[llvm-branch-commits] [clang] [Clang] [C++26] Expansion Statements (Part 11: Final Touches and Tests) (PR #169690)
via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Wed Dec 3 13:23:15 PST 2025
https://github.com/Sirraide updated https://github.com/llvm/llvm-project/pull/169690
>From 3b874f53ac31c9fa05568aeecaf2734d6601bc07 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 26 Nov 2025 18:03:57 +0100
Subject: [PATCH 1/4] [Clang] [C++26] Expansion Statements (Part 11)
---
clang/docs/ReleaseNotes.rst | 2 +
.../clang/Basic/DiagnosticCommonKinds.td | 4 -
clang/test/AST/ast-dump-expansion-stmt.cpp | 49 +++++++++
clang/test/AST/ast-print-expansion-stmts.cpp | 104 ++++++++++++++++++
clang/www/cxx_status.html | 2 +-
5 files changed, 156 insertions(+), 5 deletions(-)
create mode 100644 clang/test/AST/ast-dump-expansion-stmt.cpp
create mode 100644 clang/test/AST/ast-print-expansion-stmts.cpp
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 51f07256c5d9f..14f31c0ee5a2b 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -187,6 +187,8 @@ C++2c Feature Support
At this timem, references to constexpr and decomposition of *tuple-like* types are not supported
(only arrays and aggregates are).
+- Implemented `P1306R5 <https://wg21.link/P1306R5>`_ Expansion Statements.
+
C++23 Feature Support
^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/Basic/DiagnosticCommonKinds.td b/clang/include/clang/Basic/DiagnosticCommonKinds.td
index 0b9225980e826..6e50e225a8cc1 100644
--- a/clang/include/clang/Basic/DiagnosticCommonKinds.td
+++ b/clang/include/clang/Basic/DiagnosticCommonKinds.td
@@ -22,10 +22,6 @@ def select_constexpr_spec_kind : TextSubstitution<
def fatal_too_many_errors
: Error<"too many errors emitted, stopping now">, DefaultFatal;
-// TODO: Remove this.
-def err_expansion_statements_todo : Error<
- "TODO (expansion statements)">;
-
def warn_stack_exhausted : Warning<
"stack nearly exhausted; compilation time may suffer, and "
"crashes due to stack overflow are likely">,
diff --git a/clang/test/AST/ast-dump-expansion-stmt.cpp b/clang/test/AST/ast-dump-expansion-stmt.cpp
new file mode 100644
index 0000000000000..146157e2c13e6
--- /dev/null
+++ b/clang/test/AST/ast-dump-expansion-stmt.cpp
@@ -0,0 +1,49 @@
+// Test without serialization:
+// RUN: %clang_cc1 -std=c++26 -triple x86_64-unknown-unknown -ast-dump %s
+//
+// Test with serialization:
+// RUN: %clang_cc1 -std=c++26 -triple x86_64-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -x c++ -std=c++26 -triple x86_64-unknown-unknown -include-pch %t -ast-dump-all /dev/null \
+// RUN: | sed -e "s/ <undeserialized declarations>//" -e "s/ imported//"
+
+template <typename T, __SIZE_TYPE__ size>
+struct Array {
+ T data[size]{};
+ constexpr const T* begin() const { return data; }
+ constexpr const T* end() const { return data + size; }
+};
+
+void foo(int);
+
+template <typename T>
+void test(T t) {
+ // CHECK: CXXExpansionStmtDecl
+ // CHECK-NEXT: CXXEnumeratingExpansionStmtPattern
+ // CHECK: CXXExpansionStmtInstantiation
+ template for (auto x : {1, 2, 3}) {
+ foo(x);
+ }
+
+ // CHECK: CXXExpansionStmtDecl
+ // CHECK-NEXT: CXXIteratingExpansionStmtPattern
+ // CHECK: CXXExpansionStmtInstantiation
+ static constexpr Array<int, 3> a;
+ template for (auto x : a) {
+ foo(x);
+ }
+
+ // CHECK: CXXExpansionStmtDecl
+ // CHECK-NEXT: CXXDestructuringExpansionStmtPattern
+ // CHECK: CXXExpansionStmtInstantiation
+ int arr[3]{1, 2, 3};
+ template for (auto x : arr) {
+ foo(x);
+ }
+
+ // CHECK: CXXExpansionStmtDecl
+ // CHECK-NEXT: CXXDependentExpansionStmtPattern
+ // CHECK-NOT: CXXExpansionStmtInstantiation
+ template for (auto x : t) {
+ foo(x);
+ }
+}
diff --git a/clang/test/AST/ast-print-expansion-stmts.cpp b/clang/test/AST/ast-print-expansion-stmts.cpp
new file mode 100644
index 0000000000000..bb9f79c6644c0
--- /dev/null
+++ b/clang/test/AST/ast-print-expansion-stmts.cpp
@@ -0,0 +1,104 @@
+// Without serialization:
+// RUN: %clang_cc1 -std=c++26 -ast-print %s | FileCheck %s
+//
+// With serialization:
+// RUN: %clang_cc1 -std=c++26 -emit-pch -o %t %s
+// RUN: %clang_cc1 -x c++ -std=c++26 -include-pch %t -ast-print /dev/null | FileCheck %s
+
+template <typename T, __SIZE_TYPE__ size>
+struct Array {
+ T data[size]{};
+ constexpr const T* begin() const { return data; }
+ constexpr const T* end() const { return data + size; }
+};
+
+// CHECK: void foo(int);
+void foo(int);
+
+// CHECK: template <typename T> void test(T t) {
+template <typename T>
+void test(T t) {
+ // Enumerating expansion statement.
