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#!/usr/bin/python
import os
import re
import string
import sys
curdir = os.path.dirname (sys.argv[0])
gendir = os.path.join (curdir, '../../../../libglusterfs/src')
sys.path.append (gendir)
from generator import ops, fop_subs, cbk_subs, generate
# See the big header comment at the start of gen_fdl.py to see how the stages
# fit together. The big difference here is that *all* of the C code is in the
# template file as labelled fragments, instead of as Python strings. That
# makes it much easier to edit in one place, with proper syntax highlighting
# and indentation.
#
# Stage 1 uses type-specific fragments to generate FUNCTION_BODY, instead of
# LEN_*_TEMPLATE and SERLZ_*_TEMPLATE to generate LEN_CODE and SER_CODE.
#
# Stage 2 uses the FOP and CASE fragments instead of RECON_TEMPLATE and
# FOP_TEMPLATE. The expanded FOP code (including FUNCTION_BODY substitution
# in the middle of each function) is emitted immediately; the expanded CASE
# code is saved for the next stage.
#
# Stage 3 uses the PROLOG and EPILOG fragments, with the expanded CASE code
# in the middle of EPILOG, to generate the whole output file.
#
# Another way of looking at it is to consider how the fragments appear in
# the final output:
#
# PROLOG
# FOP (expanded for CREATE)
# FOP before FUNCTION_BODY
# LOC, INTEGER, GFID, etc. (one per arg, by type)
# FOP after FUNCTION_BODY
# FOP (expanded for WRITEV)
# FOP before FUNCTION_BODY
# GFID, VECTOR, etc. (one per arg, by type)
# FOP after FUNCTION_BODY
# (more FOPs)
# EPILOG
# EPILOG before CASE
# CASE statements (one per fop)
# EPILOG after CASE
typemap = {
'dict_t *': "DICT",
'fd_t *': "FD",
'dev_t': "DOUBLE",
'gf_xattrop_flags_t': "INTEGER",
'int32_t': "INTEGER",
'mode_t': "INTEGER",
'off_t': "DOUBLE",
'size_t': "DOUBLE",
'uint32_t': "INTEGER",
'loc_t *': "LOC",
'const char *': "STRING",
'struct iovec *': "VECTOR",
'struct iatt *': "IATT",
'struct iobref *': "IOBREF",
}
def get_special_subs (name, args, fop_type):
code = ""
cleanups = ""
links = ""
s_args = []
for arg in args:
if arg[0] == 'extra':
code += "\t%s %s;\n\n" % (arg[2], arg[1])
s_args.append(arg[3])
continue
if arg[0] == 'link':
links += fragments["LINK"].replace("@INODE_ARG@",arg[1]) \
.replace("@IATT_ARG@",arg[2])
continue
if arg[0] != 'fop-arg':
continue
if (name, arg[1]) == ('writev', 'count'):
# Special case: just skip this. We can't mark it as 'nosync'
# because of the way the translator and dumper generators look for
# that after 'stub-name' which we don't define. Instead of adding a
# bunch of generic infrastructure for this one case, just pound it
# here.
continue
recon_type = typemap[arg[2]]
# print "/* %s.%s => %s (%s)*/" % (name, arg[1], recon_type, fop_type)
if (name == "create") and (arg[1] == "fd"):
# Special case: fd for create is new, not looked up.
# print "/* change to NEW_FD */"
recon_type = "NEW_FD"
elif (recon_type == "LOC") and (fop_type == "entry-op"):
# Need to treat this differently for inode vs. entry ops.
# Special case: link source is treated like inode-op.
if (name != "link") or (arg[1] != "oldloc"):
# print "/* change to PARENT_LOC */"
recon_type = "PARENT_LOC"
code += fragments[recon_type].replace("@ARGNAME@",arg[1]) \
.replace("@ARGTYPE@",arg[2])
cleanup_key = recon_type + "_CLEANUP"
if fragments.has_key(cleanup_key):
new_frag = fragments[cleanup_key].replace("@ARGNAME@",arg[1])
