Add --strict convention checker for dual-mode composability

.claude/skills/tupfile-patterns/SKILL.md

@@ -160,6 +160,8 @@ CFLAGS = -I$(B)/$(GMP_DIR) -I$(S)/$(GMP_DIR)
 
 Prefixed DIR vars (`GMP_DIR`, `MPFR_DIR`) are needed because `include_rules` merges ALL `Tuprules.tup` from root to leaf — a single `DIR` variable would collide.
 
+Verify conventions with `putup parse --strict` — flags `=` instead of `?=` for anchor/toolchain variables in component Tuprules.tup files.
+
 ## Scoped tup.config
 
 Each subdirectory can have its own `tup.config` for `@(VAR)` config variables:

CLAUDE.md

@@ -60,6 +60,7 @@ make test                                 # Run all tests
 ./build/test/unit/putup_test '[target]'     # Target parsing tests
 ./build/test/unit/putup_test '[shell]'      # Shell fixture tests
 ./build/test/unit/putup_test '[configure]'  # Two-pass config generation tests
+./build/test/unit/putup_test '[strict]'     # Convention checker (--strict) tests
 ```
 
 ### Writing E2E Tests

DESIGN.md

@@ -43,7 +43,7 @@ With libstdc++ eliminated, putup provides its own runtime primitives:
 | `Function<Sig>` | `std::function<Sig>` | Move-only type-erased callable (32-byte SBO) |
 | `SteadyClock` / `SystemClock` | `std::chrono` clocks | Platform-implemented clocks |
 | `CPath` | manual `.c_str()` | Null-termination wrapper for string_view at C API boundary |
-| `throw_stubs.cpp` | libstdc++ runtime | operator new/delete, `__cxa_guard_*`, `__throw_*` stubs |
+| `throw_stubs.cpp` | libstdc++ runtime | operator new/delete, `__cxa_guard_*`, `__throw_*` stubs, macOS `__libcpp_verbose_abort` |
 
 All threading (`std::thread`, `std::mutex`, `std::atomic`, `std::future`) has been eliminated. The scheduler uses a single-threaded `poll()`-based event loop. Multi-variant parallelism uses `fork()`+`waitpid()` via `platform::run_parallel_tasks()`.
 
@@ -1883,7 +1883,7 @@ Putup links with `-nostdlib++` and provides its own runtime primitives:
 - **Portability** - No dependency on a specific C++ standard library version; only requires a C runtime (libc)
 - **Control** - Custom `StringPool`, `Vec<T>`, `Function<Sig>`, and clock types are purpose-built for the build system's needs, with no overhead from generality
 
-The `throw_stubs.cpp` file provides the minimal runtime surface: `operator new`/`delete` (delegating to `malloc`/`free`), `__cxa_guard_*` (for thread-safe static initialization), and `__throw_*` stubs that abort on use. Multi-variant parallelism uses `fork()`+`waitpid()` via `platform::run_parallel_tasks()` instead of `std::async`.
+The `throw_stubs.cpp` file provides the minimal runtime surface: `operator new`/`delete` (delegating to `malloc`/`free`), `__cxa_guard_*` (for thread-safe static initialization), and `__throw_*` stubs that abort on use. On macOS, libc++ also requires `std::__1::__libcpp_verbose_abort` (used by `variant`/`optional` failure paths); the stub matches libc++'s `__1` inline ABI namespace directly. Multi-variant parallelism uses `fork()`+`waitpid()` via `platform::run_parallel_tasks()` instead of `std::async`.
 
 ---
 

SKILL.md

@@ -49,6 +49,7 @@ make test                                 # All tests
 | `[scoped-config]` | Scoped configure commands |
 | `[shell]` | Shell fixture tests (`test.sh`) |
 | `[show]` | Show command (script, compdb, graph) |
+| `[strict]` | Convention checker (`--strict` flag) |
 | `[target]` | Target parsing tests |
 | `[variant]` | Out-of-tree/variant builds, ghost nodes |
 

Tupfile

@@ -60,6 +60,7 @@ srcs-y += src/cli/context.cpp
 srcs-y += src/cli/multi_variant.cpp
 srcs-y += src/cli/options.cpp
 srcs-y += src/cli/output.cpp
+srcs-y += src/cli/strict_checks.cpp
 srcs-y += src/cli/target.cpp
 
 # Platform

bootstrap-linux.sh

@@ -19,6 +19,7 @@ mkdir -p "build/test/unit"
