| author |  Matthew Lugg <mlugg@mlugg.co.uk> 2025-01-01 11:30:33+00:00 |
| committer | Matthew Lugg <mlugg@mlugg.co.uk> 2025-01-01 16:20:40+00:00 |
| log | 5333d2443a80a82b34940be68e4ca8d1129b7ab7 |
| tree | 49d430c90b50b7296638628635ac06665b58c3e3 |
| parent | d02c2c76fc718a4d55977cfa776c98dac1a90032 |
Sema: fix invalid coercion `*[n:x]T` -> `*[m]T` for `n != m`
The change in `Sema.coerceExtra` is just to avoid an unhelpful error
message, covered by the added test case.
Resolves: #223732 files changed, 73 insertions(+), 1 deletions(-)
src- test
- cases
- compile_errors
src/Sema.zig+3-1
| ... | @@ -29736,6 +29736,7 @@ fn coerceExtra( | ... | @@ -29736,6 +29736,7 @@ fn coerceExtra( |
| 29736 | // Coercions where the source is a single pointer to an array. | 29736 | // Coercions where the source is a single pointer to an array. |
| 29737 | src_array_ptr: { | 29737 | src_array_ptr: { |
| 29738 | if (!inst_ty.isSinglePointer(zcu)) break :src_array_ptr; | 29738 | if (!inst_ty.isSinglePointer(zcu)) break :src_array_ptr; |
| 29739 | if (dest_info.flags.size == .One) break :src_array_ptr; // `*[n]T` -> `*T` isn't valid | ||
| 29739 | if (!sema.checkPtrAttributes(dest_ty, inst_ty, &in_memory_result)) break :pointer; | 29740 | if (!sema.checkPtrAttributes(dest_ty, inst_ty, &in_memory_result)) break :pointer; |
| 29740 | const array_ty = inst_ty.childType(zcu); | 29741 | const array_ty = inst_ty.childType(zcu); |
| 29741 | if (array_ty.zigTypeTag(zcu) != .array) break :src_array_ptr; | 29742 | if (array_ty.zigTypeTag(zcu) != .array) break :src_array_ptr; |
| ... | @@ -29791,7 +29792,7 @@ fn coerceExtra( | ... | @@ -29791,7 +29792,7 @@ fn coerceExtra( |
| 29791 | // *[N]T to [*]T | 29792 | // *[N]T to [*]T |
| 29792 | return sema.coerceCompatiblePtrs(block, dest_ty, inst, inst_src); | 29793 | return sema.coerceCompatiblePtrs(block, dest_ty, inst, inst_src); |
| 29793 | }, | 29794 | }, |
| 29794 | .One => {}, | 29795 | .One => unreachable, // early exit at top of block |
| 29795 | } | 29796 | } |
| 29796 | } | 29797 | } |
| 29797 | 29798 | ||
| ... | @@ -31259,6 +31260,7 @@ fn coerceInMemoryAllowedPtrs( | ... | @@ -31259,6 +31260,7 @@ fn coerceInMemoryAllowedPtrs( |
| 31259 | // As a special case, we also allow coercing `*[n:s]T` to `*[n]T`, akin to dropping the sentinel from a slice. | 31260 | // As a special case, we also allow coercing `*[n:s]T` to `*[n]T`, akin to dropping the sentinel from a slice. |
| 31260 | // `*[n:s]T` cannot coerce in memory to `*[n]T` since they have different sizes. | 31261 | // `*[n:s]T` cannot coerce in memory to `*[n]T` since they have different sizes. |
| 31261 | if (src_child.zigTypeTag(zcu) == .array and dest_child.zigTypeTag(zcu) == .array and | 31262 | if (src_child.zigTypeTag(zcu) == .array and dest_child.zigTypeTag(zcu) == .array and |
| 31263 | src_child.arrayLen(zcu) == dest_child.arrayLen(zcu) and | ||
| 31262 | src_child.sentinel(zcu) != null and dest_child.sentinel(zcu) == null and | 31264 | src_child.sentinel(zcu) != null and dest_child.sentinel(zcu) == null and |
| 31263 | .ok == try sema.coerceInMemoryAllowed(block, dest_child.childType(zcu), src_child.childType(zcu), !dest_info.flags.is_const, target, dest_src, src_src, null)) | 31265 | .ok == try sema.coerceInMemoryAllowed(block, dest_child.childType(zcu), src_child.childType(zcu), !dest_info.flags.is_const, target, dest_src, src_src, null)) |
| 31264 | { | 31266 | { |
test/cases/compile_errors/coerce_array_to_different_size.zig created+70
