Commit f154cd1fdc
Changed files (5)
src/Sema.zig
@@ -30797,7 +30797,8 @@ const InMemoryCoercionResult = union(enum) {
ptr_addrspace: AddressSpace,
ptr_sentinel: Sentinel,
ptr_size: Size,
- ptr_qualifiers: Qualifiers,
+ ptr_const: Pair,
+ ptr_volatile: Pair,
ptr_allowzero: Pair,
ptr_bit_range: BitRange,
ptr_alignment: AlignPair,
@@ -30861,13 +30862,6 @@ const InMemoryCoercionResult = union(enum) {
wanted: std.builtin.Type.Pointer.Size,
};
- const Qualifiers = struct {
- actual_const: bool,
- wanted_const: bool,
- actual_volatile: bool,
- wanted_volatile: bool,
- };
-
const AddressSpace = struct {
actual: std.builtin.AddressSpace,
wanted: std.builtin.AddressSpace,
@@ -31067,16 +31061,6 @@ const InMemoryCoercionResult = union(enum) {
try sema.errNote(src, msg, "a {s} pointer cannot cast into a {s} pointer", .{ pointerSizeString(size.actual), pointerSizeString(size.wanted) });
break;
},
- .ptr_qualifiers => |qualifiers| {
- const ok_const = !qualifiers.actual_const or qualifiers.wanted_const;
- const ok_volatile = !qualifiers.actual_volatile or qualifiers.wanted_volatile;
- if (!ok_const) {
- try sema.errNote(src, msg, "cast discards const qualifier", .{});
- } else if (!ok_volatile) {
- try sema.errNote(src, msg, "cast discards volatile qualifier", .{});
- }
- break;
- },
.ptr_allowzero => |pair| {
const wanted_allow_zero = pair.wanted.ptrAllowsZero(pt.zcu);
const actual_allow_zero = pair.actual.ptrAllowsZero(pt.zcu);
@@ -31085,8 +31069,32 @@ const InMemoryCoercionResult = union(enum) {
pair.actual.fmt(pt), pair.wanted.fmt(pt),
});
} else {
- try sema.errNote(src, msg, "mutable '{}' allows illegal null values stored to type '{}'", .{
- pair.actual.fmt(pt), pair.wanted.fmt(pt),
+ try sema.errNote(src, msg, "mutable '{}' would allow illegal null values stored to type '{}'", .{
+ pair.wanted.fmt(pt), pair.actual.fmt(pt),
+ });
+ }
+ break;
+ },
+ .ptr_const => |pair| {
+ const wanted_const = pair.wanted.isConstPtr(pt.zcu);
+ const actual_const = pair.actual.isConstPtr(pt.zcu);
+ if (actual_const and !wanted_const) {
+ try sema.errNote(src, msg, "cast discards const qualifier", .{});
+ } else {
+ try sema.errNote(src, msg, "mutable '{}' would allow illegal const pointers stored to type '{}'", .{
+ pair.wanted.fmt(pt), pair.actual.fmt(pt),
+ });
+ }
+ break;
+ },
+ .ptr_volatile => |pair| {
+ const wanted_volatile = pair.wanted.isVolatilePtr(pt.zcu);
+ const actual_volatile = pair.actual.isVolatilePtr(pt.zcu);
+ if (actual_volatile and !wanted_volatile) {
+ try sema.errNote(src, msg, "cast discards volatile qualifier", .{});
+ } else {
+ try sema.errNote(src, msg, "mutable '{}' would allow illegal volatile pointers stored to type '{}'", .{
+ pair.wanted.fmt(pt), pair.actual.fmt(pt),
});
}
break;
@@ -31136,20 +31144,22 @@ fn pointerSizeString(size: std.builtin.Type.Pointer.Size) []const u8 {
};
}
-/// If pointers have the same representation in runtime memory, a bitcast AIR instruction
-/// may be used for the coercion.
-/// * `const` attribute can be gained
-/// * `volatile` attribute can be gained
-/// * `allowzero` attribute can be gained (whether from explicit attribute, C pointer, or optional pointer) but only if !dest_is_mut
-/// * alignment can be decreased
-/// * bit offset attributes must match exactly
-/// * `*`/`[*]` must match exactly, but `[*c]` matches either one
-/// * sentinel-terminated pointers can coerce into `[*]`
+/// If types `A` and `B` have identical representations in runtime memory, they are considered
+/// "in-memory coercible". This is a subset of normal coercions. Not only can `A` coerce to `B`, but
+/// also, coercions can happen through pointers. For instance, `*const A` can coerce to `*const B`.
