build: allow openwrt.git packages to be replaced by feeds

Currently, replacing a package available in openwrt.git requires
modifications in openwrt.git, or requires duplicating the package in a
feed but with a different name, which causes all kind of problems
related to dependencies (all packages selecting it would have to be
modified accordingly to select the new package).

With this change, if a package with the same name is present both in
feeds/ and package/ folders, the one in feeds/ can override the one
in package/, both in the menuconfig and during the build, by passing the
"-f" option to "./scripts/feeds install"

This mechanism is particularly useful for vendor tree, or in general for
application which needs to replace one particular package which exists
within openwrt.git by a custom/newer version.

Signed-off-by: Mathieu Olivari <mathieu@qca.qualcomm.com>

SVN-Revision: 44334

include/scan.awk

@@ -0,0 +1,17 @@
+BEGIN { FS="/" }
+$1 ~ /^feeds/ { FEEDS[$NF]=$0 }
+$1 !~ /^feeds/ { PKGS[$NF]=$0 }
+END {
+	# Filter-out OpenWrt packages which have a feeds equivalent
+	for (pkg in PKGS)
+		if (pkg in FEEDS)
+			delete PKGS[pkg]
+	n = asort(PKGS)
+	for (i=1; i <= n; i++) {
+		print PKGS[i]
+	}
+	n = asort(FEEDS)
+	for (i=1; i <= n; i++){
+		print FEEDS[i]
+	}
+}

include/scan.mk

@@ -43,7 +43,7 @@ endef
 
 $(FILELIST):
 	rm -f $(TMP_DIR)/info/.files-$(SCAN_TARGET)-*
-	$(call FIND_L, $(SCAN_DIR)) $(SCAN_EXTRA) -mindepth 1 $(if $(SCAN_DEPTH),-maxdepth $(SCAN_DEPTH)) -name Makefile | xargs grep -HE 'call (Build/DefaultTargets|Build(Package|Target)|.+Package)' | sed -e 's#^$(SCAN_DIR)/##' -e 's#/Makefile:.*##' | uniq > $@
+	$(call FIND_L, $(SCAN_DIR)) $(SCAN_EXTRA) -mindepth 1 $(if $(SCAN_DEPTH),-maxdepth $(SCAN_DEPTH)) -name Makefile | xargs grep -HE 'call (Build/DefaultTargets|Build(Package|Target)|.+Package)' | sed -e 's#^$(SCAN_DIR)/##' -e 's#/Makefile:.*##' | uniq | awk -f include/scan.awk > $@
 
 $(TMP_DIR)/info/.files-$(SCAN_TARGET).mk: $(FILELIST)
 	( \

scripts/feeds

@@ -358,6 +358,7 @@ sub is_core_package($) {
 sub install_package {
 	my $feed = shift;
 	my $name = shift;
+	my $force = shift;
 	my $ret = 0;
 
 	$feed = lookup_package($feed, $name);
@@ -382,14 +383,26 @@ sub install_package {
 	my $type = $feed->[0];
 	$src or $src = $name;
 
+	# If it's a core package and we don't want to override, just return
+	!$force and is_core_package($src) and return 0;
+
 	# previously installed packages set the runtime package
-	# newly installed packages set the source package
-	$installed{$src} and return 0;
+	# newly installed packages set the source package to 1
+	$installed{$src} and $installed{$src} == 1 and return 0;
+
+	# we'll trigger the override only with the 3 conditions below:
+	# - override is allowed by command line (-f)
+	# - a package with the same src exists in the core packages list
+	# - the package previously installed is not from a feed
+	my $override = 1 if ($force and is_core_package($src) and !$installed{$name}->{feed});
 
 	# check previously installed packages
-	$installed{$name} and return 0;
+	$installed{$name} and !$override and return 0;
 	$installed{$src} = 1;
-	warn "Installing package '$src'\n";
+
+	defined($override) and $override == 1
+		and warn "Overriding package '$src'\n"
+		or warn "Installing package '$src'\n";
 
 	$install_method{$type} or do {
 		warn "Unknown installation method: '$type'\n";
@@ -409,7 +422,7 @@ sub install_package {
 			$dep =~ s/^.+://;
 			$dep =~ s/\/.+$//;
 			next unless $dep;
-			install_package($feed, $dep) == 0 or $ret = 1;
+			install_package($feed, $dep, 0) == 0 or $ret = 1;
 		}
 	}
 
@@ -436,7 +449,7 @@ sub install {
 	my $feed;
 	my $ret = 0;
 
-	getopts('ap:d:h', \%opts);
+	getopts('ap:d:fh', \%opts);
 
 	if ($opts{h}) {
 		usage();
@@ -462,7 +475,7 @@ sub install {
 					my $p = $feed_package->{$name};
 					next if $p->{vdepends};
 					if( $p->{name} ) {
-						install_package($feed, $p->{name}) == 0 or $ret = 1;
+						install_package($feed, $p->{name}, exists($opts{f})) == 0 or $ret = 1;
 						get_feed($f->[1]);
 					}
 				}
@@ -470,7 +483,7 @@ sub install {
 		}
 	} else {
 		while ($name = shift @ARGV) {
-			install_package($feed, $name) == 0 or $ret = 1;
+			install_package($feed, $name, exists($opts{f})) == 0 or $ret = 1;
 		}
 	}
 
@@ -638,6 +651,7 @@ Commands:
 	    -a :           Install all packages from all feeds or from the specified feed using the -p option.
 	    -p <feedname>: Prefer this feed when installing packages.
 	    -d <y|m|n>:    Set default for newly installed packages.
+	    -f :           Install will be forced even if the package exists in core OpenWrt (override)
 
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