Merge tag 'localmodconfig-v3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-kconfig

Pull localmodconfig updates from Steven Rostedt:
 "Improve localmodconfig to remove even more unused module configs.

  These changes drastically improve the amount of module configs removed
  from a config file.  It also adds some debug that I can have users
  easily enable if things do not work for them."

* tag 'localmodconfig-v3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-kconfig:
  localmodconfig: Add debug environment variable LOCALMODCONFIG_DEBUG
  localmodconfig: Check if configs are already set for selects
  localmodconfig: Read in orig config file to avoid extra processing
  localmodconfig: Comments and cleanup for streamline_config.pl

1 files changed, 158 insertions, 17 deletions

diff --git a/scripts/kconfig/streamline_config.pl b/scripts/kconfig/streamline_config.pl
index bccf07ddd0b6..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`;
@@ -113,6 +123,10 @@ sub find_config {
 
 find_config;
 
+# Read in the entire config file into config_file
+my @config_file = <CIN>;
+close CIN;
+
 # Parse options
 my $localmodconfig = 0;
 my $localyesconfig = 0;
@@ -186,6 +200,7 @@ sub read_kconfig {
             $state = "NEW";
             $config = $2;
 
+            # Add depends for 'if' nesting
             for (my $i = 0; $i < $iflevel; $i++) {
                 if ($i) {
                     $depends{$config} .= " " . $ifdeps[$i];
@@ -204,10 +219,11 @@ sub read_kconfig {
 
         # Get the configs that select this config
         } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
-            if (defined($selects{$1})) {
-                $selects{$1} .= " " . $config;
+            my $conf = $1;
+            if (defined($selects{$conf})) {
+                $selects{$conf} .= " " . $config;
             } else {
-                $selects{$1} = $config;
+                $selects{$conf} = $config;
             }
 
         # configs without prompts must be selected
@@ -250,6 +266,7 @@ if ($kconfig) {
     read_kconfig($kconfig);
 }
 
+# Makefiles can use variables to define their dependencies
 sub convert_vars {
     my ($line, %vars) = @_;
 
@@ -293,6 +310,7 @@ foreach my $makefile (@makefiles) {
 
         my $objs;
 
+        # Convert variables in a line (could define configs)
         $_ = convert_vars($_, %make_vars);
 
         # collect objects after obj-$(CONFIG_FOO_BAR)
@@ -373,13 +391,15 @@ while (<LIN>) {
 close (LIN);
 
 # add to the configs hash all configs that are needed to enable
-# a loaded module.
+# a loaded module. This is a direct obj-${CONFIG_FOO} += bar.o
+# where we know we need bar.o so we add FOO to the list.
 my %configs;
 foreach my $module (keys(%modules)) {
     if (defined($objects{$module})) {
         my @arr = @{$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.
@@ -387,9 +407,24 @@ foreach my $module (keys(%modules)) {
     }
 }
 
+# Read the current config, and see what is enabled. We want to
+# ignore configs that we would not enable anyway.
+
+my %orig_configs;
 my $valid = "A-Za-z_0-9";
+
+foreach my $line (@config_file) {
+    $_ = $line;
+
+    if (/(CONFIG_[$valid]*)=(m|y)/) {
+        $orig_configs{$1} = $2;
+    }
+}
+
 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
@@ -398,7 +433,7 @@ my $repeat = 1;
 # to keep on. If A was on in the original config, B would not have been
 # and B would not be turned on by this script.
 #
-sub parse_config_dep_select
+sub parse_config_depends
 {
     my ($p) = @_;
 
@@ -409,10 +444,16 @@ sub parse_config_dep_select
 
             $p =~ s/^[^$valid]*[$valid]+//;
 
+            # We only need to process if the depend config is a module
+            if (!defined($orig_configs{$conf}) || !$orig_configs{conf} eq "m") {
+                next;
+            }
+
             if (!defined($configs{$conf})) {
                 # 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 {
@@ -421,31 +462,132 @@ sub parse_config_dep_select
     }
 }
 
