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Peephole optimise adjacent pairs of nextstate ops.
[perl5.git] / regen_perly.pl
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1#!/usr/bin/perl
2#
3# regen_perly.pl, DAPM 12-Feb-04
4#
1d325971 5# Copyright (c) 2004, 2005 Larry Wall
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6#
7# Given an input file perly.y, run bison on it and produce
8# the following output files:
9#
10# perly.h standard bison header file with minor doctoring of
11# #line directives plus adding a #ifdef PERL_CORE
12#
13# perly.tab the parser table C definitions extracted from the bison output
0539ab63 14# plus an extra table generated by this script.
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15#
16# perly.act the action case statements extracted from the bison output
17#
18# Note that perly.c is *not* regenerated - this is now a static file which
19# is not dependent on perly.y any more.
20#
21# If a filename of the form foo.y is given on the command line, then
22# this is used instead as the basename for all the files mentioned
23# above.
24#
25# Note that temporary files of the form perlytmp.h and perlytmp.c are
26# created and then deleted during this process
27#
28# Note also that this script is intended to be run on a UNIX system;
29# it may work elsewhere but no specific attempt has been made to make it
30# portable.
31
32sub usage { die "usage: $0 [ -b bison_executable ] [ file.y ]\n" }
33
34use warnings;
35use strict;
36
37my $bison = 'bison';
38
39if (@ARGV >= 2 and $ARGV[0] eq '-b') {
40 shift;
41 $bison = shift;
42}
43
44my $y_file = shift || 'perly.y';
45
46usage unless @ARGV==0 && $y_file =~ /\.y$/;
47
48(my $h_file = $y_file) =~ s/\.y$/.h/;
49(my $act_file = $y_file) =~ s/\.y$/.act/;
50(my $tab_file = $y_file) =~ s/\.y$/.tab/;
51(my $tmpc_file = $y_file) =~ s/\.y$/tmp.c/;
52(my $tmph_file = $y_file) =~ s/\.y$/tmp.h/;
53
54# the yytranslate[] table generated by bison is ASCII/EBCDIC sensitive
55
56die "$0: must be run on an ASCII system\n" unless ord 'A' == 65;
57
58# check for correct version number. The constraints are:
59# * must be >= 1.24 to avoid licensing issues.
60# * it must generate the yystos[] table. Version 1.28 doesn't generate
61# this; 1.35+ does
62# * Must produce output which is extractable by the regexes below
63# * Must produce the right values.
64# These last two contstraints may well be met by earlier versions, but
65# I simply haven't tested them yet. If it works for you, then modify
66# the test below to allow that version too. DAPM Feb 04.
67
68my $version = `$bison -V`;
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69unless ($version) { die <<EOF; }
70Could not find a version of bison in your path. Please install bison.
71EOF
72
ce1534ab 73unless ($version =~ /\b(1\.875[a-z]?|2\.[0134])\b/) { die <<EOF; }
0de566d7 74
2080282f 75You have the wrong version of bison in your path; currently 1.875
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762.0, 2.1, 2.3 or 2.4 is required. Try installing
77 http://ftp.gnu.org/gnu/bison/bison-2.4.1.tar.gz
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78or similar. Your bison identifies itself as:
79
80$version
81EOF
82
83# creates $tmpc_file and $tmph_file
84my_system("$bison -d -o $tmpc_file $y_file");
85
86open CTMPFILE, $tmpc_file or die "Can't open $tmpc_file: $!\n";
87my $clines;
88{ local $/; $clines = <CTMPFILE>; }
89die "failed to read $tmpc_file: length mismatch\n"
90 unless length $clines == -s $tmpc_file;
91close CTMPFILE;
92
93my ($actlines, $tablines) = extract($clines);
94
d5c6462e 95$tablines .= make_type_tab($y_file, $tablines);
0539ab63 96
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97chmod 0644, $act_file;
98open ACTFILE, ">$act_file" or die "can't open $act_file: $!\n";
99print ACTFILE $actlines;
100close ACTFILE;
101chmod 0444, $act_file;
102
103chmod 0644, $tab_file;
104open TABFILE, ">$tab_file" or die "can't open $tab_file: $!\n";
105print TABFILE $tablines;
106close TABFILE;
107chmod 0444, $tab_file;
108
109unlink $tmpc_file;
110
111# Wrap PERL_CORE round the symbol definitions. Also, the
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112# C<#line 30 "perly.y"> confuses the Win32 resource compiler and the
113# C<#line 188 "perlytmp.h"> gets picked up by make depend, so remove them.
