carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-05 22:02:55 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Implement "unused pattern bindings" p2022 - parsing (#6460)

Browse Source 
This implements proposal #2022, with changes from #3763 and leads
answers on #6448

Detection of unusedness is happening in
~~`toolchain/check/dataflow_analysis.cpp`~~ next PR. See
[here](https://github.com/burakemir/carbon-lang/tree/unused_pattern_bindings_p2022_impl_part2)
for preview.

~~All test cases with unused bindings were updated in order to avoid
polluting test output.~~

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
This commit is contained in:
Burak Emir
2025-12-17 15:40:20 +00:00
committed by GitHub
co-authored by Dana Jansens
parent ad7ea755b0
commit fec6ce2f9f
16 changed files with 851 additions and 66 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docs/design/pattern_matching.md
+44 -11
View File
@@ -16,13 +16,14 @@ SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
- [Alternatives considered](#alternatives-considered)
- [Binding patterns](#binding-patterns)
- [Name binding patterns](#name-binding-patterns)
- [Unused bindings](#unused-bindings)
- [Anonymous bindings](#anonymous-bindings)
- [Alternatives considered](#alternatives-considered-1)
- [Compile-time bindings](#compile-time-bindings)
- [`auto` and type deduction](#auto-and-type-deduction)
- [Alternatives considered](#alternatives-considered-2)
- [`var`](#var)
- [Alternatives considered](#alternatives-considered-3)
- [`unused`](#unused)
- [Tuple patterns](#tuple-patterns)
- [Struct patterns](#struct-patterns)
- [Alternatives considered](#alternatives-considered-4)
@@ -198,17 +199,12 @@ fn H(n: i32) {
}
```
#### Unused bindings
#### Anonymous bindings
A syntax like a binding but with `_` in place of an identifier, or `unused`
before the name, can be used to ignore part of a value. Names that are qualified
with the `unused` keyword are visible for name lookup but uses are invalid,
including when they cause ambiguous name lookup errors. If attempted to be used,
a compiler error will be shown to the user, instructing them to either remove
the `unused` qualifier or remove the use.
A syntax like a binding but with `_` in place of an identifier can be used to
ignore part of a value.
- _binding-pattern_ ::= `_` `:` _expression_
- _binding-pattern_ ::= `unused` _identifier_ `:` _expression_
```carbon
fn F(n: i32) {
@@ -233,8 +229,6 @@ fn J(n: i32);
fn G(_: i32) {}
// ❌ Error: name of parameter does not match declaration.
fn H(m: i32) {}
// ✅ Does not use `n`.
fn J(unused n: i32);
```
##### Alternatives considered
@@ -345,6 +339,45 @@ _pattern_ `=` _expression_ `;`.
- [Make `var` a binding pattern modifier](/proposals/p5164.md#make-var-a-binding-pattern-modifier)
- [Initialize storage once pattern matching succeeds](/proposals/p5164.md#initialize-storage-once-pattern-matching-succeeds)
### `unused`
When a name introduced by a binding is not used, a warning is issued. It is
possible to avoid the warning while keeping a name, by using an `unused` marker.
An `unused` marker indicates that all names in a pattern are visible for name
lookup but uses are invalid. This includes situations when they cause ambiguous
name lookup errors. If attempted to be used, a compiler error will be shown to
the user, instructing them to either remove the `unused` qualifier or remove the
use.
- _proper-pattern_ ::= `unused` _proper-pattern_
An `unused` marker can be applied to any pattern and it will apply to all name
bindings in a pattern. Nesting `unused` markers is an error. When an `unused`
marker applies only to anonymous bindings `_` and is thus redundant, a warning
is produced. `var` and `unused` may appear in any order in a pattern.
As specified in [#3763](/proposals/p3763.md), `unused` markers may only appear
on definitions, not on non-defining declarations. Function redeclarations that
are also definitions may have difference due to `unused` markers, but they may
not have different names.
```carbon
fn J(n: i32);
// ✅ Does not use `n`.
fn J(unused n: i32) { ... };
fn G() {
match ((1, 2)) {
// `x` is unused
case (var n: i32, unused x: i32) => { F(&n); }
// `n` and `m` are both unused
case unused (n: i32, m: i32) => { J(42); }
}
}
```
### Tuple patterns
A tuple of patterns can be used as a pattern.
toolchain/check/handle_binding_pattern.cpp
+4
View File
@@ -456,4 +456,8 @@ auto HandleParseNode(Context& context, Parse::TemplateBindingNameId node_id)
return true;
}
auto HandleParseNode(Context& context, Parse::UnusedPatternId node_id) -> bool {
return context.TODO(node_id, "unused");
}
} // namespace Carbon::Check