+///
+/// If this function is called, the coercion must be applied, or a compile error emitted if `.ok`
+/// is not returned. This is because this function may modify inferred error sets to make a
+/// coercion possible, even if `.ok` is not returned.
pub fn coerceInMemoryAllowed(
sema: *Sema,
block: *Block,
dest_ty: Type,
src_ty: Type,
+ /// If `true`, this query comes from an attempted coercion of the form `*Src` -> `*Dest`, where
+ /// both pointers are mutable. If this coercion is allowed, one could store to the `*Dest` and
+ /// load from the `*Src` to effectively perform an in-memory coercion from `Dest` to `Src`.
+ /// Therefore, when `dest_is_mut`, the in-memory coercion must be valid in *both directions*.
dest_is_mut: bool,
target: std.Target,
dest_src: LazySrcLoc,
@@ -31224,7 +31234,7 @@ pub fn coerceInMemoryAllowed(
// Functions
if (dest_tag == .@"fn" and src_tag == .@"fn") {
- return try sema.coerceInMemoryAllowedFns(block, dest_ty, src_ty, target, dest_src, src_src);
+ return try sema.coerceInMemoryAllowedFns(block, dest_ty, src_ty, dest_is_mut, target, dest_src, src_src);
}
// Error Unions
@@ -31233,7 +31243,7 @@ pub fn coerceInMemoryAllowed(
const src_payload = src_ty.errorUnionPayload(zcu);
const child = try sema.coerceInMemoryAllowed(block, dest_payload, src_payload, dest_is_mut, target, dest_src, src_src, null);
if (child != .ok) {
- return InMemoryCoercionResult{ .error_union_payload = .{
+ return .{ .error_union_payload = .{
.child = try child.dupe(sema.arena),
.actual = src_payload,
.wanted = dest_payload,
@@ -31244,7 +31254,11 @@ pub fn coerceInMemoryAllowed(
// Error Sets
if (dest_tag == .error_set and src_tag == .error_set) {
- return try sema.coerceInMemoryAllowedErrorSets(block, dest_ty, src_ty, dest_src, src_src);
+ const res1 = try sema.coerceInMemoryAllowedErrorSets(block, dest_ty, src_ty, dest_src, src_src);
+ if (!dest_is_mut or res1 != .ok) return res1;
+ // src -> dest is okay, but `dest_is_mut`, so it needs to be allowed in the other direction.
+ const res2 = try sema.coerceInMemoryAllowedErrorSets(block, src_ty, dest_ty, src_src, dest_src);
+ return res2;
}
// Arrays
@@ -31252,7 +31266,7 @@ pub fn coerceInMemoryAllowed(
const dest_info = dest_ty.arrayInfo(zcu);
const src_info = src_ty.arrayInfo(zcu);
if (dest_info.len != src_info.len) {
- return InMemoryCoercionResult{ .array_len = .{
+ return .{ .array_len = .{
.actual = src_info.len,
.wanted = dest_info.len,
} };
@@ -31263,7 +31277,7 @@ pub fn coerceInMemoryAllowed(
.ok => {},
.no_match => return child,
else => {
- return InMemoryCoercionResult{ .array_elem = .{
+ return .{ .array_elem = .{
.child = try child.dupe(sema.arena),
.actual = src_info.elem_type,
.wanted = dest_info.elem_type,
@@ -31279,7 +31293,7 @@ pub fn coerceInMemoryAllowed(
zcu,
));
if (!ok_sent) {
- return InMemoryCoercionResult{ .array_sentinel = .{
+ return .{ .array_sentinel = .{
.actual = src_info.sentinel orelse Value.@"unreachable",
.wanted = dest_info.sentinel orelse Value.@"unreachable",
.ty = dest_info.elem_type,
@@ -31293,7 +31307,7 @@ pub fn coerceInMemoryAllowed(
