#! /usr/bin/perl -w

# Copyright (C) 2006, 2008 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
# it under the terms of the GNU General Public License as published by
# 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,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# 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, see <http://www.gnu.org/licenses/>.

=head1 NAME

bench.pl - perform benches on Bison parsers.

=head1 SYNOPSIS

  ./bench.pl

=head1 OPTIONS

=over 4

=item B<-b>, B<--bench>=I<bench-name>

Specify the set of benches to run.  I<bench-name> should be one of:

=over 4

=item I<fusion>

Test F<lalr1.cc> with three stacks against F<lalr1-fusion.cc> which
uses a single one.

=item I<push>

Test the push parser vs. the pull interface.  Use the C parser.

=item I<variant>

Test the use of variants instead of union in the C++ parser.

=back

=item B<-c>, B<--cflags>=I<flags>

Flags to pass to the C or C++ compiler.

=item B<-i>, B<--iterations>=I<integer>

Say how many times a single test of the bench must be run.  If
negative, specify the minimum number of CPU seconds to run.  Defaults
to -3.

=item B<-v>, B<--verbose>

Raise the verbosity level.  Currently only affects B<--help>.

=back

=cut

use IO::File;

##################################################################

=head1 VARIABLES

=over 4

=item C<$bison>

The Bison program to use to compile the grammar.

=item C<$cc>

The C compiler.

=item C<$cxx>

The C++ compiler.

=item C<$cflags>

Compiler flags (C or C++).

=item C<$iterations>

The number of times the parser is run for a bench.

=item C<$verbose>

Verbosity level.

=back

=cut

my $bison = $ENV{'BISON'} || '@abs_top_builddir@/tests/bison';
my $cc = $ENV{'CC'} || 'gcc';
my $cxx = $ENV{'CXX'} || 'g++';
my $cflags = '';
my $iterations = -3;
my $verbose = 0;

=head1 FUNCTIONS

=over 4

=item C<verbose($level, $message)>

Report the C<$message> is C<$level> E<lt>= C<$verbose>.

=cut

sub verbose($$)
{
  my ($level, $message) = @_;
  print STDERR $message
    if $level <= $verbose;
}

=item C<directives($bench, @directive)>

Format the list of directives for Bison for bench named C<$bench>.

The special fake C<%variant> directive requests the use of
Boost.Variants instead of a regular union.  So don't pass it, it is
not a valid directive.

=cut

sub directives($@)
{
  my ($bench, @directive) = @_;
  my $res = "/* Directives for bench `$bench'. */\n";
  for my $d (@directive)
    {
      $res .= $d . "\n"
        unless $d eq '%variant';
    }
  $res .= "/* End of directives for bench `$bench'. */\n";
  return $res;
}

=item C<triangular_grammar ($base, $max, @directive)>

Create a large triangular grammar which looks like :

  input:
    exp        { if ($1 != 0) abort (); $$ = $1; }
  | input exp  { if ($2 != $1 + 1) abort (); $$ = $2; }
  ;

  exp:
    END                         { $$ = 0; }
  | "1"  END                    { $$ = 1; }
  | "1" "2"  END                { $$ = 2; }
  | "1" "2" "3"  END            { $$ = 3; }
  | "1" "2" "3" "4"  END        { $$ = 4; }
  | "1" "2" "3" "4" "5"  END    { $$ = 5; }
  ;

C<$base> is the base name for the file to create (F<$base.y>).
C<$max> is the number of such rules (here, 5).  You may pass
additional Bison C<@directive>.

