fix: correct cmake library interdependencies

[EpsilonPrime]

This eliminates the cycles described in #99.

PlanPrinterVisitor is now part of symbol_table.
BasePlanProtoVisitor (which PlanPrinterVisitor depends on) is now its own library.

[ingomueller-net]

Awesome -- thank you for the quick fix! Probably a much better fix than what I had in mind :)

For completeness, here are the dependency graphs before and after this PR. Before the change, we can see several inter-dependent targets; after the change, it's a nice DAG.

Before:

After:

I generated them running cmake --graphviz=foo.dot .. -DBUILD_SHARED_LIBS=OFF && dot -Tpng -o foo.png foo.dot in the build folder, where I put a file called CMakeGraphVizOptions.cmake with the following content (for removing the external dependencies from the graph):

set(GRAPHVIZ_IGNORE_TARGETS "absl_*;gmock*;gtest*;protobuf*;yaml-cpp*;fmt*;-lrt;Threads*;/usr/*;.*_test"

[westonpace]

Approve if CI passes. I won't pretend to have fully internalized these changes but I don't see anything odd or out of place.

[EpsilonPrime]

Thanks for finding this issue as well as providing the visualization of the dependencies. I'll probably use this trick to prevent such issues in the future.

[ingomueller-net]

Thanks for finding this issue as well as providing the visualization of the dependencies. I'll probably use this trick to prevent such issues in the future.

Sure thing! Another possibility is to (also) build with BUILD_SHARED_LIBS in CI...