COMPONENT_DIRS and EXTRA_COMPONENT_DIRS should be defined as CMake
lists, using 'set' or 'list' commands. Some applications written
for earlier versions of ESP-IDF used to define these variables as
space separated strings.
For example, the following is correct:
set(EXTRA_COMPONENT_DIRS path/to/components path/to/more/components)
The following is not correct:
set(EXTRA_COMPONENT_DIRS "${EXTRA_COMPONENT_DIRS} component1")
set(EXTRA_COMPONENT_DIRS "${EXTRA_COMPONENT_DIRS} component2")
The string "component1 component2" may indicate a single directory
name with a space, or two directory names separated by space.
However due to the fact that such way of defining EXTRA_COMPONENT_DIRS
was supported in IDF 4.3 and earlier, we need to provide backward
compatibility for it.
This commit introduces a new script, split_paths_by_spaces.py, which
is invoked if EXTRA_COMPONENT_DIRS or COMPONENT_DIRS variable contains
spaces. The script tries to determine if each space should be
interpreted as a separator or as part of the directory name.
When this cannot be done unambiguously, the script reports an error.
In all cases when space separators are detected, the script reports
a warning, and prints instructions for fixing the CMakeLists.txt.
Breaking change in this commit: specifying non-existent directories
in COMPONENT_DIRS or EXTRA_COMPONENT_DIRS is no longer allowed.
