7842 - new directory organization

Baremetal is now the default build target and therefore has its sources
at the top-level. Baremetal programs build using the phase-2 Mu toolchain
that requires a Linux kernel. This phase-2 codebase which used to be at
the top-level is now under the linux/ directory. Finally, the phase-2 toolchain,
while self-hosting, has a way to bootstrap from a C implementation, which
is now stored in linux/bootstrap. The bootstrap C implementation uses some
literate programming tools that are now in linux/bootstrap/tools.

So the whole thing has gotten inverted. Each directory should build one
artifact and include the main sources (along with standard library). Tools
used for building it are relegated to sub-directories, even though those
tools are often useful in their own right, and have had lots of interesting
programs written using them.

A couple of things have gotten dropped in this process:
  - I had old ways to run on just a Linux kernel, or with a Soso kernel.
    No more.
  - I had some old tooling for running a single test at the cursor. I haven't
    used that lately. Maybe I'll bring it back one day.

The reorg isn't done yet. Still to do:
  - redo documentation everywhere. All the README files, all other markdown,
    particularly vocabulary.md.
  - clean up how-to-run comments at the start of programs everywhere
  - rethink what to do with the html/ directory. Do we even want to keep
    supporting it?

In spite of these shortcomings, all the scripts at the top-level, linux/
and linux/bootstrap are working. The names of the scripts also feel reasonable.
This is a good milestone to take stock at.

1 files changed, 30 insertions, 0 deletions

diff --git a/linux/translate_subx_debug b/linux/translate_subx_debug
new file mode 100755
index 00000000..e18eca31
--- /dev/null
+++ b/linux/translate_subx_debug
@@ -0,0 +1,30 @@
+#!/bin/sh
+# Translate given SubX files with debug information on Linux.
+#
+# Mu provides 3 canonical ways to translate unsafe SubX programs:
+#   0. The C++ translator 'bootstrap translate' can generate traces for
+#   debugging on Linux or BSD or Mac, but doesn't support any syntax sugar.
+#   1. The self-hosted translator can be run natively on Linux using
+#   'translate_subx'. It is fast and supports all syntax sugar, but you get no
+#   trace for debugging.
+#   2. The self-hosted translator can be run emulated on Linux or BSD or Mac
+#   using 'translate_subx_emulated'. It supports all syntax sugar. However, it
+#   can be slow if you generate traces.
+#
+# This script fills in the gap above by stitching together aspects from
+# multiple approaches. It translates syntax sugar natively, but emulates lower
+# levels using the C++ translator. The result is complete and relatively fast
+# even when generating traces.
+#
+# The cost: it needs Linux. There is no script to generate traces while
+# running emulated on BSD or Mac. That's often impractically slow.
+
+set -e
+
+cat $*          |./braces          > a.braces
+cat a.braces    |./calls           > a.calls
+cat a.calls     |./sigils          > a.sigils
+
+bootstrap/bootstrap --debug translate a.sigils -o a.elf
+
+chmod +x a.elf