Commit c9dde10f86
Changed files (3)
doc/langref.html.in
@@ -10405,7 +10405,7 @@ pub fn main() !void {
<p>String literals such as {#syntax#}"foo"{#endsyntax#} are in the global constant data section.
This is why it is an error to pass a string literal to a mutable slice, like this:
</p>
- {#code_begin|test_err|expected type '[]u8'#}
+ {#code_begin|test_err|cannot cast pointer to array literal to slice type '[]u8'#}
fn foo(s: []u8) void {
_ = s;
}
src/stage1/ir.cpp
@@ -7843,7 +7843,7 @@ static Stage1AirInst *ir_analyze_cast(IrAnalyze *ira, Scope *scope, AstNode *sou
bool const_ok = (slice_ptr_type->data.pointer.is_const || array_type->data.array.len == 0
|| !actual_type->data.pointer.is_const);
- if (const_ok && types_match_const_cast_only(ira, slice_ptr_type->data.pointer.child_type,
+ if (types_match_const_cast_only(ira, slice_ptr_type->data.pointer.child_type,
array_type->data.array.child_type, source_node,
!slice_ptr_type->data.pointer.is_const).id == ConstCastResultIdOk &&
(slice_ptr_type->data.pointer.sentinel == nullptr ||
@@ -7851,6 +7851,14 @@ static Stage1AirInst *ir_analyze_cast(IrAnalyze *ira, Scope *scope, AstNode *sou
const_values_equal(ira->codegen, array_type->data.array.sentinel,
slice_ptr_type->data.pointer.sentinel))))
{
+ if (!const_ok) {
+ ErrorMsg *msg = ir_add_error_node(ira, source_node,
+ buf_sprintf("cannot cast pointer to array literal to slice type '%s'",
+ buf_ptr(&wanted_type->name)));
+ add_error_note(ira->codegen, msg, source_node,
+ buf_sprintf("cast discards const qualifier"));
+ return ira->codegen->invalid_inst_gen;
+ }
// If the pointers both have ABI align, it works.
// Or if the array length is 0, alignment doesn't matter.
bool ok_align = array_type->data.array.len == 0 ||
@@ -8208,8 +8216,16 @@ static Stage1AirInst *ir_analyze_cast(IrAnalyze *ira, Scope *scope, AstNode *sou
ZigType *wanted_child = wanted_type->data.pointer.child_type;
bool const_ok = (!actual_type->data.pointer.is_const || wanted_type->data.pointer.is_const);
if (wanted_child->id == ZigTypeIdArray && (is_array_init || field_count == 0) &&
- wanted_child->data.array.len == field_count && (const_ok || field_count == 0))
+ wanted_child->data.array.len == field_count)
{
+ if (!const_ok && field_count != 0) {
+ ErrorMsg *msg = ir_add_error_node(ira, source_node,
+ buf_sprintf("cannot cast pointer to array literal to '%s'",
+ buf_ptr(&wanted_type->name)));
+ add_error_note(ira->codegen, msg, source_node,
+ buf_sprintf("cast discards const qualifier"));
+ return ira->codegen->invalid_inst_gen;
+ }
Stage1AirInst *res = ir_analyze_struct_literal_to_array(ira, scope, source_node, value, anon_type, wanted_child);
if (res->value->type->id == ZigTypeIdPointer)
return res;
@@ -8241,6 +8257,13 @@ static Stage1AirInst *ir_analyze_cast(IrAnalyze *ira, Scope *scope, AstNode *sou
res = ir_get_ref(ira, scope, source_node, res, actual_type->data.pointer.is_const, actual_type->data.pointer.is_volatile);
return ir_resolve_ptr_of_array_to_slice(ira, scope, source_node, res, wanted_type, nullptr);
+ } else if (!slice_type->data.pointer.is_const && actual_type->data.pointer.is_const && field_count != 0) {
+ ErrorMsg *msg = ir_add_error_node(ira, source_node,
+ buf_sprintf("cannot cast pointer to array literal to slice type '%s'",
+ buf_ptr(&wanted_type->name)));
+ add_error_note(ira->codegen, msg, source_node,
+ buf_sprintf("cast discards const qualifier"));
+ return ira->codegen->invalid_inst_gen;
}
}
}
@@ -15068,7 +15091,7 @@ static Stage1AirInst *ir_analyze_instruction_elem_ptr(IrAnalyze *ira, Stage1ZirI