+ //
+ // CHECK: template for (auto x : { 1, 2, 3 }) {
+ // CHECK-NEXT: foo(x);
+ // CHECK-NEXT: }
+ template for (auto x : {1, 2, 3}) {
+ foo(x);
+ }
+
+ // Iterating expansion statement.
+ //
+ // CHECK: static constexpr Array<int, 3> a;
+ // CHECK-NEXT: template for (auto x : a) {
+ // CHECK-NEXT: foo(x);
+ // CHECK-NEXT: }
+ static constexpr Array<int, 3> a;
+ template for (auto x : a) {
+ foo(x);
+ }
+
+ // Destructuring expansion statement.
+ //
+ // CHECK: int arr[3]{1, 2, 3};
+ // CHECK-NEXT: template for (auto x : arr) {
+ // CHECK-NEXT: foo(x);
+ // CHECK-NEXT: }
+ int arr[3]{1, 2, 3};
+ template for (auto x : arr) {
+ foo(x);
+ }
+
+ // Dependent expansion statement.
+ //
+ // CHECK: template for (auto x : t) {
+ // CHECK-NEXT: foo(x);
+ // CHECK-NEXT: }
+ template for (auto x : t) {
+ foo(x);
+ }
+}
+
+// CHECK: template <typename T> void test2(T t) {
+template <typename T>
+void test2(T t) {
+ // Enumerating expansion statement.
+ //
+ // CHECK: template for (int x : { 1, 2, 3 }) {
+ // CHECK-NEXT: foo(x);
+ // CHECK-NEXT: }
+ template for (int x : {1, 2, 3}) {
+ foo(x);
+ }
+
+ // Iterating expansion statement.
+ //
+ // CHECK: static constexpr Array<int, 3> a;
+ // CHECK-NEXT: template for (int x : a) {
+ // CHECK-NEXT: foo(x);
+ // CHECK-NEXT: }
+ static constexpr Array<int, 3> a;
+ template for (int x : a) {
+ foo(x);
+ }
+
+ // Destructuring expansion statement.
+ //
+ // CHECK: int arr[3]{1, 2, 3};
+ // CHECK-NEXT: template for (int x : arr) {
+ // CHECK-NEXT: foo(x);
+ // CHECK-NEXT: }
+ int arr[3]{1, 2, 3};
+ template for (int x : arr) {
+ foo(x);
+ }
+
+ // Dependent expansion statement.
+ //
+ // CHECK: template for (int x : t) {
+ // CHECK-NEXT: foo(x);
+ // CHECK-NEXT: }
+ template for (int x : t) {
+ foo(x);
+ }
+}
diff --git a/clang/www/cxx_status.html b/clang/www/cxx_status.html
index 2618ff930a0e4..0bb2d5440775a 100755
--- a/clang/www/cxx_status.html
+++ b/clang/www/cxx_status.html
@@ -317,7 +317,7 @@ <h2 id="cxx26">C++2c implementation status</h2>
<tr>
<td>Expansion Statements</td>
<td><a href="https://wg21.link/P1306">P1306R5</a></td>
- <td class="none" align="center">No</td>
+ <td class="unreleased" align="center">Clang 22</td>
</tr>
<tr>
<td>constexpr virtual inheritance</td>
>From 55a9d031eedd97bfc9dc38f210218fe3ced333a2 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 3 Dec 2025 03:15:55 +0100
Subject: [PATCH 2/4] CWG 3131
---
clang/test/AST/ast-print-expansion-stmts.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/test/AST/ast-print-expansion-stmts.cpp b/clang/test/AST/ast-print-expansion-stmts.cpp
index bb9f79c6644c0..19ffe2f3028e4 100644
--- a/clang/test/AST/ast-print-expansion-stmts.cpp
+++ b/clang/test/AST/ast-print-expansion-stmts.cpp
@@ -30,7 +30,7 @@ void test(T t) {
// Iterating expansion statement.
