From: Peter Rabbitson <ribasushi@cpan.org>
Date: Sun, 10 Apr 2016 03:04:16 +0000 (+0200)
Subject: Switch to EU::HC (with an inc::latest-like approach)
X-Git-Tag: 0.27~2
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit%2Fnamespace-clean.git;a=commitdiff_plain;h=58cd9d451f194f4edecde0915ba6a8346af5ba14

Switch to EU::HC (with an inc::latest-like approach)

Implement semi-elaborate Makefile.PL boilerplate for EU::HC use. While at
this point EU::HC seems rather stable, it still hasn't settled enough for
complete comfort.

This allow loading of "more-recent-than INC", in order to decrease amount of
needed release churn to work around newly-found problems.
---

diff --git a/Makefile.PL b/Makefile.PL
index c7a36f7..04f20c3 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -19,7 +19,6 @@ my %META = (
     configure => {
       requires => {
         'ExtUtils::MakeMaker'   => 0,
-        'ExtUtils::CBuilder'    => 0.27,
       }
     },
     runtime => {
@@ -59,13 +58,87 @@ my %MM_ARGS = ( (
     and
   namespace::clean::_Util::_namer_load_error()
     and
-  can_xs()
+  usable_compiler_present()
 )
   # when changing version, also change $sn_ver in namespace/clean/_Util.pm
   ? ( PREREQ_PM => { 'Sub::Name' => '0.04' } )
   : ()
 );
 
+## XS-checking BOILERPLATE ###################################################
+sub usable_compiler_present {
+  return 0 if parse_args()->{PUREPERL_ONLY};
+
+  my $ucp;
+
+  local $@;
+  eval {
+    # poor man's inc::latest
+    my $euhc_fn = 'ExtUtils/HasCompiler.pm';
+    my $euhc_found_in_INC_dir;
+
+    ( ($euhc_found_in_INC_dir) = grep {
+      not length ref $_
+        and
+      -f "$_/$euhc_fn"
+        and
+      -r "$_/$euhc_fn"
+    } @INC )
+      and
+    (
+      MM->parse_version("$euhc_found_in_INC_dir/$euhc_fn")
+        >
+      MM->parse_version("inc/$euhc_fn")
+    )
+      and
+    eval { require ExtUtils::HasCompiler };
+
+    unless ( $INC{'ExtUtils/HasCompiler.pm'} ) {
+      local @INC = ( "inc", @INC );
+      require ExtUtils::HasCompiler;
+    }
+
+    $ucp = ExtUtils::HasCompiler::can_compile_loadable_object(quiet => 1)
+      ? 1
+      : 0
+    ;
+
+    1;
+  };
+
+  if( my $used_fn = $INC{'ExtUtils/HasCompiler.pm'} ) {
+    printf
+      "ExtUtils::HasCompiler::can_compile_loadable_object() v%s (loaded from %s) returned: %s\n",
+      ExtUtils::HasCompiler->VERSION,
+      $used_fn,
+      ( defined($ucp) ? $ucp : "UNKNOWN" ),
+    ;
+  }
+  else {
+    print "Something went wrong when trying to load/use ExtUtils::HasCompiler:\n$@\n\n";
+  }
+
+  $ucp;
+}
+
+
+# FIXME - this has been cargo-culted from
+# https://metacpan.org/source/HAARG/strictures-2.000002/Makefile.PL
+# There likely will be better ways to handle %ENV and @ARGV directly within
+# EU::HC in the future
+sub parse_args {
+  # copied from EUMM
+  require ExtUtils::MakeMaker;
+  require Text::ParseWords;
+  ExtUtils::MakeMaker::parse_args(
+    my $tmp = {},
+    Text::ParseWords::shellwords($ENV{PERL_MM_OPT} || ''),
+    @ARGV,
+  );
+  return $tmp->{ARGS} || {};
+}
+## END XS-checking BOILERPLATE ###############################################
+
 
 ## BOILERPLATE ###############################################################
 require ExtUtils::MakeMaker;
@@ -108,106 +181,3 @@ delete $MM_ARGS{CONFIGURE_REQUIRES}
 
