pkgman: Add "search --not-required".

List only the packages that are not required by any other package.

Most useful then used as "pkgman search --installed-only --non-required",
but works for non-installed packages too.

Based on OscarL's initial version, rewritten by me to use the real
dependency resolution system instead. One tweak from madmax to get
it to actually work properly.

Co-authored-by: Oscar Lesta <[email protected]>

src/bin/pkgman/command_search.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013, Haiku, Inc. All Rights Reserved.
+ * Copyright 2013-2023, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -20,6 +20,8 @@
 #include <Locale.h>
 
 #include <package/solver/SolverPackage.h>
+#include <package/solver/SolverPackageSpecifier.h>
+#include <package/solver/SolverPackageSpecifierList.h>
 #include <TextTable.h>
 
 #include "Command.h"
@@ -55,6 +57,9 @@ static const char* const kLongUsage =
 	"    Only find installed packages.\n"
 	"  -u, --uninstalled-only\n"
 	"    Only find not installed packages.\n"
+	"  -n, --not-required\n"
+	"    List only the packages that are not required by any other package.\n"
+	"    Note: Implies --all, and omits listing \"_source\" and \"_debuginfo\" packages.\n"
 	"  -r, --requirements\n"
 	"    Search packages with <search-string> as requirements.\n"
 	"  -s <scope>, --search-scope=<scope>\n"
@@ -136,6 +141,75 @@ compare_packages(const BSolverPackage* a, const BSolverPackage* b,
 }
 
 
+struct ResolvableExpressionComparator {
+	bool operator()(const BPackageResolvableExpression& a,
+		const BPackageResolvableExpression& b) const
+	{
+		return a.ToString() < b.ToString();
+	}
+};
+
+
+static status_t
+filter_required_packages(const BPackageManager& packageManager,
+	BObjectList<BSolverPackage>& packages)
+{
+	std::set<BSolverPackage*> packagesSet;
+	BSolverPackageSpecifierList requirements;
+	for (int32 i = 0; i < packages.CountItems(); i++) {
+		BSolverPackage* package = packages.ItemAt(i);
+		if (package->Name().EndsWith("_source") || package->Name().EndsWith("_debuginfo"))
+			continue;
+
+		packagesSet.insert(package);
+
+		BObjectList<BPackageResolvableExpression> requiresList
+			= package->Info().RequiresList();
+		for (int32 j = 0; j < requiresList.CountItems(); j++)
+			requirements.AppendSpecifier(requiresList.ItemAt(j)->ToString());
+	}
+	packages.MakeEmpty();
+
+	BObjectList<BSolverPackage> requiredPackages;
+	const BSolverPackageSpecifier* unmatched;
+	status_t status = packageManager.Solver()->FindPackages(requirements,
+		0, requiredPackages, &unmatched);
+	if (status != B_OK) {
+		fprintf(stderr, "Failed to filter required packages: %s\n", strerror(status));
+		if (unmatched != NULL) {
+			// Try to find the package this requirement comes from.
+			std::set<BSolverPackage*>::const_iterator setIterator = packagesSet.begin();
+			for (; setIterator != packagesSet.end(); setIterator++) {
+				BSolverPackage* package = *setIterator;
+				BObjectList<BPackageResolvableExpression> requiresList
+					= package->Info().RequiresList();
+				for (int32 j = 0; j < requiresList.CountItems(); j++) {
+					if (requiresList.ItemAt(j)->ToString() != unmatched->SelectString())
+						continue;
+
+					fprintf(stderr, "\t(unmatched: %s, required by %s)\n",
+						unmatched->SelectString().String(), package->Name().String());
+					return status;
+				}
+			}
+
+			// We couldn't find it, just print the requirement itself.
+			fprintf(stderr, "\t(unmatched: %s)\n", unmatched->SelectString().String());
+		}
+		return status;
+	}
+
+	for (int32 i = 0; i < requiredPackages.CountItems(); i++)
+		packagesSet.erase(requiredPackages.ItemAt(i));
+
+	std::set<BSolverPackage*>::const_iterator setIterator = packagesSet.begin();
+	for (; setIterator != packagesSet.end(); setIterator++)
+		packages.AddItem(*setIterator);
+
+	return B_OK;
+}
+
+
 int
 SearchCommand::Execute(int argc, const char* const* argv)
 {
@@ -144,12 +218,14 @@ SearchCommand::Execute(int argc, const char* const* argv)
 	bool nameOnly = false;
 	bool fullSearch = false;
 	bool listAll = false;
+	bool listNotRequiredOnly = false;
 	bool details = false;
 	bool requirements = false;
 
 	while (true) {
 		static struct option sLongOptions[] = {
 			{ "all", no_argument, 0, 'a' },
+			{ "not-required", no_argument, 0, 'n' },
 			{ "debug", required_argument, 0, OPTION_DEBUG },
 			{ "details", no_argument, 0, 'D' },
 			{ "help", no_argument, 0, 'h' },
@@ -161,7 +237,7 @@ SearchCommand::Execute(int argc, const char* const* argv)
 		};
 
 		opterr = 0; // don't print errors
-		int c = getopt_long(argc, (char**)argv, "aDhiurs:", sLongOptions, NULL);
+		int c = getopt_long(argc, (char**)argv, "aDhinurs:", sLongOptions, NULL);
 		if (c == -1)
 			break;
 
@@ -195,6 +271,10 @@ SearchCommand::Execute(int argc, const char* const* argv)
 				requirements = true;
 				break;
 
+			case 'n':
+				listNotRequiredOnly = true;
+				break;
+
 			case 's':
 				if (strcmp(optarg, "name") == 0)
 					nameOnly = true;
@@ -211,12 +291,13 @@ SearchCommand::Execute(int argc, const char* const* argv)
 		}
 	}
 
-	// The remaining argument is the search string. Ignored when --all has been
+	// The remaining argument is the search string. Ignored when --all or --not-required has been
 	// specified.
-	if ((!listAll && argc != optind + 1) || (listAll && requirements))
+	if ((!(listAll || listNotRequiredOnly) && argc != optind + 1)
+		|| ((listAll || listNotRequiredOnly) && requirements))
 		PrintUsageAndExit(true);
 
-	const char* searchString = listAll ? "" : argv[optind++];
+	const char* searchString = (listAll || listNotRequiredOnly) ? "" : argv[optind++];
 
 	// create the solver
 	PackageManager packageManager(B_PACKAGE_INSTALLATION_LOCATION_HOME);
@@ -251,6 +332,12 @@ SearchCommand::Execute(int argc, const char* const* argv)
 		return 0;
 	}
 
+	if (listNotRequiredOnly) {
+		error = filter_required_packages(packageManager, packages);
+		if (error != B_OK)
+			return error;
+	}
+
 	// sort packages by name and installation location/repository
 	const BSolverRepository* systemRepository
 		= static_cast<const BSolverRepository*>(