tidy-up: delete parallel/unused feature flags

Detecting headers and lib separately makes sense when headers come in
variations or with extra ones, but this wasn't the case here. These were
duplicate/parallel macros that we had to keep in sync with each other
for a working build. This patch leaves a single macro for each of these
dependencies:

- Rely on `HAVE_LIBZ`, delete parallel `HAVE_ZLIB_H`.

  Also delete CMake logic making sure these two were in sync, along with
  a toggle to turn off that logic, called `CURL_SPECIAL_LIBZ`.

  Also delete stray `HAVE_ZLIB` defines.

  There is also a `USE_ZLIB` variant in `lib/config-dos.h`. This patch
  retains it for compatibility and deprecates it.

- Rely on `USE_LIBSSH2`, delete parallel `HAVE_LIBSSH2_H`.

  Also delete `LIBSSH2_WIN32`, `LIBSSH2_LIBRARY` from
  `winbuild/MakefileBuild.vc`, these have a role when building libssh2
  itself. And `CURL_USE_LIBSSH`, which had no use at all.

  Also delete stray `HAVE_LIBSSH2` defines.

- Rely on `USE_LIBSSH`, delete parallel `HAVE_LIBSSH_LIBSSH_H`.

  Also delete `LIBSSH_WIN32`, `LIBSSH_LIBRARY` and `HAVE_LIBSSH` from
  `winbuild/MakefileBuild.vc`, these were the result of copy-pasting the
  libssh2 line, and were not having any use.

- Delete unused `HAVE_LIBPSL_H` and `HAVE_LIBPSL`.

Reviewed-by: Daniel Stenberg

Closes #9652

1 files changed, 1 insertions, 36 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7fa6569d8..4cb983750 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -678,11 +678,9 @@ if(WIN32)
 endif()
 
 set(HAVE_LIBZ OFF)
-set(HAVE_ZLIB_H OFF)
 set(USE_ZLIB OFF)
 optional_dependency(ZLIB)
 if(ZLIB_FOUND)
-  set(HAVE_ZLIB_H ON)
   set(HAVE_LIBZ ON)
   set(USE_ZLIB ON)
 
@@ -730,24 +728,14 @@ endif()
 option(CURL_USE_LIBPSL "Use libPSL" ON)
 mark_as_advanced(CURL_USE_LIBPSL)
 set(USE_LIBPSL OFF)
-set(HAVE_LIBPSL OFF)
-set(HAVE_LIBSPSL_H OFF)
 
 if(CURL_USE_LIBPSL)
   find_package(LibPSL)
   if(LIBPSL_FOUND)
     list(APPEND CURL_LIBS ${LIBPSL_LIBRARY})
-    set(CMAKE_REQUIRED_LIBRARIES ${LIBPSL_LIBRARY})
     list(APPEND CMAKE_REQUIRED_INCLUDES "${LIBPSL_INCLUDE_DIR}")
     include_directories("${LIBPSL_INCLUDE_DIR}")
-    set(HAVE_LIBPSL ON)
     set(USE_LIBPSL ON)
-
-    # find_package has already found the headers
-    set(HAVE_LIBPSL_H ON)
-    set(CURL_INCLUDES ${CURL_INCLUDES} "${LIBPSL_INCLUDE_DIR}/libpsl.h")
-    set(CURL_TEST_DEFINES "${CURL_TEST_DEFINES} -DHAVE_LIBPSL_H")
-    unset(CMAKE_REQUIRED_LIBRARIES)
   endif()
 endif()
 
@@ -755,38 +743,27 @@ endif()
 option(CURL_USE_LIBSSH2 "Use libSSH2" ON)
 mark_as_advanced(CURL_USE_LIBSSH2)
 set(USE_LIBSSH2 OFF)
-set(HAVE_LIBSSH2 OFF)
-set(HAVE_LIBSSH2_H OFF)
 
 if(CURL_USE_LIBSSH2)
   find_package(LibSSH2)
   if(LIBSSH2_FOUND)
     list(APPEND CURL_LIBS ${LIBSSH2_LIBRARY})
-    set(CMAKE_REQUIRED_LIBRARIES ${LIBSSH2_LIBRARY})
     list(APPEND CMAKE_REQUIRED_INCLUDES "${LIBSSH2_INCLUDE_DIR}")
     include_directories("${LIBSSH2_INCLUDE_DIR}")
-    set(HAVE_LIBSSH2 ON)
     set(USE_LIBSSH2 ON)
-
-    # find_package has already found the headers
-    set(HAVE_LIBSSH2_H ON)
-    set(CURL_INCLUDES ${CURL_INCLUDES} "${LIBSSH2_INCLUDE_DIR}/libssh2.h")
-    set(CURL_TEST_DEFINES "${CURL_TEST_DEFINES} -DHAVE_LIBSSH2_H")
-    unset(CMAKE_REQUIRED_LIBRARIES)
   endif()
 endif()
 
 # libssh
 option(CURL_USE_LIBSSH "Use libSSH" OFF)
 mark_as_advanced(CURL_USE_LIBSSH)
-if(NOT HAVE_LIBSSH2 AND CURL_USE_LIBSSH)
+if(NOT USE_LIBSSH2 AND CURL_USE_LIBSSH)
   find_package(libssh CONFIG)
   if(libssh_FOUND)
     message(STATUS "Found libssh ${libssh_VERSION}")
     # Use imported target for include and library paths.
     list(APPEND CURL_LIBS ssh)
     set(USE_LIBSSH ON)
-    set(HAVE_LIBSSH_LIBSSH_H 1)
   endif()
 endif()
 
@@ -1236,18 +1213,6 @@ if(NOT HAVE_IN_ADDR_T)
   set(in_addr_t "unsigned long")
 endif()
 
-# Fix libz / zlib.h
-
-if(NOT CURL_SPECIAL_LIBZ)
-  if(NOT HAVE_LIBZ)
-    set(HAVE_ZLIB_H 0)
-  endif()
-
-  if(NOT HAVE_ZLIB_H)
-    set(HAVE_LIBZ 0)
-  endif()
-endif()
-
 # Check for nonblocking
 set(HAVE_DISABLED_NONBLOCKING 1)
 if(HAVE_FIONBIO OR