 ExtUtils::MakeMaker::WriteMakefile(%MM_ARGS);
 ## END BOILERPLATE ###########################################################
-
-
-# FIXME
-# Need to replace with EU::HC, but too many changes for this release already
-###########################################
-# can we locate a (the) C compiler
-sub can_cc {
-  my @chunks = split(/ /, $Config::Config{cc}) or return;
-
-  # $Config{cc} may contain args; try to find out the program part
-  while (@chunks) {
-    return can_run("@chunks") || (pop(@chunks), next);
-  }
-
-  return;
-}
-
-# check if we can run some command
-sub can_run {
-  my ($cmd) = @_;
-
-  return $cmd if -x $cmd;
-  if (my $found_cmd = MM->maybe_command($cmd)) {
-    return $found_cmd;
-  }
-
-  require File::Spec;
-  for my $dir ((split /$Config::Config{path_sep}/, $ENV{PATH}), '.') {
-    next if $dir eq '';
-    my $abs = File::Spec->catfile($dir, $cmd);
-    return $abs if (-x $abs or $abs = MM->maybe_command($abs));
-  }
-
-  return;
-}
-
-# Can our C compiler environment build XS files
-sub can_xs {
-  # Do we have the configure_requires checker?
-  local $@;
-  eval "require ExtUtils::CBuilder; ExtUtils::CBuilder->VERSION(0.27)";
-  if ( $@ ) {
-    # They don't obey configure_requires, so it is
-    # someone old and delicate. Try to avoid hurting
-    # them by falling back to an older simpler test.
-    return can_cc();
-  }
-
-  # Do we have a working C compiler
-  my $builder = ExtUtils::CBuilder->new(
-    quiet => 1,
-  );
-  unless ( $builder->have_compiler ) {
-    # No working C compiler
-    return 0;
-  }
-
-  # Write a C file representative of what XS becomes
-  require File::Temp;
-  my ( $FH, $tmpfile ) = File::Temp::tempfile(
-    "compilexs-XXXXX",
-    SUFFIX => '.c',
-  );
-  binmode $FH;
-  print $FH <<'END_C';
-#include "EXTERN.h"
-#include "perl.h"
-#include "XSUB.h"
-
-int main(int argc, char **argv) {
-    return 0;
-}
-
-int boot_sanexs() {
-    return 1;
-}
-
-END_C
-  close $FH;
-
-  # Can the C compiler access the same headers XS does
-  my @libs   = ();
-  my $object = undef;
-  eval {
-    local $^W = 0;
-    $object = $builder->compile(
-      source => $tmpfile,
-    );
-    @libs = $builder->link(
-      objects     => $object,
-      module_name => 'sanexs',
-    );
-  };
-  my $result = $@ ? 0 : 1;
-
-  # Clean up all the build files
-  foreach ( $tmpfile, $object, @libs ) {
-    next unless defined $_;
-    1 while unlink;
-  }
-
-  return $result;
-}
diff --git a/inc/ExtUtils/HasCompiler.pm b/inc/ExtUtils/HasCompiler.pm
new file mode 100644
index 0000000..6991ece
--- /dev/null
+++ b/inc/ExtUtils/HasCompiler.pm
@@ -0,0 +1,160 @@
+package ExtUtils::HasCompiler;
+$ExtUtils::HasCompiler::VERSION = '0.014';
+use strict;
+use warnings;
+
+use base 'Exporter';
+our @EXPORT_OK = qw/can_compile_loadable_object/;
+our %EXPORT_TAGS = (all => \@EXPORT_OK);
+
+use Config;
+use Carp 'carp';
+use File::Basename 'basename';
+use File::Spec::Functions qw/catfile catdir rel2abs/;
+use File::Temp qw/tempdir tempfile/;
+
+my $tempdir = tempdir('HASCOMPILERXXXX', CLEANUP => 1, DIR => '.');
+
+my $loadable_object_format = <<'END';
+#define PERL_NO_GET_CONTEXT
+#include "EXTERN.h"
+#include "perl.h"
+#include "XSUB.h"
+
+#ifndef PERL_UNUSED_VAR
+#define PERL_UNUSED_VAR(var)
+#endif
+
+XS(exported) {
+#ifdef dVAR
+	dVAR;
+#endif
+	dXSARGS;
+
+	PERL_UNUSED_VAR(cv); /* -W */
+	PERL_UNUSED_VAR(items); /* -W */
+
+	XSRETURN_IV(42);
+}
+
+#ifndef XS_EXTERNAL
+#define XS_EXTERNAL(foo) XS(foo)
+#endif
+
+/* we don't want to mess with .def files on mingw */
+#if defined(WIN32) && defined(__GNUC__)
+#  define EXPORT __declspec(dllexport)
+#else
+#  define EXPORT
+#endif
+
+EXPORT XS_EXTERNAL(boot_%s) {
+#ifdef dVAR
+	dVAR;
+#endif
+	dXSARGS;
+
+	PERL_UNUSED_VAR(cv); /* -W */
+	PERL_UNUSED_VAR(items); /* -W */
+
+	newXS("%s::exported", exported, __FILE__);
+}
+
+END
+
+my $counter = 1;
+my %prelinking = map { $_ => 1 } qw/MSWin32 VMS aix/;
+
+sub can_compile_loadable_object {