 (cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/context.cpp -o build/context.o)
 (cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/config_commands.cpp -o build/config_commands.o)
 (cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/cmd_parse.cpp -o build/cmd_parse.o)
+(cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/strict_checks.cpp -o build/strict_checks.o)
 (cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/cmd_show.cpp -o build/cmd_show.o)
 (cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/cmd_configure.cpp -o build/cmd_configure.o)
 (cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/cmd_clean.cpp -o build/cmd_clean.o)
@@ -61,8 +62,8 @@ mkdir -p "build/test/unit"
 (cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/core/hash.cpp -o build/hash.o)
 (cd "." && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/core/arena.cpp -o build/arena.o)
 (cd "." && gcc -std=c11 -Wall -Wextra -Werror -fPIC -I./third_party  -O2 -ffunction-sections -fdata-sections -Wno-error -c third_party/sha256/sha256.c -o build/sha256.o)
-(cd "." && g++ build/sha256.o build/arena.o build/hash.o build/id_array.o build/id_bitset.o build/layout.o build/metrics.o build/path.o build/path_utils.o build/sorted_id_vec.o build/string_pool.o build/global_pool.o build/buf.o build/heap_buf.o build/string_utils.o build/terminal.o build/ast.o build/config.o build/depfile.o build/eval.o build/glob.o build/ignore.o build/lexer.o build/parser.o build/var_tracking.o build/builder.o build/dag.o build/dep_scanner.o build/rule_pattern.o build/gcc.o build/topo.o build/entry.o build/reader.o build/writer.o build/progress_display.o build/runner.o build/scheduler.o build/cmd_build.o build/cmd_clean.o build/cmd_configure.o build/cmd_show.o build/cmd_parse.o build/config_commands.o build/context.o build/multi_variant.o build/options.o build/output.o build/target.o build/process-posix.o build/file_io-posix.o build/env-posix.o build/path-posix.o build/main.o build/throw_stubs.o -o build/putup -nostdlib++ -Wl,--gc-sections )
-(cd "." && ar rcs build/libputup.a build/sha256.o build/arena.o build/hash.o build/id_array.o build/id_bitset.o build/layout.o build/metrics.o build/path.o build/path_utils.o build/sorted_id_vec.o build/string_pool.o build/global_pool.o build/buf.o build/heap_buf.o build/string_utils.o build/terminal.o build/ast.o build/config.o build/depfile.o build/eval.o build/glob.o build/ignore.o build/lexer.o build/parser.o build/var_tracking.o build/builder.o build/dag.o build/dep_scanner.o build/rule_pattern.o build/gcc.o build/topo.o build/entry.o build/reader.o build/writer.o build/progress_display.o build/runner.o build/scheduler.o build/cmd_build.o build/cmd_clean.o build/cmd_configure.o build/cmd_show.o build/cmd_parse.o build/config_commands.o build/context.o build/multi_variant.o build/options.o build/output.o build/target.o build/process-posix.o build/file_io-posix.o build/env-posix.o build/path-posix.o)
+(cd "." && g++ build/sha256.o build/arena.o build/hash.o build/id_array.o build/id_bitset.o build/layout.o build/metrics.o build/path.o build/path_utils.o build/sorted_id_vec.o build/string_pool.o build/global_pool.o build/buf.o build/heap_buf.o build/string_utils.o build/terminal.o build/ast.o build/config.o build/depfile.o build/eval.o build/glob.o build/ignore.o build/lexer.o build/parser.o build/var_tracking.o build/builder.o build/dag.o build/dep_scanner.o build/rule_pattern.o build/gcc.o build/topo.o build/entry.o build/reader.o build/writer.o build/progress_display.o build/runner.o build/scheduler.o build/cmd_build.o build/cmd_clean.o build/cmd_configure.o build/cmd_show.o build/cmd_parse.o build/strict_checks.o build/config_commands.o build/context.o build/multi_variant.o build/options.o build/output.o build/target.o build/process-posix.o build/file_io-posix.o build/env-posix.o build/path-posix.o build/main.o build/throw_stubs.o -o build/putup -nostdlib++ -Wl,--gc-sections )