const dest_len = dest_ty.vectorLen(zcu);
const src_len = src_ty.vectorLen(zcu);
if (dest_len != src_len) {
- return InMemoryCoercionResult{ .vector_len = .{
+ return .{ .vector_len = .{
.actual = src_len,
.wanted = dest_len,
} };
@@ -31303,7 +31317,7 @@ pub fn coerceInMemoryAllowed(
const src_elem_ty = src_ty.scalarType(zcu);
const child = try sema.coerceInMemoryAllowed(block, dest_elem_ty, src_elem_ty, dest_is_mut, target, dest_src, src_src, null);
if (child != .ok) {
- return InMemoryCoercionResult{ .vector_elem = .{
+ return .{ .vector_elem = .{
.child = try child.dupe(sema.arena),
.actual = src_elem_ty,
.wanted = dest_elem_ty,
@@ -31320,7 +31334,7 @@ pub fn coerceInMemoryAllowed(
const dest_len = dest_ty.arrayLen(zcu);
const src_len = src_ty.arrayLen(zcu);
if (dest_len != src_len) {
- return InMemoryCoercionResult{ .array_len = .{
+ return .{ .array_len = .{
.actual = src_len,
.wanted = dest_len,
} };
@@ -31330,7 +31344,7 @@ pub fn coerceInMemoryAllowed(
const src_elem_ty = src_ty.childType(zcu);
const child = try sema.coerceInMemoryAllowed(block, dest_elem_ty, src_elem_ty, dest_is_mut, target, dest_src, src_src, null);
if (child != .ok) {
- return InMemoryCoercionResult{ .array_elem = .{
+ return .{ .array_elem = .{
.child = try child.dupe(sema.arena),
.actual = src_elem_ty,
.wanted = dest_elem_ty,
@@ -31340,7 +31354,7 @@ pub fn coerceInMemoryAllowed(
if (dest_tag == .array) {
const dest_info = dest_ty.arrayInfo(zcu);
if (dest_info.sentinel != null) {
- return InMemoryCoercionResult{ .array_sentinel = .{
+ return .{ .array_sentinel = .{
.actual = Value.@"unreachable",
.wanted = dest_info.sentinel.?,
.ty = dest_info.elem_type,
@@ -31360,7 +31374,7 @@ pub fn coerceInMemoryAllowed(
// Optionals
if (dest_tag == .optional and src_tag == .optional) {
if ((maybe_dest_ptr_ty != null) != (maybe_src_ptr_ty != null)) {
- return InMemoryCoercionResult{ .optional_shape = .{
+ return .{ .optional_shape = .{
.actual = src_ty,
.wanted = dest_ty,
} };
@@ -31370,7 +31384,7 @@ pub fn coerceInMemoryAllowed(
const child = try sema.coerceInMemoryAllowed(block, dest_child_type, src_child_type, dest_is_mut, target, dest_src, src_src, null);
if (child != .ok) {
- return InMemoryCoercionResult{ .optional_child = .{
+ return .{ .optional_child = .{
.child = try child.dupe(sema.arena),
.actual = src_child_type,
.wanted = dest_child_type,
@@ -31382,7 +31396,6 @@ pub fn coerceInMemoryAllowed(
// Tuples (with in-memory-coercible fields)
if (dest_ty.isTuple(zcu) and src_ty.isTuple(zcu)) tuple: {
- if (dest_ty.containerLayout(zcu) != src_ty.containerLayout(zcu)) break :tuple;
if (dest_ty.structFieldCount(zcu) != src_ty.structFieldCount(zcu)) break :tuple;
const field_count = dest_ty.structFieldCount(zcu);
for (0..field_count) |field_idx| {
@@ -31396,7 +31409,7 @@ pub fn coerceInMemoryAllowed(
return .ok;
}
- return InMemoryCoercionResult{ .no_match = .{
+ return .{ .no_match = .{
.actual = dest_ty,
.wanted = src_ty,
} };
@@ -31505,6 +31518,8 @@ fn coerceInMemoryAllowedFns(
block: *Block,
dest_ty: Type,
src_ty: Type,
+ /// If set, the coercion must be valid in both directions.
