commit 7090f0471c0169c60a9476b537b09eebe1bdf6af (tree)
parent 8033767082f2178416fba8cb4a4b03fef961d318
Author: Veikka Tuominen <git@vexu.eu>
Date: Tue, 12 Jul 2022 19:37:02 +0300
Merge pull request #12083 from Vexu/c-container-err
parser: add helpful error for C style container declarations
Diffstat:
5 files changed, 121 insertions(+), 37 deletions(-)
diff --git a/lib/std/zig/Ast.zig b/lib/std/zig/Ast.zig
@@ -334,6 +334,16 @@ pub fn renderError(tree: Ast, parse_error: Error, stream: anytype) !void {
.invalid_ampersand_ampersand => {
return stream.writeAll("ambiguous use of '&&'; use 'and' for logical AND, or change whitespace to ' & &' for bitwise AND");
},
+ .c_style_container => {
+ return stream.print("'{s} {s}' is invalid", .{
+ parse_error.extra.expected_tag.symbol(), tree.tokenSlice(parse_error.token),
+ });
+ },
+ .zig_style_container => {
+ return stream.print("to declare a container do 'const {s} = {s}'", .{
+ tree.tokenSlice(parse_error.token), parse_error.extra.expected_tag.symbol(),
+ });
+ },
.previous_field => {
return stream.writeAll("field before declarations here");
},
@@ -2541,7 +2551,9 @@ pub const Error = struct {
expected_initializer,
mismatched_binary_op_whitespace,
invalid_ampersand_ampersand,
+ c_style_container,
+ zig_style_container,
previous_field,
next_field,
diff --git a/lib/std/zig/parse.zig b/lib/std/zig/parse.zig
@@ -178,7 +178,6 @@ const Parser = struct {
.expected_block_or_assignment,
.expected_block_or_expr,
.expected_block_or_field,
- .expected_container_members,
.expected_expr,
.expected_expr_or_assignment,
.expected_fn,
@@ -401,10 +400,12 @@ const Parser = struct {
});
try p.warnMsg(.{
.tag = .previous_field,
+ .is_note = true,
.token = last_field,
});
try p.warnMsg(.{
.tag = .next_field,
+ .is_note = true,
.token = identifier,
});
// Continue parsing; error will be reported later.
@@ -440,9 +441,15 @@ const Parser = struct {
break;
},
else => {
- try p.warn(.expected_container_members);
- // This was likely not supposed to end yet; try to find the next declaration.
- p.findNextContainerMember();
+ const c_container = p.parseCStyleContainer() catch |err| switch (err) {
+ error.OutOfMemory => return error.OutOfMemory,
+ error.ParseError => false,
+ };
+ if (!c_container) {
+ try p.warn(.expected_container_members);
+ // This was likely not supposed to end yet; try to find the next declaration.
+ p.findNextContainerMember();
+ }
},
}
}
@@ -978,6 +985,20 @@ const Parser = struct {
}),
.keyword_switch => return p.expectSwitchExpr(),
.keyword_if => return p.expectIfStatement(),
+ .keyword_enum, .keyword_struct, .keyword_union => {
+ const identifier = p.tok_i + 1;
+ if (try p.parseCStyleContainer()) {
+ // Return something so that `expectStatement` is happy.
+ return p.addNode(.{
+ .tag = .identifier,
+ .main_token = identifier,
+ .data = .{
+ .lhs = undefined,
+ .rhs = undefined,
+ },
+ });
+ }
+ },
else => {},
}
@@ -3466,6 +3487,37 @@ const Parser = struct {
}
}
+ /// Give a helpful error message for those transitioning from
+ /// C's 'struct Foo {};' to Zig's 'const Foo = struct {};'.
+ fn parseCStyleContainer(p: *Parser) Error!bool {
+ const main_token = p.tok_i;
+ switch (p.token_tags[p.tok_i]) {
+ .keyword_enum, .keyword_union, .keyword_struct => {},
+ else => return false,
+ }
+ const identifier = p.tok_i + 1;
+ if (p.token_tags[identifier] != .identifier) return false;
+ p.tok_i += 2;
+
+ try p.warnMsg(.{
+ .tag = .c_style_container,
+ .token = identifier,
+ .extra = .{ .expected_tag = p.token_tags[main_token] },
+ });
+ try p.warnMsg(.{
+ .tag = .zig_style_container,
+ .is_note = true,
+ .token = identifier,
+ .extra = .{ .expected_tag = p.token_tags[main_token] },
+ });
+
+ _ = try p.expectToken(.l_brace);
+ _ = try p.parseContainerMembers();
+ _ = try p.expectToken(.r_brace);
+ try p.expectSemicolon(.expected_semi_after_decl, true);
+ return true;
+ }
+
/// Holds temporary data until we are ready to construct the full ContainerDecl AST node.
