1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
#!/usr/bin/python3
from __future__ import print_function
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 cleanup_key in fragments:
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, &preop, &postop, xdata'
elif name == 'symlink':
# Swap 'linkpath' and 'loc'.
s_args_str = '&loc, linkpath, &iatt, xdata'
elif name == 'xattrop':
s_args_str = '&loc, flags, dict, xdata, NULL'
elif name == 'fxattrop':
s_args_str = 'fd, flags, dict, xdata, NULL'
else:
s_args_str = ', '.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.items():
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.items():
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 */")
|