+ dest_is_mut: bool,
target: std.Target,
dest_src: LazySrcLoc,
src_src: LazySrcLoc,
@@ -31525,40 +31540,49 @@ fn coerceInMemoryAllowedFns(
return InMemoryCoercionResult{ .fn_generic = dest_info.is_generic };
}
- if (!callconvCoerceAllowed(target, src_info.cc, dest_info.cc)) {
+ const callconv_ok = callconvCoerceAllowed(target, src_info.cc, dest_info.cc) and
+ (!dest_is_mut or callconvCoerceAllowed(target, dest_info.cc, src_info.cc));
+
+ if (!callconv_ok) {
return .{ .fn_cc = .{
.actual = src_info.cc,
.wanted = dest_info.cc,
} };
}
- switch (src_info.return_type) {
- .noreturn_type, .generic_poison_type => {},
- else => {
- const dest_return_type = Type.fromInterned(dest_info.return_type);
- const src_return_type = Type.fromInterned(src_info.return_type);
- const rt = try sema.coerceInMemoryAllowed(block, dest_return_type, src_return_type, false, target, dest_src, src_src, null);
- if (rt != .ok) {
- return InMemoryCoercionResult{ .fn_return_type = .{
- .child = try rt.dupe(sema.arena),
- .actual = src_return_type,
- .wanted = dest_return_type,
- } };
- }
- },
+ if (!switch (src_info.return_type) {
+ .generic_poison_type => true,
+ .noreturn_type => !dest_is_mut,
+ else => false,
+ }) {
+ const rt = try sema.coerceInMemoryAllowed(
+ block,
+ .fromInterned(dest_info.return_type),
+ .fromInterned(src_info.return_type),
+ dest_is_mut,
+ target,
+ dest_src,
+ src_src,
+ null,
+ );
+ if (rt != .ok) return .{ .fn_return_type = .{
+ .child = try rt.dupe(sema.arena),
+ .actual = .fromInterned(src_info.return_type),
+ .wanted = .fromInterned(dest_info.return_type),
+ } };
}
}
const params_len = params_len: {
if (dest_info.param_types.len != src_info.param_types.len) {
- return InMemoryCoercionResult{ .fn_param_count = .{
+ return .{ .fn_param_count = .{
.actual = src_info.param_types.len,
.wanted = dest_info.param_types.len,
} };
}
if (dest_info.noalias_bits != src_info.noalias_bits) {
- return InMemoryCoercionResult{ .fn_param_noalias = .{
+ return .{ .fn_param_noalias = .{
.actual = src_info.noalias_bits,
.wanted = dest_info.noalias_bits,
} };
@@ -31568,14 +31592,15 @@ fn coerceInMemoryAllowedFns(
};
for (0..params_len) |param_i| {
- const dest_param_ty = Type.fromInterned(dest_info.param_types.get(ip)[param_i]);
- const src_param_ty = Type.fromInterned(src_info.param_types.get(ip)[param_i]);
+ const dest_param_ty: Type = .fromInterned(dest_info.param_types.get(ip)[param_i]);
+ const src_param_ty: Type = .fromInterned(src_info.param_types.get(ip)[param_i]);
- const param_i_small: u5 = @intCast(param_i);
- if (dest_info.paramIsComptime(param_i_small) != src_info.paramIsComptime(param_i_small)) {
- return InMemoryCoercionResult{ .fn_param_comptime = .{
+ const src_is_comptime = src_info.paramIsComptime(@intCast(param_i));
+ const dest_is_comptime = dest_info.paramIsComptime(@intCast(param_i));
+ if (src_is_comptime != dest_is_comptime) {
+ return .{ .fn_param_comptime = .{
.index = param_i,
- .wanted = dest_info.paramIsComptime(param_i_small),
+ .wanted = dest_is_comptime,
} };
}
@@ -31583,9 +31608,9 @@ fn coerceInMemoryAllowedFns(
.generic_poison_type => {},
else => {
// Note: Cast direction is reversed here.
