Add support for multiple config files & directories

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

diff --git a/bitfield b/bitfield
index d470c7ce2958d5f7a22eff2e7f42ba4aba31d064..965d8cac2c2c5eee17bae01748c7b173f71e0347 100644 (file)
--- a/bitfield
+++ b/bitfield
@@ -13,7 +13,10 @@ from pyparsing import Literal, Word, ZeroOrMore, Group, Dict, Optional, \
         printables, ParseException, restOfLine
 from getopt import getopt, GetoptError
 
-conf = os.path.join(os.getenv("HOME"), ".bitfields.conf")
+# List of paths to look for configuration files. If a directory is specified,
+# it will be (recursively) scanned for .conf files.
+configs = [os.path.join(os.getenv("HOME"), ".bitfields.conf"),
+               os.path.join(os.getenv("HOME"), ".bitfields.d")]
 
 class bitfield:
        def __init__(self, start_bit, end_bit, name):
@@ -114,33 +117,19 @@ class ConfigurationError(Exception):
                self.file = file
                self.message = message
 
-def parse_config(file):
-       lbrack = Literal("[").suppress()
-       rbrack = Literal("]").suppress()
-       colon  = Literal(":").suppress()
-       semi   = Literal(";")
-
-       comment = semi + Optional( restOfLine )
-
-       nonrbrack = "".join( [ c for c in printables if c != "]" ] ) + " \t"
-       nonequals = "".join( [ c for c in printables if c != ":" ] ) + " \t"
-
-       sectionDef = lbrack + Word( nonrbrack ) + rbrack
-       keyDef = ~lbrack + Word( nonequals ) + colon + restOfLine
-
-       bnf = Dict(ZeroOrMore(Group(sectionDef + ZeroOrMore(Group(keyDef)))))
-       bnf.ignore(comment)
-
+def parse_config(bnf, regs, file):
        f = open(file)
 
        tokens = bnf.parseString("".join(f.readlines()))
 
-       regs = {}
-
        for tok in tokens:
                ts = tok.asList()
                id = ts.pop(0)
 
+               if regs.has_key(id):
+                       raise ConfigurationError(file,
+                               "Register %s is already defined" % id)
+
                # default to 64 bit registers
                width = 64
                name = None
@@ -159,19 +148,19 @@ def parse_config(file):
                                                "Invalid field in %s" % id)
                                fields.append(f)
                        elif t[0] == 'value':
-                               f = fields[-1]
-                               if f is None:
+                               if len(fields) == 0:
                                        raise ConfigurationError(file,
                                                "No field for value in %s" % id)
                                v = bitfield.parse_value(t[1])
                                if v is None:
                                        raise ConfigurationError(file,
                                                "Invalid value in %s" % id)
-                               f.add_value(v[0], v[1])
+
+                               fields[-1].add_value(v[0], v[1])
 
                if name is None or name == '':
                        raise ConfigurationError(file,
-                               "No name for entry %s" %id)
+                               "No name for entry %s" % id)
 
                if len(fields) == 0:
                        raise ConfigurationError(file,
@@ -183,8 +172,48 @@ def parse_config(file):
 
                regs[id] = r
 
-       return regs
+def parse_config_dir(data, dir, fnames):
+       (bnf, regs) = data
+       for fname in fnames:
+               full_fname = os.path.join(dir, fname)
 
+               if os.path.isdir(full_fname):
+                       continue
+
+               if fname.endswith('.conf'):
+                       parse_config(bnf, regs, full_fname)
+
+def parse_all_configs(configs):
+       regs = {}
+
+       # set up the bnf to be used for each file
+       lbrack = Literal("[").suppress()
+       rbrack = Literal("]").suppress()
+       colon  = Literal(":").suppress()
+       semi   = Literal(";")
+
+       comment = semi + Optional(restOfLine)
+
+       nonrbrack = "".join([c for c in printables if c != "]"]) + " \t"
+       noncolon  = "".join([c for c in printables if c != ":"]) + " \t"
+
+       sectionDef = lbrack + Word(nonrbrack) + rbrack
+       keyDef = ~lbrack + Word(noncolon) + colon + restOfLine
+
+       bnf = Dict(ZeroOrMore(Group(sectionDef + ZeroOrMore(Group(keyDef)))))
+       bnf.ignore(comment)
+
+       # bundle into a single var that can be passed to os.path.walk
+       conf_data = (bnf, regs)
+
+       for conf in configs:
+               if not os.path.exists(conf):
+                       continue
+               if os.path.isdir(conf):
+                       os.path.walk(conf, parse_config_dir, conf_data)
+               else:
+                       parse_config(bnf, regs, conf)
+       return regs
 
 def usage(prog):
        print "Usage: %s <-l> | <-s pattern> | register [value...]" % prog
@@ -198,13 +227,16 @@ def main():
                return 1
 
        try:
-               regs = parse_config(conf)
-
+               regs = parse_all_configs(configs)
        except ConfigurationError, e:
                print "Error parsing configuration file %s:\n\t%s" % \
                        (e.file, e.message)
                return 1
 
+       if regs == {}:
+               print "No configuration available"
+               return 1
+
        for o, a in opts:
                if o in ("-h", "--help"):
                        usage(sys.argv[0])