toolchain/check/testdata/class/import_base.carbon
Vendored
+40 -40
View File
@@ -21,7 +21,7 @@ base class Base {
fn Unused[self: Self]();
var x: i32;
var unused: i32;
var unused_y: i32;
}
class Child {
@@ -35,7 +35,7 @@ library "[[@TEST_NAME]]";
import library "a";
fn Run() {
var a: Child = {.base = {.x = 0, .unused = 1}};
var a: Child = {.base = {.x = 0, .unused_y = 1}};
a.x = 2;
a.F();
}
@@ -54,8 +54,8 @@ fn Run() {
// CHECK:STDOUT: %Int.generic: %Int.type = struct_value () [concrete]
// CHECK:STDOUT: %i32: type = class_type @Int, @Int(%int_32) [concrete]
// CHECK:STDOUT: %Base.elem: type = unbound_element_type %Base, %i32 [concrete]
// CHECK:STDOUT: %struct_type.x.unused: type = struct_type {.x: %i32, .unused: %i32} [concrete]
// CHECK:STDOUT: %complete_type.20c: <witness> = complete_type_witness %struct_type.x.unused [concrete]
// CHECK:STDOUT: %struct_type.x.unused_y: type = struct_type {.x: %i32, .unused_y: %i32} [concrete]
// CHECK:STDOUT: %complete_type.cf1: <witness> = complete_type_witness %struct_type.x.unused_y [concrete]
// CHECK:STDOUT: %Child: type = class_type @Child [concrete]
// CHECK:STDOUT: %Child.elem: type = unbound_element_type %Child, %Base [concrete]
// CHECK:STDOUT: %struct_type.base: type = struct_type {.base: %Base} [concrete]
@@ -104,8 +104,8 @@ fn Run() {
// CHECK:STDOUT: %.loc8: %Base.elem = field_decl x, element0 [concrete]
// CHECK:STDOUT: %int_32.loc9: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
// CHECK:STDOUT: %i32.loc9: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
// CHECK:STDOUT: %.loc9: %Base.elem = field_decl unused, element1 [concrete]
// CHECK:STDOUT: %complete_type: <witness> = complete_type_witness constants.%struct_type.x.unused [concrete = constants.%complete_type.20c]
// CHECK:STDOUT: %.loc9: %Base.elem = field_decl unused_y, element1 [concrete]
// CHECK:STDOUT: %complete_type: <witness> = complete_type_witness constants.%struct_type.x.unused_y [concrete = constants.%complete_type.cf1]
// CHECK:STDOUT: complete_type_witness = %complete_type
// CHECK:STDOUT:
// CHECK:STDOUT: !members:
@@ -113,7 +113,7 @@ fn Run() {
// CHECK:STDOUT: .F = %Base.F.decl
// CHECK:STDOUT: .Unused = %Base.Unused.decl
// CHECK:STDOUT: .x = %.loc8
// CHECK:STDOUT: .unused = %.loc9
// CHECK:STDOUT: .unused_y = %.loc9
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: class @Child {
@@ -143,17 +143,17 @@ fn Run() {
// CHECK:STDOUT: %Base: type = class_type @Base [concrete]
// CHECK:STDOUT: %int_32: Core.IntLiteral = int_value 32 [concrete]
// CHECK:STDOUT: %i32: type = class_type @Int, @Int(%int_32) [concrete]
// CHECK:STDOUT: %struct_type.x.unused.7d5: type = struct_type {.x: %i32, .unused: %i32} [concrete]
// CHECK:STDOUT: %complete_type.90f: <witness> = complete_type_witness %struct_type.x.unused.7d5 [concrete]
// CHECK:STDOUT: %struct_type.x.unused_y.9fc: type = struct_type {.x: %i32, .unused_y: %i32} [concrete]
// CHECK:STDOUT: %complete_type.2da: <witness> = complete_type_witness %struct_type.x.unused_y.9fc [concrete]
// CHECK:STDOUT: %struct_type.base.27a: type = struct_type {.base: %Base} [concrete]
// CHECK:STDOUT: %complete_type.5a1: <witness> = complete_type_witness %struct_type.base.27a [concrete]
// CHECK:STDOUT: %pattern_type.454: type = pattern_type %Child [concrete]
// CHECK:STDOUT: %int_0.5c6: Core.IntLiteral = int_value 0 [concrete]
// CHECK:STDOUT: %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
// CHECK:STDOUT: %struct_type.x.unused.c45: type = struct_type {.x: Core.IntLiteral, .unused: Core.IntLiteral} [concrete]
// CHECK:STDOUT: %struct.9cc: %struct_type.x.unused.c45 = struct_value (%int_0.5c6, %int_1.5b8) [concrete]
// CHECK:STDOUT: %struct_type.base.6c7: type = struct_type {.base: %struct_type.x.unused.c45} [concrete]
// CHECK:STDOUT: %struct.133: %struct_type.base.6c7 = struct_value (%struct.9cc) [concrete]
// CHECK:STDOUT: %struct_type.x.unused_y.76a: type = struct_type {.x: Core.IntLiteral, .unused_y: Core.IntLiteral} [concrete]
// CHECK:STDOUT: %struct.0bf: %struct_type.x.unused_y.76a = struct_value (%int_0.5c6, %int_1.5b8) [concrete]
// CHECK:STDOUT: %struct_type.base.503: type = struct_type {.base: %struct_type.x.unused_y.76a} [concrete]
// CHECK:STDOUT: %struct.cb5: %struct_type.base.503 = struct_value (%struct.0bf) [concrete]
// CHECK:STDOUT: %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
// CHECK:STDOUT: %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
// CHECK:STDOUT: %ImplicitAs.type.bd9: type = facet_type <@ImplicitAs, @ImplicitAs(%i32)> [concrete]
@@ -199,12 +199,12 @@ fn Run() {
// CHECK:STDOUT: import Core//prelude
// CHECK:STDOUT: import Core//prelude/...
