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Sema: validate extern types

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This commit is contained in:
Veikka Tuominen 2022-07-11 17:54:53 +03:00
parent 3ceb27c840
commit d00da05ecb
12 changed files with 240 additions and 52 deletions
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2
lib/std/start.zig
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@ -108,7 +108,7 @@ fn callMain2() noreturn {
exit2(0);
}
fn wasiMain2() noreturn {
fn wasiMain2() callconv(.C) noreturn {
switch (@typeInfo(@typeInfo(@TypeOf(root.main)).Fn.return_type.?)) {
.Void => {
root.main();

175
src/Sema.zig
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@ -4740,12 +4740,19 @@ pub fn analyzeExport(
try mod.ensureDeclAnalyzed(exported_decl_index);
const exported_decl = mod.declPtr(exported_decl_index);
// TODO run the same checks as we do for C ABI struct fields
switch (exported_decl.ty.zigTypeTag()) {
.Fn, .Int, .Enum, .Struct, .Union, .Array, .Float, .Pointer, .Optional => {},
else => return sema.fail(block, src, "unable to export type '{}'", .{
exported_decl.ty.fmt(sema.mod),
}),
if (!(try sema.validateExternType(exported_decl.ty, .other))) {
const msg = msg: {
const msg = try sema.errMsg(block, src, "unable to export type '{}'", .{exported_decl.ty.fmt(sema.mod)});
errdefer msg.destroy(sema.gpa);
const src_decl = sema.mod.declPtr(block.src_decl);
try sema.explainWhyTypeIsNotExtern(block, src, msg, src.toSrcLoc(src_decl), exported_decl.ty, .other);
try sema.addDeclaredHereNote(msg, exported_decl.ty);
break :msg msg;
};
return sema.failWithOwnedErrorMsg(block, msg);
}
const gpa = mod.gpa;
@ -13799,7 +13806,20 @@ fn validatePtrTy(sema: *Sema, block: *Block, elem_src: LazySrcLoc, ty: Type) Com
} else if (ptr_info.size == .Many and pointee_tag == .Opaque) {
return sema.fail(block, elem_src, "unknown-length pointer to opaque not allowed", .{});
} else if (ptr_info.size == .C) {
// TODO check extern type
const elem_ty = ptr_info.pointee_type;
if (!(try sema.validateExternType(elem_ty, .other))) {
const msg = msg: {
const msg = try sema.errMsg(block, elem_src, "C pointers cannot point to non-C-ABI-compatible type '{}'", .{elem_ty.fmt(sema.mod)});
errdefer msg.destroy(sema.gpa);
const src_decl = sema.mod.declPtr(block.src_decl);
try sema.explainWhyTypeIsNotExtern(block, elem_src, msg, elem_src.toSrcLoc(src_decl), elem_ty, .other);
try sema.addDeclaredHereNote(msg, elem_ty);
break :msg msg;
};
return sema.failWithOwnedErrorMsg(block, msg);
}
if (pointee_tag == .Opaque) {
return sema.fail(block, elem_src, "C pointers cannot point to opaque types", .{});
}
@ -18169,6 +18189,119 @@ fn explainWhyTypeIsComptime(
}
}
const ExternPosition = enum {
ret_ty,
param_ty,
other,
};
fn validateExternType(sema: *Sema, ty: Type, position: ExternPosition) CompileError!bool {
switch (ty.zigTypeTag()) {
.Type,
.ComptimeFloat,
.ComptimeInt,
.EnumLiteral,
.Undefined,
.Null,
.ErrorUnion,
.ErrorSet,
.BoundFn,
.Void,
.Frame,
=> return false,
.NoReturn => return position == .ret_ty,
.Opaque,
.Bool,
.Float,
.Pointer,
.AnyFrame,
=> return true,
.Int => switch (ty.intInfo(sema.mod.getTarget()).bits) {
8, 16, 32, 64, 128 => return true,
else => return false,
},
.Fn => return !ty.fnCallingConventionAllowsZigTypes(),
.Enum => {
var buf: Type.Payload.Bits = undefined;
return sema.validateExternType(ty.intTagType(&buf), position);
},
.Struct, .Union => switch (ty.containerLayout()) {
.Extern, .Packed => return true,
else => return false,
},
.Array => {
if (position == .ret_ty or position == .param_ty) return false;
return sema.validateExternType(ty.elemType2(), .other);
},
.Vector => return sema.validateExternType(ty.elemType2(), .other),
.Optional => return ty.isPtrLikeOptional(),
}
}
fn explainWhyTypeIsNotExtern(
sema: *Sema,
