Revamp CURL integration. Exclude it from APPLE

CMakeLists.txt

@@ -43,6 +43,14 @@ set(SLIC3R_GTK "2" CACHE STRING "GTK version to use with wxWidgets on Linux")
 
 set(IS_CROSS_COMPILE FALSE)
 
+if (SLIC3R_STATIC)
+    # Prefer config scripts over find modules. This is helpful when building with
+    # the static dependencies. Many libraries have their own export scripts
+    # while having a Find<PkgName> module in standard cmake installation.
+    # (e.g. CURL)
+    set(CMAKE_FIND_PACKAGE_PREFER_CONFIG ON)
+endif ()
+
 if (APPLE)
     set(CMAKE_FIND_FRAMEWORK LAST)
     set(CMAKE_FIND_APPBUNDLE LAST)
@@ -438,23 +446,6 @@ else()
     target_link_libraries(libcurl INTERFACE crypt32)
 endif()
 
-if (SLIC3R_STATIC AND NOT SLIC3R_STATIC_EXCLUDE_CURL)
-    if (NOT APPLE)
-        # libcurl is always linked dynamically to the system libcurl on OSX.
-        # On other systems, libcurl is linked statically if SLIC3R_STATIC is set.
-        target_compile_definitions(libcurl INTERFACE CURL_STATICLIB)
-    endif()
-    if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
-        # As of now, our build system produces a statically linked libcurl,
-        # which links the OpenSSL library dynamically.
-        find_package(OpenSSL REQUIRED)
-        message("OpenSSL include dir: ${OPENSSL_INCLUDE_DIR}")
-        message("OpenSSL libraries: ${OPENSSL_LIBRARIES}")
-        target_include_directories(libcurl INTERFACE ${OPENSSL_INCLUDE_DIR})
-        target_link_libraries(libcurl INTERFACE ${OPENSSL_LIBRARIES})
-    endif()
-endif()
-
 ## OPTIONAL packages
 
 # Find eigen3 or use bundled version
@@ -472,6 +463,10 @@ include_directories(BEFORE SYSTEM ${EIGEN3_INCLUDE_DIR})
 
 find_package(EXPAT REQUIRED)
 
+if (NOT TARGET EXPAT::EXPAT AND TARGET expat::expat)
+    add_library(EXPAT::EXPAT ALIAS expat::expat)
+endif ()
+
 find_package(PNG REQUIRED)
 
 set(OpenGL_GL_PREFERENCE "LEGACY")

deps/CMakeLists.txt

@@ -179,7 +179,12 @@ include(CGAL/CGAL.cmake)
 include(NLopt/NLopt.cmake)
 
 include(OpenSSL/OpenSSL.cmake)
+
+set(CURL_PKG "")
+if (NOT CURL_FOUND) 
     include(CURL/CURL.cmake)
+    set(CURL_PKG dep_CURL)
+endif ()
 
 include(JPEG/JPEG.cmake)
 include(TIFF/TIFF.cmake)
@@ -188,7 +193,7 @@ include(wxWidgets/wxWidgets.cmake)
 set(_dep_list
     dep_Boost
     dep_TBB
-    dep_CURL
+    ${CURL_PKG}
     dep_wxWidgets
     dep_Cereal
     dep_NLopt

deps/CURL/CURL.cmake

@@ -48,10 +48,12 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
   )
 endif ()
 
-if (BUILD_SHARED_LIBS)
+set(_patch_command "")
-  set(_curl_static OFF)
+if (UNIX AND NOT APPLE)
-else()
+  # On non-apple UNIX platforms, finding the location of OpenSSL certificates is necessary at runtime, as there is no standard location usable across platforms.
-  set(_curl_static ON)
+  # The OPENSSL_CERT_OVERRIDE flag is understood by PrusaSlicer and will trigger the search of certificates at initial application launch. 
+  # Then ask the user for consent about the correctness of the found location.
+  set (_patch_command echo set_target_properties(CURL::libcurl PROPERTIES INTERFACE_COMPILE_DEFINITIONS OPENSSL_CERT_OVERRIDE) >> CMake/curl-config.cmake.in)
 endif ()
 
 prusaslicer_add_cmake_project(CURL
@@ -62,10 +64,10 @@ prusaslicer_add_cmake_project(CURL
   DEPENDS             ${ZLIB_PKG}
   # PATCH_COMMAND       ${GIT_EXECUTABLE} checkout -f -- . && git clean -df && 
   #                     ${GIT_EXECUTABLE} apply --whitespace=fix ${CMAKE_CURRENT_LIST_DIR}/curl-mods.patch
+  PATCH_COMMAND       "${_patch_command}"
   CMAKE_ARGS
     -DBUILD_TESTING:BOOL=OFF
     -DCMAKE_POSITION_INDEPENDENT_CODE=ON
-    -DCURL_STATICLIB=${_curl_static}
     ${_curl_platform_flags}
 )
 

deps/deps-macos.cmake

@@ -15,6 +15,11 @@ set(DEP_CMAKE_OPTS
 
 include("deps-unix-common.cmake")
 
+find_package(CURL QUIET)
+if (NOT CURL_FOUND)
+    message(WARNING "No CURL dev package found in system, building static library. Mac SDK should include CURL from at least version 10.12. Check your SDK installation.")
+endif ()
+
 
 # ExternalProject_Add(dep_boost
 #     EXCLUDE_FROM_ALL 1

src/slic3r/CMakeLists.txt

@@ -288,10 +288,6 @@ if (SLIC3R_STATIC)
     target_compile_definitions(libslic3r_gui PUBLIC -DwxDEBUG_LEVEL=0)
 endif()
 
-if (SLIC3R_STATIC AND NOT SLIC3R_STATIC_EXCLUDE_CURL AND UNIX AND NOT APPLE)
-    target_compile_definitions(libslic3r_gui PRIVATE OPENSSL_CERT_OVERRIDE)
-endif ()
-
 if (SLIC3R_PCH AND NOT SLIC3R_SYNTAXONLY)
     add_precompiled_header(libslic3r_gui pchheader.hpp FORCEINCLUDE)
 endif ()