+(cd "." && ar rcs build/libputup.a build/sha256.o build/arena.o build/hash.o build/id_array.o build/id_bitset.o build/layout.o build/metrics.o build/path.o build/path_utils.o build/sorted_id_vec.o build/string_pool.o build/global_pool.o build/buf.o build/heap_buf.o build/string_utils.o build/terminal.o build/ast.o build/config.o build/depfile.o build/eval.o build/glob.o build/ignore.o build/lexer.o build/parser.o build/var_tracking.o build/builder.o build/dag.o build/dep_scanner.o build/rule_pattern.o build/gcc.o build/topo.o build/entry.o build/reader.o build/writer.o build/progress_display.o build/runner.o build/scheduler.o build/cmd_build.o build/cmd_clean.o build/cmd_configure.o build/cmd_show.o build/cmd_parse.o build/strict_checks.o build/config_commands.o build/context.o build/multi_variant.o build/options.o build/output.o build/target.o build/process-posix.o build/file_io-posix.o build/env-posix.o build/path-posix.o)
 (cd "test/unit" && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I../../include -I../../third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c test_var_tracking.cpp -o ../../build/test/unit/test_var_tracking.o)
 (cd "test/unit" && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I../../include -I../../third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c test_types.cpp -o ../../build/test/unit/test_types.o)
 (cd "test/unit" && g++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I../../include -I../../third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c test_target.cpp -o ../../build/test/unit/test_target.o)

bootstrap-macos.sh

@@ -19,6 +19,7 @@ mkdir -p "build/test/unit"
 (cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/context.cpp -o build/context.o)
 (cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/config_commands.cpp -o build/config_commands.o)
 (cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/cmd_parse.cpp -o build/cmd_parse.o)
+(cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/strict_checks.cpp -o build/strict_checks.o)
 (cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/cmd_show.cpp -o build/cmd_show.o)
 (cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/cmd_configure.cpp -o build/cmd_configure.o)
 (cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/cli/cmd_clean.cpp -o build/cmd_clean.o)
@@ -61,8 +62,8 @@ mkdir -p "build/test/unit"
 (cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/core/hash.cpp -o build/hash.o)
 (cd "." && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I./include -I./third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c src/core/arena.cpp -o build/arena.o)
 (cd "." && clang -std=c11 -Wall -Wextra -Werror -fPIC -I./third_party  -O2 -ffunction-sections -fdata-sections -Wno-error -c third_party/sha256/sha256.c -o build/sha256.o)
-(cd "." && clang++ build/sha256.o build/arena.o build/hash.o build/id_array.o build/id_bitset.o build/layout.o build/metrics.o build/path.o build/path_utils.o build/sorted_id_vec.o build/string_pool.o build/global_pool.o build/buf.o build/heap_buf.o build/string_utils.o build/terminal.o build/ast.o build/config.o build/depfile.o build/eval.o build/glob.o build/ignore.o build/lexer.o build/parser.o build/var_tracking.o build/builder.o build/dag.o build/dep_scanner.o build/rule_pattern.o build/gcc.o build/topo.o build/entry.o build/reader.o build/writer.o build/progress_display.o build/runner.o build/scheduler.o build/cmd_build.o build/cmd_clean.o build/cmd_configure.o build/cmd_show.o build/cmd_parse.o build/config_commands.o build/context.o build/multi_variant.o build/options.o build/output.o build/target.o build/process-posix.o build/file_io-posix.o build/env-posix.o build/path-posix.o build/main.o build/throw_stubs.o -o build/putup -nostdlib++ -Wl,-dead_strip )
