1 files changed, 216 insertions, 0 deletions
diff --git a/doc/devel/variadic_debug/07-shortcut.cocci b/doc/devel/variadic_debug/07-shortcut.cocci
new file mode 100644
index 0000000..99b3b55
--- /dev/null
+++ b/doc/devel/variadic_debug/07-shortcut.cocci
@@ -0,0 +1,216 @@
+// Splice string `s` into the format string `fmtstring` replacing the
+// %-parameter at position `pos`
+@initialize:python@
+@@
+
+# regex from https://stackoverflow.com/questions/30011379/how-can-i-parse-a-c-format-string-in-python
+import re
+fmtstring = '''\
+(                                  # start of capture group 1
+%                                  # literal "%"
+(?:                                # first option
+(?:[-+0 #]{0,5})                   # optional flags
+(?:\d+|\*)?                        # width
+(?:\.(?:\d+|\*))?                  # precision
+(?:h|l|ll|w|I|I32|I64)?            # size
+[cCdiouxXeEfgGaAnpsSZ]             # type
+) |                                # OR
+%%)                                # literal "%%"
+'''
+
+regex = re.compile(fmtstring, re.X)
+
+def parse_format(f):
+    return tuple((m.span(), m.group()) for m in
+        regex.finditer(f))
+
+def insert_at_pos(fmt, s, pos):
+    formats = parse_format(fmt)
+    span, format = formats[pos]
+    acc = fmt[:span[0]]
+    if s.startswith('"'):
+        acc += s[1:]
+    else:
+        acc += '" '
+        acc += s
+    if acc.endswith('"'):
+        acc = acc[:-1] + fmt[span[1]:]
+    else:
+        acc += ' "'
+        acc += fmt[span[1]:]
+    return acc
+
+// rest of the file implements the same as 09-merge.cocci
+// The main difference is that we only match on snprintf and Debug that are
+// directly adjacent, not based on control flow information which trips
+// coccinelle's model-checker
+@shortcut@
+identifier buf;
+expression E, L;
+expression list args_before, args, args_after;
+expression format1, format2;
+position p1, p2;
+@@
+
+snprintf@p1( buf, E, format1, args );
+Debug@p2( L, format2, args_before, buf, args_after );
+
+// use insert_at_pos above to construct the new format-string
+@script:python shortcut_process@
+format1 << shortcut.format1;
+format2 << shortcut.format2;
+args_before << shortcut.args_before;
+merged;
+@@
+
+pos = len(args_before.elements)
+coccinelle.merged = insert_at_pos(format2, format1, pos)
+
+@shortcut_replace@
+position shortcut.p1, shortcut.p2;
+identifier shortcut_process.merged;
+
+identifier buf;
+expression E, L;
+expression list args_before, args, args_after;
+expression format1, format2;
+@@
+
+-snprintf@p1( buf, E, format1, args );
+-Debug@p2( L, format2, args_before, buf, args_after );
++Debug( L, merged, args_before, args, args_after );
+
+@shortcut_locked@
+identifier buf;
+expression E, L, lock;
+expression list args_before, args, args_after;
+expression format1, format2;
+position p1, p2;
+@@
+
+ldap_pvt_thread_mutex_lock(lock);
+snprintf@p1( buf, E, format1, args );
+ldap_pvt_thread_mutex_unlock(lock);
+Debug@p2( L, format2, args_before, buf, args_after );
+
+// use insert_at_pos above to construct the new format-string
+@script:python shortcut_locked_process@
+format1 << shortcut_locked.format1;
+format2 << shortcut_locked.format2;
+args_before << shortcut_locked.args_before;
+merged;
+@@
+
+pos = len(args_before.elements)
+coccinelle.merged = insert_at_pos(format2, format1, pos)
+
+@shortcut_locked_replace@
+position shortcut_locked.p1, shortcut_locked.p2;
+identifier shortcut_locked_process.merged;
+
+identifier buf;
+expression E, L, lock;
+expression list args_before, args, args_after;
+expression format1, format2;
+@@
+
+ldap_pvt_thread_mutex_lock(lock);
+-snprintf@p1( buf, E, format1, args );
++Debug( L, merged, args_before, args, args_after );
+ldap_pvt_thread_mutex_unlock(lock);
+-Debug@p2( L, format2, args_before, buf, args_after );
+
+// so long as we don't reference 'buf' afterwards, no need to keep it defined.
+// A lot of pattern-matching is spelled out explicitly to work around the fact
+// that the state space doesn't get compressed otherwise.
+@@
+type T;
+identifier buf, id;
+expression E, lock;
+initializer I;
+@@
+{
+-\( T buf = I; \| T buf; \)
+(
+ ldap_pvt_thread_mutex_lock(lock);
+|
+)
+(
+ Debug( ... );
+&
+ ... when != buf
+)
+(
+ ldap_pvt_thread_mutex_unlock(lock);
+|
+)
+(
+|
+ continue;
+|
+ break;
+|
+ goto id;
+|
+ \(
+  return E;
+ \&
+  ... when != buf
+ \)
+)
+}
+
+// the rest identifies and removes a (newly-)redundant LogTest check
+@if_guard@
+position p;
+statement s;
+@@
+
+(
+ if ( ... ) {@p 
+  Debug( ... );
+ } else s
+|
+ if ( ... ) {@p
+  Debug( ... );
+ }
+)
+
+@else_guard@
+position p;
+statement s;
+@@
+
+if ( ... ) s
+else {@p
+ Debug( ... );
+}
+
+@loop_guard@
+position p;
+@@
+
+(
+ while ( ... ) {@p
+  Debug( ... );
+ }
+|
+ for ( ...;...;... ) {@p
+  Debug( ... );
+ }
+)
+
+@@
+position p != { if_guard.p , else_guard.p, loop_guard.p };
+@@
+-{@p
+ Debug( ... );
+-}
+
+@useless_if@
+expression L;
+@@
+
+-if ( LogTest( L ) ) {
+ Debug( L, ... );
+-}