Commit 672bc8141fd26b29eb645571be27420db8e4c27e | zig

author	Will Lillis <will.lillis24@gmail.com> 2025-01-26 13:38:07-05:00
committer	GitHub <noreply@github.com> 2025-01-26 19:38:07+01:00
log	672bc8141fd26b29eb645571be27420db8e4c27e
tree	2f6879b2a1bb3190493a09de66f14f479fff8237
parent	9c6d728b0c9350b0661c8da1134d4fd623b88713
signature	Signed by PGP key B5690EEEBB952194

fix: Only suggest try on destructure of error union if payload type can be destructured (#21510)

2 files changed, 25 insertions(+), 8 deletions(-)

src
- Sema.zig
test
- cases
  - compile_errors
    invalid_destructure_error_union.zig

src/Sema.zig+12-8

 @@ -5525,6 +5525,14 @@ fn zirValidateDeref(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileErr
     }
 }
+fn typeIsDestructurable(ty: Type, zcu: *const Zcu) bool {
+    return switch (ty.zigTypeTag(zcu)) {
+        .array, .vector => true,
+        .@"struct" => ty.isTuple(zcu),
+        else => false,
+    };
+}
 fn zirValidateDestructure(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!void {
     const pt = sema.pt;
     const zcu = pt.zcu;
 @@ -5535,19 +5543,15 @@ fn zirValidateDestructure(sema: *Sema, block: *Block, inst: Zir.Inst.Index) Comp
     const operand = try sema.resolveInst(extra.operand);
     const operand_ty = sema.typeOf(operand);
-    const can_destructure = switch (operand_ty.zigTypeTag(zcu)) {
+    if (!typeIsDestructurable(operand_ty, zcu)) {
-        .array, .vector => true,
-        .@"struct" => operand_ty.isTuple(zcu),
-        else => false,
-    };
-    if (!can_destructure) {
         return sema.failWithOwnedErrorMsg(block, msg: {
             const msg = try sema.errMsg(src, "type '{}' cannot be destructured", .{operand_ty.fmt(pt)});
             errdefer msg.destroy(sema.gpa);
             try sema.errNote(destructure_src, msg, "result destructured here", .{});
             if (operand_ty.zigTypeTag(pt.zcu) == .error_union) {
-                try sema.errNote(src, msg, "consider using 'try', 'catch', or 'if'", .{});
+                const base_op_ty = operand_ty.errorUnionPayload(zcu);
+                if (typeIsDestructurable(base_op_ty, zcu))
+                    try sema.errNote(src, msg, "consider using 'try', 'catch', or 'if'", .{});
             }
             break :msg msg;
         });

test/cases/compile_errors/invalid_destructure_error_union.zig created+13

...	@@ -0,0 +1,13 @@
1	pub export fn entry() void {
2	const foo: anyerror!u32 = error.Failure;
3	const bar, const baz = foo;
4	_ = bar;
5	_ = baz;
6	}
7
8	// error
9	// backend=stage2
10	// target=native
11	//
12	// :3:28: error: type 'anyerror!u32' cannot be destructured
13	// :3:26: note: result destructured here