Remove libappimage git submodule

The submodule is replaced with CMake FetchContent commands, which fetch the source at configure time (We need to include scripts.cmake from libappimage. ExternalProject_Add only downloads at build time).

Also update libappimage version to latest (otherwise the build fails on g++11) and patch in AppImageCommunity/libappimage#160 (to allow using latest libappimage in AppImageKit.

Also update squashfs-tools version to latest release (otherwise the build fails on g++11)

Also related to #1165

Author: lalten

.gitmodules

@@ -1,6 +1,3 @@
 [submodule "cmake/sanitizers-cmake"]
 	path = cmake/sanitizers-cmake
 	url = https://github.com/arsenm/sanitizers-cmake
-[submodule "lib/libappimage"]
-	path = lib/libappimage
-	url = https://github.com/AppImage/libappimage.git

CMakeLists.txt

@@ -64,11 +64,6 @@ set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 ##########################
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${PROJECT_SOURCE_DIR}/cmake)
-
-# configure dependencies
-add_subdirectory(lib)
-
-include(lib/libappimage/cmake/tools.cmake)
 include(cmake/dependencies.cmake)
 
 

cmake/dependencies.cmake

@@ -1,8 +1,26 @@
-# >= 3.2 required for ExternalProject_Add_StepDependencies
-cmake_minimum_required(VERSION 3.2)
-
-
-include(${PROJECT_SOURCE_DIR}/lib/libappimage/cmake/scripts.cmake)
+# >= 3.11 required for FetchContent
+cmake_minimum_required(VERSION 3.11)
+
+include(FetchContent)
+
+# Need this patch until https://github.com/AppImage/libappimage/pull/160 is resolved
+FetchContent_Declare(libappimage_patch
+    URL https://github.com/AppImage/libappimage/commit/b3398bb496e47947864b4b8bc2999c8427f86a9a.patch
+    DOWNLOAD_NO_EXTRACT TRUE
+)
+FetchContent_MakeAvailable(libappimage_patch)
+
+FetchContent_Declare(libappimage
+    # We can not use a URL source with a github-generated source archive: libappimage's gtest submodule would be missing
+    GIT_REPOSITORY https://github.com/AppImage/libappimage
+    GIT_TAG 1d4d57622de2c7d39f7cc6c4980144c713cc59ca  # latest as of 2022-04-03
+    # The patch command has || true to prevent the build from failing if the patch has already been applied
+    PATCH_COMMAND patch -p 1 < ${libappimage_patch_SOURCE_DIR}/b3398bb496e47947864b4b8bc2999c8427f86a9a.patch || true
+)
+FetchContent_MakeAvailable(libappimage)
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${libappimage_SOURCE_DIR}/cmake)
+include(${libappimage_SOURCE_DIR}/cmake/scripts.cmake)
+include(${libappimage_SOURCE_DIR}/cmake/tools.cmake)
 
 
 # the names of the targets need to differ from the library filenames
@@ -53,9 +71,10 @@ if(NOT USE_SYSTEM_MKSQUASHFS)
 
     ExternalProject_Add(mksquashfs
         GIT_REPOSITORY https://github.com/plougher/squashfs-tools/
-        GIT_TAG 4.4
+        GIT_TAG 4.5.1
         UPDATE_COMMAND ""  # Make sure CMake won't try to fetch updates unnecessarily and hence rebuild the dependency every time
         CONFIGURE_COMMAND ${SED} -i "s|CFLAGS += -DXZ_SUPPORT|CFLAGS += ${mksquashfs_cflags}|g" <SOURCE_DIR>/squashfs-tools/Makefile
+        COMMAND ${SED} -i "/INSTALL_MANPAGES_DIR/d" <SOURCE_DIR>/squashfs-tools/Makefile
         COMMAND ${SED} -i "s|LIBS += -llzma|LIBS += -Bstatic ${mksquashfs_ldflags}|g" <SOURCE_DIR>/squashfs-tools/Makefile
         COMMAND ${SED} -i "s|install: mksquashfs unsquashfs|install: mksquashfs|g" squashfs-tools/Makefile
         COMMAND ${SED} -i "/cp unsquashfs/d" squashfs-tools/Makefile

lib/CMakeLists.txt

@@ -57,10 +57,6 @@ target_compile_definitions(appimagetool
     PRIVATE -DENABLE_BINRELOC
 )
 
-target_include_directories(appimagetool
-    PUBLIC $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include/>
-    INTERFACE $<INSTALL_INTERFACE:include/>
-)
 
 if(AUXILIARY_FILES_DESTINATION)
     message(STATUS "Installing auxiliary files in path: ${AUXILIARY_FILES_DESTINATION}")

lib/libappimage

@@ -45,8 +45,6 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 
-#include "binreloc.h"
-
 #include <libgen.h>
 
 #include <unistd.h>
@@ -56,7 +54,9 @@
 #include <gpgme.h>
 #include <assert.h>
 
-#include "appimage/appimage.h"
+#include <appimage/appimage_shared.h>
+
+#include "binreloc.h"
 #include "appimagetool_sign.h"
 
 #ifdef __linux__

src/CMakeLists.txt

@@ -27,8 +27,8 @@ set(runtime_cflags
     -DGIT_COMMIT=\\"${GIT_COMMIT}\\"
     -I${squashfuse_INCLUDE_DIRS}
     -I${PROJECT_SOURCE_DIR}/include
-    -I${PROJECT_SOURCE_DIR}/lib/libappimage/include
-    -I${PROJECT_SOURCE_DIR}/lib/libappimage/src/libappimage_hashlib/include
+    -I${libappimage_SOURCE_DIR}/include
+    -I${libappimage_SOURCE_DIR}/src/libappimage_hashlib/include
     ${DEPENDENCIES_CFLAGS}
 )
 # must not include -Wl,--gc-sections in the following flags, otherwise the data sections will be stripped out

src/appimagetool.c

@@ -12,8 +12,8 @@
 #include <fcntl.h>
 #include <sys/mman.h>
 
-#include "appimage/appimage.h"
-#include "appimage/appimage_shared.h"
+#include <appimage/appimage_shared.h>
+
 #include "light_elf.h"
 
 typedef unsigned char byte;