- const param = try sema.coerceInMemoryAllowed(block, src_param_ty, dest_param_ty, false, target, dest_src, src_src, null);
+ const param = try sema.coerceInMemoryAllowed(block, src_param_ty, dest_param_ty, dest_is_mut, target, dest_src, src_src, null);
if (param != .ok) {
- return InMemoryCoercionResult{ .fn_param = .{
+ return .{ .fn_param = .{
.child = try param.dupe(sema.arena),
.actual = src_param_ty,
.wanted = dest_param_ty,
@@ -31644,6 +31669,7 @@ fn coerceInMemoryAllowedPtrs(
src_ty: Type,
dest_ptr_ty: Type,
src_ptr_ty: Type,
+ /// If set, the coercion must be valid in both directions.
dest_is_mut: bool,
target: std.Target,
dest_src: LazySrcLoc,
@@ -31663,21 +31689,34 @@ fn coerceInMemoryAllowedPtrs(
} };
}
- const ok_cv_qualifiers =
- (!src_info.flags.is_const or dest_info.flags.is_const) and
- (!src_info.flags.is_volatile or dest_info.flags.is_volatile);
+ const ok_const = src_info.flags.is_const == dest_info.flags.is_const or
+ (!dest_is_mut and dest_info.flags.is_const);
- if (!ok_cv_qualifiers) {
- return InMemoryCoercionResult{ .ptr_qualifiers = .{
- .actual_const = src_info.flags.is_const,
- .wanted_const = dest_info.flags.is_const,
- .actual_volatile = src_info.flags.is_volatile,
- .wanted_volatile = dest_info.flags.is_volatile,
- } };
- }
+ if (!ok_const) return .{ .ptr_const = .{
+ .actual = src_ty,
+ .wanted = dest_ty,
+ } };
+
+ const ok_volatile = src_info.flags.is_volatile == dest_info.flags.is_volatile or
+ (!dest_is_mut and dest_info.flags.is_volatile);
+
+ if (!ok_volatile) return .{ .ptr_volatile = .{
+ .actual = src_ty,
+ .wanted = dest_ty,
+ } };
+
+ const dest_allowzero = dest_ty.ptrAllowsZero(zcu);
+ const src_allowzero = src_ty.ptrAllowsZero(zcu);
+ const ok_allowzero = src_allowzero == dest_allowzero or
+ (!dest_is_mut and dest_allowzero);
+
+ if (!ok_allowzero) return .{ .ptr_allowzero = .{
+ .actual = src_ty,
+ .wanted = dest_ty,
+ } };
if (dest_info.flags.address_space != src_info.flags.address_space) {
- return InMemoryCoercionResult{ .ptr_addrspace = .{
+ return .{ .ptr_addrspace = .{
.actual = src_info.flags.address_space,
.wanted = dest_info.flags.address_space,
} };
@@ -31685,8 +31724,28 @@ fn coerceInMemoryAllowedPtrs(
const dest_child = Type.fromInterned(dest_info.child);
const src_child = Type.fromInterned(src_info.child);
- const child = try sema.coerceInMemoryAllowed(block, dest_child, src_child, !dest_info.flags.is_const, target, dest_src, src_src, null);
- if (child != .ok) allow: {
+ const child = try sema.coerceInMemoryAllowed(
+ block,
+ dest_child,
+ src_child,
+ // We must also include `dest_is_mut`.
+ // Otherwise, this code is valid:
+ //
+ // const b: B = ...;
+ // var pa: *const A = undefined;
+ // const ppa: **const A = &pa;
+ // const ppb: **const B = ppa; // <-- this is what that allows
+ // ppb.* = &b;
+ // const a: A = pa.*;
+ //
+ // ...effectively performing an in-memory coercion from B to A.
