cmake: tidy-ups

- tidy-up comments.
- use lowercase, underscore prefixed names for internal variables.
- use `IN LISTS` and `IN ITEMS` in `foreach()` loops.
- rename variable name `OUTPUT` to a more distinctive one.
- tidy-up `STREQUAL` syntax.
- delete commented code.
- indent/whitespace.

Closes #14197

src/CMakeLists.txt

@@ -48,9 +48,9 @@ else()
     DEPENDS
       "${CMAKE_CURRENT_SOURCE_DIR}/tool_hugehelp.h"
     VERBATIM)
-
 endif()
 
+# Get 'CURL_CFILES', 'CURLX_CFILES', 'CURL_HFILES', 'CURLTOOL_LIBCURL_CFILES' variables
 transform_makefile_inc("Makefile.inc" "${CMAKE_CURRENT_BINARY_DIR}/Makefile.inc.cmake")
 include(${CMAKE_CURRENT_BINARY_DIR}/Makefile.inc.cmake)
 
@@ -74,8 +74,6 @@ if(WIN32)
   list(APPEND CURL_CFILES curl.rc)
 endif()
 
-# CURL_CFILES, CURLX_CFILES, CURL_HFILES, CURLTOOL_LIBCURL_CFILES
-# come from Makefile.inc
 if(BUILD_STATIC_CURL)
   set(CURLX_CFILES ${CURLTOOL_LIBCURL_CFILES})
 endif()
@@ -89,12 +87,12 @@ endif()
 add_executable(
   ${EXE_NAME}
   ${CURL_CFILES} ${CURLX_CFILES} ${CURL_HFILES}
-  )
+)
 
 add_executable(
   ${PROJECT_NAME}::${EXE_NAME}
   ALIAS ${EXE_NAME}
-  )
+)
 
 add_library(
   curltool  # special libcurltool library just for unittests
@@ -125,21 +123,15 @@ include_directories(
   ${CURL_BINARY_DIR}/include  # for "curl/curl.h"
   # This is needed as tool_hugehelp.c is generated in the binary dir
   ${CURL_SOURCE_DIR}/src      # for "tool_hugehelp.h"
-  )
+)
 
 # Build curl executable
 target_link_libraries(${EXE_NAME} ${LIB_SELECTED_FOR_EXE} ${CURL_LIBS})
 
 ################################################################################
 
-#set_target_properties(${EXE_NAME} ARCHIVE_OUTPUT_DIRECTORY "blah blah blah")
-#set_target_properties(${EXE_NAME} RUNTIME_OUTPUT_DIRECTORY "blah blah blah")
-#set_target_properties(${EXE_NAME} LIBRARY_OUTPUT_DIRECTORY "blah blah blah")
-
-#include(ModuleInstall OPTIONAL)
-
 install(TARGETS ${EXE_NAME} EXPORT ${TARGETS_EXPORT_NAME} DESTINATION ${CMAKE_INSTALL_BINDIR})
 export(TARGETS ${EXE_NAME}
-       FILE ${PROJECT_BINARY_DIR}/curl-target.cmake
-       NAMESPACE ${PROJECT_NAME}::
+  FILE ${PROJECT_BINARY_DIR}/curl-target.cmake
+  NAMESPACE ${PROJECT_NAME}::
 )