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114
115open TMPH_FILE, $tmph_file or die "Can't open $tmph_file: $!\n";
116chmod 0644, $h_file;
117open H_FILE, ">$h_file" or die "Can't open $h_file: $!\n";
118my $endcore_done = 0;
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119# Token macros need to be generated manually on bison 2.4
120my $gather_tokens = ($version =~ /\b2\.4\b/ ? undef : 0);
121my $tokens;
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122while (<TMPH_FILE>) {
123 print H_FILE "#ifdef PERL_CORE\n" if $. == 1;
124 if (!$endcore_done and /YYSTYPE_IS_DECLARED/) {
125 print H_FILE "#endif /* PERL_CORE */\n";
126 $endcore_done = 1;
127 }
96f4e226 128 next if /^#line \d+ ".*"/;
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129 if (not defined $gather_tokens) {
130 $gather_tokens = 1 if /^\s* enum \s* yytokentype \s* \{/x;
131 }
132 elsif ($gather_tokens) {
133 if (/^\# \s* endif/x) { # The #endif just after the end of the token enum
134 $gather_tokens = 0;
135 $_ .= "\n/* Tokens. */\n$tokens";
136 }
137 else {
138 my ($tok, $val) = /(\w+) \s* = \s* (\d+)/x;
139 $tokens .= "#define $tok $val\n" if $tok;
140 }
141 }
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142 print H_FILE $_;
143}
144close TMPH_FILE;
145close H_FILE;
146chmod 0444, $h_file;
147unlink $tmph_file;
148
149print "rebuilt: $h_file $tab_file $act_file\n";
150
151exit 0;
152
153
154sub extract {
155 my $clines = shift;
156 my $tablines;
157 my $actlines;
158
159 $clines =~ m@
160 (?:
161 ^/* YYFINAL[^\n]+\n #optional comment
162 )?
163 \# \s* define \s* YYFINAL # first #define
164 .*? # other defines + most tables
165 yystos\[\]\s*= # start of last table
166 .*?
167 }\s*; # end of last table
168 @xms
169 or die "Can't extract tables from $tmpc_file\n";
170 $tablines = $&;
171
172
173 $clines =~ m@
174 switch \s* \( \s* \w+ \s* \) \s* { \s*
175 (
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176 case \s* \d+ \s* :
177 \s*
178 (?: \s* /\* .*? \*/ \s* )* # optional C-comments
179 \s*
2ade6388 180 \#line [^\n]+"\Q$y_file\E"
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181 .*?
182 )
183 }
184 \s*
ce1534ab 185 (?: \s* /\* .*? \*/ \s* )* # optional C-comments
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186 \s*
187 (
188 \#line[^\n]+\.c"
189 |
190 \#line[^\n]+\.simple"
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191 |
192 YY_SYMBOL_PRINT
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193 )
194 @xms
195 or die "Can't extract actions from $tmpc_file\n";
196 $actlines = $1;
197
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198 # Remove extraneous comments from bison 2.4
199 $actlines =~ s!\s* /\* \s* Line \s* \d+ \s* of \s* yacc\.c \s* \*/!!gx;
200
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201 # C<#line 188 "perlytmp.c"> gets picked up by make depend, so remove them.
