Introduce EXIM_BUILD_SUFFIX for src/Makefile and testsuite

This enables parallel builds in a shared directory, if they have
the same os-type and arch-type. Think about EXIM_BUILD_SUFFIX
as 'name of your linux distro'

6 files changed, 84 insertions, 55 deletions

diff --git a/src/Makefile b/src/Makefile
index adda7ceb3..ccaca1c13 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -19,8 +19,14 @@ RM_COMMAND=/bin/rm
 # provide an override for the OS type and architecture type; they still have
 # to be used for the OS-specific files. To override them, you can set the
 # shell variables OSTYPE and ARCHTYPE when running make.
-
-buildname=$${build:-`$(SHELL) scripts/os-type`-`$(SHELL) scripts/arch-type`}
+#
+# EXIM_BUILD_SUFFIX should be used to enable parallel builds on a file
+# system shared among different Linux distros (same os-type, same
+# arch-type). The ../test/runtest script is expected to honour the
+# EXIM_BUILD_SUFFIX when searching the Exim binary.
+# NOTE: EXIM_BUILD_SUFFIX is considered *experimental*.
+
+buildname=$${build:-`$(SHELL) scripts/os-type`-`$(SHELL) scripts/arch-type`}$${EXIM_BUILD_SUFFIX:+.$$EXIM_BUILD_SUFFIX}
 
 # The default target checks for the existence of Local/Makefile, that the main
 # makefile is built and up-to-date, and then it runs it.
diff --git a/test/lib/Exim/Runtest.pm b/test/lib/Exim/Runtest.pm
index 851c29d3b..1677ae3e6 100644
--- a/test/lib/Exim/Runtest.pm
+++ b/test/lib/Exim/Runtest.pm
@@ -3,10 +3,11 @@ use 5.010;
 use strict;
 use warnings;
 use IO::Socket::INET;
+use Cwd;
 use Carp;
 
 use parent 'Exporter';
-our @EXPORT_OK = qw(mailgroup dynamic_socket);
+our @EXPORT_OK = qw(mailgroup dynamic_socket exim_binary);
 our %EXPORT_TAGS = (
     all => \@EXPORT_OK,
 );
@@ -57,6 +58,53 @@ sub dynamic_socket {
     croak 'Can not allocate a free port.';
 }
 
+sub exim_binary {
+
+    # two simple cases, absolute path or relative path and executable
+    return @_ if $_[0] =~ /^\//;
+    return Cwd::abs_path(shift), @_ if -x $_[0];
+
+    # so we're still here, if the simple approach didn't help.
+
+    # if there is '../exim-snapshot/<build-dir>/exim', use this
+    # if there is '../exim4/<build-dir>/exim', use this
+    # if there is '../exim-*.*/<build-dir>/exim', use the one with the highest version
+    #   4.84 < 4.85RC1 < 4.85RC2 < 4.85 < 4.86RC1 < … < 4.86
+    # if there is '../src/<build-dir>', use this
+    #
+
+    my $prefix = '..';  # was intended for testing.
+
+    # get a list of directories having the "scripts/{os,arch}-type"
+    # scripts
+    my @candidates = grep { -x "$_/scripts/os-type" and -x "$_/scripts/arch-type" }
+        "$prefix/exim-snapshot", "$prefix/exim4", # highest priority
+        (reverse sort {                           # list of exim-*.* directories
+        # split version number from RC number
+        my @a = ($a =~ /(\d+\.\d+)(?:RC(\d+))?/);
+        my @b = ($b =~ /(\d+\.\d+)(?:RC(\d+))?/);
+        # if the versions are not equal, we're fine,
+        # but otherwise we've to compare the RC number, where an
+        # empty RC number is better than a non-empty
+        ($a[0] cmp $b[0]) || (defined $a[1] ? defined $b[1] ? $a[1] cmp $b[1] : -1 : 1)
+        } glob "$prefix/exim-*.*"),
+        "$prefix/src";                       # the "normal" source
+
+    # binaries should be found now depending on the os-type and
+    # arch-type in the directories we got above
+    my @binaries = grep { -x }
+        map { ("$_/exim", "$_/exim4") }
+        map {
+            my $os = `$_/scripts/os-type`;
+            my $arch = `$_/scripts/arch-type`;
+            chomp($os, $arch);
+            "$_/build-$os-$arch" . ($ENV{EXIM_BUILD_SUFFIX} ? ".$ENV{EXIM_BUILD_SUFFIX}" : '');
+        } @candidates;
+
+    return $binaries[0], @_;
+}
+
+
 1;
 
 __END__
@@ -75,6 +123,14 @@ group name or some other random but existing group.
 Return a dynamically allocated listener socket in the range
 between 1024 and 65534;
 
+=item ($binary, @argv) = B<exim_binary>(I<@argv>)
+
+Find the Exim binary. Consider the first element of I<@argv>
+and remove it from I<@argv>, if it is an executable binary.
+Otherwise search the binary (while honouring C<EXIM_BUILD_SUFFIX>,
+C<../scripts/os-type> and C<../os-arch>) and return the
+the path to the binary and the unmodified I<@argv>.
+
 =back
 
 =cut
diff --git a/test/runtest b/test/runtest
index 38047b1eb..8b735c1ff 100755
--- a/test/runtest
+++ b/test/runtest
@@ -17,6 +17,7 @@
 
 #use strict;
 use 5.010;
+use feature 'state';	# included in 5.010
 use warnings;
 
 use Errno;
@@ -2444,7 +2445,7 @@ else
 # as the path to the binary. If the first argument does not start with a
 # '/' but exists in the file system, it's assumed to be the Exim binary.
 