+ dest_is_mut or !dest_info.flags.is_const,
+ target,
+ dest_src,
+ src_src,
+ null,
+ );
+ if (child != .ok and !dest_is_mut) 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
@@ -31695,30 +31754,17 @@ fn coerceInMemoryAllowedPtrs(
{
break :allow;
}
- return InMemoryCoercionResult{ .ptr_child = .{
+ return .{ .ptr_child = .{
.child = try child.dupe(sema.arena),
- .actual = Type.fromInterned(src_info.child),
- .wanted = Type.fromInterned(dest_info.child),
- } };
- }
-
- const dest_allow_zero = dest_ty.ptrAllowsZero(zcu);
- const src_allow_zero = src_ty.ptrAllowsZero(zcu);
-
- const ok_allows_zero = (dest_allow_zero and
- (src_allow_zero or !dest_is_mut)) or
- (!dest_allow_zero and !src_allow_zero);
- if (!ok_allows_zero) {
- return InMemoryCoercionResult{ .ptr_allowzero = .{
- .actual = src_ty,
- .wanted = dest_ty,
+ .actual = .fromInterned(src_info.child),
+ .wanted = .fromInterned(dest_info.child),
} };
}
if (src_info.packed_offset.host_size != dest_info.packed_offset.host_size or
src_info.packed_offset.bit_offset != dest_info.packed_offset.bit_offset)
{
- return InMemoryCoercionResult{ .ptr_bit_range = .{
+ return .{ .ptr_bit_range = .{
.actual_host = src_info.packed_offset.host_size,
.wanted_host = dest_info.packed_offset.host_size,
.actual_offset = src_info.packed_offset.bit_offset,
@@ -31726,11 +31772,20 @@ fn coerceInMemoryAllowedPtrs(
} };
}
- const ok_sent = dest_info.sentinel == .none or src_info.flags.size == .C or
- (src_info.sentinel != .none and
- dest_info.sentinel == try zcu.intern_pool.getCoerced(sema.gpa, pt.tid, src_info.sentinel, dest_info.child));
- if (!ok_sent) {
- return InMemoryCoercionResult{ .ptr_sentinel = .{
+ const sentinel_ok = ok: {
+ const ss = src_info.sentinel;
+ const ds = dest_info.sentinel;
+ if (ss == .none and ds == .none) break :ok true;
+ if (ss != .none and ds != .none) {
+ if (ds == try zcu.intern_pool.getCoerced(sema.gpa, pt.tid, ss, dest_info.child)) break :ok true;
+ }
+ if (src_info.flags.size == .C) break :ok true;
+ if (!dest_is_mut and dest_info.sentinel == .none) break :ok true;
+ break :ok false;
+ };
+
+ if (!sentinel_ok) {
+ return .{ .ptr_sentinel = .{
.actual = switch (src_info.sentinel) {
.none => Value.@"unreachable",
else => Value.fromInterned(src_info.sentinel),
@@ -31760,7 +31815,7 @@ fn coerceInMemoryAllowedPtrs(
else
try Type.fromInterned(dest_info.child).abiAlignmentSema(pt);
- if (dest_align.compare(.gt, src_align)) {
+ if (dest_align.compare(if (dest_is_mut) .neq else .gt, src_align)) {
return InMemoryCoercionResult{ .ptr_alignment = .{
.actual = src_align,
.wanted = dest_align,
@@ -32252,19 +32307,23 @@ fn checkPtrAttributes(sema: *Sema, dest_ty: Type, inst_ty: Type, in_memory_resul
(Type.fromInterned(inst_info.child).arrayLen(zcu) == 0 and dest_info.sentinel == .none and dest_info.flags.size != .C and dest_info.flags.size != .Many))) or
(Type.fromInterned(inst_info.child).isTuple(zcu) and Type.fromInterned(inst_info.child).structFieldCount(zcu) == 0);
- const ok_cv_qualifiers =
- ((!inst_info.flags.is_const or dest_info.flags.is_const) or len0) and
- (!inst_info.flags.is_volatile or dest_info.flags.is_volatile);
-
- if (!ok_cv_qualifiers) {
- in_memory_result.* = .{ .ptr_qualifiers = .{
- .actual_const = inst_info.flags.is_const,
- .wanted_const = dest_info.flags.is_const,
- .actual_volatile = inst_info.flags.is_volatile,
- .wanted_volatile = dest_info.flags.is_volatile,
+ const ok_const = (!inst_info.flags.is_const or dest_info.flags.is_const) or len0;
+ const ok_volatile = !inst_info.flags.is_volatile or dest_info.flags.is_volatile;
+ if (!ok_const) {
+ in_memory_result.* = .{ .ptr_const = .{
+ .actual = inst_ty,
+ .wanted = dest_ty,
} };
return false;
}
+ if (!ok_volatile) {
+ in_memory_result.* = .{ .ptr_volatile = .{
