Add libsigmf as an external project

external/CMakeLists.txt

@@ -19,6 +19,7 @@ set(LIBIIO_TAG 826563e41b5ce9890b75506f672017de8d76d52d)
 set(AIRSPYHF_TAG "1af81c0ca18944b8c9897c3c98dc0a991815b686")
 set(PERSEUS_TAG afefa23e3140ac79d845acb68cf0beeb86d09028)
 set(MIRISDR_TAG "v2.0.0")
+set(LIBSIGMF_TAG "new-namespaces")
 
 set(PTHREADS4W_TAG "Version-2-11-0-release")
 set(RTLSDR_TAG 5e73f90f1d85d8db2e583f3dbf1cff052d71d59b)
@@ -750,6 +751,23 @@ if ((NOT LIBDSDCC_FOUND OR LIBDSDCC_EXTERNAL) AND LIBMBE_FOUND)
     endif ()
 endif ((NOT LIBDSDCC_FOUND OR LIBDSDCC_EXTERNAL) AND LIBMBE_FOUND)
 
+if (LINUX AND (NOT LIBSIGMF_FOUND OR LIBSIGMF_EXTERNAL))
+    set(LIBSIGMF_LIBRARIES "${EXTERNAL_BUILD_LIBRARIES}/lib${LIB_SUFFIX}/libsigmf${CMAKE_SHARED_LIBRARY_SUFFIX}" CACHE INTERNAL "")
+    ExternalProject_Add(libsigmf
+            GIT_REPOSITORY https://github.com/f4exb/libsigmf.git
+            GIT_TAG ${LIBSIGMF_TAG}
+            PREFIX "${EXTERNAL_BUILD_LIBRARIES}/libsigmf"
+            CMAKE_ARGS ${COMMON_CMAKE_ARGS}
+            BUILD_BYPRODUCTS "${LIBSIGMF_LIBRARIES}"
+            INSTALL_COMMAND ""
+            TEST_COMMAND ""
+            )
+    ExternalProject_Get_Property(libsigmf source_dir binary_dir)
+    set_global_cache(LIBSIGMF_FOUND ON)
+    set(LIBSIGMF_EXTERNAL ON CACHE INTERNAL "")
+    set(LIBSIGMF_INCLUDE_DIR "${EXTERNAL_BUILD_LIBRARIES}/libsigmf/src" CACHE INTERNAL "")
+endif (LINUX AND (NOT LIBSIGMF_FOUND OR LIBSIGMF_EXTERNAL))
+
 # For APT demodulator
 if(ENABLE_CHANNELRX_DEMODAPT)
     if (WIN32)