The created parser is self contained: it includes its scanner, and
source of input.
=cut

sub triangular_grammar ($$$)
{
  my ($base, $max, @directive) = @_;
  my $directives = directives ($base, @directive);

  my $out = new IO::File ">$base.y"
    or die;
  print $out <<EOF;
%error-verbose
%debug
%{
#include <stdio.h>
#include <stdlib.h>

static int yylex (void);
static void yyerror (const char *msg);
%}
$directives
%union
{
  int val;
};

%token END "end"
%type <val> exp input
EOF

  for my $size (1 .. $max)
    {
      print $out "%token t$size $size \"$size\"\n";
    };

print $out <<EOF;
%%
input:
  exp        { if (\$1 != 0) abort (); \$\$ = \$1; }
| input exp  { if (\$2 != \$1 + 1) abort (); \$\$ = \$2; }
;

exp:
  END
    { \$\$ = 0; }
EOF

for my $size (1 .. $max)
  {
    use Text::Wrap;
    print $out wrap ("| ", "   ",
		     (map { "\"$_\"" } (1 .. $size)),
		     " END \n"),
               "    { \$\$ = $size; }\n";
  };
print $out ";\n";

print $out <<EOF;
%%
static int
yylex (void)
{
  static int inner = 1;
  static int outer = 0;
  if (outer > $max)
    return 0;
  else if (inner > outer)
    {
      inner = 1;
      ++outer;
      return END;
    }
  return inner++;
}

static void
yyerror (const char *msg)
{
  fprintf (stderr, "%s\\n", msg);
}

int
main (void)
{
  yydebug = !!getenv ("YYDEBUG");
  return yyparse ();
}
EOF
}

##################################################################

=item C<calc_input ($base, $max)>

Generate the input file F<$base.input> for the calc parser.  The input
is composed of two expressions.  The first one is using left recursion
only and consumes no stack.  The second one requires a deep stack.
These two expressions are repeated C<$max> times in the output file.

