Implement automatic loading of directory buildfiles

Now instead of explicitly writing:

d = foo/ bar/
./: $d
include $d

We can (usually) just write:

./: foo/ bar/

9 files changed, 75 insertions, 14 deletions

diff --git a/tests/buildfile b/tests/buildfile
index c0a50e3..0384c45 100644
--- a/tests/buildfile
+++ b/tests/buildfile
@@ -2,6 +2,6 @@
 # copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
-d = directive/ eval/ expansion/ function/ test/ value/
-./: $d file{common.test}
-include $d
+./: directive/ eval/ expansion/ function/ search/ test/ value/ \
+file{common.test}
+
diff --git a/tests/common.test b/tests/common.test
index 2311ae1..d495da0 100644
--- a/tests/common.test
+++ b/tests/common.test
@@ -15,6 +15,6 @@ test.options += --jobs 1 --quiet --buildfile -
 
 # By default just load the buildfile.
 #
-if ($empty($test.arguments))
+if ($null($test.arguments))
   test.arguments = noop
 end
diff --git a/tests/function/buildfile b/tests/function/buildfile
index 4e043cf..8034f2b 100644
--- a/tests/function/buildfile
+++ b/tests/function/buildfile
@@ -2,6 +2,4 @@
 # copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
-d = builtin/ path/
-./: $d
-include $d
+./: builtin/ path/
diff --git a/tests/function/builtin/testscript b/tests/function/builtin/testscript
index 82df683..0b005f3 100644
--- a/tests/function/builtin/testscript
+++ b/tests/function/builtin/testscript
@@ -1,4 +1,4 @@
-# file      : tests/function/path/testscript
+# file      : tests/function/builtin/testscript
 # copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
diff --git a/tests/search/buildfile b/tests/search/buildfile
new file mode 100644
index 0000000..a72ca71
--- /dev/null
+++ b/tests/search/buildfile
@@ -0,0 +1,5 @@
+# file      : tests/search/buildfile
+# copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+# license   : MIT; see accompanying LICENSE file
+
+./: dir/
diff --git a/tests/search/dir/buildfile b/tests/search/dir/buildfile
new file mode 100644
index 0000000..03afc85
--- /dev/null
+++ b/tests/search/dir/buildfile
@@ -0,0 +1,8 @@
+# file      : tests/search/dir/buildfile
+# copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+# license   : MIT; see accompanying LICENSE file
+
+# Test loading of dir{} buildfiles during target search.
+#
+
+./: test{testscript} $b
diff --git a/tests/search/dir/testscript b/tests/search/dir/testscript
new file mode 100644
index 0000000..4c427b2
--- /dev/null
+++ b/tests/search/dir/testscript
@@ -0,0 +1,51 @@
+# file      : tests/search/dir/testscript
+# copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+# license   : MIT; see accompanying LICENSE file
+
+test.arguments = 'update(../)'
+
+.include ../../common.test
+
+# foo/ has no buildfile
+# bar/ has valid buildfile
+# baz/ has invalid buildfile
+#
++mkdir foo bar baz
++cat <<EOI >>>bar/buildfile
+print bar
+./:
+EOI
++cat <'assert false' >>>baz/buildfile
+
+: no-buildfile
+:
+$* <'./: foo/' 2>>/EOE != 0
+error: no explicit target for prerequisite ../:dir{foo/}
+  info: did you forget to include the corresponding buildfile?
+info: while applying rule alias to update dir{../}
+EOE
+
+: basic
+:
+$* <'./: bar/' >'bar'
+
+: existing-scope
+:
+$* <<EOI >'bar'
+bar/: x = y
+./: bar/
+EOI
+
+: existing-target-implied
+:
+$* <<EOI >'bar'
+dir{bar/}: x = y
+./: bar/
+EOI
+
+: existing-target-real
+:
+$* <<EOI
+dir{baz/}:
+./: baz/
+EOI
diff --git a/tests/test/buildfile b/tests/test/buildfile
index 85ae8be..e01048f 100644
--- a/tests/test/buildfile
+++ b/tests/test/buildfile
@@ -2,6 +2,6 @@
 # copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
-d = config-test/ script/ script-integration/
-./: $d file{common.test}
-include $d
+./: config-test/ script/ script-integration/ \
+file{common.test}
+
diff --git a/tests/test/script/buildfile b/tests/test/script/buildfile
index b57c983..8ce3cc7 100644
--- a/tests/test/script/buildfile
+++ b/tests/test/script/buildfile
@@ -2,6 +2,5 @@
 # copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
-d = builtin/ runner/
-./: $d file{common.test}
-include $d
+./: builtin/ runner/ file{common.test}
+