util/dofile.pl, util/perl/OpenSSL/Template.pm: move parts of dofile.pl

We make a module OpenSSL::Template from the central parts of
util/dofile.pl, and also reduce the amount of ugly code with more
proper use of Text::Template.  OpenSSL::Template is a simply subclass
of Text::Template.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9693)

util/dofile.pl

@@ -14,9 +14,11 @@
 use strict;
 use warnings;
 
-use Getopt::Std;
 use FindBin;
 use lib "$FindBin::Bin/perl";
+use OpenSSL::fallback "$FindBin::Bin/../external/perl/MODULES.txt";
+use Getopt::Std;
+use OpenSSL::Template;
 
 # We actually expect to get the following hash tables from configdata:
 #
@@ -27,115 +29,8 @@ use lib "$FindBin::Bin/perl";
 #
 # We just do a minimal test to see that we got what we expected.
 # $config{target} must exist as an absolute minimum.
-die "You must run this script with -Mconfigdata\n" if !exists($config{target});
-
-# Make a subclass of Text::Template to override append_text_to_result,
-# as recommended here:
-#
-# http://search.cpan.org/~mjd/Text-Template-1.46/lib/Text/Template.pm#Automatic_postprocessing_of_template_hunks
-
-package OpenSSL::Template;
-
-# Because we know that Text::Template isn't a core Perl module, we use
-# a fallback in case it's not installed on the system
-use OpenSSL::fallback "$FindBin::Bin/../external/perl/MODULES.txt";
-use Text::Template 1.46;
-
-#use parent qw/Text::Template/;
-use vars qw/@ISA/;
-push @ISA, qw/Text::Template/;
-
-# Override constructor
-sub new {
-    my ($class) = shift;
-
-    # Call the constructor of the parent class, Person.
-    my $self = $class->SUPER::new( @_ );
-    # Add few more attributes
-    $self->{_output_off}   = 0;	# Default to output hunks
-    bless $self, $class;
-    return $self;
-}
-
-sub append_text_to_output {
-    my $self = shift;
-
-    if ($self->{_output_off} == 0) {
-	$self->SUPER::append_text_to_output(@_);
-    }
-
-    return;
-}
-
-sub output_reset_on {
-    my $self = shift;
-    $self->{_output_off} = 0;
-}
-
-sub output_on {
-    my $self = shift;
-    if (--$self->{_output_off} < 0) {
-	$self->{_output_off} = 0;
-    }
-}
-
-sub output_off {
-    my $self = shift;
-    $self->{_output_off}++;
-}
-
-# Come back to main
-
-package main;
-
-# Helper functions for the templates #################################
-
-# It might be practical to quotify some strings and have them protected
-# from possible harm.  These functions primarily quote things that might
-# be interpreted wrongly by a perl eval.
-
-# quotify1 STRING
-# This adds quotes (") around the given string, and escapes any $, @, \,
-# " and ' by prepending a \ to them.
-sub quotify1 {
-    my $s = shift @_;
-    $s =~ s/([\$\@\\"'])/\\$1/g;
-    '"'.$s.'"';
-}
-
-# quotify_l LIST
-# For each defined element in LIST (i.e. elements that aren't undef), have
-# it quotified with 'quotify1'
-sub quotify_l {
-    map {
-        if (!defined($_)) {
-            ();
-        } else {
-            quotify1($_);
-        }
-    } @_;
-}
-
-# Error reporter #####################################################
-
-# The error reporter uses %lines to figure out exactly which file the
-# error happened and at what line.  Not that the line number may be
-# the start of a perl snippet rather than the exact line where it
-# happened.  Nothing we can do about that here.
-
-my %lines = ();
-sub broken {
-    my %args = @_;
-    my $filename = "<STDIN>";
-    my $deducelines = 0;
-    foreach (sort keys %lines) {
-        $filename = $lines{$_};
-        last if ($_ > $args{lineno});
-        $deducelines += $_;
-    }
-    print STDERR $args{error}," in $filename, fragment starting at line ",$args{lineno}-$deducelines;
-    undef;
-}
+die "You must run this script with -Mconfigdata\n"
+    if !exists($config{target});
 
