add flag to specify demo

demos/README.md

@@ -208,6 +208,26 @@ For example:
 cmake -DCMAKE_BUILD_TYPE=Release -DENABLE_PYTHON=ON <open_model_zoo>/demos
 ```
 
+### <a name="build_specific_demos"></a>Build Specific Demos
+
+To build specific demos, follow the instructions for building the demo applications above,
+but add `--target <list of demos>` to the `cmake` or `--target="<list of demos>"` to the `build_demos*` command.
+Note,  CMake `--build` tool supports multiple targets starting with version 3.15. With lower versions you can specify only one target.
+For example:
+
+```sh
+cmake -DCMAKE_BUILD_TYPE=Release <open_model_zoo>/demos
+cmake --build . --config Release --target  <Demo_1> <Demo_2>
+```
+
+```sh
+build_demos.sh --target="classification_demo segmentation_demo"
+```
+
+```bat
+build_demos_msvc.bat --target="classification_demo segmentation_demo"
+```
+
 ## Get Ready for Running the Demo Applications
 
 ### Get Ready for Running the Demo Applications on Linux*

demos/build_demos.sh

@@ -26,12 +26,18 @@ error() {
 trap 'error ${LINENO}' ERR
 
 extra_cmake_opts=()
+extra_cmake_build_opts=()
 
 for opt in "$@"; do
     case "$opt" in
     -DENABLE_PYTHON=*)
         extra_cmake_opts+=("$opt")
         ;;
+    --target=*)
+        tmp="${opt%\"}"
+        tmp="${tmp#\"}"
+        extra_cmake_build_opts+=("${tmp//=/ }")
+        ;;
     *)
         printf "Unknown option: %q\n" "$opt"
         exit 1
@@ -82,6 +88,7 @@ fi
 mkdir -p "$build_dir"
 
 (cd "$build_dir" && cmake -DCMAKE_BUILD_TYPE=Release "${extra_cmake_opts[@]}" "$DEMOS_PATH")
-cmake --build "$build_dir" -- "$NUM_THREADS"
+c="cmake --build $build_dir ${extra_cmake_build_opts[@]} -- $NUM_THREADS"
+eval "$c"
 
-printf "\nBuild completed, you can find binaries for all demos in the %s subfolder.\n\n" "$build_dir/$OS_PATH/Release"
+printf "\nBuild completed, you can find binaries for demos in the %s subfolder.\n\n" "$build_dir/$OS_PATH/Release"

demos/build_demos_msvc.bat

@@ -34,6 +34,14 @@ if not "%1" == "" (
         shift & shift
         goto argParse
     )
+    rem to build more than one specific demo use quotation marks,
+    rem list the necessary demos separated by space,
+    rem ex. --target="classification_demo segmentation_demo"
+    if "%1" == "--target" (
+        set EXTRA_CMAKE_BUILD_OPTS=%EXTRA_CMAKE_BUILD_OPTS% %1 %~2
+        shift & shift
+        goto argParse
+    )
 
     if not "%VS_VERSION%" == "" (
         echo Unexpected argument: "%1"
@@ -122,8 +130,7 @@ cd "%SOLUTION_DIR64%" && cmake -G "Visual Studio !VS_VERSION!" -A %PLATFORM% %EX
 echo.
 echo ###############^|^| Build Open Model Zoo Demos using MS Visual Studio ^|^|###############
 echo.
-echo cmake --build . --config Release
-cmake --build . --config Release
+cmake --build . --config Release %EXTRA_CMAKE_BUILD_OPTS%
 if ERRORLEVEL 1 goto errorHandling
 
 echo Done.