#!./perl -w
# What does this test?
# Test that changes to perl header files don't cause external
# references by simplying #including them.  This breaks library probe
# code on CPAN, and can break cflags.SH.
#
# Why do we test this?
# See https://github.com/Perl/perl5/issues/12824
#
# It's broken - how do I fix it?
# You added an initializer or static function to a header file that
# references some symbol you didn't define, you need to remove it.
BEGIN {
  require "./test.pl";
  unshift @INC, ".." if -f "../TestInit.pm";
}
use TestInit qw(T A); # T is chdir to the top level, A makes paths absolute
use strict;
use warnings;
use Config;
use File::Path 'rmtree';
use Cwd;
use IPC::Cmd qw(can_run);
if ($Config{'usecrosscompile'} && !can_run($Config{'cc'})) {
    skip_all("compiler not available (cross-compiling)");
} else {
    plan(tests => 1);
}
my $VERBOSE = grep {$_ eq '-v'} @ARGV;
ok(try_compile_and_link(<<'CODE'));
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
int main(int argc, char **argv) {
  return 0;
}
CODE
# from Time::HiRes's Makefile.PL with minor modifications
sub try_compile_and_link {
    my ($c, %args) = @_;
    my $ld_exeext = ($^O eq 'cygwin' || $^O eq 'MSWin32' ||
                 $^O eq 'os2' && $Config{ldflags} =~ /-Zexe\b/) ? '.exe' :
                (($^O eq 'vos') ? $Config{exe_ext} : '');
    my ($ok) = 0;
    my $tempdir = tempfile();
    my $cwd = getcwd();
    mkdir $tempdir;
    chdir $tempdir;
    my ($tmp) = "temp";
    my $obj_ext = $Config{obj_ext} || ".o";
    if (open(my $tmpc, ">$tmp.c")) {
        print $tmpc $c;
        unless (close($tmpc)) {
            chdir($cwd);
            rmtree($tempdir);
            warn "Failing closing code file: $!\n" if $VERBOSE;
            return 0;
        }
        my $COREincdir =
            File::Spec->catdir(File::Spec->updir, File::Spec->updir);
        my $ccflags = $Config{'ccflags'} . ' ' . "-I$COREincdir"
         . ' -DPERL_NO_INLINE_FUNCTIONS';
        if ($^O eq "MSWin32") {
            $ccflags .= " -I../../win32 -I../../win32/include";
        }
        my $libs = '';
        # Include libs to be sure of linking against bufferoverflowU.lib for
        # the SDK2003 compiler on Windows. See win32/Makefile for more details.
        if ($^O eq "MSWin32" && $Config{cc} =~ /\bcl\b/i) {
            $libs = " /link $Config{'libs'}";
        }
        my $null = File::Spec->devnull;
        my $errornull = $VERBOSE ? '' : ">$null 2>$null";
        # Darwin g++ 4.2.1 is fussy and demands a space.
        # FreeBSD g++ 4.2.1 does not.
        # We do not know the reaction of either to the presence of brown M&Ms.
        my $out_opt = "-o ";
        if ($^O eq "MSWin32" && $Config{cc} =~ /\bcl\b/i) {
            $out_opt = "/Fe";
        }
        my $tmp_exe = "$tmp$ld_exeext";
        my $cccmd = "$Config{'cc'} $out_opt$tmp_exe $ccflags $tmp.c $libs $errornull";
        if ($^O eq 'VMS') {
            $cccmd = "$Config{'cc'} /include=($COREincdir) $tmp.c";
        }
       if ($^O eq 'VMS') {
            open( my $cmdfile, ">$tmp.com" );
            print $cmdfile "\$ SET MESSAGE/NOFACILITY/NOSEVERITY/NOIDENT/NOTEXT\n";
            print $cmdfile "\$ $cccmd\n";
            print $cmdfile "\$ IF \$SEVERITY .NE. 1 THEN EXIT 44\n"; # escalate
            close $cmdfile;
            system("\@ $tmp.com");
            $ok = $?==0;
            chdir($cwd);
            rmtree($tempdir);
        }
        else
        {
            printf "cccmd = $cccmd\n" if $VERBOSE;
            my $res = system($cccmd);
            $ok = defined($res) && $res == 0 && -s $tmp_exe && -x _;
            chdir($cwd);
            rmtree($tempdir);
        }
    }
    return $ok;
}