cmake: avoid linking executable for some tests with cmake 3.6+

With CMAKE_TRY_COMPILE_TARGET_TYPE set to STATIC_LIBRARY, the try_compile()
(which is used by check_c_source_compiles()) will build static library
instead of executable. This avoids linking additional libraries in and thus
speeds up those checks a little.

This commit also avoids #3743 (GSSAPI build errors) on itself with cmake
3.6 or above. That issue was fixed separately for all versions.

Ref: #3744

1 files changed, 40 insertions, 35 deletions

diff --git a/CMake/OtherTests.cmake b/CMake/OtherTests.cmake
index c180a5888..c1c9aa32a 100644
--- a/CMake/OtherTests.cmake
+++ b/CMake/OtherTests.cmake
@@ -24,6 +24,8 @@ else()
   add_header_include(HAVE_SYS_SOCKET_H "sys/socket.h")
 endif()
 
+set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
+
 check_c_source_compiles("${_source_epilogue}
 int main(void) {
     recv(0, 0, 0, 0);
@@ -177,6 +179,44 @@ int main(void) {
   return 0;
 }" HAVE_STRUCT_TIMEVAL)
 
+set(HAVE_SIG_ATOMIC_T 1)
+set(CMAKE_REQUIRED_FLAGS)
+if(HAVE_SIGNAL_H)
+  set(CMAKE_REQUIRED_FLAGS "-DHAVE_SIGNAL_H")
+  set(CMAKE_EXTRA_INCLUDE_FILES "signal.h")
+endif()
+check_type_size("sig_atomic_t" SIZEOF_SIG_ATOMIC_T)
+if(HAVE_SIZEOF_SIG_ATOMIC_T)
+  check_c_source_compiles("
+    #ifdef HAVE_SIGNAL_H
+    #  include <signal.h>
+    #endif
+    int main(void) {
+      static volatile sig_atomic_t dummy = 0;
+      (void)dummy;
+      return 0;
+    }" HAVE_SIG_ATOMIC_T_NOT_VOLATILE)
+  if(NOT HAVE_SIG_ATOMIC_T_NOT_VOLATILE)
+    set(HAVE_SIG_ATOMIC_T_VOLATILE 1)
+  endif()
+endif()
+
+if(HAVE_WINDOWS_H)
+  set(CMAKE_EXTRA_INCLUDE_FILES winsock2.h)
+else()
+  set(CMAKE_EXTRA_INCLUDE_FILES)
+  if(HAVE_SYS_SOCKET_H)
+    set(CMAKE_EXTRA_INCLUDE_FILES sys/socket.h)
+  endif()
+endif()
+
+check_type_size("struct sockaddr_storage" SIZEOF_STRUCT_SOCKADDR_STORAGE)
+if(HAVE_SIZEOF_STRUCT_SOCKADDR_STORAGE)
+  set(HAVE_STRUCT_SOCKADDR_STORAGE 1)
+endif()
+
+unset(CMAKE_TRY_COMPILE_TARGET_TYPE)
+
 if(NOT DEFINED CMAKE_TOOLCHAIN_FILE)
   # if not cross-compilation...
   include(CheckCSourceRuns)
@@ -222,38 +262,3 @@ if(NOT DEFINED CMAKE_TOOLCHAIN_FILE)
     }" HAVE_POLL_FINE)
 endif()
 
-set(HAVE_SIG_ATOMIC_T 1)
-set(CMAKE_REQUIRED_FLAGS)
-if(HAVE_SIGNAL_H)
-  set(CMAKE_REQUIRED_FLAGS "-DHAVE_SIGNAL_H")
-  set(CMAKE_EXTRA_INCLUDE_FILES "signal.h")
-endif()
-check_type_size("sig_atomic_t" SIZEOF_SIG_ATOMIC_T)
-if(HAVE_SIZEOF_SIG_ATOMIC_T)
-  check_c_source_compiles("
-    #ifdef HAVE_SIGNAL_H
-    #  include <signal.h>
-    #endif
-    int main(void) {
-      static volatile sig_atomic_t dummy = 0;
-      (void)dummy;
-      return 0;
-    }" HAVE_SIG_ATOMIC_T_NOT_VOLATILE)
-  if(NOT HAVE_SIG_ATOMIC_T_NOT_VOLATILE)
-    set(HAVE_SIG_ATOMIC_T_VOLATILE 1)
-  endif()
-endif()
-
-if(HAVE_WINDOWS_H)
-  set(CMAKE_EXTRA_INCLUDE_FILES winsock2.h)
-else()
-  set(CMAKE_EXTRA_INCLUDE_FILES)
-  if(HAVE_SYS_SOCKET_H)
-    set(CMAKE_EXTRA_INCLUDE_FILES sys/socket.h)
-  endif()
-endif()
-
-check_type_size("struct sockaddr_storage" SIZEOF_STRUCT_SOCKADDR_STORAGE)
-if(HAVE_SIZEOF_STRUCT_SOCKADDR_STORAGE)
-  set(HAVE_STRUCT_SOCKADDR_STORAGE 1)
-endif()