return ira->codegen->invalid_inst_gen;
if (actual_array_type->id != ZigTypeIdArray) {
ir_add_error_node(ira, elem_ptr_instruction->init_array_type_source_node,
- buf_sprintf("array literal requires address-of operator to coerce to slice type '%s'",
+ buf_sprintf("array literal requires address-of operator (&) to coerce to slice type '%s'",
buf_ptr(&actual_array_type->name)));
return ira->codegen->invalid_inst_gen;
}
@@ -17473,7 +17496,7 @@ static Stage1AirInst *ir_analyze_instruction_container_init_list(IrAnalyze *ira,
if (is_slice(container_type)) {
ir_add_error_node(ira, instruction->init_array_type_source_node,
- buf_sprintf("array literal requires address-of operator to coerce to slice type '%s'",
+ buf_sprintf("array literal requires address-of operator (&) to coerce to slice type '%s'",
buf_ptr(&container_type->name)));
return ira->codegen->invalid_inst_gen;
}
test/compile_errors.zig
@@ -86,9 +86,12 @@ pub fn addCases(ctx: *TestContext) !void {
\\ _ = c;
\\}
, &[_][]const u8{
- "tmp.zig:2:31: error: expected type '[][]const u8', found '*const struct:2:31'",
- "tmp.zig:6:33: error: expected type '*[2][]const u8', found '*const struct:6:33'",
+ "tmp.zig:2:31: error: cannot cast pointer to array literal to slice type '[][]const u8'",
+ "tmp.zig:2:31: note: cast discards const qualifier",
+ "tmp.zig:6:33: error: cannot cast pointer to array literal to '*[2][]const u8'",
+ "tmp.zig:6:33: note: cast discards const qualifier",
"tmp.zig:11:21: error: expected type '*S', found '*const struct:11:21'",
+ "tmp.zig:11:21: note: cast discards const qualifier",
});
ctx.objErrStage1("@Type() union payload is undefined",
@@ -1962,7 +1965,7 @@ pub fn addCases(ctx: *TestContext) !void {
\\ _ = geo_data;
\\}
, &[_][]const u8{
- "tmp.zig:4:30: error: array literal requires address-of operator to coerce to slice type '[][2]f32'",
+ "tmp.zig:4:30: error: array literal requires address-of operator (&) to coerce to slice type '[][2]f32'",
});
ctx.objErrStage1("slicing of global undefined pointer",
@@ -2537,7 +2540,7 @@ pub fn addCases(ctx: *TestContext) !void {
\\ _ = x;
\\}
, &[_][]const u8{
- "tmp.zig:2:15: error: array literal requires address-of operator to coerce to slice type '[]u8'",
+ "tmp.zig:2:15: error: array literal requires address-of operator (&) to coerce to slice type '[]u8'",
});
ctx.objErrStage1("slice passed as array init type",
@@ -2546,7 +2549,7 @@ pub fn addCases(ctx: *TestContext) !void {
\\ _ = x;
\\}
, &[_][]const u8{
- "tmp.zig:2:15: error: array literal requires address-of operator to coerce to slice type '[]u8'",
+ "tmp.zig:2:15: error: array literal requires address-of operator (&) to coerce to slice type '[]u8'",
});
ctx.objErrStage1("inferred array size invalid here",
@@ -3493,7 +3496,8 @@ pub fn addCases(ctx: *TestContext) !void {
\\ _ = sliceA;
\\}
, &[_][]const u8{
- "tmp.zig:3:27: error: expected type '[]u8', found '*const [1]u8'",
+ "tmp.zig:3:27: error: cannot cast pointer to array literal to slice type '[]u8'",
+ "tmp.zig:3:27: note: cast discards const qualifier",
});
ctx.objErrStage1("deref slice and get len field",
@@ -8717,7 +8721,8 @@ pub fn addCases(ctx: *TestContext) !void {
\\ comptime ignore(@typeInfo(MyStruct).Struct.fields[0]);
\\}
, &[_][]const u8{
- ":5:28: error: expected type '[]u8', found '*const [3:0]u8'",
+ ":5:28: error: cannot cast pointer to array literal to slice type '[]u8'",
+ ":5:28: note: cast discards const qualifier",
});
ctx.objErrStage1("integer underflow error",