localmodconfig: Add debug environment variable LOCALMODCONFIG_DEBUG

If the environment variable LOCALMODCONFIG_DEBUG is set, then debug output
will appear in the make localmodconfig. This will simplify debugging what
people get with their output, as I can just tell people to do:

  LOCALMODCONFIG_DEBUG=1 make localmodconfig 2>out.txt

and have them send me the out.txt. I'll be able to see why things are not
working as they think it should be.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/scripts/kconfig/streamline_config.pl b/scripts/kconfig/streamline_config.pl
index fcfcb302b0d7..2fbbbc1ddea0 100644
--- a/scripts/kconfig/streamline_config.pl
+++ b/scripts/kconfig/streamline_config.pl
@@ -45,6 +45,16 @@
 use strict;
 use Getopt::Long;
 
+# set the environment variable LOCALMODCONFIG_DEBUG to get
+# debug output.
+my $debugprint = 0;
+$debugprint = 1 if (defined($ENV{LOCALMODCONFIG_DEBUG}));
+
+sub dprint {
+    return if (!$debugprint);
+    print STDERR @_;
+}
+
 my $config = ".config";
 
 my $uname = `uname -r`;
@@ -389,6 +399,7 @@ foreach my $module (keys(%modules)) {
         my @arr = @{$objects{$module}};
         foreach my $conf (@arr) {
             $configs{$conf} = $module;
+            dprint "$conf added by direct ($module)\n";
         }
     } else {
         # Most likely, someone has a custom (binary?) module loaded.
@@ -412,6 +423,8 @@ foreach my $line (@config_file) {
 
 my $repeat = 1;
 
+my $depconfig;
+
 #
 # Note, we do not care about operands (like: &&, ||, !) we want to add any
 # config that is in the depend list of another config. This script does
@@ -440,6 +453,7 @@ sub parse_config_depends
                 # We must make sure that this config has its
                 # dependencies met.
                 $repeat = 1; # do again
+                dprint "$conf selected by depend $depconfig\n";
                 $configs{$conf} = 1;
             }
         } else {
@@ -473,15 +487,18 @@ sub parse_config_selects
 
             # Make sure that this config exists in the current .config file
             if (!defined($orig_configs{$conf})) {
+                dprint "$conf not set for $config select\n";
                 next;
             }
 
             # Check if something other than a module selects this config
             if (defined($orig_configs{$conf}) && $orig_configs{$conf} ne "m") {
+                dprint "$conf (non module) selects config, we are good\n";
                 # we are good with this
                 return;
             }
             if (defined($configs{$conf})) {
+                dprint "$conf selects $config so we are good\n";
                 # A set config selects this config, we are good
                 return;
             }
@@ -506,6 +523,7 @@ sub parse_config_selects
     $repeat = 1;
     # Make this config need to be selected
     $configs{$next_config} = 1;
+    dprint "$next_config selected by select $config\n";
 }
 
 my %process_selects;
@@ -526,6 +544,7 @@ sub loop_depend {
             }
 
             $config =~ s/^CONFIG_//;
+            $depconfig = $config;
 
             if (defined($depends{$config})) {
                 # This config has dependencies. Make sure they are also included
@@ -546,6 +565,8 @@ sub loop_select {
     foreach my $config (keys %process_selects) {
         $config =~ s/^CONFIG_//;
 
+        dprint "Process select $config\n";
+
         # config has no prompt and must be selected.
         parse_config_selects $config, $selects{$config};
     }