=cut

sub calc_input ($$)
{
  my ($base, $max) = @_;
  my $out = new IO::File ">$base.input"
    or die;
  foreach (1 .. $max)
    {
      print $out "0+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+55+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70+71+72+73+74+75+76+77+78+79+80+81+82+83+84+85+86+87+88+89+90+91+92+93+94+95+96+97+98+99\n";
      print $out "1+1*(2+2*(3+3*(4+4*(5+5*(6+6*(7+7*(8+8*(9+9*(10+10*(11+11*(12+12*(13+13*(14+14*(15+15*(16+16*(17+17*(18+18*(19+19*(20+20*(21+21*(22+22*(23+23*(24+24*(25+25*(26+26*(27+27*(28+28*(29+29*(30+30*(31+31*(32+32*(33+33*(34+34*(35+35*(36+36*(37+37*(38+38*(39+39*(40+40*(41+41*(42+42*(43+43*(44+44*(45+45*(46+46*(47+47*(48+48*(49+49*(50+50*(51+51*(52+52*(53+53*(54+54*(55+55*(56+56*(57+57*(58+58*(59+59*(60+60*(61+61*(62+62*(63+63*(64+64*(65+65*(66+66*(67+67*(68+68*(69+69*(70+70*(71+71*(72+72*(73+73*(74+74*(75+75*(76+76*(77+77*(78+78*(79+79*(80+80*(81+81*(82+82*(83+83*(84+84*(85+85*(86+86*(87+87*(88+88*(89+89*(90+90*(91+91*(92+92*(93+93*(94+94*(95+95*(96+96*(97+97*(98+98*(99+99*(100+100*(101+101*(102+102*(103+103*(104+104*(105+105*(106+106*(107+107*(108+108*(109+109*(110+110*(111+111*(112+112*(113+113*(114+114*(115+115*(116+116*(117+117*(118+118*(119+119*(120+120*(121+121*(122+122*(123+123*(124+124*(125+125*(126+126*(127+127*(128+128*(129+129*(130+130*(131+131*(132+132*(133+133*(134+134*(135+135*(136+136*(137+137*(138+138*(139+139*(140+140*(141+141*(142+142*(143+143*(144+144*(145+145*(146+146*(147+147*(148+148*(149+149*(150+150*(151+151*(152+152*(153+153*(154+154*(155+155*(156+156*(157+157*(158+158*(159+159*(160+160*(161+161*(162+162*(163+163*(164+164*(165+165*(166+166*(167+167*(168+168*(169+169*(170+170*(171+171*(172+172*(173+173*(174+174*(175+175*(176+176*(177+177*(178+178*(179+179*(180+180*(181+181*(182+182*(183+183*(184+184*(185+185*(186+186*(187+187*(188+188*(189+189*(190+190*(191+191*(192+192*(193+193*(194+194*(195+195*(196+196*(197+197*(198+198*(199+199*(200+200*(201+201*(202+202*(203+203*(204+204*(205+205*(206+206*(207+207*(208+208*(209+209*(210+210*(211+211*(212+212*(213+213*(214+214*(215+215*(216+216*(217+217*(218+218*(219+219*(220+220*(221+221*(222+222*(223+223*(224+224*(225+225*(226+226*(227+227*(228+228*(229+229*(230+230*(231+231*(232+232*(233+233*(234+234*(235+235*(236+236*(237+237*(238+238*(239+239*(240+240*(241+241*(242+242*(243+243*(244+244*(245+245*(246+246*(247+247*(248+248*(249+249*(250+250*(251+251*(252+252*(253+253*(254+254*(255+255*(256+256*(257+257*(258+258*(259+259*(260+260*(261+261*(262+262*(263+263*(264+264*(265+265*(266+266*(267+267*(268+268*(269+269*(270+270*(271+271*(272+272*(273+273*(274+274*(275+275*(276+276*(277+277*(278+278*(279+279*(280+280*(281+281*(282+282*(283+283*(284+284*(285+285*(286+286*(287+287*(288+288*(289+289*(290+290*(291+291*(292+292*(293+293*(294+294*(295+295*(296+296*(297+297*(298+298*(299+299*(300+300*(301+301*(302+302*(303+303*(304+304*(305+305*(306+306*(307+307*(308+308*(309+309*(310+310*(311+311*(312+312*(313+313*(314+314*(315+315*(316+316*(317+317*(318+318*(319+319*(320+320*(321+321*(322+322*(323+323*(324+324*(325+325*(326+326*(327+327*(328+328*(329+329*(330+330*(331+331*(332+332*(333+333*(334+334*(335+335*(336+336*(337+337*(338+338*(339+339*(340+340*(341+341*(342+342*(343+343*(344+344*(345+345*(346+346*(347+347*(348+348*(349+349*(350+350*(351+351*(352+352*(353+353*(354+354*(355+355*(356+356*(357+357*(358+358*(359+359*(360+360*(361+361*(362+362*(363+363*(364+364*(365+365*(366+366*(367+367*(368+368*(369+369*(370+370*(371+371*(372+372*(373+373*(374+374*(375+375*(376+376*(377+377*(378+378*(379+379*(380+380*(381+381*(382+382*(383+383*(384+384*(385+385*(386+386*(387+387*(388+388*(389+389*(390+390*(391+391*(392+392*(393+393*(394+394*(395+395*(396+396*(397+397*(398+398*(399+399*(400+400*(401+401*(402+402*(403+403*(404+404*(405+405*(406+406*(407+407*(408+408*(409+409*(410+410*(411+411*(412+412*(413+413*(414+414*(415+415*(416+416*(417+417*(418+418*(419+419*(420+420*(421+421*(422+422*(423+423*(424+424*(425+425*(426+426*(427+427*(428+428*(429+429*(430+430*(431+431*(432+432*(433+433*(434+434*(435+435*(436+436*(437+437*(438+438*(439+439*(440+440*(441+441*(442+442*(443+443*(444+444*(445+445*(446+446*(447+447*(448+448*(449+449*(450+450*(451+451*(452+452*(453+453*(454+454*(455+455*(456+456*(457+457*(458+458*(459+459*(460+460*(461+461*(462+462*(463+463*(464+464*(465+465*(466+466*(467+467*(468+468*(469+469*(470+470*(471+471*(472+472*(473+473*(474+474*(475+475*(476+476*(477+477*(478+478*(479+479*(480+480*(481+481*(482+482*(483+483*(484+484*(485+485*(486+486*(487+487*(488+488*(489+489*(490+490*(491+491*(492+492*(493+493*(494+494*(495+495*(496+