+ .actual = inst_ty,
+ .wanted = dest_ty,
+ } };
+ return false;
+ }
+
if (dest_info.flags.address_space != inst_info.flags.address_space) {
in_memory_result.* = .{ .ptr_addrspace = .{
.actual = inst_info.flags.address_space,
@@ -35441,11 +35500,11 @@ fn resolvePeerTypesInner(
.peer_idx_b = i,
} };
// ty -> cur_ty
- if (.ok == try sema.coerceInMemoryAllowedFns(block, cur_ty, ty, target, src, src)) {
+ if (.ok == try sema.coerceInMemoryAllowedFns(block, cur_ty, ty, false, target, src, src)) {
continue;
}
// cur_ty -> ty
- if (.ok == try sema.coerceInMemoryAllowedFns(block, ty, cur_ty, target, src, src)) {
+ if (.ok == try sema.coerceInMemoryAllowedFns(block, ty, cur_ty, false, target, src, src)) {
opt_cur_ty = ty;
continue;
}
@@ -35834,12 +35893,12 @@ fn resolvePairInMemoryCoercible(sema: *Sema, block: *Block, src: LazySrcLoc, ty_
const target = sema.pt.zcu.getTarget();
// ty_b -> ty_a
- if (.ok == try sema.coerceInMemoryAllowed(block, ty_a, ty_b, true, target, src, src, null)) {
+ if (.ok == try sema.coerceInMemoryAllowed(block, ty_a, ty_b, false, target, src, src, null)) {
return ty_a;
}
// ty_a -> ty_b
- if (.ok == try sema.coerceInMemoryAllowed(block, ty_b, ty_a, true, target, src, src, null)) {
+ if (.ok == try sema.coerceInMemoryAllowed(block, ty_b, ty_a, false, target, src, src, null)) {
return ty_b;
}
test/cases/compile_errors/implicit_cast_between_C_pointer_and_Zig_pointer-bad_const-align-child.zig
@@ -38,7 +38,7 @@ export fn f() void {
// :8:18: error: expected type '*u8', found '[*c]const u8'
// :8:18: note: cast discards const qualifier
// :13:19: error: expected type '*u32', found '[*c]u8'
-// :13:19: note: pointer type child 'u8' cannot cast into pointer type child 'u32'
+// :13:19: note: '[*c]u8' could have null values which are illegal in type '*u32'
// :18:22: error: expected type '[*c]u32', found '*align(1) u32'
// :18:22: note: pointer alignment '1' cannot cast into pointer alignment '4'
// :23:21: error: expected type '[*c]u8', found '*const u8'
test/cases/compile_errors/implicit_casting_C_pointers_which_would_mess_up_null_semantics.zig
@@ -13,7 +13,7 @@ export fn entry2() void {
var slice: []u8 = &buf;
var opt_many_ptr: [*]u8 = slice.ptr;
var ptr_opt_many_ptr = &opt_many_ptr;
- var c_ptr: [*c][*c]const u8 = ptr_opt_many_ptr;
+ var c_ptr: [*c][*c]u8 = ptr_opt_many_ptr;
_ = &slice;
_ = &ptr_opt_many_ptr;
_ = &c_ptr;
@@ -24,8 +24,7 @@ export fn entry2() void {
// target=native
//
// :6:24: error: expected type '*const [*]const u8', found '[*c]const [*c]const u8'
-// :6:24: note: pointer type child '[*c]const u8' cannot cast into pointer type child '[*]const u8'
-// :6:24: note: '[*c]const u8' could have null values which are illegal in type '[*]const u8'
-// :16:35: error: expected type '[*c][*c]const u8', found '*[*]u8'
-// :16:35: note: pointer type child '[*]u8' cannot cast into pointer type child '[*c]const u8'
-// :16:35: note: mutable '[*]u8' allows illegal null values stored to type '[*c]const u8'
+// :6:24: note: '[*c]const [*c]const u8' could have null values which are illegal in type '*const [*]const u8'
+// :16:29: error: expected type '[*c][*c]u8', found '*[*]u8'
+// :16:29: note: pointer type child '[*]u8' cannot cast into pointer type child '[*c]u8'
+// :16:29: note: mutable '[*c]u8' would allow illegal null values stored to type '[*]u8'
test/cases/compile_errors/invalid_pointer_coercions.zig
@@ -0,0 +1,77 @@
+//! This file contains pointer coercions which are invalid because the element types are only
+//! in-memory coercible *in one direction*. When casting a mutable pointer, the element type
+//! must coerce in both directions for the pointer to coerce. Otherwise, you could do something
+//! like this, where `A` coerces to `B` but not vice-versa:
+//!
