Clean up the rat's nest that all my trace management globals had
gradually turned into.
a) Get rid of 'Start_tracing'. Horryibly named, I don't know how I
missed that until now.
b) Never use START_TRACING_UNTIL_END_OF_SCOPE in main(). It's
confusing to combine it with atexit(delete Trace_stream), because the
atexit() never has to run. Instead we'll just manually initialize
Trace_stream and let atexit() clean up.
c) If we run tests we only want a trace for the test run itself. So
delete the Trace_stream that was initialized at the top of main --
once it's clear we had no load-time errors.
d) Clean up horribly "Load Recipes" waypoints, combine them with the better
name, "Mu Prelude".
Putting these together, we have the following manual tests:
- CFLAGS=-g mu x.mu
Should not create last_run.
- CFLAGS=-g mu --trace x.mu
Should create last_run.
Should write it out exactly once.
- CFLAGS=-g mu --trace x.mu # when x.mu has an error
Should create last_run.
Should write it out exactly once.
- CFLAGS=-g mu --trace test copy_literal # C test
Should create last_run.
Should write it out exactly once.
- CFLAGS=-g mu --trace test recipe_with_header # Mu test
Should create last_run.
Should write it out exactly once.
I don't know how to automate these scenarios yet. We need a way to run
our build toolchain atop our stack.
I've been working on this slowly over several weeks, but it's too hard
to support 0 as the null value for addresses. I constantly have to add
exceptions for scalar value corresponding to an address type (now
occupying 2 locations). The final straw is the test for 'reload':
x:num <- reload text
'reload' returns an address. But there's no way to know that for
arbitrary instructions.
New plan: let's put this off for a bit and first create support for
literals. Then use 'null' instead of '0' for addresses everywhere. Then
it'll be easy to just change what 'null' means.
Solution to a minor puzzle that came up during today's lesson with Ella:
some sandboxes were showing the address of text results, while others
were showing their contents. It took a while to realize that the
distinction lay in whether the sandbox was saving the results in a text
variable:
new [abc]
=> <some address>
x:text <- new [abc]
=> abc
It took *much* longer to realize why I couldn't make the first case work
like the second. Eventually I realized why: recipes were reclaiming
their results if they weren't 'escaping' -- that is, being saved in a
variable in the caller so they could be used later.
Any solution to this would be a hack, so I'm going to just leave it
alone. Type abbreviations should help minimize the extra typing needed
to get sandboxes to show text contents.
Deconstruct the tracing layer which had been an exception to our
includes-types-prototypes-globals-functions organization thus far.
To do this we predefine a few primitive globals before the types that
use them, and we pull some method definitions out of struct definitions
at the cost of having to manually write a couple of prototypes.
Kartik Agaram