496*(497+497*(498+498*(499+499*(500+500*(501+501*(502+502*(503+503*(504+504*(505+505*(506+506*(507+507*(508+508*(509+509*(510+510*(511+511*(512+512*(513+513*(514+514*(515+515*(516+516*(517+517*(518+518*(519+519*(520+520*(521+521*(522+522*(523+523*(524+524*(525+525*(526+526*(527+527*(528+528*(529+529*(530+530*(531+531*(532+532*(533+533*(534+534*(535+535*(536+536*(537+537*(538+538*(539+539*(540+540*(541+541*(542+542*(543+543*(544+544*(545+545*(546+546*(547+547*(548+548*(549+549*(550+550*(551+551*(552+552*(553+553*(554+554*(555+555*(556+556*(557+557*(558+558*(559+559*(560+560*(561+561*(562+562*(563+563*(564+564*(565+565*(566+566*(567+567*(568+568*(569+569*(570+570*(571+571*(572+572*(573+573*(574+574*(575+575*(576+576*(577+577*(578+578*(579+579*(580+580*(581+581*(582+582*(583+583*(584+584*(585+585*(586+586*(587+587*(588+588*(589+589*(590+590*(591+591*(592+592*(593+593*(594+594*(595+595*(596+596*(597+597*(598+598*(599+599*(600+600*(601+601*(602+602*(603+603*(604+604*(605+605*(606+606*(607+607*(608+608*(609+609*(610+610*(611+611*(612+612*(613+613*(614+614*(615+615*(616+616*(617+617*(618+618*(619+619*(620+620*(621+621*(622+622*(623+623*(624+624*(625+625*(626+626*(627+627*(628+628*(629+629*(630+630*(631+631*(632+632*(633+633*(634+634*(635+635*(636+636*(637+637*(638+638*(639+639*(640+640*(641+641*(642+642*(643+643*(644+644*(645+645*(646+646*(647+647*(648+648*(649+649*(650+650*(651+651*(652+652*(653+653*(654+654*(655+655*(656+656*(657+657*(658+658*(659+659*(660+660*(661+661*(662+662*(663+663*(664+664*(665+665*(666+666*(667+667*(668+668*(669+669*(670+670*(671+671*(672+672*(673+673*(674+674*(675+675*(676+676*(677+677*(678+678*(679+679*(680+680*(681+681*(682+682*(683+683*(684+684*(685+685*(686+686*(687+687*(688+688*(689+689*(690+690*(691+691*(692+692*(693+693*(694+694*(695+695*(696+696*(697+697*(698+698*(699+699*(700+700*(701+701*(702+702*(703+703*(704+704*(705+705*(706+706*(707+707*(708+708*(709+709*(710+710*(711+711*(712+712*(713+713*(714+714*(715+715*(716+716*(717+717*(718+718*(719+719*(720+720*(721+721*(722+722*(723+723*(724+724*(725+725*(726+726*(727+727*(728+728*(729+729*(730+730*(731+731*(732+732*(733+733*(734+734*(735+735*(736+736*(737+737*(738+738*(739+739*(740+740*(741+741*(742+742*(743+743*(744+744*(745+745*(746+746*(747+747*(748+748*(749+749*(750+750*(751+751*(752+752*(753+753*(754+754*(755+755*(756+756*(757+757*(758+758*(759+759*(760+760*(761+761*(762+762*(763+763*(764+764*(765+765*(766+766*(767+767*(768+768*(769+769*(770+770*(771+771*(772+772*(773+773*(774+774*(775+775*(776+776*(777+777*(778+778*(779+779*(780+780*(781+781*(782+782*(783+783*(784+784*(785+785*(786+786*(787+787*(788+788*(789+789*(790+790*(791+791*(792+792*(793+793*(794+794*(795+795*(796+796*(797+797*(798+798*(799+799*(800+800*(801+801*(802+802*(803+803*(804+804*(805+805*(806+806*(807+807*(808+808*(809+809*(810+810*(811+811*(812+812*(813+813*(814+814*(815+815*(816+816*(817+817*(818+818*(819+819*(820+820*(821+821*(822+822*(823+823*(824+824*(825+825*(826+826*(827+827*(828+828*(829+829*(830+830*(831+831*(832+832*(833+833*(834+834*(835+835*(836+836*(837+837*(838+838*(839+839*(840+840*(841+841*(842+842*(843+843*(844+844*(845+845*(846+846*(847+847*(848+848*(849+849*(850+850*(851+851*(852+852*(853+853*(854+854*(855+855*(856+856*(857+857*(858+858*(859+859*(860+860*(861+861*(862+862*(863+863*(864+864*(865+865*(866+866*(867+867*(868+868*(869+869*(870+870*(871+871*(872+872*(873+873*(874+874*(875+875*(876+876*(877+877*(878+878*(879+879*(880+880*(881+881*(882+882*(883+883*(884+884*(885+885*(886+886*(887+887*(888+888*(889+889*(890+890*(891+891*(892+892*(893+893*(894+894*(895+895*(896+896*(897+897*(898+898*(899+899*(900+900*(901+901*(902+902*(903+903*(904+904*(905+905*(906+906*(907+907*(908+908*(909+909*(910+910*(911+911*(912+912*(913+913*(914+914*(915+915*(916+916*(917+917*(918+918*(919+919*(920+920*(921+921*(922+922*(923+923*(924+924*(925+925*(926+926*(927+927*(928+928*(929+929*(930+930*(931+931*(932+932*(933+933*(934+934*(935+935*(936+936*(937+937*(938+938*(939+939*(940+940*(941+941*(942+942*(943+943*(944+944*(945+945*(946+946*(947+947*(948+948*(949+949*(950+950*(951+951*(952+952*(953+953*(954+954*(955+955*(956+956*(957+957*(958+958*(959+959*(960+960*(961+961*(962+962*(963+963*(964+964*(965+965*(966+966*(967+967*(968+968*(969+969*(970+970*(971+971*(972+972*(973+973*(974+974*(975+975*(976+976*(977+977*(978+978*(979+979*(980+980*(981+981*(982+982*(983+983*(984+984*(985+985*(986+986*(987+987*(988+988*(989+989*(990+990*(991+991*(992+992*(993+993*(994+994*(995+995*(996+996*(997+997*(998+998*(999+999*(1000+1000*(1001))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))\n";
    }
}

