feat(targets): per-target entry-scoped flags + required_features; test --profile (#131)#132
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…t --profile; 0.0.55 (#131) Resolve issue #131 without violating the compile-once model. Configuration that must reach shared code stays at the package/feature boundary; a target only carries flags private to its own exclusive entry. - [targets.<name>]: new `defines` / `cxxflags` / `cflags`, applied ONLY to that target's exclusive entry source (its `main`) — never to shared module/impl objects (compile-once). Fits flags that affect just a binary's own entry (e.g. a per-test contract evaluation semantic). - [targets.<name>]: new `required_features` gate — a target is emitted only when all listed features are active; otherwise silently skipped. Pure build-selection, runs before the modgraph so gated-out targets cost nothing. - Unsupported keys under [targets.<name>] now warn (error under --strict) and point at workspace / features / profile, instead of being dropped silently (the historic footgun behind #131). - `mcpp test` now accepts --profile / --features / --strict, so the code-under-test plus test binaries build under the chosen whole-build mode (sanitizers, contract semantics, ...). - docs/05-mcpp-toml.md (+ zh): document the new keys and a "where build configuration goes" decision guide. Design: .agents/docs/2026-06-18-... Tests: tests/unit/test_manifest.cpp covers parsing + unsupported-key warning + std-flag guard; e2e 57 (per-target flags, shared source stays neutral), 58 (required_features gate), 59 (mcpp test --profile reaches code-under-test).
…xxflag on own entry) Mirrors the issue's `[targets.test_contracts] cxxflags=[...]` shape: a single bin target whose per-target codegen flag must affect only its own `main`, not shared code. Uses -fno-exceptions (preprocessor-observable via __EXCEPTIONS) as a portable stand-in for -fcontract-evaluation-semantic=observe, which needs a contracts-enabled toolchain not guaranteed across the Linux/macOS/Windows CI matrix. Checks: reaches the entry, does NOT leak to a shared unit, appears on the target's main edge in build.ninja, and the binary builds + runs.
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Resolves #131 — per-target
cxxflagsoverride — but by the book, without breaking mcpp's compile-once model.Approach
A source maps to one object (and one BMI for modules), shared by every target, so a shared source cannot be compiled two ways in one build. Configuration that must reach shared code therefore stays at the package/feature boundary; a target only carries flags private to its own exclusive entry. Design rationale in
.agents/docs/2026-06-18-per-target-build-config-design.md.What's in
[targets.<name>]→defines/cxxflags/cflags— applied only to that target's exclusive entry source (itsmain), never to shared module/impl objects. Fits flags that affect just a binary's (or test's) own entry — e.g. a per-test contract evaluation semantic where the entry exercises the violation.[targets.<name>]→required_features— a target is emitted only when all listed features are active; otherwise silently skipped. Pure build-selection; runs before the modgraph so gated-out targets cost nothing.[targets.<name>]now warn (error under--strict) and point at workspace / features / profile — instead of being dropped silently (the historic footgun behind this issue).mcpp testaccepts--profile/--features/--strict— so the code-under-test plus the test binaries build under the chosen whole-build mode (sanitizers, contract semantics, ...).docs/05-mcpp-toml.md(+docs/zh): the new keys + a "where build configuration goes" decision guide.Not in scope (deliberately)
General per-target flags over the shared compile pool / variant partitioning — high cost (BMI×variant, infectious along the import graph) and the need is already served by workspace members + features + profiles.
Tests
tests/unit/test_manifest.cpp: per-target key parsing, unsupported-key warning,-std=guard.tests/e2e/57_per_target_flags.sh: two bin targets, each its own-D; a shared source stays neutral.tests/e2e/58_required_features_gate.sh:--features Xbuilds only the matching target.tests/e2e/59_test_profile_features.sh:mcpp test --profile observereaches the code-under-test.Local:
mcpp buildself-host OK;mcpp test18/18; new e2e 57/58/59 + multi-target/workspace/static/shared/package-flags regression set all pass.Version bumped to 0.0.55; CHANGELOG updated.