MAGIC_VERSION / MAGIC_REVISION / MAGIC_COMMIT / MAGIC_BUILDDATE were on the
global DFLAGS, so every object's compile command line carried them. Because
the command line is part of ccache/sccache's hash key and MAGIC_BUILDDATE
changes every second, that meant a cache miss on every unit on every build;
it also smeared the baked-in date/commit across "whenever each file last
recompiled".
Move the four values into a single translation unit:
* utils/magic_buildinfo.h -- extern MagicVersion/MagicRevision/MagicCommit/
MagicCompileTime (MagicCommit is new; the other three moved here from
utils/magic.h, which now includes this header).
* utils/buildinfo.c -- the ONLY unit compiled with the version defines
(target-specific `buildinfo.o: DFLAGS += ${DFLAGS_MAGICVERSION}` in
utils/Makefile.in); it defines the four globals. ${DFLAGS_MAGICVERSION}
is removed from the global DFLAGS/DFLAGS_NOSTUB.
Consumers updated to read the runtime symbol instead of the compile-time
macro:
* magicTop.c / tclmagic.c no longer define the globals (the MAGIC_WRAPPER
duplicate-symbol guard is gone -- buildinfo.o owns them for every variant,
including WASM, which links both mains).
* Tcl_PkgProvide/PkgRequire in router/ext2spice/lef/ext2sim/plot/tclmagic
now pass MagicVersion.
* extflat: EFVersion (a static-initialized copy of MAGIC_VERSION) is dropped;
EFread.c compares the .ext version against MagicVersion directly -- the same
value ExtCell.c already *writes* into .ext files, so read and write are now
consistent.
Verified: only buildinfo.o carries -DMAGIC_* (hash/DBio/windCmdSZ carry none);
Tcl (375 files) and --without-tcl builds rc=0, version/commit/date embedded in
tclmagic.so, magicTop.o no longer defines MagicVersion; in-tree source clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Darryl L. Miles