 # Check options ######################################################
 
@@ -146,74 +41,41 @@ my %opts = ();
 getopt('o', \%opts);
 
 my @autowarntext = ("WARNING: do not edit!",
-		    "Generated"
-		    . (defined($opts{o}) ? " by ".$opts{o} : "")
-		    . (scalar(@ARGV) > 0 ? " from ".join(", ",@ARGV) : ""));
+                    "Generated"
+                    . (defined($opts{o}) ? " by ".$opts{o} : "")
+                    . (scalar(@ARGV) > 0 ? " from ".join(", ",@ARGV) : ""));
 
-# Template reading ###################################################
+# Template setup #####################################################
 
-# Read in all the templates into $text, while keeping track of each
-# file and its size in lines, to try to help report errors with the
-# correct file name and line number.
-
-my $prev_linecount = 0;
-my $text =
+my @template_settings =
     @ARGV
-    ? join("", map { my $x = Text::Template::_load_text($_);
-                     if (!defined($x)) {
-                         die $Text::Template::ERROR, "\n";
-                     }
-                     $x = "{- output_reset_on() -}" . $x;
-                     my $linecount = $x =~ tr/\n//;
-                     $prev_linecount = ($linecount += $prev_linecount);
-                     $lines{$linecount} = $_;
-                     $x } @ARGV)
-    : join("", <STDIN>);
+    ? map { { TYPE => 'FILE', SOURCE => $_, FILENAME => $_ } } @ARGV
+    : ( { TYPE => 'FILEHANDLE', SOURCE => \*STDIN, FILENAME => '<stdin>' } );
 
 # Engage! ############################################################
 
-# Load the full template (combination of files) into Text::Template
-# and fill it up with our data.  Output goes directly to STDOUT
-
-my $prepend = qq{
+my $prepend = <<"_____";
 use File::Spec::Functions;
-use lib catdir('$config{sourcedir}', 'util', 'perl');
-};
-$prepend .= qq{
-use lib catdir('$config{sourcedir}', 'Configurations');
+_____
+$prepend .= <<"_____" if defined $target{perl_platform};
+use lib "$FindBin::Bin/../Configurations";
 use lib '$config{builddir}';
 use platform;
-} if defined $target{perl_platform};
-
-my $template =
-    OpenSSL::Template->new(TYPE => 'STRING',
-                           SOURCE => $text,
-                           PREPEND => $prepend);
-
-sub output_reset_on {
-    $template->output_reset_on();
-    "";
-}
-sub output_on {
-    $template->output_on();
-    "";
+_____
+
+foreach (@template_settings) {
+    my $template = OpenSSL::Template->new(%$_);
+    $template->fill_in(%$_,
+                       OUTPUT => \*STDOUT,
+                       HASH => { config => \%config,
+                                 target => \%target,
+                                 disabled => \%disabled,
+                                 withargs => \%withargs,
+                                 unified_info => \%unified_info,
+                                 autowarntext => \@autowarntext },
+                       PREPEND => $prepend,
+                       # To ensure that global variables and functions
+                       # defined in one template stick around for the
+                       # next, making them combinable
+                       PACKAGE => 'OpenSSL::safe');
 }
-sub output_off {
-    $template->output_off();
-    "";
-}
-
-$template->fill_in(OUTPUT => \*STDOUT,
-                   HASH => { config => \%config,
-                             target => \%target,
-                             disabled => \%disabled,
-                             withargs => \%withargs,
-                             unified_info => \%unified_info,
-                             autowarntext => \@autowarntext,
-                             quotify1 => \&quotify1,
-                             quotify_l => \&quotify_l,
-                             output_reset_on => \&output_reset_on,
-                             output_on => \&output_on,
-                             output_off => \&output_off },
-                   DELIMITERS => [ "{-", "-}" ],
-                   BROKEN => \&broken);