-while ($repeat) {
-    $repeat = 0;
+# Select is treated a bit differently than depends. We call this
+# when a config has no prompt and requires another config to be
+# selected. We use to just select all configs that selected this
+# config, but found that that can balloon into enabling hundreds
+# of configs that we do not care about.
+#
+# The idea is we look at all the configs that select it. If one
+# is already in our list of configs to enable, then there's nothing
+# else to do. If there isn't, we pick the first config that was
+# enabled in the orignal config and use that.
+sub parse_config_selects
+{
+    my ($config, $p) = @_;
 
-    foreach my $config (keys %configs) {
-        $config =~ s/^CONFIG_//;
+    my $next_config;
+
+    while ($p =~ /[$valid]/) {
 
-        if (defined($depends{$config})) {
-            # This config has dependencies. Make sure they are also included
-            parse_config_dep_select $depends{$config};
+        if ($p =~ /^[^$valid]*([$valid]+)/) {
+            my $conf = "CONFIG_" . $1;
+
+            $p =~ s/^[^$valid]*[$valid]+//;
+
+            # Make sure that this config exists in the current .config file
+            if (!defined($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 $config so we are good\n";
+                # A set config selects this config, we are good
+                return;
+            }
+            # Set this config to be selected
+            if (!defined($next_config)) {
+                $next_config = $conf;
+            }
+        } else {
+            die "this should never happen";
         }
+    }
 
-        if (defined($prompts{$config}) || !defined($selects{$config})) {
-            next;
+    # If no possible config selected this, then something happened.
+    if (!defined($next_config)) {
+        print STDERR "WARNING: $config is required, but nothing in the\n";
+        print STDERR "  current config selects it.\n";
+        return;
+    }
+
+    # If we are here, then we found no config that is set and
+    # selects this config. Repeat.
+    $repeat = 1;
+    # Make this config need to be selected
+    $configs{$next_config} = 1;
+    dprint "$next_config selected by select $config\n";
+}
+
+my %process_selects;
+
+# loop through all configs, select their dependencies.
+sub loop_depend {
+    $repeat = 1;
+
+    while ($repeat) {
+        $repeat = 0;
+
+      forloop:
+        foreach my $config (keys %configs) {
+
+            # If this config is not a module, we do not need to process it
+            if (defined($orig_configs{$config}) && $orig_configs{$config} ne "m") {
+                next forloop;
+            }
+
+            $config =~ s/^CONFIG_//;
+            $depconfig = $config;
+
+            if (defined($depends{$config})) {
+                # This config has dependencies. Make sure they are also included
+                parse_config_depends $depends{$config};
+            }
+
+            # If the config has no prompt, then we need to check if a config
+            # that is enabled selected it. Or if we need to enable one.
+            if (!defined($prompts{$config}) && defined($selects{$config})) {
+                $process_selects{$config} = 1;
+            }
         }
+    }
+}
+
+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_dep_select $selects{$config};
+        parse_config_selects $config, $selects{$config};
     }
 }
 
+while ($repeat) {
+    # Get the first set of configs and their dependencies.
+    loop_depend;
+
+    $repeat = 0;
+
+    # Now we need to see if we have to check selects;
+    loop_select;
+}           
+
 my %setconfigs;
 
 # Finally, read the .config file and turn off any module enabled that
 # we could not find a reason to keep enabled.
-while(<CIN>) {
+foreach my $line (@config_file) {
+    $_ = $line;
 
     if (/CONFIG_IKCONFIG/) {
         if (/# CONFIG_IKCONFIG is not set/) {
@@ -473,7 +615,6 @@ while(<CIN>) {
     }
     print;
 }
-close(CIN);
 
 # Integrity check, make sure all modules that we want enabled do
 # indeed have their configs set.