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Sema: add error for non-comptime param in comptime func

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Adds error for taking a non comptime parameter in a function returning a
comptime-only type but not when that type is dependent on a parameter.

Co-authored-by: Veikka Tuominen <git@vexu.eu>
This commit is contained in:
antlilja
2022-08-06 22:32:00 +02:00
committed by Veikka Tuominen
parent da95da438e
commit ae8d26a6a0
10 changed files with 95 additions and 26 deletions
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61
src/Sema.zig
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@@ -7816,19 +7816,17 @@ fn funcCommon(
};
}
var is_comptime_ret = false;
const ret_poison = if (!is_generic) rp: {
if (sema.typeRequiresComptime(block, ret_ty_src, bare_return_type)) |ret_comptime| {
is_comptime_ret = ret_comptime;
break :rp bare_return_type.tag() == .generic_poison;
} else |err| switch (err) {
error.GenericPoison => {
is_generic = true;
break :rp true;
},
else => |e| return e,
}
} else bare_return_type.tag() == .generic_poison;
var ret_ty_requires_comptime = false;
const ret_poison = if (sema.typeRequiresComptime(block, ret_ty_src, bare_return_type)) |ret_comptime| rp: {
ret_ty_requires_comptime = ret_comptime;
break :rp bare_return_type.tag() == .generic_poison;
} else |err| switch (err) {
error.GenericPoison => rp: {
is_generic = true;
break :rp true;
},
else => |e| return e,
};
const return_type = if (!inferred_error_set or ret_poison)
bare_return_type
@@ -7873,6 +7871,41 @@ fn funcCommon(
return sema.failWithOwnedErrorMsg(msg);
}
// If the return type is comptime only but not dependent on parameters then all parameter types also need to be comptime
if (!sema.is_generic_instantiation and has_body and ret_ty_requires_comptime) comptime_check: {
for (block.params.items) |param| {
if (!param.is_comptime) break;
} else break :comptime_check;
const msg = try sema.errMsg(
block,
ret_ty_src,
"function with comptime only return type '{}' requires all parameters to be comptime",
.{return_type.fmt(sema.mod)},
);
try sema.explainWhyTypeIsComptime(block, ret_ty_src, msg, ret_ty_src.toSrcLoc(sema.owner_decl), return_type);
const tags = sema.code.instructions.items(.tag);
const data = sema.code.instructions.items(.data);
const param_body = sema.code.getParamBody(func_inst);
for (block.params.items) |param, i| {
if (!param.is_comptime) {
const param_index = param_body[i];
const param_src = switch (tags[param_index]) {
.param => data[param_index].pl_tok.src(),
.param_anytype => data[param_index].str_tok.src(),
else => unreachable,
};
if (param.name.len != 0) {
try sema.errNote(block, param_src, msg, "param '{s}' is required to be comptime", .{param.name});
} else {
try sema.errNote(block, param_src, msg, "param is required to be comptime", .{});
}
}
}
return sema.failWithOwnedErrorMsg(msg);
}
const arch = sema.mod.getTarget().cpu.arch;
if (switch (cc_workaround) {
.Unspecified, .C, .Naked, .Async, .Inline => null,
@@ -7917,7 +7950,7 @@ fn funcCommon(
}
if (is_generic and sema.no_partial_func_ty) return error.GenericPoison;
for (comptime_params) |ct| is_generic = is_generic or ct;
is_generic = is_generic or is_comptime_ret;
is_generic = is_generic or ret_ty_requires_comptime;
break :fn_ty try Type.Tag.function.create(sema.arena, .{
.param_types = param_types,