Pass data between tools / recipes

[bburgin]

For passing data between, here are some basic cases:
a. A compiler tool may output its path to downstream recipes, for the downstream recipes to
call the tool
b. A build recipe may output some paths to downstream recipes, for the downstream recipes to
use
c. A build recipe may output some scripts to downstream recipes, for the downstream recipes to
parameterize and call
d. A test recipe may run a test and output the path to a performance data file.
Then in my external sequencer, I could run Mussels again passing in the path to a graph
render recipe.

[micahsnyder]

I like this idea, but am unsure how to implement it, or what it would look like in the tool yaml and recipe yaml files.
I am thinking about a related issue where a tool may define a variable that would be available to any recipes that use the tool.
For example, a visualstudio 2017 tool yaml may define cmake_generator to "Visual Studio 15 2017" while the 2019 yaml would define it to "Visual Studio 16 2019". Then in a recipe which needs to specify the generator, it could do so with -G "{cmake_generator}".

I wonder if there's an elegant way to combine these two features or if they should be separate.

[micahsnyder]

or maybe it should be referenced like this, {visualstudio.cmake_generator} so that any tool/recipe could define variables that could be used downstream... Still not sure how to set it though... Some magic format characters in the build scripts, perhaps?

[bburgin]

I like your idea of namespacing data, #include msvc14.yaml and then reference msvc14.cmake_gen

[micahsnyder]

msvc14.yaml + msvc14.cmake_gen certainly is easier on the fingers.

I'll play around with it a bit today to see what I can come up with.

[micahsnyder]

Ok here's a PR to pass static variables from tools to the recipes that use them: #29

It doesn't really solve the whole feature request. I still don't have a good idea of how to set variables dynamically in a recipe to be used by downstream recipes. If you have any good ideas, lemme know.

[bburgin]

Looks good to me. For recipes passing data to downstream recipes, could a recipe have its own namespace?

recipeA
msvc_bin = call some script

recipeB
#include recipeA and then recipeA.msvc_bin