libswiftnav 0.21 (new formula)

Closes #7958.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Formula/libswiftnav.rb

@@ -0,0 +1,39 @@
+class Libswiftnav < Formula
+  desc "C library implementing GNSS related functions and algorithms."
+  homepage "https://github.com/swift-nav/libswiftnav"
+  url "https://github.com/swift-nav/libswiftnav/archive/v0.21.tar.gz"
+  sha256 "99e7ac3f190d76b2c1ceb17dae76d24b86d1a71501db4f6a49759539bb393756"
+
+  depends_on "cmake" => :build
+  depends_on "pkg-config" => :build
+
+  def install
+    system "cmake", ".", *std_cmake_args
+    system "make", "install"
+  end
+
+  test do
+    (testpath/"test.c").write <<-EOS.undent
+      #include <stdlib.h>
+      #include <stdio.h>
+      #include <libswiftnav/edc.h>
+
+      const u8 *test_data = (u8*)"123456789";
+
+      int main() {
+        u32 crc;
+
+        crc = crc24q(test_data, 9, 0xB704CE);
+        if (crc != 0x21CF02) {
+          printf("libswiftnav CRC quick test failed: CRC of \\"123456789\\" with init value 0xB704CE should be 0x21CF02, not 0x%06X\\n", crc);
+          exit(1);
+        } else {
+          printf("libswiftnav CRC quick test successful, CRC = 0x21CF02\\n");
+          exit(0);
+        }
+      }
+    EOS
+    system ENV.cc, "-L", lib, "-lswiftnav", "-o", "test", "test.c"
+    system "./test"
+  end
+end