mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-02-12 20:37:54 +00:00
Code Issues Packages Projects Releases Wiki Activity

stage2: add error for unused labels

Browse Source
This commit is contained in:
Veikka Tuominen 2020-12-26 02:36:12 +02:00
parent 40aad4f47e
commit a50759325c
No known key found for this signature in database
GPG Key ID: 59AEB8936E16A6AC
3 changed files with 40 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/Module.zig
View File

@ -804,7 +804,7 @@ pub const Scope = struct {
pub const Label = struct {
token: ast.TokenIndex,
block_inst: *zir.Inst.Block,
result_loc: astgen.ResultLoc,
used: bool = false,
};
};

23
src/astgen.zig
View File

@ -348,8 +348,9 @@ fn breakExpr(mod: *Module, parent_scope: *Scope, node: *ast.Node.ControlFlowExpr
const block_inst = blk: {
if (node.getLabel()) |break_label| {
if (gen_zir.label) |label| {
if (gen_zir.label) |*label| {
if (try tokenIdentEql(mod, parent_scope, label.token, break_label)) {
label.used = true;
break :blk label.block_inst;
}
}
@ -407,8 +408,9 @@ fn continueExpr(mod: *Module, parent_scope: *Scope, node: *ast.Node.ControlFlowE
continue;
};
if (node.getLabel()) |break_label| blk: {
if (gen_zir.label) |label| {
if (gen_zir.label) |*label| {
if (try tokenIdentEql(mod, parent_scope, label.token, break_label)) {
label.used = true;
break :blk;
}
}
@ -485,6 +487,9 @@ fn labeledBlockExpr(
defer block_scope.instructions.deinit(mod.gpa);
try blockExprStmts(mod, &block_scope.base, &block_node.base, block_node.statements());
if (!block_scope.label.?.used) {
return mod.fail(parent_scope, tree.token_locs[block_node.label].start, "unused block label", .{});
}
block_inst.positionals.body.instructions = try block_scope.arena.dupe(*zir.Inst, block_scope.instructions.items);
try gen_zir.instructions.append(mod.gpa, &block_inst.base);
@ -1398,7 +1403,7 @@ fn whileExpr(mod: *Module, scope: *Scope, rl: ResultLoc, while_node: *ast.Node.W
loop_scope.break_block = while_block;
loop_scope.continue_block = cond_block;
if (while_node.label) |some| {
loop_scope.label = @as(?Scope.GenZIR.Label, Scope.GenZIR.Label{
loop_scope.label = @as(?Scope.GenZIR.Label, Scope.GenZIR.Label{
.token = some,
.block_inst = while_block,
});
@ -1465,6 +1470,11 @@ fn whileExpr(mod: *Module, scope: *Scope, rl: ResultLoc, while_node: *ast.Node.W
condbr.positionals.else_body = .{
.instructions = try else_scope.arena.dupe(*zir.Inst, else_scope.instructions.items),
};
if (loop_scope.label) |some| {
if (!some.used) {
return mod.fail(scope, tree.token_locs[some.token].start, "unused while label", .{});
}
}
return &while_block.base;
}
@ -1555,7 +1565,7 @@ fn forExpr(mod: *Module, scope: *Scope, rl: ResultLoc, for_node: *ast.Node.For)
loop_scope.break_block = for_block;
loop_scope.continue_block = cond_block;
if (for_node.label) |some| {
loop_scope.label = @as(?Scope.GenZIR.Label, Scope.GenZIR.Label{
loop_scope.label = @as(?Scope.GenZIR.Label, Scope.GenZIR.Label{
.token = some,
.block_inst = for_block,
});
@ -1646,6 +1656,11 @@ fn forExpr(mod: *Module, scope: *Scope, rl: ResultLoc, for_node: *ast.Node.For)
condbr.positionals.else_body = .{
.instructions = try else_scope.arena.dupe(*zir.Inst, else_scope.instructions.items),
};
if (loop_scope.label) |some| {
if (!some.used) {
return mod.fail(scope, tree.token_locs[some.token].start, "unused for label", .{});
}
}
return &for_block.base;
}

21
test/stage2/test.zig
View File

@ -1207,7 +1207,7 @@ pub fn addCases(ctx: *TestContext) !void {
{
var case = ctx.exe("break/continue", linux_x64);
// Break out of loop
case.addCompareOutput(
\\export fn _start() noreturn {
@ -1296,4 +1296,23 @@ pub fn addCases(ctx: *TestContext) !void {
"",
);
}
{
var case = ctx.exe("unused labels", linux_x64);
case.addError(
\\comptime {
\\ foo: {}
\\}
, &[_][]const u8{":2:5: error: unused block label"});
case.addError(
\\comptime {
\\ foo: while (true) {}
\\}
, &[_][]const u8{":2:5: error: unused while label"});
case.addError(
\\comptime {
\\ foo: for ("foo") |_| {}
\\}
, &[_][]const u8{":2:5: error: unused for label"});
}
}