CMake: clean up and improve build procedures

- remove check for unsupported old CMake versions

- do not link to c-ares library twice

- modernize custom Find modules

    - FindLibSSH2:
        - pass version to FPHSA to show it in the output
        - use LIBSSH2_VERSION define to extract the version number in
          one shot. This variable exists in the header for 10 years.
        - remove unneeded code

    - FindNGHTTP2.cmake:
        - drop needless FPHSA argument
        - mark found variables as advanced

    - FindNSS.cmake:
        - show version number

    - FindCARES.cmake:
        - drop default paths
        - use FPHSA instead of checking things by hand

- remove needless explict variable dereference

- simplify count_true()

- allow all policies up to version 3.16 to be set to NEW

- do not rerun check for -Wstrict-aliasing=3 every time

In contrast to every other compiler flag this has a = in it, which CMake
can't have in a variable name.

- only read the interesting strings from curlver.h

Reviewed-by: Peter Wu

Closes https://github.com/curl/curl/pull/4975

1 files changed, 3 insertions, 1 deletions

diff --git a/CMake/FindNSS.cmake b/CMake/FindNSS.cmake
index 277c7dfb2..0043ce853 100644
--- a/CMake/FindNSS.cmake
+++ b/CMake/FindNSS.cmake
@@ -10,6 +10,8 @@ set(NSS_LIBRARIES ${PC_NSS_LINK_LIBRARIES})
 set(NSS_INCLUDE_DIRS ${PC_NSS_INCLUDE_DIRS})
 
 include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(NSS DEFAULT_MSG NSS_INCLUDE_DIRS NSS_LIBRARIES)
+find_package_handle_standard_args(NSS
+    REQUIRED_VARS NSS_LIBRARIES NSS_INCLUDE_DIRS
+    VERSION_VAR PC_NSS_VERSION)
 
 mark_as_advanced(NSS_INCLUDE_DIRS NSS_LIBRARIES)