Vector AP StartApplication编译脚本解析

```shell
#!/bin/bash
#######################################################################################################################
#  COPYRIGHT
#  -------------------------------------------------------------------------------------------------------------------
#  \verbatim
#  Copyright (c) 2023 by Vector Informatik GmbH. All rights reserved.
#
#                This software is copyright protected and proprietary to Vector Informatik GmbH.
#                Vector Informatik GmbH grants to you only those rights as set out in the license conditions.
#                All other rights remain with Vector Informatik GmbH.
#  \endverbatim
#  -------------------------------------------------------------------------------------------------------------------
#  FILE DESCRIPTION
#  -------------------------------------------------------------------------------------------------------------------
#         \file  build_startapplication.sh
#        \brief  Build the Start Application using TACO build environment.
#######################################################################################################################

# 脚本运行出错立即停止
set -e
# 脚本管道出错，立即停止
set -o pipefail

EXEC=echo
DRY_RUN=1
COMPILE_ONLY=false

# 获取startapplication 所在目录
STARTAPPLICATION_DIR="$(cd "$(dirname "$0")" && pwd)"
SIP_DIR=$STARTAPPLICATION_DIR/../..
# 编译目录
BUILD_DIR=BuildStartApplication
# 安装目录
INSTALL_DIR=$BUILD_DIR/install
# 插件目录
INSTALL_ADDON_DIR=$BUILD_DIR/install_addon

# cmake的--preset，其含义是cmake的预配置文件，可以搜索找到这个文件
PRESET="gcc_fsl_aarch64"
# CMake 将使用指定路径下的 fsl_aarch64_gcc.cmake 文件作为初始缓存文件。
# CMake 初始缓存文件包含了一系列 CMake 变量和选项的设置，用于配置构建过程。
# 通过使用这个文件，你可以预先定义一些构建选项，而不需要在命令行中手动指定。
CMAKE_INITIAL_CACHE_FILE="$SIP_DIR/CMakeConfig/fsl_aarch64_gcc.cmake"

# 打印字体的颜色
RED='\033[0;31m'
NOCOLOR='\033[0m'

help_text () {
      echo ""
      echo "Usage:"
      echo "  build_startapplication.sh [options]"
      echo ""
      echo "The execution of the build script without any options will run the script in the dry run mode."
      echo "The parameter --execute must be given explicitly along with the following options to execute the Start Application build."
      echo "Otherwise a dry run of the script takes place."
      echo ""
      echo "Options:"
      echo
      echo "  --execute                          Execute the Start Application build."
      echo "  --cmake-preset <compiler-name>     Use another compiler."
      echo "                                     e.g. --cmake-preset gcc7_linux_x86_64"
      echo "  --cmake-initial-cache-file <path>  Provide the path to a cmake initial cache file."
      echo "                                     This path must be relative to the SIP directory."
      echo "                                     e.g.  --cmake-initial-cache-file ./CMakeConfig/linux_gcc7.cmake"
      echo "  --cmake-settings <settings>        Use non-default compiler and cmake settings."
      echo "                                     e.g. --cmake-settings \"-D AMSR_IPCMULTICAST_IMPL=DAEMON"
      echo "                                                            -D CMAKE_BUILD_TYPE=Release\""
      echo "  --compile-only                     Skip build cache initialisations and generator calls and perform"
      echo "                                     only build and install of the targets."
      echo "  --help                             Display the usage and other script options."
      echo ""
}

# Extract arguments and corresponding values
# 我们的startapplication编译就是用的--execute，实际是清空变量，什么都没干
while [ $# -gt 0 ]
do
  argument="$1"

case $argument in
    --execute)
      # 清空 EXEC
      EXEC=""
      # 清空 DRY_RUN
      DRY_RUN=0
      # 清空 IGNORE_COMMAND
      IGNORE_COMMAND=""
      # Shift argument and value
      shift
      ;;
    --cmake-preset)
      if [ -z $2 ]; then
        echo -e "${RED}Error: Invalid argument value"
        echo "--cmake-preset is empty"
        exit 1
      fi
      PRESET="$2"
      # Shift argument and value
      shift
      shift
      ;;
    --cmake-initial-cache-file)
      if [ -z $2 ]; then
        echo -e "${RED}Error: Invalid argument value"
        echo "--cmake-initial-cache-file is empty"
        exit 1
      fi
      CMAKE_INITIAL_CACHE_FILE="$SIP_DIR/$2"
      if [ ! -f "$CMAKE_INITIAL_CACHE_FILE" ]; then
         echo -e "${RED}Error: File not exists: $SIP_DIR/$2"
         exit 1
      fi
      # Shift argument and value
      shift
      shift
      ;;
    --cmake-settings)
      if [ -z $2 ]; then
        echo -e "${RED}Error: No cmake options set"
        echo "--cmake-settings is empty"
      fi
      CMAKE_SETTINGS="$2"
      # Shift argument and value
      shift
      shift
      ;;
    --compile-only)
      COMPILE_ONLY=true
      # Check if Build Cache is available
      if [ ! -d $SIP_DIR/$BUILD_DIR ]; then
        echo -e "${RED}Error: No build cache available"
        echo -e "${NOCOLOR}Use --execute to run a full build of the Start Application."
