scons: Populate top_srcdir and top_builddir variables when reading Makefiles.sources.

This is not entirely correct, as scons doesn't put binaries in a
"src" subdirectory, but doesn't seem to be a problem for now.

1 files changed, 4 insertions, 0 deletions

diff --git a/scons/custom.py b/scons/custom.py
index cc953bd999a..43e7727aa42 100644
--- a/scons/custom.py
+++ b/scons/custom.py
@@ -235,6 +235,10 @@ def parse_source_list(env, filename, names=None):
     # parse the source list file
     parser = source_list.SourceListParser()
     src = env.File(filename).srcnode()
+
+    parser.add_symbol('top_srcdir', env.Dir('#').abspath)
+    parser.add_symbol('top_builddir', env['build_dir'])
+
     sym_table = parser.parse(src.abspath)
 
     if names: