Case 119: Internal struct loses a field (non-public, scoped)¶

Field	Value
Verdict	✅ NO_CHANGE
Category	No Change
Platforms	Linux, macOS, Windows
Flags	—
Detected `ChangeKind`s	—
Source files	`examples/case119_internal_struct_field_removed_scoped/`

Category: Public-surface scoping (ADR-024) | Verdict: ✅ NO_CHANGE (exit 0, with --scope-public-headers)

What changes¶

struct InternalStats drops a field (int errors;). Removing a field is normally an ABI break for that struct — but InternalStats is not on the public ABI surface: no exported, header-declared public function reaches it. The public API (Point, translate) is unchanged.

Why this is not a false positive¶

Downstream consumers only observe the public API. Since nothing public reaches InternalStats, removing one of its fields cannot break a caller that uses only translate()/Point. With ADR-024 public-surface scoping the finding is moved to the filtered audit ledger (visible via --show-filtered) instead of being reported, and the verdict is NO_CHANGE.

abicheck compare libfoo_v1.so libfoo_v2.so -H v1.h \
    --scope-public-headers --show-filtered
# verdict: NO_CHANGE (exit 0); filtered: type_field_removed: InternalStats

Scoping never hides a leak: if InternalStats were reachable from a public API, the reachability closure keeps it on the surface and the removal is reported as breaking.

How to fix¶

N/A — confined to an internal type, this is the intended compatible outcome.

Source files¶

app.c
v1.c
v1.h
v2.c
v2.h