Files
fantemp/test/CMakeLists.txt
BlackMark 0f5e40510c perf: the console's constants move to flash, -378 B and -214 B of RAM
8382 -> 8004 B of flash, 725 -> 511 B of RAM on a part that has 2048.

The command names were a std::to_array of string_view, and on a Harvard
machine that is the worst of both: the characters land in .data and so does
the table's own pointer-and-length pair for each of them, so the firmware
carried 216 B of RAM for thirteen words that never change - and paid for them
in flash too, since .data is copied out of an initialiser image at startup.

They are one NUL-separated blob in flash now, walked with lpm. Separators
rather than an offset table, because an offset table is the RAM this exists to
give back; the names sit in it in match order, so the walk that finds a name
is the same walk that compares it and measures it. Flash falls further than
RAM does: the initialiser image and the two tables were 216 B of it, and the
blob is 87.

The header said the names "cannot" be in flash because they are matched at run
time. Being matched at run time is not a reason to be in RAM on a machine with
two address spaces - only being *written* is, and nothing writes these.

Two smaller things came with it. `reset`'s exact-match rule was a bool on
every entry to protect one; it is an index found by searching the list, so
reordering the commands cannot move the protection onto a different one. And
`version` was the last string_view left, holding its own characters and a
pointer to them.

The matching is now pinned rather than assumed: lookup() is constexpr and the
battery asserts the load-bearing order the README documents - `s` is show and
not statistics, `st` is statistics, no abbreviation of `reset` resolves, and
`helpful` is not `help`. Red-checked by claiming `s` is statistics.

Both modes byte-identical, ten tests green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-23 05:29:01 +02:00

32 lines
1.4 KiB
CMake

libavr_format_test()
# The image must stay below the boot section at 0x7e00, and the README states
# what it measures; a library advance that moves it says nothing on its own.
libavr_size_claim_test(fantemp 8004)
# The README says the two modes emit the same image, and only a tree with
# both built can say whether they do.
libavr_mode_identity_test(fantemp)
# The battery is a compile: a static_assert that fails is the failure. It is a
# target rather than only a ctest so a plain build catches a regression too.
add_library(consteval_tests OBJECT consteval.cpp)
target_include_directories(consteval_tests PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../src)
target_link_libraries(consteval_tests PRIVATE libavr)
add_test(NAME fantemp.consteval
COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target consteval_tests)
# The board has no reset line and no programming header, so the loader-entry
# route in the emitted image is the only thing standing between a firmware change
# and an unreflashable board.
find_package(Python3 COMPONENTS Interpreter)
if(Python3_FOUND)
add_test(NAME fantemp.reachability
COMMAND ${Python3_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/check_reachability.py
--objdump ${CMAKE_OBJDUMP} --elf $<TARGET_FILE:fantemp>
--image $<TARGET_FILE_DIR:fantemp>/fantemp.bin)
else()
message(STATUS "Python not found - the reachability check is skipped")
endif()