// CHECK:STDOUT: }
// CHECK:STDOUT: %Main.import_ref.239: <witness> = import_ref Main//a, loc10_1, loaded [concrete = constants.%complete_type.90f]
// CHECK:STDOUT: %Main.import_ref.8f2: <witness> = import_ref Main//a, loc10_1, loaded [concrete = constants.%complete_type.2da]
// CHECK:STDOUT: %Main.import_ref.691 = import_ref Main//a, inst{{[0-9A-F]+}} [no loc], unloaded
// CHECK:STDOUT: %Main.import_ref.062: %Base.F.type = import_ref Main//a, loc5_21, loaded [concrete = constants.%Base.F]
// CHECK:STDOUT: %Main.import_ref.7b8 = import_ref Main//a, loc6_26, unloaded
// CHECK:STDOUT: %Main.import_ref.183: %Base.elem = import_ref Main//a, loc8_8, loaded [concrete = %.61a]
// CHECK:STDOUT: %Main.import_ref.adb = import_ref Main//a, loc9_13, unloaded
// CHECK:STDOUT: %Main.import_ref.7c0 = import_ref Main//a, loc9_15, unloaded
// CHECK:STDOUT: %Main.import_ref.44c: <witness> = import_ref Main//a, loc14_1, loaded [concrete = constants.%complete_type.5a1]
// CHECK:STDOUT: %Main.import_ref.d37 = import_ref Main//a, inst{{[0-9A-F]+}} [no loc], unloaded
// CHECK:STDOUT: %Main.import_ref.4a6 = import_ref Main//a, loc13_20, unloaded
@@ -240,14 +240,14 @@ fn Run() {
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: class @Base [from "a.carbon"] {
// CHECK:STDOUT: complete_type_witness = imports.%Main.import_ref.239
// CHECK:STDOUT: complete_type_witness = imports.%Main.import_ref.8f2
// CHECK:STDOUT:
// CHECK:STDOUT: !members:
// CHECK:STDOUT: .Self = imports.%Main.import_ref.691
// CHECK:STDOUT: .F = imports.%Main.import_ref.062
// CHECK:STDOUT: .Unused = imports.%Main.import_ref.7b8
// CHECK:STDOUT: .x = imports.%Main.import_ref.183
// CHECK:STDOUT: .unused = imports.%Main.import_ref.adb
// CHECK:STDOUT: .unused_y = imports.%Main.import_ref.7c0
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @Run() {
@@ -259,29 +259,29 @@ fn Run() {
// CHECK:STDOUT: %a.var: ref %Child = var %a.var_patt
// CHECK:STDOUT: %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0.5c6]
// CHECK:STDOUT: %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
// CHECK:STDOUT: %.loc7_47.1: %struct_type.x.unused.c45 = struct_literal (%int_0, %int_1) [concrete = constants.%struct.9cc]
// CHECK:STDOUT: %.loc7_48.1: %struct_type.base.6c7 = struct_literal (%.loc7_47.1) [concrete = constants.%struct.133]
// CHECK:STDOUT: %impl.elem0.loc7_47.1: %.d0f = impl_witness_access constants.%ImplicitAs.impl_witness.377, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.8ce]
// CHECK:STDOUT: %bound_method.loc7_47.1: <bound method> = bound_method %int_0, %impl.elem0.loc7_47.1 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.bound.6ae]
// CHECK:STDOUT: %specific_fn.loc7_47.1: <specific function> = specific_function %impl.elem0.loc7_47.1, @Core.IntLiteral.as.ImplicitAs.impl.Convert(constants.%int_32) [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.specific_fn]
// CHECK:STDOUT: %bound_method.loc7_47.2: <bound method> = bound_method %int_0, %specific_fn.loc7_47.1 [concrete = constants.%bound_method.74d]
// CHECK:STDOUT: %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc7_47.1: init %i32 = call %bound_method.loc7_47.2(%int_0) [concrete = constants.%int_0.263]
// CHECK:STDOUT: %.loc7_47.2: init %i32 = converted %int_0, %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc7_47.1 [concrete = constants.%int_0.263]
// CHECK:STDOUT: %.loc7_48.2: ref %Base = class_element_access %a.var, element0
// CHECK:STDOUT: %.loc7_47.3: ref %i32 = class_element_access %.loc7_48.2, element0
// CHECK:STDOUT: %.loc7_47.4: init %i32 = initialize_from %.loc7_47.2 to %.loc7_47.3 [concrete = constants.%int_0.263]
// CHECK:STDOUT: %impl.elem0.loc7_47.2: %.d0f = impl_witness_access constants.%ImplicitAs.impl_witness.377, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.8ce]
// CHECK:STDOUT: %bound_method.loc7_47.3: <bound method> = bound_method %int_1, %impl.elem0.loc7_47.2 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.bound.9ed]
// CHECK:STDOUT: %specific_fn.loc7_47.2: <specific function> = specific_function %impl.elem0.loc7_47.2, @Core.IntLiteral.as.ImplicitAs.impl.Convert(constants.%int_32) [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.specific_fn]
// CHECK:STDOUT: %bound_method.loc7_47.4: <bound method> = bound_method %int_1, %specific_fn.loc7_47.2 [concrete = constants.%bound_method.a30]
// CHECK:STDOUT: %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc7_47.2: init %i32 = call %bound_method.loc7_47.4(%int_1) [concrete = constants.%int_1.47b]
// CHECK:STDOUT: %.loc7_47.5: init %i32 = converted %int_1, %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc7_47.2 [concrete = constants.%int_1.47b]
// CHECK:STDOUT: %.loc7_47.6: ref %i32 = class_element_access %.loc7_48.2, element1
// CHECK:STDOUT: %.loc7_47.7: init %i32 = initialize_from %.loc7_47.5 to %.loc7_47.6 [concrete = constants.%int_1.47b]
// CHECK:STDOUT: %.loc7_47.8: init %Base = class_init (%.loc7_47.4, %.loc7_47.7), %.loc7_48.2 [concrete = constants.%Base.val]
// CHECK:STDOUT: %.loc7_48.3: init %Base = converted %.loc7_47.1, %.loc7_47.8 [concrete = constants.%Base.val]
// CHECK:STDOUT: %.loc7_48.4: init %Child = class_init (%.loc7_48.3), %a.var [concrete = constants.%Child.val]
// CHECK:STDOUT: %.loc7_3: init %Child = converted %.loc7_48.1, %.loc7_48.4 [concrete = constants.%Child.val]
// CHECK:STDOUT: %.loc7_49.1: %struct_type.x.unused_y.76a = struct_literal (%int_0, %int_1) [concrete = constants.%struct.0bf]
// CHECK:STDOUT: %.loc7_50.1: %struct_type.base.503 = struct_literal (%.loc7_49.1) [concrete = constants.%struct.cb5]
// CHECK:STDOUT: %impl.elem0.loc7_49.1: %.d0f = impl_witness_access constants.%ImplicitAs.impl_witness.377, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.8ce]
