From 82c7d6187fdaeaa1b9cfbd6637d9b047a78f17ec Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 21 Dec 2022 11:52:11 +0200
Subject: [PATCH] Track Android API levels with a bitmask

---
 source/androidtools.cpp | 29 +++++++++++++++++------------
 source/androidtools.h   |  8 +++++---
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/source/androidtools.cpp b/source/androidtools.cpp
index 5ef2bec..1633b8b 100644
--- a/source/androidtools.cpp
+++ b/source/androidtools.cpp
@@ -1,3 +1,4 @@
+#include <msp/core/algorithm.h>
 #include <msp/core/environ.h>
 #include <msp/fs/dir.h>
 #include <msp/fs/stat.h>
@@ -53,13 +54,20 @@ AndroidDevKit::AndroidDevKit(Builder &b, const string &type, const FS::Path &def
 		return;
 
 	builder.get_logger().log("files", format("Traversing %s", platforms_dir.str()));
+	supported_api_levels = 0;
 	for(const string &p: list_filtered(platforms_dir, "^android-[1-9][0-9]*$"))
-		supported_api_levels.insert(lexical_cast<unsigned>(p.substr(8)));
+	{
+		unsigned api = lexical_cast<unsigned>(p.substr(8));
+		if(api>63)
+			builder.get_logger().log("problems", format("API level %d is too high", api));
+		else
+			supported_api_levels |= 1<<api;
+	}
 }
 
 void AndroidDevKit::select_api_level(unsigned api)
 {
-	if(!supported_api_levels.count(api))
+	if(!(supported_api_levels&(1<<api)))
 		throw invalid_argument("AndroidDevKit::select_api_level");
 
 	init_api_level(api);
@@ -219,17 +227,14 @@ AndroidTools::AndroidTools(Builder &builder, const Architecture &arch):
 	sdk(builder),
 	ndk(builder, arch, sdk)
 {
-	const set<unsigned> &sdk_api_levels = sdk.get_supported_api_levels();
-	const set<unsigned> &ndk_api_levels = ndk.get_supported_api_levels();
-	unsigned highest_common = 0;
-	for(auto i=sdk_api_levels.rbegin(); (!highest_common && i!=sdk_api_levels.rend()); ++i)
-		if(ndk_api_levels.count(*i))
-			highest_common = *i;
-
-	if(highest_common)
+	if(uint64_t common_api_levels = sdk.get_supported_api_levels()&ndk.get_supported_api_levels())
 	{
-		sdk.select_api_level(highest_common);
-		ndk.select_api_level(highest_common);
+		unsigned api = 0;
+		for(unsigned i=32; i>0; i>>=1)
+			api += i*!!(common_api_levels>>(api+i));
+		builder.get_logger().log("tools", format("Using Android API level %d", api));
+		sdk.select_api_level(api);
+		ndk.select_api_level(api);
 	}
 	else
 		builder.get_logger().log("problems", "No usable Android platforms found");
diff --git a/source/androidtools.h b/source/androidtools.h
index bef95f8..b08691c 100644
--- a/source/androidtools.h
+++ b/source/androidtools.h
@@ -1,7 +1,7 @@
 #ifndef ANDROIDTOOLS_H_
 #define ANDROIDTOOLS_H_
 
-#include <set>
+#include <cstdint>
 #include <msp/fs/path.h>
 #include "toolchain.h"
 
@@ -13,14 +13,16 @@ class AndroidDevKit
 protected:
 	Builder &builder;
 	Msp::FS::Path root;
-	std::set<unsigned> supported_api_levels;
+	/* Needs refactoring if API levels go over 63.  At present rate this will
+	take decades to occur. */
+	uint64_t supported_api_levels;
 
 	AndroidDevKit(Builder &, const std::string &, const Msp::FS::Path & = Msp::FS::Path());
 	~AndroidDevKit() { }
 
 public:
 	const Msp::FS::Path &get_root_dir() const { return root; }
-	const std::set<unsigned> &get_supported_api_levels() const { return supported_api_levels; }
+	uint64_t get_supported_api_levels() const { return supported_api_levels; }
 	void select_api_level(unsigned);
 protected:
 	virtual void init_api_level(unsigned) = 0;
-- 
2.45.2