Files
akbasic/CMakeLists.txt
Andrew Kesterson e51b9a1694 Document host/script variable exchange, and file the scope hazard it exposes
The host can expose variables to a BASIC program, in both directions and for
every type, with no marshalling layer -- akbasic_environment_get() finds or
creates by name, the type comes from the suffix as it does for BASIC code, and
host and script share the same akbasic_Value. Nothing new was needed to make
that work.

Testing it before writing it up turned up a hazard worth stating plainly, so the
README documents the pattern and section 6 item 17 records the gap.

Seeding before akbasic_runtime_start() and reading after the script stops is
safe, and so is updating an existing global at any time, because the parent
chain is searched. Creating one mid-run is not, in two ways, and both are
silent. A script suspended part-way through a bounded run() is usually inside a
FOR or GOSUB scope, so a variable created through obj->environment lands in that
scope and dies when it pops -- the script reads it correctly inside the loop and
gets 0 immediately after. And reaching for the root explicitly does not help:
akbasic_environment_get only auto-creates when the environment it is given is
the active one, so with a child active it returns NULL through dest without
raising, and an unchecked host dereferences it.

This one is ours rather than inherited. It falls out of the environment pool
meeting the bounded run(), a combination the reference never had because its
run() never returned.

examples/hostvars.c demonstrates both hazards rather than describing them, and
prints what it observes, so the day this is fixed that output changes and the
example needs revisiting. Like examples/embed.c it is built and run by every
build. Both README snippets were extracted and compiled as a check.

Not fixed here: akbasic_runtime_global() would close it in about fifteen lines,
but what it should do when the script is suspended inside a user function's
scope is a design question worth settling deliberately rather than discovering.
Filed with the proposed signature and the tests it wants.

ctest 61/61; ASan+UBSan 61/61; no warnings under -Wall -Wextra.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-31 06:50:55 -04:00

