYLA.TYPE is to reduce or
diff --git a/etc/bench.pl.in b/etc/bench.pl.in
index c7bd83f2..f8fca8ac 100755
--- a/etc/bench.pl.in
+++ b/etc/bench.pl.in
@@ -580,11 +580,13 @@ sub generate_grammar_list ($$@)
my ($base, $max, @directive) = @_;
my $directives = directives ($base, @directive);
my $variant = grep { /%define "?variant"?/ } @directive;
+ my $lex_symbol = grep { /%define "?lex_symbol"?/ } @directive;
my $out = new IO::File ">$base.y"
or die;
print $out <<EOF;
%language "C++"
%defines
+%locations
$directives
%code requires // *.h
@@ -598,22 +600,18 @@ $directives
#include <iostream>
#include <sstream>
-// Prototype of the yylex function providing subsequent tokens.
-static yy::parser::token_type yylex(yy::parser::semantic_type* yylval);
-
#define STAGE_MAX ($max * 10) // max = $max
+#define USE_LEX_SYMBOL $lex_symbol
#define USE_VARIANTS $variant
-#if USE_VARIANTS
-# define IF_VARIANTS(True, False) True
-#else
-# define IF_VARIANTS(True, False) False
-#endif
-#ifdef ONE_STAGE_BUILD
-# define IF_ONE_STAGE_BUILD(True, False) True
+ // Prototype of the yylex function providing subsequent tokens.
+ static
+#if USE_LEX_SYMBOL
+ yy::parser::symbol_type yylex();
#else
-# define IF_ONE_STAGE_BUILD(True, False) False
+ yy::parser::token_type yylex(yy::parser::semantic_type* yylval,
+ yy::parser::location_type* yylloc);
#endif
// Conversion to string.
@@ -627,6 +625,8 @@ static yy::parser::token_type yylex(yy::parser::semantic_type* yylval);
return o.str ();
}
}
+
+%token END_OF_FILE 0
EOF
if ($variant)
@@ -636,7 +636,6 @@ EOF
%token <int> NUMBER
%printer { std::cerr << "Number: " << $$; } <int>
%printer { std::cerr << "Text: " << $$; } <std::string>
-%token END_OF_FILE 0
%type <std::string> text result
%%
@@ -660,7 +659,6 @@ EOF
%token <ival> NUMBER
%printer { std::cerr << "Number: " << $$; } <ival>
%printer { std::cerr << "Text: " << *$$; } <sval>
-%token END_OF_FILE 0
%type <sval> text result
%%
@@ -678,39 +676,63 @@ EOF
print $out <<'EOF';
%%
+#
+
static
-yy::parser::token_type
-yylex(yy::parser::semantic_type* yylval)
+#if USE_LEX_SYMBOL
+yy::parser::symbol_type yylex()
+#else
+yy::parser::token_type yylex(yy::parser::semantic_type* yylval,
+ yy::parser::location_type* yylloc)
+#endif
{
+ typedef yy::parser::token token;
static int stage = -1;
++stage;
if (stage == STAGE_MAX)
- return yy::parser::token::END_OF_FILE;
+ {
+#if USE_LEX_SYMBOL
+ return yy::parser::make_symbol <token::END_OF_FILE> (yy::location());
+#else
+ *yylloc = yy::location ();
+ return token::END_OF_FILE;
+#endif
+ }
else if (stage % 2)
{
-#if USE_VARIANTS
-# ifdef ONE_STAGE_BUILD
+#if USE_LEX_SYMBOL
+ return yy::parser::make_symbol <token::NUMBER> (stage, yy::location());
+#elif defined ONE_STAGE_BUILD
yylval->build(stage);
-# else
+ *yylloc = yy::location ();
+ return token::NUMBER;
+#elif USE_VARIANTS
yylval->build<int>() = stage;
-# endif
+ *yylloc = yy::location ();
+ return token::NUMBER;
#else
yylval->ival = stage;
+ *yylloc = yy::location ();
+ return token::NUMBER;
#endif
- return yy::parser::token::NUMBER;
}
else
{
-#if USE_VARIANTS
-# ifdef ONE_STAGE_BUILD
+#if USE_LEX_SYMBOL
+ return yy::parser::make_symbol <token::TEXT> ("A string.", yy::location());
+#elif defined ONE_STAGE_BUILD
yylval->build(std::string("A string."));
-# else
+ *yylloc = yy::location ();
+ return token::TEXT;
+#elif USE_VARIANTS
yylval->build<std::string>() = std::string("A string.");
-# endif
+ *yylloc = yy::location ();
+ return token::TEXT;
#else
yylval->sval = new std::string("A string.");
+ *yylloc = yy::location ();
+ return token::TEXT;
#endif
- return yy::parser::token::TEXT;
}
abort();
}
@@ -886,7 +908,7 @@ sub bench_push_parser ()
=item C<bench_variant_parser ()>
-Bench the C++ lalr1.cc parser using Boost.Variants or %union.
+Bench the C++ lalr1.cc parser using variants or %union.
=cut
@@ -894,11 +916,10 @@ sub bench_variant_parser ()
{
bench ('list',
qw(
- [ %debug ]
- &
- [ %d variant
+ [
+ %d variant
&
- [ #d ONE_STAGE_BUILD ]
+ [ #d ONE_STAGE_BUILD | %d lex_symbol ]
]
)
);
--
2.47.2