##################################################################
=item C<calc_grammar ($base, $max, @directive)>

Generate a Bison file F<$base.y> for a calculator parser in C.  Pass
the additional Bison C<@directive>.  C<$max> is ignored, but left to
have the same interface as C<triangular_grammar>.

=cut

sub calc_grammar ($$$)
{
  my ($base, $max, @directive) = @_;
  my $directives = directives ($base, @directive);

  my $out = new IO::File ">$base.y"
    or die;
  print $out <<EOF;
%{
#include <stdio.h>

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#define USE(Var)

/* Exercise pre-prologue dependency to %union.  */
typedef int semantic_value;

static semantic_value global_result = 0;
static int global_count = 0;
%}

$directives
%error-verbose
/* Exercise %union. */
%union
{
  semantic_value ival;
};

%{
static int power (int base, int exponent);
/* yyerror receives the location if:
   - %location & %pure & %glr
   - %location & %pure & %yacc & %parse-param. */
static void yyerror (const char *s);
#if YYPURE
static int yylex (YYSTYPE* yylvalp);
#else
static int yylex (void);
#endif
%}

/* Bison Declarations */
%token CALC_EOF 0 "end of input"
%token <ival> NUM "number"
%type  <ival> exp

%nonassoc '=' /* comparison	       */
%left '-' '+'
%left '*' '/'
%left NEG     /* negation--unary minus */
%right '^'    /* exponentiation        */