//
// CHECK: static constexpr Array<int, 3> a;
- // CHECK-NEXT: template for (auto x : a) {
+ // CHECK-NEXT: template for (auto x : (a)) {
// CHECK-NEXT: foo(x);
// CHECK-NEXT: }
static constexpr Array<int, 3> a;
@@ -74,7 +74,7 @@ void test2(T t) {
// Iterating expansion statement.
//
// CHECK: static constexpr Array<int, 3> a;
- // CHECK-NEXT: template for (int x : a) {
+ // CHECK-NEXT: template for (int x : (a)) {
// CHECK-NEXT: foo(x);
// CHECK-NEXT: }
static constexpr Array<int, 3> a;
>From 526887fcde5914a32e54535821846a1389d323d7 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 3 Dec 2025 18:10:06 +0100
Subject: [PATCH 3/4] Eliminate CXXExpansionInitListExpr
---
clang/test/AST/ast-print-expansion-stmts.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/test/AST/ast-print-expansion-stmts.cpp b/clang/test/AST/ast-print-expansion-stmts.cpp
index 19ffe2f3028e4..014da274af093 100644
--- a/clang/test/AST/ast-print-expansion-stmts.cpp
+++ b/clang/test/AST/ast-print-expansion-stmts.cpp
@@ -20,7 +20,7 @@ template <typename T>
void test(T t) {
// Enumerating expansion statement.
//
- // CHECK: template for (auto x : { 1, 2, 3 }) {
+ // CHECK: template for (auto x : {1, 2, 3}) {
// CHECK-NEXT: foo(x);
// CHECK-NEXT: }
template for (auto x : {1, 2, 3}) {
@@ -64,7 +64,7 @@ template <typename T>
void test2(T t) {
// Enumerating expansion statement.
//
- // CHECK: template for (int x : { 1, 2, 3 }) {
+ // CHECK: template for (int x : {1, 2, 3}) {
// CHECK-NEXT: foo(x);
// CHECK-NEXT: }
template for (int x : {1, 2, 3}) {
>From 3c9893b215ad93239216733cac021600947f11a1 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 3 Dec 2025 20:08:01 +0100
Subject: [PATCH 4/4] Merge all pattern kinds into a single AST node
---
clang/test/AST/ast-dump-expansion-stmt.cpp | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/clang/test/AST/ast-dump-expansion-stmt.cpp b/clang/test/AST/ast-dump-expansion-stmt.cpp
index 146157e2c13e6..eb9acd5e0b652 100644
--- a/clang/test/AST/ast-dump-expansion-stmt.cpp
+++ b/clang/test/AST/ast-dump-expansion-stmt.cpp
@@ -18,14 +18,14 @@ void foo(int);
template <typename T>
void test(T t) {
// CHECK: CXXExpansionStmtDecl
- // CHECK-NEXT: CXXEnumeratingExpansionStmtPattern
+ // CHECK-NEXT: CXXExpansionStmtPattern {{.*}} enumerating
// CHECK: CXXExpansionStmtInstantiation
template for (auto x : {1, 2, 3}) {
foo(x);
}
// CHECK: CXXExpansionStmtDecl
- // CHECK-NEXT: CXXIteratingExpansionStmtPattern
+ // CHECK-NEXT: CXXExpansionStmtPattern {{.*}} iterating
// CHECK: CXXExpansionStmtInstantiation
static constexpr Array<int, 3> a;
template for (auto x : a) {
@@ -33,7 +33,7 @@ void test(T t) {
}
// CHECK: CXXExpansionStmtDecl
- // CHECK-NEXT: CXXDestructuringExpansionStmtPattern
+ // CHECK-NEXT: CXXExpansionStmtPattern {{.*}} destructuring
// CHECK: CXXExpansionStmtInstantiation
int arr[3]{1, 2, 3};
template for (auto x : arr) {
@@ -41,7 +41,7 @@ void test(T t) {
}
// CHECK: CXXExpansionStmtDecl
- // CHECK-NEXT: CXXDependentExpansionStmtPattern
+ // CHECK-NEXT: CXXExpansionStmtPattern {{.*}} dependent
// CHECK-NOT: CXXExpansionStmtInstantiation
template for (auto x : t) {
foo(x);
More information about the llvm-branch-commits
mailing list