The intermediate file used to expand the generator expressions is now in
YAML format. This allows for a more robust handling of the data, as the
single quoted strings are a lot easier to escape: inside them every
character is a literal except for two single quotes (which intuitively
map to a literal single quote).
When saving a simple YAML file without genexes, the single quotes in
strings need to be escaped. However, doing so when saving the
intermediate file would make it harder to properly escape them later,
since it could be possible that the expansion of the generator
expressions would introduce new single quotes. For this reason, when
genexes are enabled, the escaping is now done in a single pass inside
the yaml-filter.cmake script.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
To move away from the JSON/YAML terminology, rename the variables that
refer to the intermediate files to "expanded" and "output" files.
Also, clean up a few "C-style" function calls and a typo in a variable
name in the same files.
No functional change introduced in this commit.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
This commit adds support for generator expressions in values and lists
to the yaml module.
Generator expressions can only be expanded by CMake after all
configuration code has been executed and the final values of the project
properties are defined. This means that contexts that contain generator
expressions are written twice:
- immediately, during the 'yaml_save()' call, a comment with the raw
unexpanded string is saved instead of the key that uses generator
expressions in the YAML file;
- after the configuration step, a custom command updates the YAML file
contents with the fully expanded values.
This two-step process also allows to overcome the issue of lists that
are extracted from generator expressions, whose elements would be
expanded into a single string if written directly to the YAML file.
Instead, the lists are stored in their CMake string format with a
special marker, expanded by CMake into a temporary JSON file, and the
conversion to a proper list is performed during the build step.
If the saved YAML file for context <name> is needed by further build
steps in this project, the target '<name>_yaml_saved' must be added as a
dependency to ensure the final contents are ready.
Note that when generator expressions are used in the context, the GENEX
keyword must be provided to yaml_set(). This is necessary to avoid
storing the genexes as raw strings in the YAML.
Signed-off-by: Luca Burelli <l.burelli@arduino.cc>