/* Grammar follows */
%%
input:
  line
| input line
;

line:
  '\\n'
| exp '\\n'           { USE (\$1); }
;

exp:
  NUM                { \$\$ = \$1;             }
| exp '=' exp
  {
    if (\$1 != \$3)
      fprintf (stderr, "calc: error: %d != %d\\n", \$1, \$3);
    \$\$ = \$1;
  }
| exp '+' exp        { \$\$ = \$1 + \$3;        }
| exp '-' exp        { \$\$ = \$1 - \$3;        }
| exp '*' exp        { \$\$ = \$1 * \$3;        }
| exp '/' exp        { \$\$ = \$1 / \$3;        }
| '-' exp  %prec NEG { \$\$ = -\$2;            }
| exp '^' exp        { \$\$ = power (\$1, \$3); }
| '(' exp ')'        { \$\$ = \$2;             }
| '(' error ')'      { \$\$ = 1111;           }
| '!'                { \$\$ = 0; YYERROR;     }
| '-' error          { \$\$ = 0; YYERROR;     }
;
%%
/* The input.  */
static FILE *input;

static void
yyerror (const char *s)
{
  fprintf (stderr, "%s\\n", s);
}

static int
get_char (void)
{
  return getc (input);
}


static void
unget_char ( int c)
{
  ungetc (c, input);
}

static int
read_signed_integer (void)
{
  int c = get_char ();
  int sign = 1;
  int n = 0;

  if (c == '-')
    {
      c = get_char ();
      sign = -1;
    }

  while (isdigit (c))
    {
      n = 10 * n + (c - '0');
      c = get_char ();
    }

  unget_char (c);

  return sign * n;
}

static int
#if YYPURE
# define yylval (*yylvalp)
yylex (YYSTYPE* yylvalp)
#else
yylex (void)
#endif
{
  int c;

  /* Skip white space.  */
  while ((c = get_char ()) == ' ' || c == '\t')
    continue;

  /* process numbers   */
  if (c == '.' || isdigit (c))
    {
      unget_char ( c);
      yylval.ival = read_signed_integer ();
      return NUM;
    }

  /* Return end-of-file.  */
  if (c == EOF)
    return CALC_EOF;

  /* Return single chars. */
  return c;
}

static int
power (int base, int exponent)
{
  int res = 1;
  if (exponent < 0)
    exit (3);
  for (/* Niente */; exponent; --exponent)
    res *= base;
  return res;
}


int
main (int argc, const char **argv)
{
  semantic_value result = 0;
  int count = 0;
  int status;

  input = fopen ("calc.input", "r");
  if (!input)
    {
      perror ("calc.input");
      return 3;
    }

  status = yyparse ();
  if (global_result != result)
    abort ();
  if (global_count != count)
    abort ();

  return status;
}
EOF
}

##################################################################

=item C<variant_grammar ($base, $max, @directive)>

Generate a Bison file F<$base.y> that uses, or not, the Boost.Variants
depending on the C<@directive>.

=cut

sub variant_grammar ($$$)
{
  my ($base, $max, @directive) = @_;
  my $directives = directives ($base, @directive);
  my $variant = grep { $_ eq '%variant' } @directive;

  my $out = new IO::File ">$base.y"
    or die;
  print $out <<EOF;
%language "C++"
%defines
$directives

%code requires // variant.h
{
#include <string>
}

%code // variant.c
{
#include <algorithm>
#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)
#define USE_VARIANTS $variant
#if USE_VARIANTS
# define IF_VARIANTS(True, False) True
#else
# define IF_VARIANTS(True, False) False
#endif
}
EOF

  if ($variant)
    {
      print $out <<'EOF';
%code variant {int,std::string}
%token <std::string> TEXT
%token <int> NUMBER
%printer { std::cerr << "Number: " << $$; } <int>
%printer { std::cerr << "Text: " << $$; } <std::string>
%token END_OF_FILE 0
%type <std::string> text result

