Reconfigured the build when the requested compiler changes (#657)

CMake records the compiler it detected inside the build directory and keeps
using it on every later configure. Since cmake/linux.cmake began honouring CC,
that made a compiler switch silently ineffective: CC=gcc-14 ./run.sh build <cfg>
against an existing build directory printed "ninja: no work to do", exited 0,
and left the previous compiler in place. Anyone verifying a change against a
second compiler would have been reading stale results while being told the
build had succeeded.

generate() now compares the compiler recorded in the build directory with the
one currently requested, and reconfigures from scratch when they differ. The
comparison uses the path as CMake records it, which is the unresolved path as
given, so /usr/bin/gcc matches command -v gcc rather than the versioned target
its symlink points at. build_libs() gets the same treatment.

Only the C compiler is consulted: both trees that use this script declare
LANGUAGES C, so no CXX compiler is ever detected.

Nothing is reconfigured unless the compiler actually changed, so repeat builds
stay incremental and the default path is unchanged.

Assisted-by: Claude Code (Opus 5)

0 files changed, 0 insertions, 0 deletions