Merge branch 'feature/doc_note_about_component_search_order' into 'master'

Add a note about handling of same-named components in different component search paths

See merge request !788
This commit is contained in:
Angus Gratton 2017-06-06 14:36:33 +08:00
commit d00b2428bb

View file

@ -125,7 +125,6 @@ These variables all have default values that can be overridden for custom behavi
- ``COMPONENTS``: A list of component names to build into the project. Defaults to all components found in the COMPONENT_DIRS directories.
- ``SRCDIRS``: Directories under the main project directory which contain project-specific "pseudo-components". Defaults to 'main'. The difference between specifying a directory here and specifying it under ``EXTRA_COMPONENT_DIRS`` is that a directory in ``SRCDIRS`` is a component itself (contains a file "component.mk"), whereas a directory in ``EXTRA_COMPONENT_DIRS`` contains component directories which contain a file "component.mk". See the `Example Project` for a concrete case of this.
Component Makefiles
-------------------
@ -133,6 +132,15 @@ Each project contains one or more components, which can either be part of esp-id
A component is any sub-directory that contains a `component.mk` file [#f1]_.
Multiple components with the same name
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
When esp-idf is collecting all the components to compile, it will do this in the order specified by ``COMPONENT_DIRS``; by default, this means the
idf components first, the project components second and optionally the components in ``EXTRA_COMPONENT_DIRS`` last. If two or more of these directories
contain component subdirectories with the same name, the component in the last place searched is used. This allows, for example, overriding esp-idf components
with a modified version by simply copying the component from the esp-idf component directory to the project component tree and then modifying it there.
If used in this way, the esp-idf directory itself can remain untouched.
Minimal Component Makefile
^^^^^^^^^^^^^^^^^^^^^^^^^^