block: *Block,
src: LazySrcLoc,
msg: *Module.ErrorMsg,
src_loc: Module.SrcLoc,
ty: Type,
position: ExternPosition,
) CompileError!void {
const mod = sema.mod;
switch (ty.zigTypeTag()) {
.Opaque,
.Bool,
.Float,
.Pointer,
.AnyFrame,
=> return,
.Type,
.ComptimeFloat,
.ComptimeInt,
.EnumLiteral,
.Undefined,
.Null,
.ErrorUnion,
.ErrorSet,
.BoundFn,
.Frame,
=> return,
.Void => try mod.errNoteNonLazy(src_loc, msg, "'void' is a zero bit type; for C 'void' use 'anyopaque'", .{}),
.NoReturn => try mod.errNoteNonLazy(src_loc, msg, "'noreturn' is only allowed as a return type", .{}),
.Int => if (ty.intInfo(sema.mod.getTarget()).bits > 128) {
try mod.errNoteNonLazy(src_loc, msg, "only integers with less than 128 bits are extern compatible", .{});
} else {
try mod.errNoteNonLazy(src_loc, msg, "only integers with power of two bits are extern compatible", .{});
},
.Fn => switch (ty.fnCallingConvention()) {
.Unspecified => try mod.errNoteNonLazy(src_loc, msg, "extern function must specify calling convention", .{}),
.Async => try mod.errNoteNonLazy(src_loc, msg, "async function cannot be extern", .{}),
.Inline => try mod.errNoteNonLazy(src_loc, msg, "inline function cannot be extern", .{}),
else => return,
},
.Enum => {
var buf: Type.Payload.Bits = undefined;
const tag_ty = ty.intTagType(&buf);
try mod.errNoteNonLazy(src_loc, msg, "enum tag type '{}' is not extern compatible", .{tag_ty.fmt(sema.mod)});
try sema.explainWhyTypeIsNotExtern(block, src, msg, src_loc, tag_ty, position);
},
.Struct => try mod.errNoteNonLazy(src_loc, msg, "only structs with packed or extern layout are extern compatible", .{}),
.Union => try mod.errNoteNonLazy(src_loc, msg, "only unions with packed or extern layout are extern compatible", .{}),
.Array => {
if (position == .ret_ty) {
try mod.errNoteNonLazy(src_loc, msg, "arrays are not allowed as a return type", .{});
} else if (position == .param_ty) {
try mod.errNoteNonLazy(src_loc, msg, "arrays are not allowed as a parameter type", .{});
}
try sema.explainWhyTypeIsNotExtern(block, src, msg, src_loc, ty.elemType2(), position);
},
.Vector => try sema.explainWhyTypeIsNotExtern(block, src, msg, src_loc, ty.elemType2(), position),
.Optional => try mod.errNoteNonLazy(src_loc, msg, "only pointer like optionals are extern compatible", .{}),
}
}
pub const PanicId = enum {
unreach,
unwrap_null,
@ -24012,6 +24145,20 @@ fn resolveStructFully(
struct_obj.status = .fully_resolved_wip;
for (struct_obj.fields.values()) |field| {
try sema.resolveTypeFully(block, src, field.ty);
if (struct_obj.layout == .Extern and !(try sema.validateExternType(field.ty, .other))) {
const msg = msg: {
const msg = try sema.errMsg(block, src, "extern structs cannot contain fields of type '{}'", .{field.ty.fmt(sema.mod)});
errdefer msg.destroy(sema.gpa);
const src_decl = sema.mod.declPtr(block.src_decl);
try sema.explainWhyTypeIsNotExtern(block, src, msg, src.toSrcLoc(src_decl), field.ty, .other);
try sema.addDeclaredHereNote(msg, field.ty);
break :msg msg;
};
return sema.failWithOwnedErrorMsg(block, msg);
}
}
struct_obj.status = .fully_resolved;
}
@ -24045,6 +24192,20 @@ fn resolveUnionFully(
union_obj.status = .fully_resolved_wip;
for (union_obj.fields.values()) |field| {
try sema.resolveTypeFully(block, src, field.ty);
if (union_obj.layout == .Extern and !(try sema.validateExternType(field.ty, .other))) {
const msg = msg: {
const msg = try sema.errMsg(block, src, "extern unions cannot contain fields of type '{}'", .{field.ty.fmt(sema.mod)});
errdefer msg.destroy(sema.gpa);
const src_decl = sema.mod.declPtr(block.src_decl);
try sema.explainWhyTypeIsNotExtern(block, src, msg, src.toSrcLoc(src_decl), field.ty, .other);
try sema.addDeclaredHereNote(msg, field.ty);
break :msg msg;
};
return sema.failWithOwnedErrorMsg(block, msg);
}
}
union_obj.status = .fully_resolved;
}

