CMake: Updates

Issue #294: "apple silicon build problem(s?)": If the "--flavor/-f" flag
is not specified on the command line, then complain loudly, print help
and exit. The script used to default to "Unix Makefiles".

Updates:

- Add missing "-DHAVE_LIBPNG" compiler command line define when the PNG
  library is detected/present for screen capture support.

- Add "clang64" to the list of MinGW64 platforms for which the
  .travis/deps.sh script can install build dependencies.

- Add PThread4W_FOUND to the condition that sets async I/O for Win32
  when using vcpkg for build dependencies.

CMake 3.28.1 INTERFACE_LINK_LIBRARIES behavior change: The file name
must now be an absolute path. Relative paths no longer accepted.
Internally, SIMH enforces this if CMAKE_VERSION >= 3.19, when REAL_PATH
was first implemented.

.travis/deps.sh

@@ -45,8 +45,22 @@ install_ucrt64() {
 	mingw-w64-ucrt-x86_64-libpcap
 }
 
+install_clang64() {
+    pacman -S --needed mingw-w64-clang-x86_64-ninja \
+	mingw-w64-clang-x86_64-cmake \
+	mingw-w64-clang-x86_64-extra-cmake-modules \
+        mingw-w64-clang-x86_64-clang \
+	mingw-w64-clang-x86_64-make \
+        mingw-w64-clang-x86_64-pcre \
+	mingw-w64-clang-x86_64-freetype \
+        mingw-w64-clang-x86_64-SDL2 \
+	mingw-w64-clang-x86_64-SDL2_ttf \
+	mingw-w64-clang-x86_64-libpcap
+}
+
+
 case "$1" in
-  osx|linux|mingw64|ucrt64)
+  osx|linux|mingw64|ucrt64|clang64)
     install_"$1"
     ;;
   *)

cmake/cmake-builder.sh

@@ -7,10 +7,6 @@ showHelp()
     cat <<EOF
 Configure and build simh simulators on Linux and *nix-like platforms.
 
-Subdirectories:
-cmake/build-unix:  Makefile-based build simulators
-cmake/build-ninja: Ninja build-based simulators
-
 Options:
 --------
 --clean (-x)      Remove the build subdirectory
@@ -23,7 +19,7 @@ Options:
 --testonly        Do not build, execute the 'ctest' test cases
 --installonly     Do not build, install the SIMH simulators
 
---flavor (-f)     Specifies the build flavor. Valid flavors are:
+--flavor (-f)     [Required] Specifies the build flavor. Valid flavors are:
                     unix
                     ninja
                     xcode
@@ -57,8 +53,8 @@ generateArgs=
 buildArgs=
 buildPostArgs=""
 buildClean=
-buildFlavor="Unix Makefiles"
-buildSubdir=build-unix
+buildFlavor=
+buildSubdir=
 buildConfig=Release
 testArgs=
 notest=no
@@ -276,6 +272,14 @@ while true; do
     esac
 done
 
+# Sanity check: buildSubdir should be set, unless the '-f' flag wasn't present.
+if [ "x${buildSubdir}" = x ]; then
+  echo ""
+  echo "${scriptName}: Build flavor is NOT SET -- see the \"--flavor\"/\"-f\" flag in the help."
+  echo ""
+  showHelp
+fi
+
 ## Determine the SIMH top-level source directory:
 simhTopDir=$(${dirname} $(${realpath} $0))
 while [ "x${simhTopDir}" != x -a ! -f "${simhTopDir}/CMakeLists.txt" ]; do
@@ -296,6 +300,7 @@ if [[ x"$buildClean" != x ]]; then
     echo "${scriptName}: Cleaning ${buildSubdir}"
     rm -rf ${buildSubdir}
 fi
+
 if [[ ! -d ${buildSubdir} ]]; then
     mkdir ${buildSubdir}
 fi

cmake/dep-link.cmake

@@ -21,6 +21,10 @@ get_target_property(_aliased ${_targ} ALIASED_TARGET)
         get_property(orig_libs TARGET ${_targ} PROPERTY INTERFACE_LINK_LIBRARIES)
         foreach(each_lib IN LISTS ${_lib})
             string(STRIP ${each_lib} stripped_lib)
+            file(TO_CMAKE_PATH "${stripped_lib}" stripped_lib)
+            if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.19")
+              file(REAL_PATH "${stripped_lib}" stripped_lib)
+            endif ()
             list(APPEND fixed_libs ${stripped_lib})
             message("** \"${each_lib}\" -> \"${stripped_lib}\"")
         endforeach ()
@@ -34,6 +38,10 @@ function (fix_libraries _lib)
     set(fixed_libs)
     foreach(each_lib IN LISTS ${_lib})
         string(STRIP ${each_lib} stripped_lib)
+        file(TO_CMAKE_PATH "${stripped_lib}" stripped_lib)
+        if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.19")
+          file(REAL_PATH "${stripped_lib}" stripped_lib)
+        endif ()
         list(APPEND fixed_libs ${stripped_lib})
     endforeach ()
     set(${_lib} ${fixed_libs} PARENT_SCOPE)
@@ -48,6 +56,11 @@ IF (WITH_VIDEO)
     foreach (lname ${FREETYPE_LIBRARIES} ${FREETYPE_LIBRARY} ${HARFBUZZ_LIBRARIES} ${HARFBUZZ_LIBRARY})
         get_filename_component(dirname "${lname}" DIRECTORY)
         if (dirname)
+            string(STRIP ${dirname} dirname)
+            file(TO_CMAKE_PATH "${dirname}" dirname)
+            if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.19")
+              file(REAL_PATH "${dirname}" dirname)
+            endif ()
             list(APPEND ldirs ${dirname})
         endif()
     endforeach ()
@@ -128,6 +141,8 @@ IF (WITH_VIDEO)
     ENDIF ()
 
     IF (PNG_FOUND)
+        target_compile_definitions(simh_video INTERFACE HAVE_LIBPNG)
+
         if (TARGET PNG::PNG)
             target_link_libraries(simh_video INTERFACE PNG::PNG)
             list(APPEND VIDEO_PKG_STATUS "interface PNG")

cmake/pthreads-dep.cmake

@@ -64,7 +64,7 @@ if (WITH_ASYNC)
         set(THREADING_PKG_STATUS "Platform-detected threading support")
     endif ()
 
-    if (THREADS_FOUND OR PTW_FOUND)
+    if (THREADS_FOUND OR PTW_FOUND OR PThreads4W_FOUND)
         target_compile_definitions(thread_lib INTERFACE USE_READER_THREAD SIM_ASYNCH_IO)
     else ()
         target_compile_definitions(thread_lib INTERFACE DONT_USE_READER_THREAD)