checkpatch: add --typedefsfile

When using checkpatch on out-of-tree code, it may occur that some
project-specific types are used, which will cause spurious warnings.
Add the --typedefsfile option as a way to extend the known types and
deal with this issue.

This was developed for OP-TEE [1].  We run a Travis job on all pull
requests [2], and checkpatch is part of that.  The typical false warning
we get on a regular basis is with some pointers to functions returning
TEE_Result [3], which is a typedef from the GlobalPlatform APIs.  We
consider it is acceptable to use GP types in the OP-TEE core
implementation, that's why this patch would be helpful for us.

[1] https://github.com/OP-TEE/optee_os
[2] https://travis-ci.org/OP-TEE/optee_os/builds
[3] https://travis-ci.org/OP-TEE/optee_os/builds/193355335#L1733

Link: http://lkml.kernel.org/r/ba1124d6dfa599bb0dd1d8919dd45dd09ce541a4.1492702192.git.jerome.forissier@linaro.org
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Cc: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 35 insertions, 17 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d2c074feaa7d..65bb50076632 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -55,6 +55,7 @@ my $spelling_file = "$D/spelling.txt";
 my $codespell = 0;
 my $codespellfile = "/usr/share/codespell/dictionary.txt";
 my $conststructsfile = "$D/const_structs.checkpatch";
+my $typedefsfile = "";
 my $color = 1;
 my $allow_c99_comments = 1;
 
@@ -113,6 +114,7 @@ Options:
   --codespell                Use the codespell dictionary for spelling/typos
                              (default:/usr/share/codespell/dictionary.txt)
   --codespellfile            Use this codespell dictionary
+  --typedefsfile             Read additional types from this file
   --color                    Use colors when output is STDOUT (default: on)
   -h, --help, --version      display this help and exit
 
@@ -208,6 +210,7 @@ GetOptions(
         'test-only=s'   => \$tst_only,
         'codespell!'    => \$codespell,
         'codespellfile=s'       => \$codespellfile,
+        'typedefsfile=s'        => \$typedefsfile,
         'color!'        => \$color,
         'h|help'        => \$help,
         'version'       => \$help
@@ -629,28 +632,43 @@ if ($codespell) {
 
 $misspellings = join("|", sort keys %spelling_fix) if keys %spelling_fix;
 
-my $const_structs = "";
-if (open(my $conststructs, '<', $conststructsfile)) {
-        while (<$conststructs>) {
-                my $line = $_;
+sub read_words {
+        my ($wordsRef, $file) = @_;
 
-                $line =~ s/\s*\n?$//g;
-                $line =~ s/^\s*//g;
+        if (open(my $words, '<', $file)) {
+                while (<$words>) {
+                        my $line = $_;
 
-                next if ($line =~ m/^\s*#/);
-                next if ($line =~ m/^\s*$/);
-                if ($line =~ /\s/) {
-                        print("$conststructsfile: '$line' invalid - ignored\n");
-                        next;
-                }
+                        $line =~ s/\s*\n?$//g;
+                        $line =~ s/^\s*//g;
 
-                $const_structs .= '|' if ($const_structs ne "");
-                $const_structs .= $line;
+                        next if ($line =~ m/^\s*#/);
+                        next if ($line =~ m/^\s*$/);
+                        if ($line =~ /\s/) {
+                                print("$file: '$line' invalid - ignored\n");
+                                next;
+                        }
+
+                        $$wordsRef .= '|' if ($$wordsRef ne "");
+                        $$wordsRef .= $line;
+                }
+                close($file);
+                return 1;
         }
-        close($conststructsfile);
-} else {
-        warn "No structs that should be const will be found - file '$conststructsfile': $!\n";
+
+        return 0;
+}
+
+my $const_structs = "";
+read_words(\$const_structs, $conststructsfile)
+    or warn "No structs that should be const will be found - file '$conststructsfile': $!\n";
+
+my $typeOtherTypedefs = "";
+if (length($typedefsfile)) {
+        read_words(\$typeOtherTypedefs, $typedefsfile)
+            or warn "No additional types will be considered - file '$typedefsfile': $!\n";
 }
+$typeTypedefs .= '|' . $typeOtherTypedefs if ($typeOtherTypedefs ne "");
 
 sub build_types {
         my $mods = "(?x:  \n" . join("|\n  ", (@modifierList, @modifierListFile)) . "\n)";