// CHECK:STDOUT: %bound_method.loc7_49.1: <bound method> = bound_method %int_0, %impl.elem0.loc7_49.1 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.bound.6ae]
// CHECK:STDOUT: %specific_fn.loc7_49.1: <specific function> = specific_function %impl.elem0.loc7_49.1, @Core.IntLiteral.as.ImplicitAs.impl.Convert(constants.%int_32) [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.specific_fn]
// CHECK:STDOUT: %bound_method.loc7_49.2: <bound method> = bound_method %int_0, %specific_fn.loc7_49.1 [concrete = constants.%bound_method.74d]
// CHECK:STDOUT: %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc7_49.1: init %i32 = call %bound_method.loc7_49.2(%int_0) [concrete = constants.%int_0.263]
// CHECK:STDOUT: %.loc7_49.2: init %i32 = converted %int_0, %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc7_49.1 [concrete = constants.%int_0.263]
// CHECK:STDOUT: %.loc7_50.2: ref %Base = class_element_access %a.var, element0
// CHECK:STDOUT: %.loc7_49.3: ref %i32 = class_element_access %.loc7_50.2, element0
// CHECK:STDOUT: %.loc7_49.4: init %i32 = initialize_from %.loc7_49.2 to %.loc7_49.3 [concrete = constants.%int_0.263]
// CHECK:STDOUT: %impl.elem0.loc7_49.2: %.d0f = impl_witness_access constants.%ImplicitAs.impl_witness.377, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.8ce]
// CHECK:STDOUT: %bound_method.loc7_49.3: <bound method> = bound_method %int_1, %impl.elem0.loc7_49.2 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.bound.9ed]
// CHECK:STDOUT: %specific_fn.loc7_49.2: <specific function> = specific_function %impl.elem0.loc7_49.2, @Core.IntLiteral.as.ImplicitAs.impl.Convert(constants.%int_32) [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.specific_fn]
// CHECK:STDOUT: %bound_method.loc7_49.4: <bound method> = bound_method %int_1, %specific_fn.loc7_49.2 [concrete = constants.%bound_method.a30]
// CHECK:STDOUT: %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc7_49.2: init %i32 = call %bound_method.loc7_49.4(%int_1) [concrete = constants.%int_1.47b]
// CHECK:STDOUT: %.loc7_49.5: init %i32 = converted %int_1, %Core.IntLiteral.as.ImplicitAs.impl.Convert.call.loc7_49.2 [concrete = constants.%int_1.47b]
// CHECK:STDOUT: %.loc7_49.6: ref %i32 = class_element_access %.loc7_50.2, element1
// CHECK:STDOUT: %.loc7_49.7: init %i32 = initialize_from %.loc7_49.5 to %.loc7_49.6 [concrete = constants.%int_1.47b]
// CHECK:STDOUT: %.loc7_49.8: init %Base = class_init (%.loc7_49.4, %.loc7_49.7), %.loc7_50.2 [concrete = constants.%Base.val]
// CHECK:STDOUT: %.loc7_50.3: init %Base = converted %.loc7_49.1, %.loc7_49.8 [concrete = constants.%Base.val]
// CHECK:STDOUT: %.loc7_50.4: init %Child = class_init (%.loc7_50.3), %a.var [concrete = constants.%Child.val]
// CHECK:STDOUT: %.loc7_3: init %Child = converted %.loc7_50.1, %.loc7_50.4 [concrete = constants.%Child.val]
// CHECK:STDOUT: assign %a.var, %.loc7_3
// CHECK:STDOUT: %Child.ref: type = name_ref Child, imports.%Main.Child [concrete = constants.%Child]
// CHECK:STDOUT: %a: ref %Child = ref_binding a, %a.var
toolchain/check/testdata/dataflow/unused.carbon
Vendored
+168
View File
@@ -0,0 +1,168 @@
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/primitives.carbon
//
// AUTOUPDATE
// TIP: To test this file alone, run:
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/dataflow/unused.carbon
// TIP: To dump output, run:
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/dataflow/unused.carbon
// --- todo_ensure_no_warning.carbon
library "[[@TEST_NAME]]";
fn ReturnVar() -> i32 {
var x: i32 = 0;
x = 1;
return x;
// TODO: ensure no warning.
}
fn ReturnLet() -> i32 {
let y: i32 = 1;
return y;
// TODO: ensure no warning.
}
fn RefParam(ref x: i32) {
x = 1;
// TODO: ensure no warning.
}
fn ReturnedVar() -> i32 {
returned var x: i32 = 0;
return var;
// TODO: ensure no warning.
}
fn ReturnVarExplicit() -> i32 {
var x: i32 = 0;
return x;
// TODO: ensure no warning.
}
fn FieldAccess() {
var x: {.a: i32} = {.a = 0};
// Accessing a field should count as a use of x.
var y: i32 = x.a;
// TODO: ensure no warning.
}
fn ParametersUsed(x: i32) -> i32 {
// TODO: ensure no warning.
return x;
}
// --- fail_todo_unused_ref_param.carbon
library "[[@TEST_NAME]]";
// CHECK:STDERR: fail_todo_unused_ref_param.carbon:[[@LINE+4]]:19: error: semantics TODO: `unused` [SemanticsTodo]
// CHECK:STDERR: fn RefParamUnused(unused ref y: i32) {
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~
// CHECK:STDERR:
fn RefParamUnused(unused ref y: i32) {
// TODO: ensure no warning
}
// --- todo_fail_local_let_named_not_used.carbon
library "[[@TEST_NAME]]";
fn F() {
let x: i32 = 0;
// TODO: warning, x is unused.
}
// --- todo_fail_local_var_named_not_used.carbon
library "[[@TEST_NAME]]";
fn F() {
var a: i32 = 0;
// TODO: warning, a is unused.
}
// --- todo_fail_local_var_shadowed_not_used.carbon
library "[[@TEST_NAME]]";
fn F() {
var x: i32 = 0;
if (true) {
var x: i32 = 1;
// TODO: warning, x is unused.
}
x = 2;
// TODO: warning, x is unused.
}
// --- todo_fail_param_let_named_not_used.carbon
library "[[@TEST_NAME]]";
fn F(p: i32) {
// TODO: warning, p is unused.
}
// --- todo_fail_param_ref_named_not_used.carbon
library "[[@TEST_NAME]]";
fn F(ref y: i32) {
// TODO: warning, y is unused.
}
// --- fail_todo_read_from_param_unused_ref.carbon
library "[[@TEST_NAME]]";
// CHECK:STDERR: fail_todo_read_from_param_unused_ref.carbon:[[@LINE+4]]:19: error: semantics TODO: `unused` [SemanticsTodo]
// CHECK:STDERR: fn RefParamUnused(unused ref y: i32) {
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~
// CHECK:STDERR:
fn RefParamUnused(unused ref y: i32) {
var _: i32 = y;
// TODO: ensure error, marked "unused" but used.
