genmatch reads match.pd and generates optimized C++ for GIMPLE and
GENERIC IR simplification. It was previously requiring users to run
./configure && make on the GCC source tree to produce its outputs.

Now genmatch is compiled and linked against libcpp (for tokenization)
and run as part of the normal build. Only gengtype outputs remain in
pre-generated/.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Add $$ → $ de-escaping in the evaluator so shell variable references
survive Tupfile expansion (e.g., for f in $(names); do ... $$f).

In 3-tree builds (-C/-S/-B), the scheduler now creates source subdirs
that exist in the config tree but not the source tree, enabling packages
whose actual source lives in a separate tree (referenced via config
variables rather than the -S tree).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Build GNU binutils 2.44 cross-assembler and cross-archiver targeting
x86_64-linux from a separate source tree via @(BINUTILS_SRC). This is
the first package to use an explicit source variable rather than the
implicit -S tree, establishing the pattern for future packages.

Single Tupfile builds BFD (38 files), libsframe (2), opcodes (4),
gas (39), and ar (11) — producing working as and ar binaries that
integrate with the existing xgcc/cc1 toolchain.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

The pattern required at least one token between the compiler name and
-c, so commands like `gcc -c foo.c -o foo.o` never matched. Also add
\s as an anchor alternative so compiler wrappers like `ccache gcc` are
recognized.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…mode

The scheduler auto-created source-tree directories when a config-tree
directory had no counterpart. This papered over a user setup issue
rather than honoring the 3-tree model: config tree mirrors source tree.

Makefile.pup now creates the binutils/ directory in the source tree as
an explicit setup step.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

The examples/ directory becomes the BSP root (-C tree). Infrastructure
(Tupfile.ini, Tuprules.tup, Makefile.pup, configs/, scripts/) moves up
from examples/gcc/. Binutils moves to examples/binutils/ as a peer
tarball group. GCC-internal packages stay under examples/gcc/ with a
new group Tuprules.tup providing ?= defaults for standalone use.

Key changes:
- Root Tuprules.tup uses gcc/ prefix for all GCC-tarball DIR variables
- Binutils uses $(S)/$(BINUTILS_DIR) instead of @(BINUTILS_SRC)
- Nested Tupfile.ini markers removed from busybox/ and helloworld/
- Source assembly model: one source-root/ subdir per extracted tarball

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Core fixes for symlink-safe path resolution in 3-tree mode:
canonicalize source/output paths in builder, scheduler, and dag
expansion so ../  components resolve correctly from physical CWD.
Add parse_scopes to limit Tupfile scanning to requested targets.
Add $$ escape for literal dollar signs in shell commands.

GCC example cleanup after end-to-end build validation (3511 commands,
0 failures, cc1/cc1plus/xgcc/xg++/cpp all link and run):

- Delete dead config/i386/Tupfile (targets/ file compiles same sources)
- Fix stale aarch64-apple-darwin HOST_MACHINE in cp/Tupfile
- Move driver-i386 compilation to target file, parameterize via
  TARGET_DRIVER_LINK so non-x86 targets can leave it empty
- Rewrite tup.configs for Linux host (basename, sbrk, *_unlocked, etc.)
- Add missing BACKTRACE/DECIMAL_FORMAT to aarch64-linux.config
- Rewrite binutils/tup.config for Linux, add darwin overlay
- Fix Makefile.pup setup-host-configs to handle binutils path

Downloads real GCC 15.2.0 + binutils 2.44 source tarballs and builds
the full examples/ BSP using the putup binary from build-linux. Smoke-
tests cc1 by compiling a trivial C file to assembly.

Also adds PUTUP variable to Makefile.pup so CI can override the binary
path without modifying the file.

Drop clang-analyzer-* (path-sensitive symbolic execution — by far the
most expensive family). Cherry-pick modernize-* (6 checks) and
cppcoreguidelines-* (7 checks) instead of enabling full families.
Modeled after DuckDB and Ladybird browser configs.

Add 'src/|test/' file filter to run-clang-tidy so third_party TUs are
never loaded, eliminating the need for --allow-no-checks and the LLVM
21 apt install (~10 min saved per CI run). Use system clang-tidy-18
from the ubuntu-24.04 runner instead.

- gcc-example SKILL.md: update build command from examples/gcc/ to
  examples/, remove stale PUP_IMPLICIT_DEPS workaround, update phase
  list from 7 to 14, fix Phase 6 description, fix scope description
- tupfile-patterns SKILL.md: fix root Tuprules example to use gcc/gmp
  paths matching actual BSP layout
- examples/README.md: add Makefile Targets + Variables section, fix
  Architecture wording (not all dirs have gcc/ prefix), fix Known
  Limitations (no Tupfile.ini, not $(CC))
- examples/Tupfile: fix stale reference to gcc/gcc/config/i386/Tupfile
  (now gcc/gcc/targets/x86_64-pc-linux-gnu.tup)
- examples/gcc/gcc/Tupfile: update header comment to 14 phases
- examples/busybox/README.md: remove deleted Tupfile.ini from table
- docs/reference.md: add -C/-S to configure Relevant Options