checkpatch: Add rule to check for hardcoded table numbers.

To avoid issues with hardcoded table numbers in future add rule
into check patch. The rule is only warning because there are still
legitimate use cases and not everything can be abstracted.

Signed-off-by: Ales Musil <[email protected]>
Acked-by: Mark Michelson <[email protected]>
Signed-off-by: Mark Michelson <[email protected]>

tests/checkpatch.at

@@ -605,3 +605,42 @@ try_checkpatch \
     Subject: netdev: This is a way to long commit summary and therefor it should report a WARNING!"
 
 AT_CLEANUP
+
+AT_SETUP([checkpatch - hardcoded table numbers])
+try_checkpatch \
+   "COMMON_PATCH_HEADER([tests/something.at])
+    +table=12(ls_in_hairpin      ), priority=1000 , match=(reg0[[14]] == 1), action=(next(pipeline=ingress, table=??);)
+    " \
+    "WARNING: Use of hardcoded table=<NUMBER> or resubmit=(,<NUMBER>) is discouraged in tests. Consider using MACRO instead.
+    #8 FILE: tests/something.at:1:
+    table=12(ls_in_hairpin      ), priority=1000 , match=(reg0[[14]] == 1), action=(next(pipeline=ingress, table=??);)
+"
+
+try_checkpatch \
+   "COMMON_PATCH_HEADER([tests/something.at])
+    +table=??(ls_in_hairpin      ), priority=1000 , match=(reg0[[14]] == 1), action=(next(pipeline=ingress, table=13);)
+    " \
+    "WARNING: Use of hardcoded table=<NUMBER> or resubmit=(,<NUMBER>) is discouraged in tests. Consider using MACRO instead.
+    #8 FILE: tests/something.at:1:
+    table=??(ls_in_hairpin      ), priority=1000 , match=(reg0[[14]] == 1), action=(next(pipeline=ingress, table=13);)
+"
+
+try_checkpatch \
+   "COMMON_PATCH_HEADER([tests/something.at])
+    +priority=1100,ip,reg15=0x1,metadata=0x1,nw_src=10.0.0.1 actions=load:0x1->OXM_OF_PKT_REG4[[49]],resubmit(,47)
+    " \
+    "WARNING: Use of hardcoded table=<NUMBER> or resubmit=(,<NUMBER>) is discouraged in tests. Consider using MACRO instead.
+    #8 FILE: tests/something.at:1:
+    priority=1100,ip,reg15=0x1,metadata=0x1,nw_src=10.0.0.1 actions=load:0x1->OXM_OF_PKT_REG4[[49]],resubmit(,47)
+"
+
+try_checkpatch \
+   "COMMON_PATCH_HEADER([tests/something.at])
+    +C_H_E_C_K([as gw1 ovs-ofctl dump-flows br-int table=42 | grep "dl_dst=00:00:02:01:02:04" | wc -l], [0], [[1]])
+    " \
+    "WARNING: Use of hardcoded table=<NUMBER> or resubmit=(,<NUMBER>) is discouraged in tests. Consider using MACRO instead.
+    #8 FILE: tests/something.at:1:
+    C_H_E_C_K([as gw1 ovs-ofctl dump-flows br-int table=42 | grep "dl_dst=00:00:02:01:02:04" | wc -l], [0], [[1]])
+"
+
+AT_CLEANUP

utilities/checkpatch.py

@@ -202,6 +202,7 @@ def reset_counters():
                                __parenthesized_constructs)
 __regex_nonascii_characters = re.compile("[^\u0000-\u007f]")
 __regex_efgrep = re.compile(r'.*[ef]grep.*$')
+__regex_hardcoded_table = re.compile(r'.*(table=[0-9]+)|.*(resubmit\(,[0-9]+\))')
 
 skip_leading_whitespace_check = False
 skip_trailing_whitespace_check = False
@@ -371,6 +372,10 @@ def has_efgrep(line):
     """Returns TRUE if the current line contains 'egrep' or 'fgrep'."""
     return __regex_efgrep.match(line) is not None
 
+def has_hardcoded_table(line):
+    """Return TRUE if the current line contains table=<NUMBER> or
+       resubmit(,<NUMBER>)"""
+    return __regex_hardcoded_table.match(line) is not None
 
 def filter_comments(current_line, keep=False):
     """remove all of the c-style comments in a line"""
@@ -656,6 +661,13 @@ def empty_return(line):
      'check': lambda x: has_efgrep(x),
      'print':
      lambda: print_error("grep -E/-F should be used instead of egrep/fgrep")},
+
+    {'regex': r'\.at$', 'match_name': None,
+     'check': lambda x: has_hardcoded_table(x),
+     'print':
+         lambda: print_warning("Use of hardcoded table=<NUMBER> or"
+                               " resubmit=(,<NUMBER>) is discouraged in tests."
+                               " Consider using MACRO instead.")},
 ]