}
// --- fail_todo_fail_unused_returned_var.carbon
library "[[@TEST_NAME]]";
fn F() -> i32 {
// CHECK:STDERR: fail_todo_fail_unused_returned_var.carbon:[[@LINE+4]]:16: error: semantics TODO: `unused` [SemanticsTodo]
// CHECK:STDERR: returned var unused x: i32 = 0;
// CHECK:STDERR: ^~~~~~~~~~~~~
// CHECK:STDERR:
returned var unused x: i32 = 0;
// TODO: ensure error, marked "unused" but used.
return var;
}
// --- fail_todo_fail_read_from_unused_local_var.carbon
library "[[@TEST_NAME]]";
fn F(x: i32) {
var _: i32 = x;
// CHECK:STDERR: fail_todo_fail_read_from_unused_local_var.carbon:[[@LINE+4]]:7: error: semantics TODO: `unused` [SemanticsTodo]
// CHECK:STDERR: var unused y: i32 = x;
// CHECK:STDERR: ^~~~~~~~~~~~~
// CHECK:STDERR:
var unused y: i32 = x;
// TODO: error, marked "unused", but used
var unused z: i32 = y;
}
// --- fail_todo_match.carbon
library "[[@TEST_NAME]]";
fn F() -> i32 {
var x: i32 = 3;
// CHECK:STDERR: fail_todo_match.carbon:[[@LINE+4]]:3: error: semantics TODO: `HandleMatchIntroducer` [SemanticsTodo]
// CHECK:STDERR: match (f(x)) {
// CHECK:STDERR: ^~~~~
// CHECK:STDERR:
match (f(x)) {
case unused var (a: i32, b: i32) => { return 0; }
case (a: i32) if (a < 0) => { return 2; }
case var unused a: i32 if (a != x) => { return 3; }
default => { return 4; }
}
return 0;
// TODO: ensure no warning (after match is implemented).
}
toolchain/diagnostics/diagnostic_kind.def
+1
View File
@@ -109,6 +109,7 @@ CARBON_DIAGNOSTIC_KIND(ExpectedVarAfterReturned)
CARBON_DIAGNOSTIC_KIND(ExpectedChoiceDefinition)
CARBON_DIAGNOSTIC_KIND(ExpectedChoiceAlternativeName)
CARBON_DIAGNOSTIC_KIND(NestedVar)
CARBON_DIAGNOSTIC_KIND(NestedUnused)
CARBON_DIAGNOSTIC_KIND(OperatorRequiresParentheses)
CARBON_DIAGNOSTIC_KIND(RefInsideVar)
CARBON_DIAGNOSTIC_KIND(StatementOperatorAsSubExpr)
toolchain/lex/token_kind.def
+1
View File
@@ -218,6 +218,7 @@ CARBON_KEYWORD_TOKEN(Type, "type")
// Underscore is tokenized as a keyword because it's part of identifiers.
CARBON_KEYWORD_TOKEN(Underscore, "_")
CARBON_KEYWORD_TOKEN(Unsafe, "unsafe")
CARBON_KEYWORD_TOKEN(Unused, "unused")
CARBON_KEYWORD_TOKEN(Virtual, "virtual")
CARBON_TOKEN_WITH_VIRTUAL_NODE(
CARBON_KEYWORD_TOKEN(Where, "where"))
toolchain/parse/context.h
+14 -4
View File
@@ -95,6 +95,13 @@ class Context {
// could help catch errors.
bool in_var_pattern : 1 = false;
// Set to true to indicate that this state is handling a pattern nested
// inside an `unused` pattern.
// TODO: This is meaningful only for patterns, and the precedence fields
// are meaningful only for expressions, so expressing them as a union
// could help catch errors.
bool in_unused_pattern : 1 = false;
// Precedence information used by expression states in order to determine
// operator precedence. The ambient_precedence deals with how the expression
// should interact with outside context, while the lhs_precedence is
@@ -112,7 +119,7 @@ class Context {
// We expect State to fit into 12 bytes:
// state = 1 byte
// has_error and in_var_pattern = 1 byte
// has_error, in_var_pattern, and in_unused_pattern = 1 byte
// ambient_precedence = 1 byte
// lhs_precedence = 1 byte
// token = 4 bytes
@@ -318,11 +325,14 @@ class Context {
.subtree_start = tree_->size()});
}
// Pushes a new state for handling a pattern. `in_var_pattern` indicates
// whether that pattern is nested inside a `var` pattern.
auto PushStateForPattern(StateKind kind, bool in_var_pattern) -> void {
// Pushes a new state for handling a pattern. `in_var_pattern` and
// `in_unused_pattern` indicate whether that pattern is nested inside a `var`
// or `unused` pattern.
