This is a small refactor to move code away from compiler.CompilePackage,
with the goal that compiler.CompilePackage will eventually be removed
entirely in favor of compiler.CompilePackage.
This package was long making the design of the compiler more complicated
than it needs to be. Previously this package implemented several
optimization passes, but those passes have since moved to work directly
with LLVM IR instead of Go SSA. The only remaining pass is the SimpleDCE
pass.
This commit removes the *ir.Function type that permeated the whole
compiler and instead switches to use *ssa.Function directly. The
SimpleDCE pass is kept but is far less tightly coupled to the rest of
the compiler so that it can easily be removed once the switch to
building and caching packages individually happens.
This commit merges NewCompiler and Compile into one simplifying the
external interface. More importantly, it does away with the entire
Compiler object so the public API becomes a lot smaller.
The refactor is not complete: eventually, the compiler should just
compile a single package without trying to load it first (that should be
done by the builder package).
This is a fairly big commit, but it actually changes very little.
getValue should really be a property of the builder (or frame), where
the previously created instructions are kept.
This results in a link error in the following commit (undefined
reference to runtime.trackedGlobalsBitmap from .debug_info). Solution:
don't emit debug info for declared but not defined symbols.
This is part of a larger rafactor that tries to shrink the ir package
and in general tries to shrink the amount of state that is kept around
in the compiler. The end goal is being able to compile packages
independent of each other, linking them together in a later stage. Along
the way, it cleans up lots of old cruft that has accumulated over the
months.
This refactor also results in globals being loaded lazily. This may be a
problem for some specific programs but will probably change back in a
commit in the near future.