+	my %args = @_;
+
+	my $output = $args{output} || \*STDOUT;
+
+	my $config = $args{config} || 'ExtUtils::HasCompiler::Config';
+	return if not $config->get('usedl');
+
+	my ($source_handle, $source_name) = tempfile('TESTXXXX', DIR => $tempdir, SUFFIX => '.c', UNLINK => 1);
+	my $basename = basename($source_name, '.c');
+
+	my $shortname = '_Loadable' . $counter++;
+	my $package = "ExtUtils::HasCompiler::$shortname";
+	printf $source_handle $loadable_object_format, $basename, $package or do { carp "Couldn't write to $source_name: $!"; return };
+	close $source_handle or do { carp "Couldn't close $source_name: $!"; return };
+
+	my $abs_basename = catfile($tempdir, $basename);
+	my $object_file = $abs_basename . $config->get('_o');
+	my $loadable_object = $abs_basename . '.' . $config->get('dlext');
+	my $incdir = catdir($config->get('archlibexp'), 'CORE');
+
+	my ($cc, $ccflags, $optimize, $cccdlflags, $ld, $ldflags, $lddlflags, $libperl, $perllibs) = map { $config->get($_) } qw/cc ccflags optimize cccdlflags ld ldflags lddlflags libperl perllibs/;
+
+	if ($prelinking{$^O}) {
+		require ExtUtils::Mksymlists;
+		ExtUtils::Mksymlists::Mksymlists(NAME => $basename, FILE => $abs_basename, IMPORTS => {});
+	}
+	my @commands;
+	if ($^O eq 'MSWin32' && $cc =~ /^cl/) {
+		push @commands, qq{$cc $ccflags $cccdlflags $optimize /I "$incdir" /c $source_name /Fo$object_file};
+		push @commands, qq{$ld $object_file $lddlflags $libperl $perllibs /out:$loadable_object /def:$abs_basename.def /pdb:$abs_basename.pdb};
+	}
+	elsif ($^O eq 'VMS') {
+		# Mksymlists is only the beginning of the story.
+		open my $opt_fh, '>>', "$abs_basename.opt" or do { carp "Couldn't append to '$abs_basename.opt'"; return };
+		print $opt_fh "PerlShr/Share\n";
+		close $opt_fh;
+
+		my $incdirs = $ccflags =~ s{ /inc[^=]+ (?:=)+ (?:\()? ( [^\/\)]* ) }{}xi ? "$1,$incdir" : $incdir;
+		push @commands, qq{$cc $ccflags $optimize /include=($incdirs) $cccdlflags $source_name /obj=$object_file};
+		push @commands, qq{$ld $ldflags $lddlflags=$loadable_object $object_file,$abs_basename.opt/OPTIONS,${incdir}perlshr_attr.opt/OPTIONS' $perllibs};
+	}
+	else {
+		my @extra;
+		if ($^O eq 'MSWin32') {
+			my $lib = '-l' . ($libperl =~ /lib([^.]+)\./)[0];
+			push @extra, "$abs_basename.def", $lib, $perllibs;
+		}
+		elsif ($^O eq 'cygwin') {
+			push @extra, catfile($incdir, $config->get('useshrplib') ? 'libperl.dll.a' : 'libperl.a');
+		}
+		elsif ($^O eq 'aix') {
+			$lddlflags =~ s/\Q$(BASEEXT)\E/$abs_basename/;
+			$lddlflags =~ s/\Q$(PERL_INC)\E/$incdir/;
+		}
+		elsif ($^O eq 'android') {
+			push @extra, qq{"-L$incdir"}, '-lperl', $perllibs;
+		}
+		push @commands, qq{$cc $ccflags $optimize "-I$incdir" $cccdlflags -c $source_name -o $object_file};
+		push @commands, qq{$cc $optimize $object_file -o $loadable_object $lddlflags @extra};
+	}
+
+	for my $command (@commands) {
+		print $output "$command\n" if not $args{quiet};
+		system $command and do { carp "Couldn't execute $command: $!"; return };
+	}
+
+	# Skip loading when cross-compiling
+	return 1 if exists $args{skip_load} ? $args{skip_load} : $config->get('usecrosscompile');
+
+	require DynaLoader;
+	local @DynaLoader::dl_require_symbols = "boot_$basename";
+	my $handle = DynaLoader::dl_load_file(rel2abs($loadable_object), 0);
+	if ($handle) {
+		my $symbol = DynaLoader::dl_find_symbol($handle, "boot_$basename") or do { carp "Couldn't find boot symbol for $basename"; return };
+		my $compilet = DynaLoader::dl_install_xsub('__ANON__::__ANON__', $symbol, $source_name);
+		my $ret = eval { $compilet->(); $package->exported } or carp $@;
+		delete $ExtUtils::HasCompiler::{"$shortname\::"};
+		eval { DynaLoader::dl_unload_file($handle) } or carp $@;
+		return defined $ret && $ret == 42;
+	}
+	else {
+		carp "Couldn't load $loadable_object: " . DynaLoader::dl_error();
+		return;
+	}
+}
+
+sub ExtUtils::HasCompiler::Config::get {
+	my (undef, $key) = @_;
+	return $ENV{uc $key} || $Config{$key};
+}
+
+1;