module builder

import os
import v2.pref

// Concern 1: the pre-parse self-host fast relink must never fire for a request
// that gen_cleanc() treats as "generation only" — otherwise a warm-cache
// `-o foo.c cmd/v2/v2.v` links an executable into foo.c instead of writing C.
fn test_fast_relink_skips_generation_only_outputs() {
    // A `.c` output is generation-only regardless of how it would be built.
    b_c := new_builder(&pref.Preferences{ backend: .cleanc })
    assert b_c.fast_relink_output_is_generation_only('/tmp/v2.c')
    assert b_c.fast_relink_output_is_generation_only('out.c')

    // A shared library is generation-only.
    b_shared := new_builder(&pref.Preferences{ backend: .cleanc, is_shared_lib: true })
    assert b_shared.fast_relink_output_is_generation_only('/tmp/lib')

    // A normal local executable build is NOT generation-only — the fast relink
    // is allowed to proceed (subject to its cache/freshness checks).
    b_exe := new_builder(&pref.Preferences{ backend: .cleanc })
    assert b_exe.can_compile_cleanc_locally() // sanity: host target compiles locally
    assert !b_exe.fast_relink_output_is_generation_only('/tmp/v3')
}

// Concern 2: the fast relink trusts the cc/cc_flags recorded in main.stamp, so a
// pre-parse fingerprint of the flag inputs that do NOT need parsing must change
// when the compiler / prod-shared mode / env CFLAGS change, and stay stable
// otherwise. A changed fingerprint is what invalidates a would-be stale relink.
fn test_preparse_flag_fingerprint_tracks_flag_settings() {
    base := new_builder(&pref.Preferences{ backend: .cleanc })
    fp0 := base.preparse_flag_fingerprint()

    // Stable for identical settings.
    assert new_builder(&pref.Preferences{ backend: .cleanc }).preparse_flag_fingerprint() == fp0

    // A different C compiler changes it.
    b_cc := new_builder(&pref.Preferences{ backend: .cleanc, ccompiler: 'some-other-cc' })
    assert b_cc.preparse_flag_fingerprint() != fp0

    // -prod changes it (different optimization flags).
    b_prod := new_builder(&pref.Preferences{ backend: .cleanc, is_prod: true })
    assert b_prod.preparse_flag_fingerprint() != fp0

    // -shared changes it (no -flto, different link mode).
    b_shared := new_builder(&pref.Preferences{ backend: .cleanc, is_shared_lib: true })
    assert b_shared.preparse_flag_fingerprint() != fp0

    // Env CFLAGS (V2CFLAGS) change it.
    prev := os.getenv('V2CFLAGS')
    os.setenv('V2CFLAGS', '-DV2_FAST_RELINK_TEST', true)
    fp_env := new_builder(&pref.Preferences{ backend: .cleanc }).preparse_flag_fingerprint()
    if prev == '' {
        os.unsetenv('V2CFLAGS')
    } else {
        os.setenv('V2CFLAGS', prev, true)
    }
    assert fp_env != fp0
}