| ... | @@ -0,0 +1,70 @@ | ||
| 1 | export fn bigger(a: *const [10]u32) void { | ||
| 2 | const b: *const [20]u32 = a; | ||
| 3 | _ = b; | ||
| 4 | } | ||
| 5 | |||
| 6 | comptime { | ||
| 7 | const a: *const [10]u32 = &@splat(0); | ||
| 8 | const b: *const [20]u32 = a; | ||
| 9 | _ = b; | ||
| 10 | } | ||
| 11 | |||
| 12 | export fn biggerSentinel(a: *const [10:0]u32) void { | ||
| 13 | const b: *const [20]u32 = a; | ||
| 14 | _ = b; | ||
| 15 | } | ||
| 16 | |||
| 17 | comptime { | ||
| 18 | const a: *const [10:0]u32 = &@splat(0); | ||
| 19 | const b: *const [20]u32 = a; | ||
| 20 | _ = b; | ||
| 21 | } | ||
| 22 | |||
| 23 | export fn smaller(a: *const [10]u32) void { | ||
| 24 | const b: *const [5]u32 = a; | ||
| 25 | _ = b; | ||
| 26 | } | ||
| 27 | |||
| 28 | comptime { | ||
| 29 | const a: *const [10]u32 = &@splat(0); | ||
| 30 | const b: *const [5]u32 = a; | ||
| 31 | _ = b; | ||
| 32 | } | ||
| 33 | |||
| 34 | export fn smallerSentinel(a: *const [10:0]u32) void { | ||
| 35 | const b: *const [5]u32 = a; | ||
| 36 | _ = b; | ||
| 37 | } | ||
| 38 | |||
| 39 | comptime { | ||
| 40 | const a: *const [10:0]u32 = &@splat(0); | ||
| 41 | const b: *const [5]u32 = a; | ||
| 42 | _ = b; | ||
| 43 | } | ||
| 44 | |||
| 45 | // error | ||
| 46 | // | ||
| 47 | // :2:31: error: expected type '*const [20]u32', found '*const [10]u32' | ||
| 48 | // :2:31: note: pointer type child '[10]u32' cannot cast into pointer type child '[20]u32' | ||
| 49 | // :2:31: note: array of length 10 cannot cast into an array of length 20 | ||
| 50 | // :8:31: error: expected type '*const [20]u32', found '*const [10]u32' | ||
| 51 | // :8:31: note: pointer type child '[10]u32' cannot cast into pointer type child '[20]u32' | ||
| 52 | // :8:31: note: array of length 10 cannot cast into an array of length 20 | ||
| 53 | // :13:31: error: expected type '*const [20]u32', found '*const [10:0]u32' | ||
| 54 | // :13:31: note: pointer type child '[10:0]u32' cannot cast into pointer type child '[20]u32' | ||
| 55 | // :13:31: note: array of length 10 cannot cast into an array of length 20 | ||
| 56 | // :19:31: error: expected type '*const [20]u32', found '*const [10:0]u32' | ||
| 57 | // :19:31: note: pointer type child '[10:0]u32' cannot cast into pointer type child '[20]u32' | ||
| 58 | // :19:31: note: array of length 10 cannot cast into an array of length 20 | ||
| 59 | // :24:30: error: expected type '*const [5]u32', found '*const [10]u32' | ||
| 60 | // :24:30: note: pointer type child '[10]u32' cannot cast into pointer type child '[5]u32' | ||
| 61 | // :24:30: note: array of length 10 cannot cast into an array of length 5 | ||
| 62 | // :30:30: error: expected type '*const [5]u32', found '*const [10]u32' | ||
| 63 | // :30:30: note: pointer type child '[10]u32' cannot cast into pointer type child '[5]u32' | ||
| 64 | // :30:30: note: array of length 10 cannot cast into an array of length 5 | ||
| 65 | // :35:30: error: expected type '*const [5]u32', found '*const [10:0]u32' | ||
| 66 | // :35:30: note: pointer type child '[10:0]u32' cannot cast into pointer type child '[5]u32' | ||
| 67 | // :35:30: note: array of length 10 cannot cast into an array of length 5 | ||
| 68 | // :41:30: error: expected type '*const [5]u32', found '*const [10:0]u32' | ||
| 69 | // :41:30: note: pointer type child '[10:0]u32' cannot cast into pointer type child '[5]u32' | ||
| 70 | // :41:30: note: array of length 10 cannot cast into an array of length 5 | ||