build: harden CPM bootstrap download

Author: ntoskrnl7

cmake/CPM.cmake

@@ -12,10 +12,23 @@ endif()
 
 if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
   message(STATUS "Downloading CPM.cmake to ${CPM_DOWNLOAD_LOCATION}")
+  get_filename_component(CPM_DOWNLOAD_DIRECTORY "${CPM_DOWNLOAD_LOCATION}" DIRECTORY)
+  file(MAKE_DIRECTORY "${CPM_DOWNLOAD_DIRECTORY}")
   file(DOWNLOAD
     https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
-    ${CPM_DOWNLOAD_LOCATION}
+    "${CPM_DOWNLOAD_LOCATION}"
+    STATUS CPM_DOWNLOAD_STATUS
+    LOG CPM_DOWNLOAD_LOG
+    TLS_VERIFY ON
   )
+  list(GET CPM_DOWNLOAD_STATUS 0 CPM_DOWNLOAD_STATUS_CODE)
+  list(GET CPM_DOWNLOAD_STATUS 1 CPM_DOWNLOAD_STATUS_MESSAGE)
+  if(NOT CPM_DOWNLOAD_STATUS_CODE EQUAL 0)
+    message(FATAL_ERROR "Failed to download CPM.cmake: ${CPM_DOWNLOAD_STATUS_MESSAGE}\n${CPM_DOWNLOAD_LOG}")
+  endif()
 endif()
 
-include(${CPM_DOWNLOAD_LOCATION})
+include("${CPM_DOWNLOAD_LOCATION}")
+if(NOT COMMAND CPMAddPackage)
+  message(FATAL_ERROR "Downloaded CPM.cmake did not define CPMAddPackage: ${CPM_DOWNLOAD_LOCATION}")
+endif()

cmake/CrtSys.cmake

@@ -67,14 +67,27 @@ else()
 endif()
 
 if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
-  message(STATUS "Downloading CPM.cmake to ${CPM_DOWNLOAD_LOCATION}")
-  file(DOWNLOAD
-    https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
-    ${CPM_DOWNLOAD_LOCATION}
-  )
+    message(STATUS "Downloading CPM.cmake to ${CPM_DOWNLOAD_LOCATION}")
+    get_filename_component(CPM_DOWNLOAD_DIRECTORY "${CPM_DOWNLOAD_LOCATION}" DIRECTORY)
+    file(MAKE_DIRECTORY "${CPM_DOWNLOAD_DIRECTORY}")
+    file(DOWNLOAD
+        https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
+        "${CPM_DOWNLOAD_LOCATION}"
+        STATUS CPM_DOWNLOAD_STATUS
+        LOG CPM_DOWNLOAD_LOG
+        TLS_VERIFY ON
+    )
+    list(GET CPM_DOWNLOAD_STATUS 0 CPM_DOWNLOAD_STATUS_CODE)
+    list(GET CPM_DOWNLOAD_STATUS 1 CPM_DOWNLOAD_STATUS_MESSAGE)
+    if(NOT CPM_DOWNLOAD_STATUS_CODE EQUAL 0)
+        message(FATAL_ERROR "Failed to download CPM.cmake: ${CPM_DOWNLOAD_STATUS_MESSAGE}\n${CPM_DOWNLOAD_LOG}")
+    endif()
 endif()
 
-include(${CPM_DOWNLOAD_LOCATION})
+include("${CPM_DOWNLOAD_LOCATION}")
+if(NOT COMMAND CPMAddPackage)
+    message(FATAL_ERROR "Downloaded CPM.cmake did not define CPMAddPackage: ${CPM_DOWNLOAD_LOCATION}")
+endif()
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