9
src/type.zig
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@ -3935,7 +3935,6 @@ pub const Type = extern union {
/// Returns true if the type is optional and would be lowered to a single pointer
/// address value, using 0 for null. Note that this returns true for C pointers.
/// See also `hasOptionalRepr`.
pub fn isPtrLikeOptional(self: Type) bool {
switch (self.tag()) {
.optional_single_const_pointer,
@ -4630,6 +4629,14 @@ pub const Type = extern union {
};
}
/// Asserts the type is a function.
pub fn fnCallingConventionAllowsZigTypes(self: Type) bool {
return switch (self.fnCallingConvention()) {
.Unspecified, .Async, .Inline, .PtxKernel => true,
else => false,
};
}
/// Asserts the type is a function.
pub fn fnIsVarArgs(self: Type) bool {
return switch (self.tag()) {

11
test/cases/compile_errors/c_pointer_to_void.zig Normal file
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@ -0,0 +1,11 @@
export fn entry() void {
var a: [*c]void = undefined;
_ = a;
}
// error
// backend=stage2
// target=native
//
// :1:1: error: C pointers cannot point to non-C-ABI-compatible type 'void'
// :1:1: note: 'void' is a zero bit type; for C 'void' use 'anyopaque'

18
test/cases/compile_errors/exported_enum_without_explicit_integer_tag_type.zig Normal file
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@ -0,0 +1,18 @@
const E = enum { one, two };
comptime {
@export(E, .{ .name = "E" });
}
const e: E = .two;
comptime {
@export(e, .{ .name = "e" });
}
// error
// backend=stage2
// target=native
//
// :3:5: error: unable to export type 'type'
// :7:5: error: unable to export type 'tmp.E'
// :7:5: note: enum tag type 'u1' is not extern compatible
// :7:5: note: only integers with power of two bits are extern compatible
// :1:11: note: enum declared here

10
test/cases/compile_errors/stage1/obj/extern_struct_with_extern-compatible_but_inferred_integer_tag_type.zig → test/cases/compile_errors/extern_struct_with_extern-compatible_but_inferred_integer_tag_type.zig
View File

@ -25,19 +25,21 @@ pub const E = enum {
@"227",@"228",@"229",@"230",@"231",@"232",@"233",@"234",@"235",
@"236",@"237",@"238",@"239",@"240",@"241",@"242",@"243",@"244",
@"245",@"246",@"247",@"248",@"249",@"250",@"251",@"252",@"253",
@"254",@"255"
@"254",@"255", @"256"
};
pub const S = extern struct {
e: E,
};
export fn entry() void {
if (@typeInfo(E).Enum.tag_type != u8) @compileError("did not infer u8 tag type");
const s: S = undefined;
_ = s;
}
// error
// backend=stage1
// backend=stage2
// target=native
//
// tmp.zig:31:5: error: extern structs cannot contain fields of type 'E'
// :33:8: error: extern structs cannot contain fields of type 'tmp.E'
// :33:8: note: enum tag type 'u9' is not extern compatible
// :33:8: note: only integers with power of two bits are extern compatible
// :1:15: note: enum declared here

17
test/cases/compile_errors/extern_struct_with_non-extern-compatible_integer_tag_type.zig Normal file
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@ -0,0 +1,17 @@
pub const E = enum(u31) { A, B, C };
pub const S = extern struct {
e: E,
};
export fn entry() void {
const s: S = undefined;
_ = s;
}
// error
// backend=stage2
// target=native
//
// :5:8: error: extern structs cannot contain fields of type 'tmp.E'
// :5:8: note: enum tag type 'u31' is not extern compatible
// :5:8: note: only integers with power of two bits are extern compatible
// :1:15: note: enum declared here

11
test/cases/compile_errors/invalid_optional_type_in_extern_struct.zig Normal file
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@ -0,0 +1,11 @@
const stroo = extern struct {
moo: ?[*c]u8,
};
export fn testf(fluff: *stroo) void { _ = fluff; }
// error
// backend=stage2
// target=native
//
// :4:8: error: extern structs cannot contain fields of type '?[*c]u8'
// :4:8: note: only pointer like optionals are extern compatible

15
test/cases/compile_errors/stage1/obj/exported_enum_without_explicit_integer_tag_type.zig
View File

@ -1,15 +0,0 @@
const E = enum { one, two };
comptime {
@export(E, .{ .name = "E" });
}
const e: E = .two;
comptime {
@export(e, .{ .name = "e" });
}
// error
// backend=stage1
// target=native
//
// tmp.zig:3:13: error: exported enum without explicit integer tag type
// tmp.zig:7:13: error: exported enum value without explicit integer tag type

14
test/cases/compile_errors/stage1/obj/extern_struct_with_non-extern-compatible_integer_tag_type.zig
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@ -1,14 +0,0 @@
pub const E = enum(u31) { A, B, C };
pub const S = extern struct {
e: E,
};
export fn entry() void {
const s: S = undefined;
_ = s;
}
// error
// backend=stage1
// target=native
//
// tmp.zig:3:5: error: extern structs cannot contain fields of type 'E'

10
test/cases/compile_errors/stage1/obj/invalid_optional_type_in_extern_struct.zig
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@ -1,10 +0,0 @@
const stroo = extern struct {
moo: ?[*c]u8,
};
export fn testf(fluff: *stroo) void { _ = fluff; }
// error
// backend=stage1
// target=native
//
// tmp.zig:2:5: error: extern structs cannot contain fields of type '?[*c]u8'

0
test/cases/compile_errors/stage1/obj/optional_pointer_to_void_in_extern_struct.zig → test/cases/compile_errors/stage1/optional_pointer_to_void_in_extern_struct.zig
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