# Make sure these get added in *reverse* order. Otherwise, a
# failure for an earlier argument might goto a label that falls
# through to the cleanup code for a variable associated with a
# later argument, but that variable might not even have been
# *declared* (let alone initialized) yet. Consider the following
# case.
#
# process argument A (on failure goto cleanup_A)
# set error label to cleanup_A
#
# declare pointer variable for argument B
# process argument B (on failure goto cleanup_B)
#
# cleanup_A:
# /* whatever */
# cleanup_B:
# free pointer variable <= "USED BUT NOT SET" error here
#
# By adding these in reverse order, we ensure that cleanup_B is
# actually *before* cleanup_A, and nothing will try to do the free
# until we've actually attempted processing of B.
cleanups = new_frag + cleanups
if 'nosync' in arg[4:]:
code += "\t(void)%s;\n" % arg[1];
continue
if arg[2] in ("loc_t *", "struct iatt *"):
# These are passed as pointers to the syncop, but they're actual
# structures in the generated code.
s_args.append("&"+arg[1]);
else:
s_args.append(arg[1])
# We have to handle a couple of special cases here, because some n00b
# defined the syncops with a different argument order than the fops they're
# based on.
if name == 'writev':
# Swap 'flags' and 'iobref'. Also, we need to add the iov count, which
# is not stored in or read from the journal. There are other ways to
# do that, but this is the only place we need anything similar and we
# already have to treat it as a special case so this is simplest.
s_args_str = 'fd, &vector, 1, off, iobref, flags, xdata'
elif name == 'symlink':
# Swap 'linkpath' and 'loc'.
s_args_str = '&loc, linkpath, &iatt, xdata'
else:
s_args_str = string.join (s_args, ", ")
return code, links, s_args_str, cleanups
# TBD: probably need to generate type-specific cleanup code as well - e.g.
# fd_unref for an fd_t, loc_wipe for a loc_t, and so on. All of these
# generated CLEANUP fragments will go at the end of the function, with goto
# labels. Meanwhile, the error-checking part of each type-specific fragment
# (e.g. LOC or FD) will need to update the indirect label that we jump to when
# an error is detected. This will probably get messy.
def gen_functions ():
code = ""
for name, value in ops.iteritems():
fop_type = [ x[1] for x in value if x[0] == "journal" ]
if not fop_type:
continue
body, links, syncop_args, cleanups = get_special_subs (name, value,
fop_type[0])
fop_subs[name]["@FUNCTION_BODY@"] = body
fop_subs[name]["@LINKS@"] = links
fop_subs[name]["@SYNCOP_ARGS@"] = syncop_args
fop_subs[name]["@CLEANUPS@"] = cleanups
if name == "writev":
# Take advantage of the fact that, *during reconciliation*, the
# vector is always a single element. In normal I/O it's not.
fop_subs[name]["@SUCCESS_VALUE@"] = "vector.iov_len"
else:
fop_subs[name]["@SUCCESS_VALUE@"] = "GFAPI_SUCCESS"
# Print the FOP fragment with @FUNCTION_BODY@ in the middle.
code += generate(fragments["FOP"],name,fop_subs)
return code
def gen_cases ():
code = ""
for name, value in ops.iteritems():
if "journal" not in [ x[0] for x in value ]:
continue
# Add the CASE fragment for this fop.
code += generate(fragments["CASE"],name,fop_subs)
return code
def load_fragments (path="recon-tmpl.c"):
pragma_re = re.compile('pragma fragment (.*)')
cur_symbol = None
cur_value = ""
result = {}
for line in open(path,"r").readlines():
m = pragma_re.search(line)
if m:
if cur_symbol:
result[cur_symbol] = cur_value
cur_symbol = m.group(1)
cur_value = ""
else:
cur_value += line
if cur_symbol:
result[cur_symbol] = cur_value
return result
if __name__ == "__main__":
fragments = load_fragments(sys.argv[1])
print "/* BEGIN GENERATED CODE - DO NOT MODIFY */"
print fragments["PROLOG"]
print gen_functions()
print fragments["EPILOG"].replace("@SWITCH_BODY@",gen_cases())
print "/* END GENERATED CODE */"
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