util/perl/OpenSSL/Template.pm

@@ -0,0 +1,195 @@
+#! /usr/bin/env perl
+# Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved.
+#
+# Licensed under the Apache License 2.0 (the "License").  You may not use
+# this file except in compliance with the License.  You can obtain a copy
+# in the file LICENSE in the source distribution or at
+# https://www.openssl.org/source/license.html
+
+# Implements the functionality to read one or more template files and run
+# them through Text::Template
+
+package OpenSSL::Template;
+
+=head1 NAME
+
+OpenSSL::Template - a private extension of Text::Template
+
+=head1 DESCRIPTION
+
+This provides exactly the functionality from Text::Template, with the
+following additions:
+
+=over 4
+
+=item -
+
+The template perl code delimiters (given with the C<DELIMITER> option)
+are set to C<{-> and C<-}> by default.
+
+=item -
+
+A few extra functions are offered to be used by the template perl code, see
+L</Functions>.
+
+=back
+
+=cut
+
+use File::Basename;
+use File::Spec::Functions;
+use Text::Template 1.46;
+
+our @ISA = qw(Text::Template);  # parent
+
+sub new {
+    my $class = shift;
+
+    # Call the constructor of the parent class.
+    my $self = $class->SUPER::new(DELIMITERS => [ '{-', '-}'],
+                                  @_ );
+
+    # Add few more attributes
+    $self->{_output_off}   = 0; # Default to output hunks
+
+    return bless $self, $class;
+}
+
+sub fill_in {
+    my $self = shift;
+    my %opts = @_;
+    my %hash = ( %{$opts{HASH}} );
+    delete $opts{HASH};
+
+    $self->SUPER::fill_in(HASH => { quotify1 => \&quotify1,
+                                    quotify_l => \&quotify_l,
+                                    output_on => sub { $self->output_on() },
+                                    output_off => sub { $self->output_off() },
+                                    %hash },
+                          %opts);
+}
+
+=head2 Functions
+
+=cut
+
+# Override Text::Template's append_text_to_result, as recommended here:
+#
+# http://search.cpan.org/~mjd/Text-Template-1.46/lib/Text/Template.pm#Automatic_postprocessing_of_template_hunks
+sub append_text_to_output {
+    my $self = shift;
+
+    if ($self->{_output_off} == 0) {
+        $self->SUPER::append_text_to_output(@_);
+    }
+
+    return;
+}
+
+=begin comment
+
+We lie about the OO nature of output_on() and output_off(), 'cause that's
+not how we pass them, see the HASH option used in fill_in() above
+
+=end comment
+
+=over 4
+
+=item output_on()
+
+=item output_off()
+
+Switch on or off template output.  Here's an example usage:
+
+=over 4
+
+ {- output_off() if CONDITION -}
+ whatever
+ {- output_on() if CONDITION -}
+
+=back
+
+In this example, C<whatever> will only become part of the template output
+if C<CONDITION> is true.
+
+=back
+
+=cut
+
+sub output_on {
+    my $self = shift;
+    if (--$self->{_output_off} < 0) {
+        $self->{_output_off} = 0;
+    }
+}
+
+sub output_off {
+    my $self = shift;
+    $self->{_output_off}++;
+}
+
+# Helper functions for the templates #################################
+
+# It might be practical to quotify some strings and have them protected
+# from possible harm.  These functions primarily quote things that might
+# be interpreted wrongly by a perl eval.
+
+# NOTE THAT THESE AREN'T CLASS METHODS!
+
+=over 4
+
+=item quotify1 STRING
+
+This adds quotes (") around the given string, and escapes any $, @, \,
+" and ' by prepending a \ to them.
+
+=back
+
+=cut
+
+sub quotify1 {
+    my $s = shift @_;
+    $s =~ s/([\$\@\\"'])/\\$1/g;
+    '"'.$s.'"';
+}
+
+=over 4
+
+=item quotify_l LIST
+
+For each defined element in LIST (i.e. elements that aren't undef), have
+it quotified with 'quotify1'.
+Undefined elements are ignored.
+
+=back
+
+=cut
+
+sub quotify_l {
+    map {
+        if (!defined($_)) {
+            ();
+        } else {
+            quotify1($_);
+        }
+    } @_;
+}
+
+=head1 SEE ALSO
+
+L<Text::Template>
+
+=head1 AUTHORS
+
+Richard Levitte E<lt>levitte@openssl.orgE<gt>
+
+=head1 COPYRIGHT
+
+Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the Apache License 2.0 (the "License").  You may not use
+this file except in compliance with the License.  You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut