CMake: Set at most one SSL library
Ref: https://github.com/curl/curl/pull/1228
diff --git a/CMake/Utilities.cmake b/CMake/Utilities.cmake
index 37cdfe3..8b6276d 100644
--- a/CMake/Utilities.cmake
+++ b/CMake/Utilities.cmake
@@ -29,3 +29,16 @@
set(${RETVAL} TRUE PARENT_SCOPE)
endif()
endfunction()
+
+# Returns a list of arguments that evaluate to true
+function(collect_true output_var output_count_var)
+ set(${output_var})
+ foreach(option_var IN LISTS ARGN)
+ if(${option_var})
+ list(APPEND ${output_var} ${option_var})
+ endif()
+ endforeach()
+ set(${output_var} ${${output_var}} PARENT_SCOPE)
+ list(LENGTH ${output_var} ${output_count_var})
+ set(${output_count_var} ${${output_count_var}} PARENT_SCOPE)
+endfunction()
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e548d81..8390c38 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -308,12 +308,22 @@
option(CMAKE_USE_MBEDTLS "Enable mbedTLS for SSL/TLS" OFF)
set(openssl_default ON)
-if(WIN32)
- set(openssl_default OFF)
+if(WIN32 OR CMAKE_USE_DARWINSSL OR CMAKE_USE_WINSSL OR CMAKE_USE_MBEDTLS)
+ set(openssl_default OFF)
endif()
option(CMAKE_USE_OPENSSL "Use OpenSSL code. Experimental" ${openssl_default})
-if(CMAKE_USE_WINSSL AND NOT SSL_ENABLED)
+collect_true(enabled_ssl_options enabled_ssl_options_count
+ CMAKE_USE_WINSSL
+ CMAKE_USE_DARWINSSL
+ CMAKE_USE_OPENSSL
+ CMAKE_USE_MBEDTLS
+)
+if(enabled_ssl_options_count GREATER 1)
+ message(FATAL_ERROR "Multiple SSL options specified: ${enabled_ssl_options}. Please pick at most one and disable the rest.")
+endif()
+
+if(CMAKE_USE_WINSSL)
set(SSL_ENABLED ON)
set(USE_SCHANNEL ON) # Windows native SSL/TLS support
set(USE_WINDOWS_SSPI ON) # CMAKE_USE_WINSSL implies CURL_WINDOWS_SSPI
@@ -324,7 +334,7 @@
set(CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS} -DSECURITY_WIN32")
endif()
-if(CMAKE_USE_DARWINSSL AND NOT SSL_ENABLED)
+if(CMAKE_USE_DARWINSSL)
find_library(COREFOUNDATION_FRAMEWORK "CoreFoundation")
if(NOT COREFOUNDATION_FRAMEWORK)
message(FATAL_ERROR "CoreFoundation framework not found")
@@ -340,7 +350,7 @@
list(APPEND CURL_LIBS "${COREFOUNDATION_FRAMEWORK}" "${SECURITY_FRAMEWORK}")
endif()
-if(CMAKE_USE_OPENSSL AND NOT SSL_ENABLED)
+if(CMAKE_USE_OPENSSL)
find_package(OpenSSL REQUIRED)
set(SSL_ENABLED ON)
set(USE_OPENSSL ON)
@@ -363,7 +373,7 @@
check_symbol_exists(RAND_egd "${CURL_INCLUDES}" HAVE_RAND_EGD)
endif()
-if(CMAKE_USE_MBEDTLS AND NOT SSL_ENABLED)
+if(CMAKE_USE_MBEDTLS)
find_package(MbedTLS REQUIRED)
set(SSL_ENABLED ON)
set(USE_MBEDTLS ON)
diff --git a/docs/INSTALL.cmake b/docs/INSTALL.cmake
index b2924e6..9c5c2d9 100644
--- a/docs/INSTALL.cmake
+++ b/docs/INSTALL.cmake
@@ -24,7 +24,8 @@
Missing features in the cmake build:
- Builds libcurl without large file support
- - Can't select which SSL library to build with, only OpenSSL
+ - Does not support all SSL libraries (only OpenSSL, WinSSL, DarwinSSL, and
+ mbed TLS)
- Doesn't build with SCP and SFTP support (libssh2)
- Doesn't allow different resolver backends (no c-ares build support)
- No RTMP support built
