add comments

find_reduced.py

@@ -43,6 +43,7 @@ def flatten(l):
             l[0:1] = l[0]
         if l: yield l.pop(0)
 
+# read mapping between Gentoo and Debian packages
 deb2gen = dict()
 gen2deb = dict()
 with open("./deb2gen_mapping.list") as f:
@@ -104,7 +105,8 @@ before = datetime.now()
 debian_deps = dict()
 missing_gen_mappings = list()
 
-# look for reduced build dependencies
+# look for reduced build dependencies of gentoo packages by extracting all
+# dependencies that need a USE flag to be set
 for i, (cat, pkg, ver, rev) in enumerate(pkgnames):
     if rev == "r0":
         pkgname = "%s/%s-%s"%(cat, pkg, ver)
@@ -119,7 +121,7 @@ for i, (cat, pkg, ver, rev) in enumerate(pkgnames):
     no_use = use_reduce(depend, matchnone=True)
     l = list()
     for a in all_use:
-        # filter out all dependencies that are also present without USE flags enabled
+        # filter out all dependencies that are also present when USE flags are disabled
         if a in no_use:
             continue
 
@@ -163,6 +165,8 @@ missing_deb_mappings = list()
 src2bin = dict()
 src_deps = dict()
 
+# get the actual Debian build dependencies for all interesting packages from a
+# Sources file
 for pkg in apt_pkg.TagFile(sys.argv[1]):
     p = pkg['Package']
     try:
@@ -172,7 +176,11 @@ for pkg in apt_pkg.TagFile(sys.argv[1]):
         src_deps[p] = []
     src2bin[p] = [b.strip() for b in pkg['Binary'].split(',')]
 
-# process all debian source packages
+all_droppable = list()
+
+# process all debian source packages and output those build dependencies that
+# build from a source package which is not needed by the corresponding Gentoo
+# package
 for d in debian_names:
     # find gentoo package name
     g = deb2gen.get(d)