+//! ```
+//! var x: A = undefined;
+//! const p: *B = &x; // `*A` -> `*B`
+//! p.* = some_b;
+//! const some_b_as_a = x;
+//! ```
+
+export fn error_set_to_larger() void {
+ var x: error{Foo} = undefined;
+ _ = @as(*const error{ Foo, Bar }, &x); // this is ok
+ _ = @as(*error{ Foo, Bar }, &x); // compile error
+}
+
+export fn error_set_to_anyerror() void {
+ var x: error{Foo} = undefined;
+ _ = @as(*const anyerror, &x); // this is ok
+ _ = @as(*anyerror, &x); // compile error
+}
+
+export fn error_union_to_anyerror_union() void {
+ var x: error{Foo}!u32 = undefined;
+ _ = @as(*const anyerror!u32, &x); // this is ok
+ _ = @as(*anyerror!u32, &x); // compile error
+}
+
+export fn ptr_to_const_ptr() void {
+ var x: *u32 = undefined;
+ _ = @as(*const *const u32, &x); // this is ok
+ _ = @as(**const u32, &x); // compile error
+}
+
+export fn ptr_to_allowzero_ptr() void {
+ var x: *u32 = undefined;
+ _ = @as(*const *allowzero u32, &x); // this is ok
+ _ = @as(**allowzero u32, &x); // compile error
+}
+
+export fn ptr_to_volatile_ptr() void {
+ var x: *u32 = undefined;
+ _ = @as(*const *volatile u32, &x); // this is ok
+ _ = @as(**volatile u32, &x); // compile error
+}
+
+export fn ptr_to_underaligned_ptr() void {
+ var x: *u32 = undefined;
+ _ = @as(*const *align(1) u32, &x); // this is ok
+ _ = @as(**align(1) u32, &x); // compile error
+}
+
+// error
+//
+// :16:33: error: expected type '*error{Foo,Bar}', found '*error{Foo}'
+// :16:33: note: pointer type child 'error{Foo}' cannot cast into pointer type child 'error{Foo,Bar}'
+// :16:33: note: 'error.Bar' not a member of destination error set
+// :22:24: error: expected type '*anyerror', found '*error{Foo}'
+// :22:24: note: pointer type child 'error{Foo}' cannot cast into pointer type child 'anyerror'
+// :22:24: note: global error set cannot cast into a smaller set
+// :28:28: error: expected type '*anyerror!u32', found '*error{Foo}!u32'
+// :28:28: note: pointer type child 'error{Foo}!u32' cannot cast into pointer type child 'anyerror!u32'
+// :28:28: note: global error set cannot cast into a smaller set
+// :34:26: error: expected type '**const u32', found '**u32'
+// :34:26: note: pointer type child '*u32' cannot cast into pointer type child '*const u32'
+// :34:26: note: mutable '*const u32' would allow illegal const pointers stored to type '*u32'
+// :40:30: error: expected type '**allowzero u32', found '**u32'
+// :40:30: note: pointer type child '*u32' cannot cast into pointer type child '*allowzero u32'
+// :40:30: note: mutable '*allowzero u32' would allow illegal null values stored to type '*u32'
+// :46:29: error: expected type '**volatile u32', found '**u32'
+// :46:29: note: pointer type child '*u32' cannot cast into pointer type child '*volatile u32'
+// :46:29: note: mutable '*volatile u32' would allow illegal volatile pointers stored to type '*u32'
+// :52:29: error: expected type '**align(1) u32', found '**u32'
+// :52:29: note: pointer type child '*u32' cannot cast into pointer type child '*align(1) u32'
+// :52:29: note: pointer alignment '4' cannot cast into pointer alignment '1'
test/cases/compile_errors/use_implicit_casts_to_assign_null_to_non-nullable_pointer.zig
@@ -12,4 +12,4 @@ export fn entry() void {
//
// :4:24: error: expected type '*?*i32', found '**i32'
// :4:24: note: pointer type child '*i32' cannot cast into pointer type child '?*i32'
-// :4:24: note: mutable '*i32' allows illegal null values stored to type '?*i32'
+// :4:24: note: mutable '?*i32' would allow illegal null values stored to type '*i32'