%%
result:
  text			{ /* Throw away the result. */ }
;

text:
  /* nothing */		{ /* This will generate an empty string */ }
| text TEXT		{ std::swap($$,$1); $$.append($2); }
| text NUMBER		{
			  std::swap($$,$1);
                          std::ostringstream ss;
			  ss << ' ' << $2;
			  $$.append(ss.str());
			 }
;
EOF
    }
  else
    {
      # Not using Boost variants.
      print $out <<'EOF';
%union {int ival; std::string* sval;}
%token <sval> TEXT
%token <ival> NUMBER
%printer { std::cerr << "Number: " << $$; } <ival>
%printer { std::cerr << "Text: " << *$$; } <sval>
%token END_OF_FILE 0
%type <sval> text result

%%
result:
  text			{ delete $1; }
;

text:
  /* nothing */		{ $$ = new std::string; }
| text TEXT		{ $$->append(*$2); delete $2; }
| text NUMBER		{
			  std::ostringstream ss;
			  ss << ' ' << $2;
			  $$->append(ss.str());
			 }
;
EOF
    }

  print $out <<'EOF';
%%
static
yy::parser::token_type
yylex(yy::parser::semantic_type* yylval)
{
  static int stage = -1;
  ++stage;
  if (stage == STAGE_MAX)
    return yy::parser::token::END_OF_FILE;
  else if (stage % 2)
    {
      IF_VARIANTS(yylval->build<int>(), yylval->ival) = stage;
      return yy::parser::token::NUMBER;
    }
  else
    {
      IF_VARIANTS(yylval->build<std::string>() =, yylval->sval = new) std::string("A string.");
      return yy::parser::token::TEXT;
    }
  abort();
}

// Mandatory error function
void
yy::parser::error(const yy::parser::location_type& yylloc,
                  const std::string& message)
{
  std::cerr << yylloc << ": " << message << std::endl;
}

int main(int argc, char *argv[])
{
  yy::parser p;
#if YYDEBUG
  p.set_debug_level(!!getenv("YYDEBUG"));
#endif
  p.parse();
  return 0;
}
EOF
}

##################################################################

=item C<compile ($base)>

Compile C<$base.y> to an executable C, Using the C or C++ compiler
depending on the %language specification in C<$base.y>.

=cut

sub compile ($)
{
  my ($base) = @_;
  my $language = `sed -ne '/%language "\\(.*\\)"/{s//\\1/;p;q;}' $base.y`;
  chomp $language;

  my $compiler = $language eq 'C++' ? $cxx : $cc;

  system ("$bison $base.y -o $base.c") == 0
    or die;
  system ("$compiler -o $base $cflags $base.c") == 0
    or die;
}

=item C<bench_grammar ($gram, %bench)>

Generate benches for C<$gram>.  C<$gram> should be C<calc> or
C<triangle>.  C<%bench> is a hash of the form:

  $name => @directive

where C<$name> is the name of the bench, and C<@directive> are the
Bison directive to use for this bench.  All the benches are compared
against each other, repeated 50 times.

=cut

sub bench_grammar ($%)
{
  my ($gram, %test) = @_;

  use Benchmark qw (:all :hireswallclock);

  # Set up the benches as expected by timethese.
  my %bench;
  # For each bench, capture the size.
  my %size;
  while (my ($name, $directives) = each %test)
    {
      verbose 1, "Generating $name\n";
      # Call the Bison input file generator.
      my $generator = "$gram" . "_grammar";
      &$generator ($name, 200, @$directives);
      # Compile the executable.
      compile ($name);
      $bench{$name} = "system ('./$name');";
      chop($size{$name} = `wc -c <$name`);
    }

  # Run the benches.
  #
  # STYLE can be any of 'all', 'none', 'noc', 'nop' or 'auto'.  'all'
  # shows each of the 5 times available ('wallclock' time, user time,
  # system time, user time of children, and system time of
  # children). 'noc' shows all except the two children times. 'nop'
  # shows only wallclock and the two children times.  'auto' (the
  # default) will act as 'all' unless the children times are both
  # zero, in which case it acts as 'noc'.  'none' prevents output.
  verbose 1, "Running the benches for $gram\n";
  my $res = timethese ($iterations, \%bench, 'nop');

