motiejus/zig
1
Fork 0
Code Releases Activity

stage2: fixes for error union semantics

Browse Source 
* Sema: avoid unnecessary safety checks when an error set is empty.
 * Sema: make zirErrorToInt handle comptime errors that are represented
   as integers.
 * Sema: make empty error sets properly integrate with
   typeHasOnePossibleValue.
 * Type: correct the ABI alignment and size of error unions which have
   both zero-bit error set and zero-bit payload. The previous code did
   not account for the fact that we still need to store a bit for
   whether there is an error.
 * LLVM: lower error unions possibly with the payload first or with the
   error code first, depending on alignment. Previously it always put
   the error code first and used a padding array.
 * LLVM: lower functions which have an empty error set as the return
   type the same as anyerror, so that they can be used where
   fn()anyerror function pointers are expected. In such functions, Zig
   will lower ret to returning zero instead of void.

As a result, one more behavior test is passing.
This commit is contained in:
Andrew Kelley
2022-05-22 21:51:44 -07:00
parent 60f0acd9b9
commit 3264abe3d8
5 changed files with 370 additions and 125 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
test/behavior/error.zig
View File

@@ -148,18 +148,39 @@ test "implicit cast to optional to error union to return result loc" {
//comptime S.entry(); TODO
}
test "error: fn returning empty error set can be passed as fn returning any error" {
test "fn returning empty error set can be passed as fn returning any error" {
entry();
comptime entry();
}
test "fn returning empty error set can be passed as fn returning any error - pointer" {
if (builtin.zig_backend == .stage1) return error.SkipZigTest;
entryPtr();
comptime entryPtr();
}
fn entry() void {
foo2(bar2);
}
fn entryPtr() void {
var ptr = &bar2;
fooPtr(ptr);
}
fn foo2(f: fn () anyerror!void) void {
const x = f();
x catch {};
x catch {
@panic("fail");
};
}
fn fooPtr(f: *const fn () anyerror!void) void {
const x = f();
x catch {
@panic("fail");
};
}
fn bar2() (error{}!void) {}
@@ -239,7 +260,11 @@ fn testComptimeTestErrorEmptySet(x: EmptyErrorSet!i32) !void {
}
test "comptime err to int of error set with only 1 possible value" {
if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
testErrToIntWithOnePossibleValue(error.A, @errorToInt(error.A));
comptime testErrToIntWithOnePossibleValue(error.A, @errorToInt(error.A));