        exit 1
      fi
      shift
      ;;
    --help)
      help_text
      shift
      exit 1
      ;;
    *)
      echo -e "${RED}Error: Invalid argument "$1" used"
      exit 1
  esac
done

echo ""
echo -e "${NOCOLOR}"
echo "=================== Build the Start Application using TACO ========================="
echo " Call CMake with the Start Application target. This will build and"
echo " install the Start Application and all required BSW components."
echo "------------------------------------------------------------------------------------"

# Export environment variable for TACO builds
$EXEC export AMSR_SRC_DIR="$SIP_DIR"

# Change directory to Examples/startapplication
$EXEC cd ${AMSR_SRC_DIR}/Examples/startapplication

if [ $COMPILE_ONLY = false ]; then
    # Initialize cache for building the Start Application using TACO
    # 展开式为：cmake -S . -B /path/to/BuildStartApplication --preset=gcc_fsl_aarch64 -C /path/to/SIP_DIR/CMakeConfig/fsl_aarch64_gcc.cmake
    $EXEC cmake -S . $CMAKE_SETTINGS \
                -B $AMSR_SRC_DIR/$BUILD_DIR \
                --preset=$PRESET \
                -C $CMAKE_INITIAL_CACHE_FILE
fi

# Change directory to the previously created build cache directory
$EXEC cd $AMSR_SRC_DIR/$BUILD_DIR

if [ $COMPILE_ONLY = false ]; then
    # Generating source code for Start Application using ctest
    $EXEC ctest -R '.*\.DvACfg\.Generate' --verbose --parallel $(nproc)
fi

# Build the Start Application by building for target startapp_apps
$EXEC cmake --build . --target startapp_apps --parallel $(nproc)
# Install the Start Application to INSTALL_DIR using parameter --prefix
$EXEC cmake --install . --component STARTAPP_Runtime --prefix $AMSR_SRC_DIR/$INSTALL_DIR

RETVAL=$?

# Generate Software Update packages
if [ -z "${SA_SKIP_GENERATE_UPDATE_PACKAGE}" ]; then
  if [ $RETVAL -ne 0 ]; then
    exit $RETVAL
  else
    $EXEC $STARTAPPLICATION_DIR/infrastructure/update_management/generate_update_packages.sh --install-dir $SIP_DIR/$INSTALL_DIR --install-addon-dir $SIP_DIR/$INSTALL_ADDON_DIR
    RETVAL=$?
  fi
fi

if [ $DRY_RUN -eq 0 ]; then
  if [ $RETVAL -ne 0 ]; then
    exit $RETVAL
  else
    echo "--------------------------------------------------------------------------------"
    echo " The Start Application was installed to:"
    echo " $SIP_DIR/$INSTALL_DIR"
    if [ ! -z $CMAKE_TOOLCHAIN_FILE_PATH ]; then
      echo " with toolchain file: $CMAKE_TOOLCHAIN_FILE_PATH"
    fi
  fi
fi

if [ $DRY_RUN -eq 1 ]; then
  echo ""
  echo "=================================================================================="
  echo "This is only a dry run."
  echo "To execute the Start Application build, call the script with --execute."
  echo "To display the help for other script options, call the script with --help."
  echo "=================================================================================="
fi

```

## cmake中不理解的地方
```cmake
dvacfg_file_gen(${TARGET}
        INPUT "${STARTAPP_ADPA_FILE}"
        OUTPUT "amsr_applicationbase.cmake"
               "amsr_em_exec_config.cmake"
               "amsr_logapi_config.cmake"
               "amsr_thread_config.cmake"
               "amsr_modelleddatatypes_api.cmake"
               "amsr_persistency_config.cmake"
        GENERATOR DvACfg::amsr_applicationbase
                  DvACfg::amsr_em_exec_config
                  DvACfg::amsr_logapi_config
                  DvACfg::amsr_thread_config
                  DvACfg::amsr_modelleddatatypes_api
                  DvACfg::amsr_persistency_config
        DIRECTORY "startapp_per_app1")
```
1、这个函数调用的用途是什么？
2、INPUT参数跟的是文件还是文件夹
3、OUTPUT参数后的`.cmake`的文件，这个文件名是自己随意取的吗？还是有遵守某种规则
4、GENERATOR后的参数`DvACfg::amsr_applicationbase`这个也是自己随意取的吗？
5、为什么Examaple中的amsr-vector-app-example-hello-world，打开工程后，达芬奇中没有dashboard