From 7091127e318c1b5c244b7ae3cbd0edf8966c14f0 Mon Sep 17 00:00:00 2001
From: Daniel Hermann <daniel.hermann@1und1.de>
Date: Thu, 3 Apr 2014 09:58:26 +0200
Subject: [PATCH] gen_config: respect dependencies (fixes out-of-tree builds)

---
 scripts/gen_config.pl | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/scripts/gen_config.pl b/scripts/gen_config.pl
index 993ce90c..465ff37b 100755
--- a/scripts/gen_config.pl
+++ b/scripts/gen_config.pl
@@ -15,6 +15,8 @@ my $DEBUG = 0;
 
 my $option;
 my $type;
+my $depends;
+my $value;
 my @default;
 my %setByEnv;
 
@@ -23,18 +25,30 @@ while (my $line = <STDIN>) {
         $option = $1;
         $setByEnv{$option} = $ENV{$option}  if exists $ENV{$option};
         printf STDERR "OPTION: %s\n", $option if $DEBUG;
-        printf STDERR "ENV: %s='%s'\n", $option, $setByEnv{$option} if $DEBUG && exists $ENV{$option};
+        printf STDERR "--> ENV: %s='%s'\n", $option, $setByEnv{$option} if $DEBUG && exists $ENV{$option};
     }
     elsif ($line =~ /^\s+(tristate|bool|int|string)\s+.*$/) {
         $type = $1;
-        printf STDERR "TYPE: %s\n", $type if $DEBUG;
+        printf STDERR "--> TYPE: %s\n", $type if $DEBUG;
+    }
+    elsif ($line =~/^\s+depends\s+on\s+(.*)$/) {
+        $depends = ($option ne 'MARS') ? $1 : '';
+        printf STDERR "--> DEPENDS: %s\n", $depends if $DEBUG;
     }
     elsif ($line =~ /^\s+default\s+(.*)$/) {
-        printf STDERR "DEFAULT: %s\n", $1 if $DEBUG;
+        if ($option eq 'MARS') {
+            $value = 'y';
+            printf STDERR "--> DEFAULT: y (OVERRIDDEN by script)\n" if $DEBUG;
+        }
+        else {
+            $value = $1;
+            printf STDERR "--> DEFAULT: %s\n", $value if $DEBUG;
+        }
         push @default, {
             option => $option,
             type => $type,
-            value => $1,
+            depends => $depends,
+            value => $value,
         } if $option;
     }
     elsif ($line =~ /^\s+---help---\s+$/) {
@@ -45,7 +59,7 @@ while (my $line = <STDIN>) {
     }
 }
 
-print STDERR Dumper(\@default) if $DEBUG;
+print STDERR Dumper(\@default) if $DEBUG >= 2;
 
 
 ##
@@ -94,6 +108,16 @@ foreach my $opt (@default) {
         next;
     }
 
+    if ($opt->{depends}) {
+        my @deps = grep { $_->{option} eq $opt->{depends} } @default;
+        if (scalar @deps && $deps[0]->{value} eq 'n') {
+            print qq%
+/* CONFIG_$optname is unset (depends on $deps[0]->{option}, which is unset) */
+%;
+            next;
+        }
+    }
+
     given ($opt->{type}) {
 
         when ('tristate') {