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| author | Justus Klausecker <justus@klausecker.de> | 2025-11-14 14:13:09 +0100 |
|---|---|---|
| committer | Matthew Lugg <mlugg@mlugg.co.uk> | 2025-11-14 23:25:54 +0000 |
| commit | 06d08dababda8fde2fef8267698a712d1966045d (patch) | |
| tree | 2517a590fd472799ebea1eee4f39cf92de023230 /src | |
| parent | c6b5945356568f6ec70ca00f9a844bd180f8ca62 (diff) | |
| download | zig-06d08dababda8fde2fef8267698a712d1966045d.tar.gz zig-06d08dababda8fde2fef8267698a712d1966045d.zip | |
Sema: fix illegal multi level pointer coercions
Moves a premature check that allowed pointers to mutable pointers to coerce
to any other pointer to a mutable pointer.
Diffstat (limited to 'src')
| -rw-r--r-- | src/Sema.zig | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/src/Sema.zig b/src/Sema.zig index 191ab34070..390ec0b926 100644 --- a/src/Sema.zig +++ b/src/Sema.zig @@ -29385,14 +29385,18 @@ const InMemoryCoercionResult = union(enum) { break; }, .array_sentinel => |sentinel| { - if (sentinel.actual.toIntern() != .unreachable_value) { - try sema.errNote(src, msg, "array sentinel '{f}' cannot cast into array sentinel '{f}'", .{ - sentinel.actual.fmtValueSema(pt, sema), sentinel.wanted.fmtValueSema(pt, sema), + if (sentinel.wanted.toIntern() == .unreachable_value) { + try sema.errNote(src, msg, "source array cannot be guaranteed to maintain '{f}' sentinel", .{ + sentinel.actual.fmtValueSema(pt, sema), }); - } else { + } else if (sentinel.actual.toIntern() == .unreachable_value) { try sema.errNote(src, msg, "destination array requires '{f}' sentinel", .{ sentinel.wanted.fmtValueSema(pt, sema), }); + } else { + try sema.errNote(src, msg, "array sentinel '{f}' cannot cast into array sentinel '{f}'", .{ + sentinel.actual.fmtValueSema(pt, sema), sentinel.wanted.fmtValueSema(pt, sema), + }); } break; }, @@ -30179,10 +30183,14 @@ fn coerceInMemoryAllowedPtrs( src_src, null, ); - if (child != .ok and !dest_is_mut) allow: { + if (child != .ok) allow: { // As a special case, we also allow coercing `*[n:s]T` to `*[n]T`, akin to dropping the sentinel from a slice. // `*[n:s]T` cannot coerce in memory to `*[n]T` since they have different sizes. - if (src_child.zigTypeTag(zcu) == .array and dest_child.zigTypeTag(zcu) == .array and + // + // We must once again include `dest_is_mut` because `**[n:s]T -> **[n]T` + // is not allowed, as it would make it possible to assign an illegal value + // to the sentinel-terminated side. + if (!dest_is_mut and src_child.zigTypeTag(zcu) == .array and dest_child.zigTypeTag(zcu) == .array and src_child.arrayLen(zcu) == dest_child.arrayLen(zcu) and src_child.sentinel(zcu) != null and dest_child.sentinel(zcu) == null and .ok == try sema.coerceInMemoryAllowed(block, dest_child.childType(zcu), src_child.childType(zcu), !dest_info.flags.is_const, target, dest_src, src_src, null)) |