python/build/libs.py: build CURL with OpenSSL support

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1059

python/build/openssl.py

@@ -0,0 +1,55 @@
+import subprocess
+
+from build.makeproject import MakeProject
+
+class OpenSSLProject(MakeProject):
+    def __init__(self, url, md5, installed,
+                 **kwargs):
+        MakeProject.__init__(self, url, md5, installed, install_target='install_dev', **kwargs)
+
+    def get_make_args(self, toolchain):
+        return MakeProject.get_make_args(self, toolchain) + [
+            'CC=' + toolchain.cc,
+            'CFLAGS=' + toolchain.cflags,
+            'CPPFLAGS=' + toolchain.cppflags,
+            'AR=' + toolchain.ar,
+            'RANLIB=' + toolchain.ranlib,
+            'build_libs',
+        ]
+
+    def build(self, toolchain):
+        src = self.unpack(toolchain, out_of_tree=False)
+
+        # OpenSSL has a weird target architecture scheme with lots of
+        # hard-coded architectures; this table translates between our
+        # "toolchain_arch" (HOST_TRIPLET) and the OpenSSL target
+        openssl_archs = {
+            # not using "android-*" because those OpenSSL targets want
+            # to know where the SDK is, but our own build scripts
+            # prepared everything already to look like a regular Linux
+            # build
+            'arm-linux-androideabi': 'linux-generic32',
+            'aarch64-linux-android': 'linux-aarch64',
+            'i686-linux-android': 'linux-x86-clang',
+            'x86_64-linux-android': 'linux-x86_64-clang',
+
+            # Kobo
+            'arm-linux-gnueabihf': 'linux-generic32',
+
+            # Windows
+            'i686-w64-mingw32': 'mingw',
+            'x86_64-w64-mingw32': 'mingw64',
+        }
+
+        openssl_arch = openssl_archs[toolchain.arch]
+
+        subprocess.check_call(['./Configure',
+                               'no-shared',
+                               'no-module', 'no-engine', 'no-static-engine',
+                               'no-async',
+                               'no-tests',
+                               'no-asm', # "asm" causes build failures on Windows
+                               openssl_arch,
+                               '--prefix=' + toolchain.install_prefix],
+                              cwd=src, env=toolchain.env)
+        MakeProject.build(self, toolchain, src)