-(cd "." && ar rcs build/libputup.a build/sha256.o build/arena.o build/hash.o build/id_array.o build/id_bitset.o build/layout.o build/metrics.o build/path.o build/path_utils.o build/sorted_id_vec.o build/string_pool.o build/global_pool.o build/buf.o build/heap_buf.o build/string_utils.o build/terminal.o build/ast.o build/config.o build/depfile.o build/eval.o build/glob.o build/ignore.o build/lexer.o build/parser.o build/var_tracking.o build/builder.o build/dag.o build/dep_scanner.o build/rule_pattern.o build/gcc.o build/topo.o build/entry.o build/reader.o build/writer.o build/progress_display.o build/runner.o build/scheduler.o build/cmd_build.o build/cmd_clean.o build/cmd_configure.o build/cmd_show.o build/cmd_parse.o build/config_commands.o build/context.o build/multi_variant.o build/options.o build/output.o build/target.o build/process-posix.o build/file_io-posix.o build/env-posix.o build/path-posix.o)
+(cd "." && clang++ build/sha256.o build/arena.o build/hash.o build/id_array.o build/id_bitset.o build/layout.o build/metrics.o build/path.o build/path_utils.o build/sorted_id_vec.o build/string_pool.o build/global_pool.o build/buf.o build/heap_buf.o build/string_utils.o build/terminal.o build/ast.o build/config.o build/depfile.o build/eval.o build/glob.o build/ignore.o build/lexer.o build/parser.o build/var_tracking.o build/builder.o build/dag.o build/dep_scanner.o build/rule_pattern.o build/gcc.o build/topo.o build/entry.o build/reader.o build/writer.o build/progress_display.o build/runner.o build/scheduler.o build/cmd_build.o build/cmd_clean.o build/cmd_configure.o build/cmd_show.o build/cmd_parse.o build/strict_checks.o build/config_commands.o build/context.o build/multi_variant.o build/options.o build/output.o build/target.o build/process-posix.o build/file_io-posix.o build/env-posix.o build/path-posix.o build/main.o build/throw_stubs.o -o build/putup -nostdlib++ -Wl,-dead_strip )
+(cd "." && ar rcs build/libputup.a build/sha256.o build/arena.o build/hash.o build/id_array.o build/id_bitset.o build/layout.o build/metrics.o build/path.o build/path_utils.o build/sorted_id_vec.o build/string_pool.o build/global_pool.o build/buf.o build/heap_buf.o build/string_utils.o build/terminal.o build/ast.o build/config.o build/depfile.o build/eval.o build/glob.o build/ignore.o build/lexer.o build/parser.o build/var_tracking.o build/builder.o build/dag.o build/dep_scanner.o build/rule_pattern.o build/gcc.o build/topo.o build/entry.o build/reader.o build/writer.o build/progress_display.o build/runner.o build/scheduler.o build/cmd_build.o build/cmd_clean.o build/cmd_configure.o build/cmd_show.o build/cmd_parse.o build/strict_checks.o build/config_commands.o build/context.o build/multi_variant.o build/options.o build/output.o build/target.o build/process-posix.o build/file_io-posix.o build/env-posix.o build/path-posix.o)
 (cd "test/unit" && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I../../include -I../../third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c test_var_tracking.cpp -o ../../build/test/unit/test_var_tracking.o)
 (cd "test/unit" && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I../../include -I../../third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c test_types.cpp -o ../../build/test/unit/test_types.o)
 (cd "test/unit" && clang++ -std=c++20 -Wall -Wextra -Werror -Wpedantic -fPIC -fno-exceptions -fno-rtti -I../../include -I../../third_party  -O2 -DNDEBUG -ffunction-sections -fdata-sections -c test_target.cpp -o ../../build/test/unit/test_target.o)