auto PushStateForPattern(StateKind kind, bool in_var_pattern,
bool in_unused_pattern) -> void {
PushState({.kind = kind,
.in_var_pattern = in_var_pattern,
.in_unused_pattern = in_unused_pattern,
.token = *position_,
.subtree_start = tree_->size()});
}
toolchain/parse/handle_pattern.cpp
+11 -3
View File
@@ -12,15 +12,23 @@ auto HandlePattern(Context& context) -> void {
switch (context.PositionKind()) {
case Lex::TokenKind::OpenParen:
context.PushStateForPattern(StateKind::PatternListAsTuple,
state.in_var_pattern);
state.in_var_pattern,
state.in_unused_pattern);
break;
case Lex::TokenKind::Var:
context.PushStateForPattern(StateKind::VariablePattern,
state.in_var_pattern);
state.in_var_pattern,
state.in_unused_pattern);
break;
case Lex::TokenKind::Unused:
context.PushStateForPattern(StateKind::UnusedPattern,
state.in_var_pattern,
state.in_unused_pattern);
break;
default:
context.PushStateForPattern(StateKind::BindingPattern,
state.in_var_pattern);
state.in_var_pattern,
state.in_unused_pattern);
break;
}
}
toolchain/parse/handle_pattern_list.cpp
+10 -5
View File
@@ -12,8 +12,10 @@ static auto HandlePatternListElement(Context& context, StateKind pattern_state,
StateKind finish_state_kind) -> void {
auto state = context.PopState();
context.PushStateForPattern(finish_state_kind, state.in_var_pattern);
context.PushStateForPattern(pattern_state, state.in_var_pattern);
context.PushStateForPattern(finish_state_kind, state.in_var_pattern,
state.in_unused_pattern);
context.PushStateForPattern(pattern_state, state.in_var_pattern,
state.in_unused_pattern);
}
auto HandlePatternListElementAsTuple(Context& context) -> void {
@@ -44,7 +46,8 @@ static auto HandlePatternListElementFinish(Context& context,
if (context.ConsumeListToken(NodeKind::PatternListComma, close_token,
state.has_error) ==
Context::ListTokenKind::Comma) {
context.PushStateForPattern(param_state_kind, state.in_var_pattern);
context.PushStateForPattern(param_state_kind, state.in_var_pattern,
state.in_unused_pattern);
}
}
@@ -71,11 +74,13 @@ static auto HandlePatternList(Context& context, NodeKind node_kind,
-> void {
auto state = context.PopState();
context.PushStateForPattern(finish_state, state.in_var_pattern);
context.PushStateForPattern(finish_state, state.in_var_pattern,
state.in_unused_pattern);
context.AddLeafNode(node_kind, context.ConsumeChecked(open_token_kind));
if (!context.PositionIs(close_token_kind)) {
context.PushStateForPattern(param_state, state.in_var_pattern);
context.PushStateForPattern(param_state, state.in_var_pattern,
state.in_unused_pattern);
}
}
toolchain/parse/handle_unused.cpp
+36
View File
@@ -0,0 +1,36 @@
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "toolchain/parse/context.h"
#include "toolchain/parse/handle.h"
namespace Carbon::Parse {
auto HandleUnusedPattern(Context& context) -> void {
auto state = context.PopState();
if (state.in_unused_pattern) {
CARBON_DIAGNOSTIC(NestedUnused, Error,
"`unused` nested within another `unused`");
context.emitter().Emit(*context.position(), NestedUnused);
state.has_error = true;
}
context.PushState(StateKind::FinishUnusedPattern);
context.ConsumeChecked(Lex::TokenKind::Unused);
context.PushStateForPattern(StateKind::Pattern, state.in_var_pattern,
/*in_unused_pattern=*/true);
}
auto HandleFinishUnusedPattern(Context& context) -> void {
auto state = context.PopState();
context.AddNode(NodeKind::UnusedPattern, state.token, state.has_error);
// Propagate errors to the parent state so that they can take different
// actions on invalid patterns.
if (state.has_error) {
context.ReturnErrorOnState();
}
}
} // namespace Carbon::Parse
toolchain/parse/handle_var.cpp
+4 -2
View File
@@ -25,7 +25,8 @@ static auto HandleVar(Context& context, StateKind finish_state_kind,
context.AddLeafNode(NodeKind::ReturnedModifier, returned_token);
}
context.PushStateForPattern(StateKind::Pattern, /*in_var_pattern=*/true);
context.PushStateForPattern(StateKind::Pattern, /*in_var_pattern=*/true,
/*in_unused_pattern=*/false);
}
auto HandleVarAsRegular(Context& context) -> void {
@@ -142,7 +143,8 @@ auto HandleVariablePattern(Context& context) -> void {
context.PushState(StateKind::FinishVariablePattern);
context.ConsumeChecked(Lex::TokenKind::Var);
context.PushStateForPattern(StateKind::Pattern, /*in_var_pattern=*/true);
context.PushStateForPattern(StateKind::Pattern, /*in_var_pattern=*/true,
state.in_unused_pattern);
}
auto HandleFinishVariablePattern(Context& context) -> void {
toolchain/parse/node_kind.def
+1
View File
@@ -170,6 +170,7 @@ CARBON_PARSE_NODE_KIND(ArrayExprComma)
CARBON_PARSE_NODE_KIND(ArrayExpr)
CARBON_PARSE_NODE_KIND(RefBindingName)
CARBON_PARSE_NODE_KIND(UnusedPattern)
CARBON_PARSE_NODE_KIND(LetBindingPattern)
CARBON_PARSE_NODE_KIND(AssociatedConstantNameAndType)
CARBON_PARSE_NODE_KIND(VarBindingPattern)
toolchain/parse/state.def
+19
View File
@@ -1035,6 +1035,10 @@ CARBON_PARSE_STATE(ParenExprFinish)
// ...
// ^
// 1. BindingPattern
//
// ...
// ^
// 1. UnusedPattern
CARBON_PARSE_STATE(Pattern)
// Handles the initial part of a binding pattern, enqueuing type expression
@@ -1085,6 +1089,21 @@ CARBON_PARSE_STATE(VariablePattern)
// (state done)
CARBON_PARSE_STATE(FinishVariablePattern)
// Handles `unused` in a pattern context.
//
// unused ...
// ^~~~~~
// 1. Pattern
// 2. FinishUnusedPattern
CARBON_PARSE_STATE(UnusedPattern)
// Finishes `unused` in a pattern context.
//
// unused ...
// ^
// (state done)
CARBON_PARSE_STATE(FinishUnusedPattern)
// Handles a single statement. While typically within a statement block, this
// can also be used for error recovery where we expect a statement block and
// are missing braces.