277 lines
10 KiB
CMake

cmake_minimum_required(VERSION 3.10)
# The single source of truth for the version, in the shape libakstdlib and
# libakgl both use. It flows into the library SOVERSION and nothing else spells
# a version number.
#
# 0.x on purpose: TODO.md section 12 records eleven defects carried over from the
# Go reference that are deliberately reproduced and not yet fixed, so the
# language surface is not being promised yet.
project(akbasic VERSION 0.1.0 LANGUAGES C)
# Pre-1.0 the ABI may break on a minor bump, so the soname carries MAJOR.MINOR.
# At 1.0 this becomes ${PROJECT_VERSION_MAJOR} alone.
if(PROJECT_VERSION_MAJOR EQUAL 0)
set(AKBASIC_SOVERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}")
else()
set(AKBASIC_SOVERSION "${PROJECT_VERSION_MAJOR}")
endif()
include(CTest)
include(GNUInstallDirs)
option(AKBASIC_WITH_AKGL "Build the libakgl-backed text sink and link SDL3" OFF)
option(AKBASIC_BUILD_EXAMPLES "Build the embedding example in examples/" ON)
option(AKBASIC_COVERAGE "Instrument the build with gcov coverage counters" OFF)
option(AKBASIC_SANITIZE "Build with ASan + UBSan" OFF)
# ---------------------------------------------------------------------------
# Dependencies
#
# libakgl vendors its own copies of libakerror and libakstdlib and guards every
# dependency with if(NOT TARGET ...), so akerror::akerror and akstdlib::akstdlib
# must exist *before* add_subdirectory(deps/libakgl) or the targets are declared
# twice.
#
# All three dependencies register their CTest tests unconditionally. Pulled in
# EXCLUDE_FROM_ALL their test binaries are never built, so each one would land in
# our suite as "Not Run" and fail. CMake has no way to un-register a test and
# set_tests_properties cannot reach across directory scopes, so add_test() and
# set_tests_properties() are shadowed for the duration of the add_subdirectory()
# calls. Note libakstdlib carries the same shadow but only arms it when *it* is
# top-level, so it does nothing for us -- this one has to wrap all three.
#
# libakerror additionally namespaces its `mutation` target when embedded but not
# its `coverage` target (deps/libakerror/CMakeLists.txt:194 vs :172), so a
# coverage build collides on the `coverage` target and fails to configure at all.
# Rename the dependency's on the way past. Remove this once libakerror applies
# the same CMAKE_SOURCE_DIR test to `coverage` that it already applies to
# `mutation` -- filed in deps/libakstdlib/TODO.md section 2.3.
# ---------------------------------------------------------------------------
set(AKBASIC_SUPPRESS_ADD_TEST TRUE)
function(add_test)
if(NOT AKBASIC_SUPPRESS_ADD_TEST)
_add_test(${ARGV})
endif()
endfunction()
function(set_tests_properties)
if(NOT AKBASIC_SUPPRESS_ADD_TEST)
_set_tests_properties(${ARGV})
endif()
endfunction()
function(add_custom_target _name)
if(AKBASIC_SUPPRESS_ADD_TEST AND _name STREQUAL "coverage")
_add_custom_target(akerror_coverage ${ARGN})
else()
_add_custom_target(${ARGV})
endif()
endfunction()
add_subdirectory(deps/libakerror EXCLUDE_FROM_ALL)
add_subdirectory(deps/libakstdlib EXCLUDE_FROM_ALL)
if(AKBASIC_WITH_AKGL)
add_subdirectory(deps/libakgl EXCLUDE_FROM_ALL)
endif()
set(AKBASIC_SUPPRESS_ADD_TEST FALSE)
# ---------------------------------------------------------------------------
# Instrumentation, applied per target so it never leaks into an exported
# interface.
# ---------------------------------------------------------------------------
function(akbasic_instrument _target)
if(AKBASIC_COVERAGE)
target_compile_options(${_target} PRIVATE --coverage -O0 -g)
target_link_options(${_target} PRIVATE --coverage)
endif()
if(AKBASIC_SANITIZE)
target_compile_options(${_target} PRIVATE -fsanitize=address,undefined -fno-omit-frame-pointer -g)
target_link_options(${_target} PRIVATE -fsanitize=address,undefined)
endif()
endfunction()
# ---------------------------------------------------------------------------
# The interpreter library. Everything here must be free of SDL, free of any
# process-terminating call, and buildable with no libakgl present.
# ---------------------------------------------------------------------------
set(AKBASIC_SOURCES
src/convert.c
src/environment.c
src/error.c
src/grammar.c
src/parser.c
src/parser_commands.c
src/runtime.c
src/runtime_commands.c
src/runtime_functions.c
src/scanner.c
src/sink_stdio.c
src/symtab.c
src/value.c
src/variable.c
src/verbs.c
)
add_library(akbasic ${AKBASIC_SOURCES})
add_library(akbasic::akbasic ALIAS akbasic)
target_include_directories(akbasic PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/>
)
target_compile_options(akbasic PRIVATE -Wall -Wextra)
target_link_libraries(akbasic PUBLIC akstdlib::akstdlib akerror::akerror)
target_link_libraries(akbasic PRIVATE m)
set_target_properties(akbasic PROPERTIES
VERSION ${PROJECT_VERSION}
SOVERSION ${AKBASIC_SOVERSION}
)
akbasic_instrument(akbasic)
