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, 4 insertions, 22 deletions

diff --git a/CMake/FindCARES.cmake b/CMake/FindCARES.cmake
index 723044a64..3d1bae6dc 100644
--- a/CMake/FindCARES.cmake
+++ b/CMake/FindCARES.cmake
@@ -7,34 +7,16 @@
 # also defined, but not for general use are
 # CARES_LIBRARY, where to find the c-ares library.
 
-find_path(CARES_INCLUDE_DIR ares.h
-  /usr/local/include
-  /usr/include
-  )
+find_path(CARES_INCLUDE_DIR ares.h)
 
 set(CARES_NAMES ${CARES_NAMES} cares)
 find_library(CARES_LIBRARY
   NAMES ${CARES_NAMES}
-  PATHS /usr/lib /usr/local/lib
   )
 
-if(CARES_LIBRARY AND CARES_INCLUDE_DIR)
-  set(CARES_LIBRARIES ${CARES_LIBRARY})
-  set(CARES_FOUND "YES")
-else()
-  set(CARES_FOUND "NO")
-endif()
-
-
-if(CARES_FOUND)
-  if(NOT CARES_FIND_QUIETLY)
-    message(STATUS "Found c-ares: ${CARES_LIBRARIES}")
-  endif()
-else()
-  if(CARES_FIND_REQUIRED)
-    message(FATAL_ERROR "Could not find c-ares library")
-  endif()
-endif()
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(CARES
+    REQUIRED_VARS CARES_LIBRARY CARES_INCLUDE_DIR)
 
 mark_as_advanced(
   CARES_LIBRARY