toolchain/parse/testdata/var/unused.carbon
Vendored
+470
View File
@@ -0,0 +1,470 @@
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
// AUTOUPDATE
// TIP: To test this file alone, run:
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/parse/testdata/var/unused.carbon
// TIP: To dump output, run:
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/var/unused.carbon
// --- fail_unused_does_not_start_declaration.carbon
// CHECK:STDERR: fail_unused_does_not_start_declaration.carbon:[[@LINE+4]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
// CHECK:STDERR: unused y: i32;
// CHECK:STDERR: ^~~~~~
// CHECK:STDERR:
unused y: i32;
// --- let_var_unused.carbon
var unused y: i32;
let unused y: i32;
let unused ref w: i32 = 0;
fn F(unused x: i32, var unused b: i32, unused ref c: i32) {
var unused y: i32;
let unused z: i32;
let unused ref w: i32 = 0;
let unused ref t: str = "hello";
}
// --- unused_tuple.carbon
let (x: (), var unused y: ()) = ((), ());
let (x: (), unused var y: ()) = ((), ());
let unused (x: (), y: ()) = ((), ());
let var (x: (), unused y: ()) = ((), ());
let var unused (x: (), y: ()) = ((), ());
// --- var_unused_function.carbon
fn F(x: (), var unused y: ());
// --- var_unused_match.carbon
fn F() -> i32 {
var x: i32 = 3;
match (f(x)) {
case unused var (a: i32, b: i32) => { return 0; }
case (a: i32) if (a < 0) => { return 2; }
case var unused a: i32 if (a != x) => { return 3; }
default => { return 4; }
}
return 0;
}
// --- unused_var_function.carbon
fn F(x: (), unused var y: ());
// --- fail_ref_unused.carbon
// CHECK:STDERR: fail_ref_unused.carbon:[[@LINE+4]]:10: error: expected name in binding pattern [ExpectedBindingPattern]
// CHECK:STDERR: fn F(ref unused y: i32);
// CHECK:STDERR: ^~~~~~
// CHECK:STDERR:
fn F(ref unused y: i32);
// --- fail_nested.carbon
// CHECK:STDERR: fail_nested.carbon:[[@LINE+4]]:12: error: `unused` nested within another `unused` [NestedUnused]
// CHECK:STDERR: var unused unused x: i32 = 0;
// CHECK:STDERR: ^~~~~~
// CHECK:STDERR:
var unused unused x: i32 = 0;
// --- fail_nested_parens.carbon
// CHECK:STDERR: fail_nested_parens.carbon:[[@LINE+4]]:13: error: `unused` nested within another `unused` [NestedUnused]
// CHECK:STDERR: var unused (unused y: i32) = (0,);
// CHECK:STDERR: ^~~~~~
// CHECK:STDERR:
var unused (unused y: i32) = (0,);
// CHECK:STDOUT: - filename: fail_unused_does_not_start_declaration.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'InvalidParseStart', text: 'unused', has_error: yes},
// CHECK:STDOUT: {kind: 'InvalidParseSubtree', text: ';', has_error: yes, subtree_size: 2},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: let_var_unused.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 5},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 7},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 6},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'w'},
// CHECK:STDOUT: {kind: 'RefBindingName', text: 'ref', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 5},
// CHECK:STDOUT: {kind: 'LetInitializer', text: '='},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 9},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierNameBeforeParams', text: 'F'},
// CHECK:STDOUT: {kind: 'ExplicitParamListStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 5},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
// CHECK:STDOUT: {kind: 'RefBindingName', text: 'ref', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 5},
// CHECK:STDOUT: {kind: 'ExplicitParamList', text: ')', subtree_size: 18},
// CHECK:STDOUT: {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 21},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 5},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 7},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'z'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 6},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'w'},
// CHECK:STDOUT: {kind: 'RefBindingName', text: 'ref', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 5},
// CHECK:STDOUT: {kind: 'LetInitializer', text: '='},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 9},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 't'},
// CHECK:STDOUT: {kind: 'RefBindingName', text: 'ref', subtree_size: 2},
// CHECK:STDOUT: {kind: 'StringTypeLiteral', text: 'str'},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 5},
// CHECK:STDOUT: {kind: 'LetInitializer', text: '='},
// CHECK:STDOUT: {kind: 'StringLiteral', text: '"hello"'},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 9},
// CHECK:STDOUT: {kind: 'FunctionDefinition', text: '}', subtree_size: 53},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: unused_tuple.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 5},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 6},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', subtree_size: 13},
// CHECK:STDOUT: {kind: 'LetInitializer', text: '='},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteralComma', text: ','},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 7},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 23},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 5},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 6},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', subtree_size: 13},
// CHECK:STDOUT: {kind: 'LetInitializer', text: '='},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteralComma', text: ','},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 7},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 23},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', subtree_size: 11},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 12},
// CHECK:STDOUT: {kind: 'LetInitializer', text: '='},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteralComma', text: ','},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 7},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 22},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 5},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', subtree_size: 12},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 13},
// CHECK:STDOUT: {kind: 'LetInitializer', text: '='},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteralComma', text: ','},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 7},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 23},
// CHECK:STDOUT: {kind: 'LetIntroducer', text: 'let'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', subtree_size: 11},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 12},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 13},
// CHECK:STDOUT: {kind: 'LetInitializer', text: '='},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteralComma', text: ','},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 7},
// CHECK:STDOUT: {kind: 'LetDecl', text: ';', subtree_size: 23},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: var_unused_function.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierNameBeforeParams', text: 'F'},
// CHECK:STDOUT: {kind: 'ExplicitParamListStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 5},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 6},
// CHECK:STDOUT: {kind: 'ExplicitParamList', text: ')', subtree_size: 13},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 16},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: var_unused_match.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierNameBeforeParams', text: 'F'},
// CHECK:STDOUT: {kind: 'ExplicitParamListStart', text: '('},
// CHECK:STDOUT: {kind: 'ExplicitParamList', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'ReturnType', text: '->', subtree_size: 2},
// CHECK:STDOUT: {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 7},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariableInitializer', text: '='},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '3'},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 8},