-$parm_exim = (@ARGV > 0 && (-x $ARGV[0] or $ARGV[0] =~ m?^/?))? Cwd::abs_path(shift @ARGV) : "";
+($parm_exim, @ARGV) = Exim::Runtest::exim_binary(@ARGV);
 print "Exim binary is $parm_exim\n" if $parm_exim ne "";
 
 
@@ -2511,55 +2512,6 @@ $parm_cwd = Cwd::getcwd();
 # takes precedence; otherwise exim-snapshot takes precedence over any numbered
 # releases.
 
-if ($parm_exim eq "")
-  {
-  my($use_srcdir) = "";
-
-  opendir DIR, ".." || die "** Failed to opendir \"..\": $!\n";
-  while ($f = readdir(DIR))
-    {
-    my($srcdir);
-
-    # Try this directory if it is "exim4" or if it is exim-snapshot or exim-n.m
-    # possibly followed by -RCx where n.m is greater than any previously tried
-    # directory. Thus, we should choose the highest version of Exim that has
-    # been compiled.
-
-    if ($f eq "exim4" || $f eq "exim-snapshot" || $f eq 'src')
-      { $srcdir = $f; }
-    else
-      { $srcdir = $f
-        if ($f =~ /^exim-\d+\.\d+(-RC\d+)?$/ && $f gt $use_srcdir); }
-
-    # Look for a build directory with a binary in it. If we find a binary,
-    # accept this source directory.
-
-    if ($srcdir)
-      {
-      opendir SRCDIR, "../$srcdir" ||
-        die "** Failed to opendir \"$cwd/../$srcdir\": $!\n";
-      while ($f = readdir(SRCDIR))
-        {
-        if ($f =~ /^build-/ && -e "../$srcdir/$f/exim")
-          {
-          $use_srcdir = $srcdir;
-          $parm_exim = "$cwd/../$srcdir/$f/exim";
-          $parm_exim =~ s'/[^/]+/\.\./'/';
-          last;
-          }
-        }
-      closedir(SRCDIR);
-      }
-
-    # If we have found "exim4" or "exim-snapshot", that takes precedence.
-    # Otherwise, continue to see if there's a later version.
-
-    last if $use_srcdir eq "exim4" || $use_srcdir eq "exim-snapshot";
-    }
-  closedir(DIR);
-  print "Exim binary found in $parm_exim\n" if $parm_exim ne "";
-  }
-
 # If $parm_exim is still empty, ask the caller
 
 if ($parm_exim eq "")
@@ -2612,7 +2564,13 @@ while(<EXIMINFO>)
       $version =~ s/^\d+\K\./_/;
       $git =~ s/^exim-//i;
       $git =~ s/.*-\Kg([[:xdigit:]]+(?:-XX)?)/$1/;
-      print "\n*** Version mismatch (Exim: $version vs. GIT: $git). ***\n\n"
+      print <<___
+
+*** Version mismatch
+*** Exim binary: $version
+*** Git        : $git
+
+___
         if not $version eq $git;
     }
   }
diff --git a/test/t/00-basic.t b/test/t/00-basic.t
index 99a3e5fbd..ae8eff77d 100644
--- a/test/t/00-basic.t
+++ b/test/t/00-basic.t
@@ -5,7 +5,7 @@ use Test::Exception;
 use lib 'lib';
 use_ok 'Exim::Runtest', qw(:all) or BAIL_OUT 'Can not load the module';
 
-can_ok 'Exim::Runtest', qw(mailgroup dynamic_socket);
+can_ok 'Exim::Runtest', qw(mailgroup dynamic_socket exim_binary);
 pod_coverage_ok 'Exim::Runtest' => 'docs complete';
 
 subtest 'mailgroup' => sub {
@@ -31,5 +31,12 @@ subtest 'dynamic_socket' => sub {
     $socket->close;
 };
 
+subtest 'exim_binary' => sub {
+    my @argv1 = qw(/bin/sh a b);
+    my @argv2 = qw(t/samples/foo a b);
+    chomp(my $cwd = `pwd`); # don't use Cwd, as we use Cwd in the tested module already
+    is_deeply [exim_binary(@argv1)], \@argv1 => 'got the binary as abs path from argv';
+    is_deeply [exim_binary(@argv2)], ["$cwd/t/samples/foo", @argv2[1,$#argv2]] => 'got the binary as rel path from argv';
+};
 
 done_testing;
diff --git a/test/t/samples/foo b/test/t/samples/foo
new file mode 100755
index 000000000..0e748db3f
--- /dev/null
+++ b/test/t/samples/foo
@@ -0,0 +1,2 @@
+# this file solely exists to be tested as
+# an executable from one of the tests in t/
diff --git a/test/t/samples/src/.directory b/test/t/samples/src/.directory
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/test/t/samples/src/.directory