[cmake]: add uninstall target

CMakeLists.txt

@@ -99,3 +99,7 @@ if(RYML_BUILD_TESTS OR RYML_BUILD_BENCHMARKS)
 endif()
 
 c4_add_dev_targets()
+
+add_custom_target(uninstall
+    "${CMAKE_COMMAND}" -P "${PROJECT_SOURCE_DIR}/cmake/uninstall.cmake"
+)

cmake/uninstall.cmake

@@ -0,0 +1,24 @@
+set(MANIFEST "${CMAKE_CURRENT_BINARY_DIR}/install_manifest.txt")
+
+if(NOT EXISTS ${MANIFEST})
+    message(FATAL_ERROR "Cannot find install manifest: '${MANIFEST}'")
+endif()
+
+file(STRINGS ${MANIFEST} files)
+foreach(file ${files})
+    if(EXISTS ${file})
+        message(STATUS "Removing file: '${file}'")
+
+        exec_program(
+            ${CMAKE_COMMAND} ARGS "-E remove ${file}"
+            OUTPUT_VARIABLE stdout
+            RETURN_VALUE result
+        )
+        
+        if(NOT "${result}" STREQUAL 0)
+            message(FATAL_ERROR "Failed to remove file: '${file}'.")
+        endif()
+    else()
+        MESSAGE(STATUS "File '${file}' does not exist.")
+    endif()
+endforeach(file)