build: Better cmake verbose behavior (#4037)

When we bumped to cmake 3.15 minimum for 2.5, we changed lots of
constructs like this:

    if (VERBOSE)
        message (STATUS "blah")
    endif ()

to this:

    message (VERBOSE "blah")

but I didn't realize that this was not enough, and to do it right
requires CMAKE_MESSAGE_LOG_LEVEL. So even when VERBOSE=ON, we weren't
actually getting all the verbose messages. Here, we fix it.

Also, when verbose, print the list of C++ compile features that cmake
discovers.

Signed-off-by: Larry Gritz <[email protected]>

CMakeLists.txt

@@ -92,6 +92,11 @@ endif ()
 
 
 option (VERBOSE "Print lots of messages while compiling" OFF)
+if (VERBOSE)
+    set (CMAKE_MESSAGE_LOG_LEVEL "VERBOSE" CACHE STRING "CMake log level to display")
+else ()
+    set (CMAKE_MESSAGE_LOG_LEVEL "STATUS" CACHE STRING "CMake log level to display")
+endif ()
 option (${PROJ_NAME}_BUILD_TOOLS "Build the command-line tools" ON)
 option (${PROJ_NAME}_BUILD_TESTS "Build the unit tests" ON)
 set (OIIO_LIBNAME_SUFFIX "" CACHE STRING

Makefile

@@ -45,7 +45,7 @@ INSTALL_PREFIX ?= ${working_dir}/${dist_dir}
 VERBOSE ?= ${SHOWCOMMANDS}
 ifneq (${VERBOSE},)
 MY_MAKE_FLAGS += VERBOSE=${VERBOSE}
-MY_CMAKE_FLAGS += -DVERBOSE:BOOL=${VERBOSE}
+MY_CMAKE_FLAGS += -DVERBOSE:BOOL=${VERBOSE} --log-level=VERBOSE
 ifneq (${VERBOSE},0)
 	MY_NINJA_FLAGS += -v
 	TEST_FLAGS += -V

src/cmake/compiler.cmake

@@ -20,6 +20,7 @@ message (VERBOSE "CMAKE_SYSTEM_VERSION   = ${CMAKE_SYSTEM_VERSION}")
 message (VERBOSE "CMAKE_SYSTEM_PROCESSOR = ${CMAKE_SYSTEM_PROCESSOR}")
 message (STATUS  "CMAKE_CXX_COMPILER     = ${CMAKE_CXX_COMPILER}")
 message (STATUS  "CMAKE_CXX_COMPILER_ID  = ${CMAKE_CXX_COMPILER_ID}")
+message (VERBOSE "CMAKE_CXX_COMPILE_FEATURES = ${CMAKE_CXX_COMPILE_FEATURES}")
 
 
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