202 $actlines =~ s/^#line \d+ "\Q$tmpc_file\E".*$//gm;
203
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204 # convert yyvsp[nnn] into ps[nnn].val
205
206 $actlines =~ s/yyvsp\[(.*?)\]/ps[$1].val/g
207 or die "Can't convert value stack name\n";
208
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209 return $actlines. "\n", $tablines. "\n";
210}
211
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212# Generate a table, yy_type_tab[], that specifies for each token, what
213# type of value it holds.
0539ab63 214#
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215# Read the .y file and extract a list of all the token names and
216# non-terminal names; then scan the string $tablines for the table yytname,
217# which gives the token index of each token/non-terminal; then use this to
218# create yy_type_tab.
0539ab63 219#
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220# ie given (in perly.y),
221#
222# %token <opval> A
223# %token <ival> B
224# %type <pval> C
225# %type <opval> D
226#
227# and (in $tablines),
228#
229# yytname[] = { "A" "B", "C", "D", "E" };
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230#
231# then return
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232#
233# typedef enum { toketype_ival, toketype_opval, toketype_pval } toketypes;
234#
235# static const toketypes yy_type_tab[]
236# = { toketype_opval, toketype_ival, toketype_pval,
237# toketype_opval, toketype_ival }
238#
239# where "E" has the default type. The default type is determined
240# by the __DEFAULT__ comment next to the appropriate union member in
241# perly.y
0539ab63 242
d5c6462e 243sub make_type_tab {
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244 my ($y_file, $tablines) = @_;
245 my %tokens;
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246 my %types;
247 my $default_token;
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248 open my $fh, '<', $y_file or die "Can't open $y_file: $!\n";
249 while (<$fh>) {
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250 if (/(\$\d+)\s*=/) {
251 warn "$y_file:$.: dangerous assignment to $1: $_";
252 }
253
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254 if (/__DEFAULT__/) {
255 m{(\w+) \s* ; \s* /\* \s* __DEFAULT__}x
256 or die "$y_file: can't parse __DEFAULT__ line: $_";
257 die "$y_file: duplicate __DEFAULT__ line: $_"
258 if defined $default_token;
259 $default_token = $1;
260 next;
261 }
262
263 next unless /^%(token|type)/;
264 s/^%(token|type)\s+<(\w+)>\s+//
265 or die "$y_file: unparseable token/type line: $_";
266 $tokens{$_} = $2 for (split ' ', $_);
267 $types{$2} = 1;
0539ab63 268 }
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269 die "$y_file: no __DEFAULT__ token defined\n" unless $default_token;
270 $types{$default_token} = 1;
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271
272 $tablines =~ /^\Qstatic const char *const yytname[] =\E\n
273 {\n
274 (.*?)
275 ^};
276 /xsm
277 or die "Can't extract yytname[] from table string\n";
278 my $fields = $1;
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279 $fields =~ s{"([^"]+)"}
280 { "toketype_" .
281 (defined $tokens{$1} ? $tokens{$1} : $default_token)
282 }ge;
283 $fields =~ s/, \s* 0 \s* $//x
284 or die "make_type_tab: couldn't delete trailing ',0'\n";
285
0539ab63 286 return
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287 "\ntypedef enum {\n\t"
288 . join(", ", map "toketype_$_", sort keys %types)
289 . "\n} toketypes;\n\n"
290 . "/* type of each token/terminal */\n"
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291 . "static const toketypes yy_type_tab[] =\n{\n"
292 . $fields
293 . "\n};\n";
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294}
295
296
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297sub my_system {
298 system(@_);
299 if ($? == -1) {
d5c6462e 300 die "failed to execute command '@_': $!\n";
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301 }
302 elsif ($? & 127) {
303 die sprintf "command '@_' died with signal %d\n",
304 ($? & 127);
305 }
306 elsif ($? >> 8) {
307 die sprintf "command '@_' exited with value %d\n", $? >> 8;
308 }
309}