Use system provided libsignal-protocol-c by default

You can still compile in tree by using --with-libsignal-in-tree flag

.travis.yml

@@ -6,7 +6,7 @@ env:
 before_install:
   - export USE_CCACHE=1
   - sudo apt-get update
-  - sudo apt-get install -y cmake valac libgee-0.8-dev libsqlite3-dev libgtk-3-dev libnotify-dev libgpgme-dev libsoup2.4-dev libgcrypt20-dev libqrencode-dev
+  - sudo apt-get install -y cmake valac libgee-0.8-dev libsqlite3-dev libgtk-3-dev libnotify-dev libgpgme-dev libsoup2.4-dev libgcrypt20-dev libqrencode-dev libsignal-protocol-c-dev
 install:
   - ./configure --with-tests $CONFIGURE_FLAGS
   - make

cmake/FindSignalProtocol.cmake

@@ -1,10 +1,11 @@
 include(PkgConfigWithFallback)
 find_pkg_config_with_fallback(SignalProtocol
-    PKG_CONFIG_NAME signal-protocol-c
+    PKG_CONFIG_NAME libsignal-protocol-c
     LIB_NAMES signal-protocol-c
     INCLUDE_NAMES signal/signal_protocol.h
 )
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(SignalProtocol
-    REQUIRED_VARS SignalProtocol_LIBRARY)
+    REQUIRED_VARS SignalProtocol_LIBRARY
+    VERSION_VAR SignalProtocol_VERSION)

configure

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 OPTS=`getopt -o "h" --long \
-help,fetch-only,no-debug,disable-fast-vapi,with-tests,release,\
+help,fetch-only,no-debug,disable-fast-vapi,with-tests,release,with-libsignal-in-tree,\
 enable-plugin:,disable-plugin:,\
 prefix:,program-prefix:,exec-prefix:,lib-suffix:,\
 bindir:,libdir:,includedir:,datadir:,\
@@ -17,6 +17,7 @@ eval set -- "$OPTS"
 PREFIX=${PREFIX:-/usr/local}
 ENABLED_PLUGINS=
 DISABLED_PLUGINS=
+BUILD_LIBSIGNAL_IN_TREE=
 BUILD_TESTS=
 BUILD_TYPE=Debug
 DISABLE_FAST_VAPI=
@@ -52,9 +53,11 @@ Configuration:
                              clean builds, but faster when doing incremental
                              builds (during development).
   --fetch-only               Only fetch the files required to run ./configure
-                             without network access later and exit
+                             without network access later and exit.
   --no-debug                 Build without debug symbols
   --release                  Configure to build an optimized release version
+  --with-libsignal-in-tree   Build libsignal-protocol-c in tree and link it
+                             statically.
   --with-tests               Also build tests.
 
 Plugin configuration:
@@ -110,6 +113,7 @@ while true; do
         --valac ) VALA_EXECUTABLE="$2"; shift; shift ;;
         --valac-flags ) VALAC_FLAGS="$2"; shift; shift ;;
         --lib-suffix ) LIB_SUFFIX="$2"; shift; shift ;;
+        --with-libsignal-in-tree ) BUILD_LIBSIGNAL_IN_TREE=yes; shift ;;
         --disable-fast-vapi ) DISABLE_FAST_VAPI=yes; shift ;;
         --no-debug ) NO_DEBUG=yes; shift ;;
         --fetch-only ) FETCH_ONLY=yes; shift ;;
@@ -141,44 +145,46 @@ while true; do
     esac
 done
 
-if [ -d ".git" ]; then
-    git submodule update --init 2>/dev/null
-else
-    tmp=0
-    for i in $(cat .gitmodules | grep -n submodule | awk -F ':' '{print $1}') $(wc -l .gitmodules | awk '{print $1}'); do
-        if ! [ $tmp -eq 0 ]; then
-            name=$(cat .gitmodules | head -n $tmp | tail -n 1 | awk -F '"' '{print $2}')
-            def=$(cat .gitmodules | head -n $i | tail -n $(expr "$i" - "$tmp") | awk -F ' ' '{print $1 $2 $3}')
-            path=$(echo "$def" | grep '^path=' | awk -F '=' '{print $2}')
-            url=$(echo "$def" | grep '^url=' | awk -F '=' '{print $2}')
-            branch=$(echo "$def" | grep '^branch=' | awk -F '=' '{print $2}')
+if [ "$BUILD_LIBSIGNAL_IN_TREE" = "yes" ] || [ "$FETCH_ONLY" = "yes" ]; then
+    if [ -d ".git" ]; then
+        git submodule update --init 2>/dev/null
+    else
+        tmp=0
+        for i in $(cat .gitmodules | grep -n submodule | awk -F ':' '{print $1}') $(wc -l .gitmodules | awk '{print $1}'); do
+            if ! [ $tmp -eq 0 ]; then
+                name=$(cat .gitmodules | head -n $tmp | tail -n 1 | awk -F '"' '{print $2}')
+                def=$(cat .gitmodules | head -n $i | tail -n $(expr "$i" - "$tmp") | awk -F ' ' '{print $1 $2 $3}')
+                path=$(echo "$def" | grep '^path=' | awk -F '=' '{print $2}')
+                url=$(echo "$def" | grep '^url=' | awk -F '=' '{print $2}')
+                branch=$(echo "$def" | grep '^branch=' | awk -F '=' '{print $2}')
 