/// ByteAlign <- KEYWORD_align LPAREN Expr RPAREN
fn parseByteAlign(p: *Parser) !Node.Index {
diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
@@ -212,6 +212,27 @@ test "zig fmt: top-level fields" {
);
}
+test "zig fmt: C style containers" {
+ try testError(
+ \\struct Foo {
+ \\ a: u32,
+ \\};
+ , &[_]Error{
+ .c_style_container,
+ .zig_style_container,
+ });
+ try testError(
+ \\test {
+ \\ struct Foo {
+ \\ a: u32,
+ \\ };
+ \\}
+ , &[_]Error{
+ .c_style_container,
+ .zig_style_container,
+ });
+}
+
test "zig fmt: decl between fields" {
try testError(
\\const S = struct {
diff --git a/src/Module.zig b/src/Module.zig
@@ -3324,17 +3324,21 @@ pub fn astGenFile(mod: *Module, file: *File) !void {
.parent_decl_node = 0,
.lazy = .{ .byte_abs = byte_abs },
}, err_msg, "invalid byte: '{'}'", .{std.zig.fmtEscapes(source[byte_abs..][0..1])});
- } else if (parse_err.tag == .decl_between_fields) {
- try mod.errNoteNonLazy(.{
- .file_scope = file,
- .parent_decl_node = 0,
- .lazy = .{ .byte_abs = token_starts[file.tree.errors[1].token] },
- }, err_msg, "field before declarations here", .{});
- try mod.errNoteNonLazy(.{
- .file_scope = file,
- .parent_decl_node = 0,
- .lazy = .{ .byte_abs = token_starts[file.tree.errors[2].token] },
- }, err_msg, "field after declarations here", .{});
+ }
+
+ for (file.tree.errors[1..]) |note| {
+ if (!note.is_note) break;
+
+ try file.tree.renderError(note, msg.writer());
+ err_msg.notes = try mod.gpa.realloc(err_msg.notes, err_msg.notes.len + 1);
+ err_msg.notes[err_msg.notes.len - 1] = .{
+ .src_loc = .{
+ .file_scope = file,
+ .parent_decl_node = 0,
+ .lazy = .{ .byte_abs = token_starts[note.token] },
+ },
+ .msg = msg.toOwnedSlice(),
+ };
}
{
diff --git a/src/main.zig b/src/main.zig
@@ -4367,7 +4367,7 @@ fn printErrsMsgToStdErr(
defer text_buf.deinit();
const writer = text_buf.writer();
try tree.renderError(parse_error, writer);
- const text = text_buf.items;
+ const text = try arena.dupe(u8, text_buf.items);
var notes_buffer: [2]Compilation.AllErrors.Message = undefined;
var notes_len: usize = 0;
@@ -4388,31 +4388,26 @@ fn printErrsMsgToStdErr(
},
};
notes_len += 1;
- } else if (parse_error.tag == .decl_between_fields) {
- const prev_loc = tree.tokenLocation(0, parse_errors[i + 1].token);
- notes_buffer[0] = .{
- .src = .{
- .src_path = path,
- .msg = "field before declarations here",
- .byte_offset = @intCast(u32, prev_loc.line_start),
- .line = @intCast(u32, prev_loc.line),
- .column = @intCast(u32, prev_loc.column),
- .source_line = tree.source[prev_loc.line_start..prev_loc.line_end],
- },
- };
- const next_loc = tree.tokenLocation(0, parse_errors[i + 2].token);
- notes_buffer[1] = .{
+ }
+
+ for (parse_errors[i + 1 ..]) |note| {
+ if (!note.is_note) break;
+
+ text_buf.items.len = 0;
+ try tree.renderError(note, writer);
+ const note_loc = tree.tokenLocation(0, note.token);
+ notes_buffer[notes_len] = .{
.src = .{
.src_path = path,
- .msg = "field after declarations here",
- .byte_offset = @intCast(u32, next_loc.line_start),
- .line = @intCast(u32, next_loc.line),
- .column = @intCast(u32, next_loc.column),
- .source_line = tree.source[next_loc.line_start..next_loc.line_end],
+ .msg = try arena.dupe(u8, text_buf.items),
+ .byte_offset = @intCast(u32, note_loc.line_start),
+ .line = @intCast(u32, note_loc.line),
+ .column = @intCast(u32, note_loc.column),
+ .source_line = tree.source[note_loc.line_start..note_loc.line_end],
},
};
- notes_len = 2;
- i += 2;
+ i += 1;
+ notes_len += 1;
}
const extra_offset = tree.errorOffset(parse_error);