// CHECK:STDOUT: {kind: 'MatchIntroducer', text: 'match'},
// CHECK:STDOUT: {kind: 'MatchConditionStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'f'},
// CHECK:STDOUT: {kind: 'CallExprStart', text: '(', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'x'},
// CHECK:STDOUT: {kind: 'CallExpr', text: ')', subtree_size: 4},
// CHECK:STDOUT: {kind: 'MatchCondition', text: ')', subtree_size: 6},
// CHECK:STDOUT: {kind: 'MatchStatementStart', text: '{', subtree_size: 8},
// CHECK:STDOUT: {kind: 'MatchCaseIntroducer', text: 'case'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', subtree_size: 9},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 10},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 11},
// CHECK:STDOUT: {kind: 'MatchCaseEqualGreater', text: '=>'},
// CHECK:STDOUT: {kind: 'MatchCaseStart', text: '{', subtree_size: 14},
// CHECK:STDOUT: {kind: 'ReturnStatementStart', text: 'return'},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'ReturnStatement', text: ';', subtree_size: 3},
// CHECK:STDOUT: {kind: 'MatchCase', text: '}', subtree_size: 18},
// CHECK:STDOUT: {kind: 'MatchCaseIntroducer', text: 'case'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', subtree_size: 5},
// CHECK:STDOUT: {kind: 'MatchCaseGuardIntroducer', text: 'if'},
// CHECK:STDOUT: {kind: 'MatchCaseGuardStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'a'},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'InfixOperatorLess', text: '<', subtree_size: 3},
// CHECK:STDOUT: {kind: 'MatchCaseGuard', text: ')', subtree_size: 6},
// CHECK:STDOUT: {kind: 'MatchCaseEqualGreater', text: '=>'},
// CHECK:STDOUT: {kind: 'MatchCaseStart', text: '{', subtree_size: 14},
// CHECK:STDOUT: {kind: 'ReturnStatementStart', text: 'return'},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '2'},
// CHECK:STDOUT: {kind: 'ReturnStatement', text: ';', subtree_size: 3},
// CHECK:STDOUT: {kind: 'MatchCase', text: '}', subtree_size: 18},
// CHECK:STDOUT: {kind: 'MatchCaseIntroducer', text: 'case'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 5},
// CHECK:STDOUT: {kind: 'MatchCaseGuardIntroducer', text: 'if'},
// CHECK:STDOUT: {kind: 'MatchCaseGuardStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'a'},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'x'},
// CHECK:STDOUT: {kind: 'InfixOperatorExclaimEqual', text: '!=', subtree_size: 3},
// CHECK:STDOUT: {kind: 'MatchCaseGuard', text: ')', subtree_size: 6},
// CHECK:STDOUT: {kind: 'MatchCaseEqualGreater', text: '=>'},
// CHECK:STDOUT: {kind: 'MatchCaseStart', text: '{', subtree_size: 14},
// CHECK:STDOUT: {kind: 'ReturnStatementStart', text: 'return'},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '3'},
// CHECK:STDOUT: {kind: 'ReturnStatement', text: ';', subtree_size: 3},
// CHECK:STDOUT: {kind: 'MatchCase', text: '}', subtree_size: 18},
// CHECK:STDOUT: {kind: 'MatchDefaultIntroducer', text: 'default'},
// CHECK:STDOUT: {kind: 'MatchDefaultEqualGreater', text: '=>'},
// CHECK:STDOUT: {kind: 'MatchDefaultStart', text: '{', subtree_size: 3},
// CHECK:STDOUT: {kind: 'ReturnStatementStart', text: 'return'},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '4'},
// CHECK:STDOUT: {kind: 'ReturnStatement', text: ';', subtree_size: 3},
// CHECK:STDOUT: {kind: 'MatchDefault', text: '}', subtree_size: 7},
// CHECK:STDOUT: {kind: 'MatchStatement', text: '}', subtree_size: 70},
// CHECK:STDOUT: {kind: 'ReturnStatementStart', text: 'return'},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'ReturnStatement', text: ';', subtree_size: 3},
// CHECK:STDOUT: {kind: 'FunctionDefinition', text: '}', subtree_size: 89},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: unused_var_function.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierNameBeforeParams', text: 'F'},
// CHECK:STDOUT: {kind: 'ExplicitParamListStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'PatternListComma', text: ','},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 5},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 6},
// CHECK:STDOUT: {kind: 'ExplicitParamList', text: ')', subtree_size: 13},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 16},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_ref_unused.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierNameBeforeParams', text: 'F'},
// CHECK:STDOUT: {kind: 'ExplicitParamListStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'unused', has_error: yes},
// CHECK:STDOUT: {kind: 'InvalidParse', text: 'unused', has_error: yes},
// CHECK:STDOUT: {kind: 'LetBindingPattern', text: 'ref', has_error: yes, subtree_size: 3},
// CHECK:STDOUT: {kind: 'ExplicitParamList', text: ')', has_error: yes, subtree_size: 5},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 8},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_nested.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 5},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 6},
// CHECK:STDOUT: {kind: 'VariableInitializer', text: '='},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 10},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_nested_parens.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 4},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', subtree_size: 6},
// CHECK:STDOUT: {kind: 'UnusedPattern', text: 'unused', subtree_size: 7},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 8},
// CHECK:STDOUT: {kind: 'VariableInitializer', text: '='},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'TupleLiteralComma', text: ','},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 15},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
toolchain/parse/testdata/var/var.carbon
Vendored
+19 -1
View File
@@ -9,9 +9,11 @@
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/var/var.carbon
var v: i32 = 0;
var _: i32 = 0;
var w: i32;
fn F() {
var s: str = "hello";
var _: str = "anonymous";
}
// CHECK:STDOUT: - filename: var.carbon
@@ -26,6 +28,14 @@ fn F() {
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 8},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'UnderscoreName', text: '_'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariableInitializer', text: '='},
// CHECK:STDOUT: {kind: 'IntLiteral', text: '0'},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 8},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'IdentifierNameNotBeforeParams', text: 'w'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
@@ -44,6 +54,14 @@ fn F() {
// CHECK:STDOUT: {kind: 'VariableInitializer', text: '='},
// CHECK:STDOUT: {kind: 'StringLiteral', text: '"hello"'},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 8},
// CHECK:STDOUT: {kind: 'FunctionDefinition', text: '}', subtree_size: 14},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'UnderscoreName', text: '_'},
// CHECK:STDOUT: {kind: 'StringTypeLiteral', text: 'str'},
// CHECK:STDOUT: {kind: 'VarBindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'VariablePattern', text: 'var', subtree_size: 4},
// CHECK:STDOUT: {kind: 'VariableInitializer', text: '='},
// CHECK:STDOUT: {kind: 'StringLiteral', text: '"anonymous"'},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 8},
// CHECK:STDOUT: {kind: 'FunctionDefinition', text: '}', subtree_size: 22},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
toolchain/parse/typed_nodes.h
+9
View File
@@ -324,6 +324,15 @@ struct Namespace {
// Pattern nodes
// -------------
// An unused pattern: `unused pattern`.
struct UnusedPattern {
static constexpr auto Kind = NodeKind::UnusedPattern.Define(
{.category = NodeCategory::Pattern, .child_count = 1});
Lex::UnusedTokenIndex token;
AnyPatternId inner;
};
// A ref binding name: `ref name`.
struct RefBindingName {
static constexpr auto Kind =