Add support for directory prefixes

For example:

cxx{driver ../{foo bar}}
cxx{driver} ../cxx{foo bar}

2 files changed, 8 insertions, 0 deletions

diff --git a/tests/build/parser/buildfile b/tests/build/parser/buildfile
new file mode 100644
index 0000000..2672a02
--- /dev/null
+++ b/tests/build/parser/buildfile
@@ -0,0 +1,2 @@
+exe{driver}: cxx{driver ../../../build/{lexer parser scope target native \
+  prerequisite context diagnostics trace utility path timestamp}}
diff --git a/tests/build/parser/driver.cxx b/tests/build/parser/driver.cxx
index a8c8fc9..8e4a60b 100644
--- a/tests/build/parser/driver.cxx
+++ b/tests/build/parser/driver.cxx
@@ -54,6 +54,12 @@ main ()
   assert (!parse ("foo: bar:"));
   assert (!parse ("exe{foo:"));
 
+  // Directory prefix.
+  //
+  assert (parse ("../{foo}: ../{bar}"));
+  assert (parse ("../exe{foo}: ../obj{bar}"));
+  assert (!parse ("../exe{exe{foo}}:"));
+
   // Directory scope.
   //
   assert (parse ("test/:\n{\n}"));