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| author | Veikka Tuominen <git@vexu.eu> | 2022-11-08 19:48:21 +0200 |
|---|---|---|
| committer | Veikka Tuominen <git@vexu.eu> | 2022-11-11 17:59:53 +0200 |
| commit | 0a188190b3b2b42906d0cc38f101b010bc07b414 (patch) | |
| tree | 60f1914391ff3467f5eb97d389a18dbe73e1684f /src | |
| parent | d2cc55109a64aaf004384b942e08e95829b9341f (diff) | |
| download | zig-0a188190b3b2b42906d0cc38f101b010bc07b414.tar.gz zig-0a188190b3b2b42906d0cc38f101b010bc07b414.zip | |
AstGen: make pointless discard error more strict
The error should only happen as a result of `_ = <expr>` not
for an operand of a break expression that is discarded.
Closes #13212
Diffstat (limited to 'src')
| -rw-r--r-- | src/AstGen.zig | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/src/AstGen.zig b/src/AstGen.zig index d876e24977..32830e3f39 100644 --- a/src/AstGen.zig +++ b/src/AstGen.zig @@ -339,6 +339,8 @@ pub const ResultInfo = struct { fn_arg, /// The expression is the right-hand side of an initializer for a `const` variable const_init, + /// The expression is the right-hand side of an assignment expression. + assignment, /// No specific operator in particular. none, }; @@ -3216,7 +3218,7 @@ fn assign(gz: *GenZir, scope: *Scope, infix_node: Ast.Node.Index) InnerError!voi // This intentionally does not support `@"_"` syntax. const ident_name = tree.tokenSlice(main_tokens[lhs]); if (mem.eql(u8, ident_name, "_")) { - _ = try expr(gz, scope, .{ .rl = .discard }, rhs); + _ = try expr(gz, scope, .{ .rl = .discard, .ctx = .assignment }, rhs); return; } } @@ -7088,7 +7090,7 @@ fn localVarRef( if (local_val.name == name_str_index) { // Locals cannot shadow anything, so we do not need to look for ambiguous // references in this case. - if (ri.rl == .discard) { + if (ri.rl == .discard and ri.ctx == .assignment) { local_val.discarded = ident_token; } else { local_val.used = ident_token; @@ -7111,7 +7113,7 @@ fn localVarRef( .local_ptr => { const local_ptr = s.cast(Scope.LocalPtr).?; if (local_ptr.name == name_str_index) { - if (ri.rl == .discard) { + if (ri.rl == .discard and ri.ctx == .assignment) { local_ptr.discarded = ident_token; } else { local_ptr.used = ident_token; @@ -10672,14 +10674,19 @@ const GenZir = struct { gz.break_result_info = parent_ri; }, - .discard, .none, .ref => { + .none, .ref => { gz.rl_ty_inst = .none; gz.break_result_info = parent_ri; }, + .discard => { + gz.rl_ty_inst = .none; + gz.break_result_info = .{ .rl = .discard }; + }, + .ptr => |ptr_res| { gz.rl_ty_inst = .none; - gz.break_result_info = .{ .rl = .{ .ptr = .{ .inst = ptr_res.inst } } }; + gz.break_result_info = .{ .rl = .{ .ptr = .{ .inst = ptr_res.inst } }, .ctx = parent_ri.ctx }; }, .inferred_ptr => |ptr| { |