# The libakgl-backed text sink, kept in its own target so the core library and
# the whole golden suite build with no SDL present.
if(AKBASIC_WITH_AKGL)
add_library(akbasic_akgl src/sink_akgl.c)
target_compile_options(akbasic_akgl PRIVATE -Wall -Wextra)
target_link_libraries(akbasic_akgl PUBLIC akbasic akgl)
akbasic_instrument(akbasic_akgl)
endif()
# ---------------------------------------------------------------------------
# The standalone driver. This is the only place FINISH_NORETURN may appear.
# ---------------------------------------------------------------------------
add_executable(basic src/main.c)
target_compile_options(basic PRIVATE -Wall -Wextra)
target_link_libraries(basic PRIVATE akbasic)
if(AKBASIC_WITH_AKGL)
target_link_libraries(basic PRIVATE akbasic_akgl)
target_compile_definitions(basic PRIVATE AKBASIC_HAVE_AKGL=1)
endif()
akbasic_instrument(basic)
# The embedding example. It is built by default and registered as a test so the
# code README.md quotes cannot rot: a signature change breaks the build.
if(AKBASIC_BUILD_EXAMPLES)
foreach(_example IN ITEMS embed hostvars)
add_executable(akbasic_example_${_example} examples/${_example}.c)
target_compile_options(akbasic_example_${_example} PRIVATE -Wall -Wextra)
target_link_libraries(akbasic_example_${_example} PRIVATE akbasic)
akbasic_instrument(akbasic_example_${_example})
_add_test(NAME example_${_example} COMMAND akbasic_example_${_example})
endforeach()
endif()
# ---------------------------------------------------------------------------
# Tests.
#
# Three lists, and two of them invert the meaning of "Passed", exactly as
# libakstdlib does:
# AKBASIC_TESTS must exit 0
# AKBASIC_WILL_FAIL_TESTS abort by design
# AKBASIC_KNOWN_FAILING_TESTS assert the *correct* contract for a defect
# recorded in TODO.md and are expected to fail.
# When one starts passing CTest reports
# "unexpectedly passed" -- that is the cue to move
# it into AKBASIC_TESTS along with the fix.
#
# Test executables are named akbasic_test_<name>, never test_<name>: a
# dependency's targets are created even under EXCLUDE_FROM_ALL, and libakstdlib
# already ships test_version. The CTest name stays bare, so `ctest -R value`
# still selects it.
# ---------------------------------------------------------------------------
set(AKBASIC_TESTS
convert
environment_scope
error_codes
grammar_leaves
parser_commands
parser_expressions
runtime_evaluate
runtime_verbs
scanner_tokens
sink_stdio
symtab
value_arithmetic
value_bitwise
value_compare
variable_subscript
verbs_table
version_check
)
set(AKBASIC_WILL_FAIL_TESTS
)
set(AKBASIC_KNOWN_FAILING_TESTS
known_reference_defects
)
foreach(_test IN LISTS AKBASIC_TESTS AKBASIC_WILL_FAIL_TESTS AKBASIC_KNOWN_FAILING_TESTS)
add_executable(akbasic_test_${_test} tests/${_test}.c)
target_compile_options(akbasic_test_${_test} PRIVATE -Wall -Wextra)
target_link_libraries(akbasic_test_${_test} PRIVATE akbasic)
target_include_directories(akbasic_test_${_test} PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/tests")
akbasic_instrument(akbasic_test_${_test})
_add_test(NAME ${_test} COMMAND akbasic_test_${_test})
endforeach()
if(AKBASIC_TESTS OR AKBASIC_WILL_FAIL_TESTS OR AKBASIC_KNOWN_FAILING_TESTS)
_set_tests_properties(
${AKBASIC_TESTS} ${AKBASIC_WILL_FAIL_TESTS} ${AKBASIC_KNOWN_FAILING_TESTS}
PROPERTIES WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/tests" TIMEOUT 30
)
endif()
if(AKBASIC_WILL_FAIL_TESTS OR AKBASIC_KNOWN_FAILING_TESTS)
_set_tests_properties(
${AKBASIC_WILL_FAIL_TESTS} ${AKBASIC_KNOWN_FAILING_TESTS}
PROPERTIES WILL_FAIL TRUE
)
endif()
# The golden-file suite. It drives deps/basicinterpret/tests/**/*.bas in place --
# the corpus is a submodule and copying it guarantees drift -- and byte-compares
# stdout against the sibling .txt. One CTest case per .bas so a failure names the
# file.
file(GLOB_RECURSE AKBASIC_GOLDEN_CASES
RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}/deps/basicinterpret"
"${CMAKE_CURRENT_SOURCE_DIR}/deps/basicinterpret/tests/*.bas"
)
foreach(_case IN LISTS AKBASIC_GOLDEN_CASES)
string(REGEX REPLACE "^tests/" "" _name "${_case}")
string(REGEX REPLACE "\\.bas$" "" _name "${_name}")
string(REPLACE "/" "_" _name "${_name}")
_add_test(
NAME golden_${_name}
COMMAND ${CMAKE_COMMAND}
-DBASIC=$<TARGET_FILE:basic>
-DCASE=${CMAKE_CURRENT_SOURCE_DIR}/deps/basicinterpret/${_case}
-P ${CMAKE_CURRENT_SOURCE_DIR}/tests/golden.cmake
)
endforeach()
if(AKBASIC_GOLDEN_CASES)
set(AKBASIC_GOLDEN_NAMES)
foreach(_case IN LISTS AKBASIC_GOLDEN_CASES)
string(REGEX REPLACE "^tests/" "" _name "${_case}")
string(REGEX REPLACE "\\.bas$" "" _name "${_name}")
string(REPLACE "/" "_" _name "${_name}")
list(APPEND AKBASIC_GOLDEN_NAMES golden_${_name})
endforeach()
_set_tests_properties(${AKBASIC_GOLDEN_NAMES} PROPERTIES TIMEOUT 30)
endif()
install(TARGETS akbasic basic
ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
)
install(DIRECTORY include/akbasic DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})