checkpatch: improve MULTISTATEMENT_MACRO_USE_DO_WHILE test

The logic currrently misses macros that start with an if statement.

e.g.:    #define foo(bar)   if (bar) baz;

Add a test for macro content that starts with if

Link: http://lkml.kernel.org/r/a9d41aafe1673889caf1a9850208fb7fd74107a0.1491783914.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Andreas Mohr <andi@lisas.de>
Original-patch-by: Alfonso Lima <alfonsolimaastor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 3a1cb9d7474e..feb9e856f11d 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4849,8 +4849,10 @@ sub process {
                             $dstat !~ /^\(\{/ &&                                                # ({...
                             $ctx !~ /^.\s*#\s*define\s+TRACE_(?:SYSTEM|INCLUDE_FILE|INCLUDE_PATH)\b/)
                         {
-
-                                if ($dstat =~ /;/) {
+                                if ($dstat =~ /^\s*if\b/) {
+                                        ERROR("MULTISTATEMENT_MACRO_USE_DO_WHILE",
+                                              "Macros starting with if should be enclosed by a do - while loop to avoid possible if/else logic defects\n" . "$herectx");
+                                } elsif ($dstat =~ /;/) {
                                         ERROR("MULTISTATEMENT_MACRO_USE_DO_WHILE",
                                               "Macros with multiple statements should be enclosed in a do - while loop\n" . "$herectx");
                                 } else {