Improve Protocol Buffers info

2019-04-21 11:51:49 +02:00 · 2019-04-21 11:51:49 +02:00 · b3ca9bda99
parent 2cba1c5e0a
commit b3ca9bda99
2 changed files with 123 additions and 116 deletions
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -1789,128 +1789,126 @@ endif()
 ################################################################################
 # Protocol Buffers https://github.com/protocolbuffers/protobuf
 ################################################################################
-option(ENABLE_PROTOBUF "Enable Protocol Buffers" ON)
-if(ENABLE_PROTOBUF)
-    set(Protobuf_VERSION "0.0.0")
-    find_package(Protobuf)
-    set_package_properties(Protobuf PROPERTIES
-        URL "https://developers.google.com/protocol-buffers/"
-        DESCRIPTION "A language-neutral, platform-neutral extensible mechanism for serializing structured data"
-        PURPOSE "Used to serialize output data in a way that can be read by other applications."
-        TYPE REQUIRED
+set(Protobuf_VERSION "0.0.0")
+find_package(Protobuf)
+set_package_properties(Protobuf PROPERTIES
+    URL "https://developers.google.com/protocol-buffers/"
+    DESCRIPTION "A language-neutral, platform-neutral extensible mechanism for serializing structured data"
+    PURPOSE "Used to serialize output data in a way that can be read by other applications."
+    TYPE REQUIRED
+)
+if(Protobuf_FOUND AND CMAKE_VERSION VERSION_LESS 3.9)
+    add_library(protobuf::libprotobuf SHARED IMPORTED)
+    set_target_properties(protobuf::libprotobuf PROPERTIES
+        IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
+        IMPORTED_LOCATION "${Protobuf_LIBRARY}"
+        INTERFACE_INCLUDE_DIRECTORIES "${Protobuf_INCLUDE_DIR}"
+        INTERFACE_LINK_LIBRARIES "${Protobuf_LIBRARY}"
    )
-    if(Protobuf_FOUND AND CMAKE_VERSION VERSION_LESS 3.9)
-        add_library(protobuf::libprotobuf SHARED IMPORTED)
-        set_target_properties(protobuf::libprotobuf PROPERTIES
-            IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
-            IMPORTED_LOCATION "${Protobuf_LIBRARY}"
-            INTERFACE_INCLUDE_DIRECTORIES "${Protobuf_INCLUDE_DIR}"
-            INTERFACE_LINK_LIBRARIES "${Protobuf_LIBRARY}"
-        )
-        add_executable(protobuf::protoc IMPORTED)
+    add_executable(protobuf::protoc IMPORTED)
+    set_target_properties(protobuf::protoc PROPERTIES
+        IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
+        IMPORTED_LOCATION "${Protobuf_PROTOC_EXECUTABLE}"
+        INTERFACE_LINK_LIBRARIES "${Protobuf_PROTOC_LIBRARY}"
+    )
+endif()
+if(Protobuf_FOUND AND CMAKE_CROSSCOMPILING)
+    find_program(PROTOC_EXECUTABLE protoc
+        HINTS
+        /usr/local/bin/
+        /usr/bin/
+        NO_SYSTEM_ENVIRONMENT_PATH
+    )
+    if(PROTOC_EXECUTABLE)
        set_target_properties(protobuf::protoc PROPERTIES
            IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
-            IMPORTED_LOCATION "${Protobuf_PROTOC_EXECUTABLE}"
-            INTERFACE_LINK_LIBRARIES "${Protobuf_PROTOC_LIBRARY}"
-        )
-    endif()
-    if(Protobuf_FOUND AND CMAKE_CROSSCOMPILING)
-        find_program(PROTOC_EXECUTABLE protoc
-            HINTS
-                /usr/local/bin/
-                /usr/bin/
-            NO_SYSTEM_ENVIRONMENT_PATH
-        )
-        if(PROTOC_EXECUTABLE)
-            set_target_properties(protobuf::protoc PROPERTIES
-                IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
-                IMPORTED_LOCATION ${PROTOC_EXECUTABLE}
-            )
-        else()
-            message(FATAL ERROR "Please install the Protocol Buffers compiter v{${Protobuf_VERSION}} in the host machine")
-        endif()
-    endif()
-    if((NOT Protobuf_FOUND) OR (NOT Protobuf_PROTOC_EXECUTABLE) OR (${Protobuf_VERSION} VERSION_LESS ${GNSSSDR_PROTOBUF_MIN_VERSION}))
-        unset(Protobuf_PROTOC_EXECUTABLE)
-        if(CMAKE_CROSSCOMPILING)
-            if(NOT Protobuf_FOUND)
-                ExternalProject_Add(protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    PREFIX ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    GIT_REPOSITORY https://github.com/protocolbuffers/protobuf
-                    GIT_TAG v${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    UPDATE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/autogen.sh
-                    CONFIGURE_COMMAND "${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/configure --prefix=${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION} --host=$ENV{OECORE_TARGET_ARCH} --with-protoc=${PROTOC_EXECUTABLE}"
-                    BUILD_COMMAND ${CMAKE_MAKE_PROGRAM}
-                    INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
-                    BUILD_BYPRODUCTS ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protobuf${CMAKE_STATIC_LIBRARY_SUFFIX}
-                    ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/bin/protoc
-                )
-            endif()
-        else()
-            if(CMAKE_VERSION VERSION_LESS 3.2)
-                ExternalProject_Add(protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    PREFIX ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    GIT_REPOSITORY https://github.com/protocolbuffers/protobuf
-                    GIT_TAG v${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    UPDATE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/autogen.sh
-                    CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/configure --prefix=${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    BUILD_COMMAND ${CMAKE_MAKE_PROGRAM}
-                    INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
-                )
-            else()
-                ExternalProject_Add(protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    PREFIX ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    GIT_REPOSITORY https://github.com/protocolbuffers/protobuf
-                    GIT_TAG v${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    UPDATE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/autogen.sh
-                    CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/configure --prefix=${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
-                    BUILD_COMMAND ${CMAKE_MAKE_PROGRAM}
-                    INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
-                    BUILD_BYPRODUCTS ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protobuf${CMAKE_STATIC_LIBRARY_SUFFIX}
-                    ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/bin/protoc
-                )
-            endif()
-
-            if(NOT TARGET protobuf::protoc)
-                add_executable(protobuf::protoc IMPORTED)
-                add_dependencies(protobuf::protoc protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION})
-            endif()
-            unset(Protobuf_PROTOC_EXECUTABLE)
-            set(PROTOBUF_PROTOC_EXECUTABLE "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/bin/protoc")
-            set_target_properties(protobuf::protoc PROPERTIES
-                IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
-                IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/bin/protoc"
-                INTERFACE_LINK_LIBRARIES "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protoc${CMAKE_STATIC_LIBRARY_SUFFIX}"
-            )
-        endif()
-        file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/include)
-        if(NOT TARGET protobuf::libprotobuf)
-            add_library(protobuf::libprotobuf STATIC IMPORTED)
-            add_dependencies(protobuf::libprotobuf protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION})
-        endif()
-        set_target_properties(protobuf::libprotobuf PROPERTIES
-            IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
-            IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protobuf${CMAKE_STATIC_LIBRARY_SUFFIX}"
-            INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/include"
-            INTERFACE_LINK_LIBRARIES "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protobuf${CMAKE_STATIC_LIBRARY_SUFFIX}"
-        )
-
-        if(${Protobuf_VERSION} VERSION_LESS ${GNSSSDR_PROTOBUF_MIN_VERSION})
-            set_package_properties(Protobuf PROPERTIES
-                PURPOSE "Protocol Buffers found (v${Protobuf_VERSION}) is too old (> v${GNSSSDR_PROTOBUF_MIN_VERSION} needed)."
-            )
-        endif()
-        set_package_properties(Protobuf PROPERTIES
-            PURPOSE "Protocol Buffers v${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION} will be downloaded and built when doing '${CMAKE_MAKE_PROGRAM_PRETTY_NAME}'."