-            if ! ls "$path"/* >/dev/null 2>/dev/null; then
-                git=$(which git)
-                if ! [ $? -eq 0 ] || ! [ -x $git ]; then
-                    echo "Failed retrieving missing files"
-                    exit 5
-                fi
-                res=$(git clone "$url" "$path" 2>&1)
-                if ! [ $? -eq 0 ] || ! [ -d $path ]; then
-                    echo "Failed retrieving missing files: $res"
-                    exit 5
-                fi
-                if [ -n "$branch" ]; then
-                    olddir="$(pwd)"
-                    cd "$path"
-                    res=$(git checkout "$branch" 2>&1)
-                    if ! [ $? -eq 0 ]; then
+                if ! ls "$path"/* >/dev/null 2>/dev/null; then
+                    git=$(which git)
+                    if ! [ $? -eq 0 ] || ! [ -x $git ]; then
+                        echo "Failed retrieving missing files"
+                        exit 5
+                    fi
+                    res=$(git clone "$url" "$path" 2>&1)
+                    if ! [ $? -eq 0 ] || ! [ -d $path ]; then
                         echo "Failed retrieving missing files: $res"
                         exit 5
                     fi
-                    cd "$olddir"
+                    if [ -n "$branch" ]; then
+                        olddir="$(pwd)"
+                        cd "$path"
+                        res=$(git checkout "$branch" 2>&1)
+                        if ! [ $? -eq 0 ]; then
+                            echo "Failed retrieving missing files: $res"
+                            exit 5
+                        fi
+                        cd "$olddir"
+                    fi
+                    echo "Submodule path '$path': checked out '$branch' (via git clone)"
                 fi
-                echo "Submodule path '$path': checked out '$branch' (via git clone)"
             fi
-        fi
-        tmp=$i
-    done
+            tmp=$i
+        done
+    fi
 fi
 
 if [ "$FETCH_ONLY" = "yes" ]; then exit 0; fi
@@ -256,6 +262,7 @@ cmake -G "$cmake_type" \
     -DENABLED_PLUGINS="$ENABLED_PLUGINS" \
     -DDISABLED_PLUGINS="$DISABLED_PLUGINS" \
     -DBUILD_TESTS="$BUILD_TESTS" \
+    -DBUILD_LIBSIGNAL_IN_TREE="$BUILD_LIBSIGNAL_IN_TREE" \
     -DVALA_EXECUTABLE="$VALAC" \
     -DCMAKE_VALA_FLAGS="$VALACFLAGS" \
     -DDISABLE_FAST_VAPI="$DISABLE_FAST_VAPI" \

plugins/signal-protocol/CMakeLists.txt

@@ -28,8 +28,11 @@ GENERATE_HEADER
 set(C_HEADERS_SRC "")
 set(C_HEADERS_TARGET "")
 
-if((SHARED_SIGNAL_PROTOCOL) OR ($ENV{SHARED_SIGNAL_PROTOCOL}))
-    find_package(SignalProtocol REQUIRED)
+if(NOT BUILD_LIBSIGNAL_IN_TREE)
+    # libsignal-protocol-c has a history of breaking compatibility on the patch level
+    # we'll have to check compatibility for every new release
+    # distro maintainers may update this dependency after compatibility tests
+    find_package(SignalProtocol 2.3.2 EXACT REQUIRED)
 else()
     add_subdirectory(libsignal-protocol-c EXCLUDE_FROM_ALL)
     set_property(TARGET curve25519 PROPERTY POSITION_INDEPENDENT_CODE ON)
@@ -129,4 +132,4 @@ if(BUILD_TESTS)
     add_executable(signal-protocol-vala-test ${SIGNAL_TEST_VALA_C})
     add_dependencies(signal-protocol-vala-test signal-protocol-vala)
     target_link_libraries(signal-protocol-vala-test signal-protocol-vala ${SIGNAL_PROTOCOL_PACKAGES})
-endif(BUILD_TESTS)
+endif(BUILD_TESTS)