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, 2 insertions, 3 deletions

diff --git a/CMake/Utilities.cmake b/CMake/Utilities.cmake
index 5cb1d4497..ffc411ae9 100644
--- a/CMake/Utilities.cmake
+++ b/CMake/Utilities.cmake
@@ -2,12 +2,11 @@
 
 # Returns a list of arguments that evaluate to true
 function(count_true output_count_var)
-  set(lst)
+  set(lst_len 0)
   foreach(option_var IN LISTS ARGN)
     if(${option_var})
-      list(APPEND lst ${option_var})
+      math(EXPR lst_len "${lst_len} + 1")
     endif()
   endforeach()
-  list(LENGTH lst lst_len)
   set(${output_count_var} ${lst_len} PARENT_SCOPE)
 endfunction()