  # Output the speed result.
  cmpthese ($res, 'nop');

  # Display the sizes.
  print "Sizes:\n";
  my $width = 10;
  for my $bench (keys %size)
    {
      $width = length $bench
        if $width < length $bench;
    }
  for my $bench (keys %size)
    {
      printf "%${width}s: %5dkB\n", $bench, int ($size{$bench} / 1024);
    }
}


=item C<bench_push_parser ()>

Bench the C push parser against the pull parser, pure and impure
interfaces.

=cut

sub bench_push_parser ()
{
  calc_input ('calc', 200);
  bench_grammar
    ('calc',
     (
      "pull-impure" => [],
      "pull-pure"   => ['%define api.pure'],
      "push-impure" => ['%define api.push_pull "both"'],
      "push-pure"   => ['%define api.push_pull "both"', '%define api.pure'],
     )
    );
}

=item C<bench_variant_parser ()>

Bench the C++ lalr1.cc parser using Boost.Variants or %union.

=cut

sub bench_variant_parser ()
{
  bench_grammar
    ('variant',
     (
      "f-union"         => ['%skeleton "lalr1-fusion.cc"'],
      "f-uni-deb"   => ['%skeleton "lalr1-fusion.cc"', '%debug'],
      "f-var"       => ['%skeleton "lalr1-fusion.cc"', '%variant'],
      "f-var-deb" => ['%skeleton "lalr1-fusion.cc"', '%debug', '%variant'],
      "f-var-dtr"       => ['%skeleton "lalr1-fusion.cc"', '%variant', "%code {\n#define VARIANT_DESTROY\n}"],
      "f-var-deb-dtr" => ['%skeleton "lalr1-fusion.cc"', '%debug', '%variant', "%code {\n#define VARIANT_DESTROY\n}"],
     )
    );
}

=item C<bench_fusion_parser ()>

Bench the C++ lalr1.cc parser using Boost.Variants or %union.

=cut

sub bench_fusion_parser ()
{
  bench_grammar
    ('variant',
     (
      "split"         => [],
      "fused"         => ['%skeleton "lalr1-fusion.cc"'],
     )
    );
}

############################################################################

sub help ($)
{
  my ($verbose) = @_;
  use Pod::Usage;
  # See <URL:http://perldoc.perl.org/pod2man.html#NOTES>.
  pod2usage( { -message => "Bench Bison parsers",
               -exitval => 0,
               -verbose => $verbose,
               -output  => \*STDOUT });
}

sub getopt ()
{
  use Getopt::Long;
  %option = (
    "b|bench=s"      => \$bench,
    "c|cflags=s"     => \$cflags,
    "h|help"         => sub { help ($verbose) },
    "i|iterations=i" => \$iterations,
    "v|verbose"      => sub { ++$verbose },
    );
  Getopt::Long::Configure ("bundling", "pass_through");
  GetOptions (%option)
    or exit 1;
}

######################################################################

getopt;
verbose 1, "Using bison=$bison.\n";
verbose 1, "Using cc=$cc.\n";
verbose 1, "Using cxx=$cxx.\n";
verbose 1, "Using cflags=$cflags.\n";

bench_fusion_parser()  if $bench eq "fusion";
bench_push_parser()    if $bench eq "push";
bench_variant_parser() if $bench eq "variant";

### Setup "GNU" style for perl-mode and cperl-mode.
## Local Variables:
## perl-indent-level: 2
## perl-continued-statement-offset: 2
## perl-continued-brace-offset: 0
## perl-brace-offset: 0
## perl-brace-imaginary-offset: 0
## perl-label-offset: -2
## cperl-indent-level: 2
## cperl-brace-offset: 0
## cperl-continued-brace-offset: 0
## cperl-label-offset: -2
## cperl-extra-newline-before-brace: t
## cperl-merge-trailing-else: nil
## cperl-continued-statement-offset: 2
## End: