Adding upstream version 9.1.upstream/9.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 100 insertions, 0 deletions

diff --git a/python/makevars.py b/python/makevars.py
new file mode 100644
index 0000000..951cd34
--- /dev/null
+++ b/python/makevars.py
@@ -0,0 +1,100 @@
+#
+# helper class to grab variables from FRR's Makefile
+#
+
+import os
+import subprocess
+import re
+
+
+class MakeVarsBase(object):
+    """
+    common code between MakeVars and MakeReVars
+    """
+
+    def __init__(self):
+        self._data = dict()
+
+    def __getitem__(self, k):
+        if k not in self._data:
+            self.getvars([k])
+        return self._data[k]
+
+    def get(self, k, defval=None):
+        if k not in self._data:
+            self.getvars([k])
+        return self._data.get(k) or defval
+
+
+class MakeVars(MakeVarsBase):
+    """
+    makevars['FOO_CFLAGS'] gets you "FOO_CFLAGS" from Makefile
+
+    This variant works by invoking make as a subprocess, i.e. Makefile must
+    be valid and working.  (This is sometimes a problem if depfiles have not
+    been generated.)
+    """
+
+    def getvars(self, varlist):
+        """
+        get a batch list of variables from make.  faster than individual calls.
+        """
+        rdfd, wrfd = os.pipe()
+
+        shvars = ["shvar-%s" % s for s in varlist]
+        make = subprocess.Popen(
+            ["make", "-s", "VARFD=%d" % wrfd] + shvars, pass_fds=[wrfd]
+        )
+        os.close(wrfd)
+        data = b""
+
+        rdf = os.fdopen(rdfd, "rb")
+        while True:
+            rdata = rdf.read()
+            if len(rdata) == 0:
+                break
+            data += rdata
+
+        del rdf
+        make.wait()
+
+        data = data.decode("US-ASCII").strip().split("\n")
+        for row in data:
+            k, v = row.split("=", 1)
+            v = v[1:-1]
+            self._data[k] = v
+
+
+class MakeReVars(MakeVarsBase):
+    """
+    makevars['FOO_CFLAGS'] gets you "FOO_CFLAGS" from Makefile
+
+    This variant works by regexing through Makefile.  This means the Makefile
+    does not need to be fully working, but on the other hand it doesn't support
+    fancy complicated make expressions.
+    """
+
+    var_re = re.compile(
+        r"^([^=#\n\s]+)[ \t]*=[ \t]*([^#\n]*)(?:#.*)?$", flags=re.MULTILINE
+    )
+    repl_re = re.compile(r"\$(?:([A-Za-z])|\(([^\)]+)\))")
+
+    def __init__(self, maketext):
+        super(MakeReVars, self).__init__()
+        self._vars = dict(self.var_re.findall(maketext.replace("\\\n", "")))
+
+    def replacevar(self, match):
+        varname = match.group(1) or match.group(2)
+        return self._vars.get(varname, "")
+
+    def getvars(self, varlist):
+        for varname in varlist:
+            if varname not in self._vars:
+                continue
+
+            val, prevval = self._vars[varname], None
+            while val != prevval:
+                prevval = val
+                val = self.repl_re.sub(self.replacevar, val)
+
+            self._data[varname] = val