+            IMPORTED_LOCATION ${PROTOC_EXECUTABLE}
        )
+    else()
+        message(FATAL ERROR "Please install the Protocol Buffers compiter v{${Protobuf_VERSION}} in the host machine")
    endif()
 endif()
+if((NOT Protobuf_FOUND) OR (NOT Protobuf_PROTOC_EXECUTABLE) OR (${Protobuf_VERSION} VERSION_LESS ${GNSSSDR_PROTOBUF_MIN_VERSION}))
+    unset(Protobuf_PROTOC_EXECUTABLE)
+    if(CMAKE_CROSSCOMPILING)
+        if(NOT Protobuf_FOUND)
+            ExternalProject_Add(protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                PREFIX ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                GIT_REPOSITORY https://github.com/protocolbuffers/protobuf
+                GIT_TAG v${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                UPDATE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/autogen.sh
+                CONFIGURE_COMMAND "${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/configure --prefix=${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION} --host=$ENV{OECORE_TARGET_ARCH} --with-protoc=${PROTOC_EXECUTABLE}"
+                BUILD_COMMAND ${CMAKE_MAKE_PROGRAM}
+                INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
+                BUILD_BYPRODUCTS ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protobuf${CMAKE_STATIC_LIBRARY_SUFFIX}
+                ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/bin/protoc
+            )
+        endif()
+    else()
+        if(CMAKE_VERSION VERSION_LESS 3.2)
+            ExternalProject_Add(protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                PREFIX ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                GIT_REPOSITORY https://github.com/protocolbuffers/protobuf
+                GIT_TAG v${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                UPDATE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/autogen.sh
+                CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/configure --prefix=${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                BUILD_COMMAND ${CMAKE_MAKE_PROGRAM}
+                INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
+            )
+        else()
+            ExternalProject_Add(protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                PREFIX ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                GIT_REPOSITORY https://github.com/protocolbuffers/protobuf
+                GIT_TAG v${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                UPDATE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/autogen.sh
+                CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/protobuf/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/configure --prefix=${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}
+                BUILD_COMMAND ${CMAKE_MAKE_PROGRAM}
+                INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
+                BUILD_BYPRODUCTS ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protobuf${CMAKE_STATIC_LIBRARY_SUFFIX}
+                ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/bin/protoc
+            )
+        endif()
+
+        if(NOT TARGET protobuf::protoc)
+            add_executable(protobuf::protoc IMPORTED)
+            add_dependencies(protobuf::protoc protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION})
+        endif()
+        unset(Protobuf_PROTOC_EXECUTABLE)
+        set(PROTOBUF_PROTOC_EXECUTABLE "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/bin/protoc")
+        set_target_properties(protobuf::protoc PROPERTIES
+            IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
+            IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/bin/protoc"
+            INTERFACE_LINK_LIBRARIES "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protoc${CMAKE_STATIC_LIBRARY_SUFFIX}"
+        )
+    endif()
+    file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/include)
+    if(NOT TARGET protobuf::libprotobuf)
+        add_library(protobuf::libprotobuf STATIC IMPORTED)
+        add_dependencies(protobuf::libprotobuf protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION})
+    endif()
+    set_target_properties(protobuf::libprotobuf PROPERTIES
+        IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
+        IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protobuf${CMAKE_STATIC_LIBRARY_SUFFIX}"
+        INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/include"
+        INTERFACE_LINK_LIBRARIES "${CMAKE_CURRENT_BINARY_DIR}/protobuf-${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}protobuf${CMAKE_STATIC_LIBRARY_SUFFIX}"
+    )
+
+    if(${Protobuf_VERSION} VERSION_LESS ${GNSSSDR_PROTOBUF_MIN_VERSION})
+        set_package_properties(Protobuf PROPERTIES
+            PURPOSE "Protocol Buffers found (v${Protobuf_VERSION}) is too old (> v${GNSSSDR_PROTOBUF_MIN_VERSION} needed)."
+        )
+    endif()
+    set_package_properties(Protobuf PROPERTIES
+        PURPOSE "Protocol Buffers v${GNSSSDR_PROTOCOLBUFFERS_LOCAL_VERSION} will be downloaded and built when doing '${CMAKE_MAKE_PROGRAM_PRETTY_NAME}'."
+    )
+endif()
+



--- a/README.md
+++ b/README.md
@ -286,6 +286,14 @@ In case the GnuTLS library with openssl extensions package is not available in y

 #### Install [Protocol Buffers](https://developers.google.com/protocol-buffers/ "Protocol Buffers' Homepage"), a portable mechanism for serialization of structured data:

+GNSS-SDR requires Protocol Buffers v3.0.0 or later. If the packages that come with your distribution are older, you will need to install it manually. First, install the dependencies:
+
+~~~~~~
+$ sudo apt-get install autoconf automake libtool curl make g++ unzip
+~~~~~~
+
+and then:
+
 ~~~~~~
 $ wget https://github.com/protocolbuffers/protobuf/releases/download/v3.7.1/protobuf-cpp-3.7.1.tar.gz
 $ tar xvfz protobuf-cpp-3.7.1.tar.gz
@ -294,6 +302,7 @@ $ ./autogen.sh
 $ ./configure
 $ make
 $ sudo make install
+$ sudo ldconfig
 ~~~~~~