[libc-commits] [libc] [libc] Modernize and extend dirent.h header. (PR #212902)
Alexey Samsonov via libc-commits
libc-commits at lists.llvm.org
Wed Jul 29 17:00:06 PDT 2026
https://github.com/vonosmas created https://github.com/llvm/llvm-project/pull/212902
Extend the `<dirent.h>` header with macro and types specified in recent POSIX.1-2024:
* Add `posix_dent` structure, which has more fields than `dirent`, that are actually used in practice. This struct would be identical to `dirent` that we have on Linux
* Add `reclen_t` type for `d_reclen` field.
* Add macro `DT_BLK` and friends
Also, extend the tests to verify the values of `d_type` field, now that we have the proper macro defined.
Assisted by: Gemini, human-verified
>From e4856398248c6960370a24a9cb59ec798eb924f9 Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <vonosmas at gmail.com>
Date: Wed, 29 Jul 2026 23:50:27 +0000
Subject: [PATCH] [libc] Modernize and extend dirent.h header.
---
libc/include/CMakeLists.txt | 5 +++
libc/include/dirent.yaml | 21 +++++++++++
libc/include/llvm-libc-macros/CMakeLists.txt | 6 ++++
libc/include/llvm-libc-macros/dirent-macros.h | 21 +++++++++++
.../llvm-libc-macros/linux/CMakeLists.txt | 6 ++++
.../llvm-libc-macros/linux/dirent-macros.h | 26 ++++++++++++++
libc/include/llvm-libc-types/CMakeLists.txt | 4 ++-
libc/include/llvm-libc-types/reclen_t.h | 19 ++++++++++
libc/include/llvm-libc-types/struct_dirent.h | 3 +-
.../llvm-libc-types/struct_posix_dent.h | 35 +++++++++++++++++++
libc/test/src/dirent/dirent_test.cpp | 16 ++++++---
11 files changed, 156 insertions(+), 6 deletions(-)
create mode 100644 libc/include/llvm-libc-macros/dirent-macros.h
create mode 100644 libc/include/llvm-libc-macros/linux/dirent-macros.h
create mode 100644 libc/include/llvm-libc-types/reclen_t.h
create mode 100644 libc/include/llvm-libc-types/struct_posix_dent.h
diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
index 37d2dc3142c4e..4cfaa73f61d1c 100644
--- a/libc/include/CMakeLists.txt
+++ b/libc/include/CMakeLists.txt
@@ -47,6 +47,11 @@ add_header_macro(
.llvm-libc-types.ino_t
.llvm-libc-types.DIR
.llvm-libc-types.struct_dirent
+ .llvm-libc-types.struct_posix_dent
+ .llvm-libc-types.reclen_t
+ .llvm-libc-types.size_t
+ .llvm-libc-types.ssize_t
+ .llvm-libc-macros.dirent_macros
)
add_header_macro(
diff --git a/libc/include/dirent.yaml b/libc/include/dirent.yaml
index 66570bca6c495..e752b564d8d44 100644
--- a/libc/include/dirent.yaml
+++ b/libc/include/dirent.yaml
@@ -1,10 +1,31 @@
header: dirent.h
standards:
- posix
+macros:
+ - macro_name: DT_UNKNOWN
+ macro_header: dirent-macros.h
+ - macro_name: DT_FIFO
+ macro_header: dirent-macros.h
+ - macro_name: DT_CHR
+ macro_header: dirent-macros.h
+ - macro_name: DT_DIR
+ macro_header: dirent-macros.h
+ - macro_name: DT_BLK
+ macro_header: dirent-macros.h
+ - macro_name: DT_REG
+ macro_header: dirent-macros.h
+ - macro_name: DT_LNK
+ macro_header: dirent-macros.h
+ - macro_name: DT_SOCK
+ macro_header: dirent-macros.h
types:
- type_name: struct_dirent
+ - type_name: struct_posix_dent
- type_name: DIR
- type_name: ino_t
+ - type_name: reclen_t
+ - type_name: size_t
+ - type_name: ssize_t
functions:
- name: alphasort
standards:
diff --git a/libc/include/llvm-libc-macros/CMakeLists.txt b/libc/include/llvm-libc-macros/CMakeLists.txt
index 3e7bdd1bed7a6..f0f9dabb00433 100644
--- a/libc/include/llvm-libc-macros/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/CMakeLists.txt
@@ -72,6 +72,12 @@ add_macro_header(
null-macro.h
)
+add_macro_header(
+ dirent_macros
+ HDR
+ dirent-macros.h
+)
+
add_macro_header(
fcntl_macros
HDR
diff --git a/libc/include/llvm-libc-macros/dirent-macros.h b/libc/include/llvm-libc-macros/dirent-macros.h
new file mode 100644
index 0000000000000..b93f9e6e74f58
--- /dev/null
+++ b/libc/include/llvm-libc-macros/dirent-macros.h
@@ -0,0 +1,21 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Definition of macros from dirent.h.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_DIRENT_MACROS_H
+#define LLVM_LIBC_MACROS_DIRENT_MACROS_H
+
+#ifdef __linux__
+#include "linux/dirent-macros.h"
+#endif
+
+#endif // LLVM_LIBC_MACROS_DIRENT_MACROS_H
diff --git a/libc/include/llvm-libc-macros/linux/CMakeLists.txt b/libc/include/llvm-libc-macros/linux/CMakeLists.txt
index 374e7e6159a5d..2a400b1c80e2c 100644
--- a/libc/include/llvm-libc-macros/linux/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/linux/CMakeLists.txt
@@ -4,6 +4,12 @@ add_header(
error-number-macros.h
)
+add_header(
+ dirent_macros
+ HDR
+ dirent-macros.h
+)
+
add_header(
fcntl_macros
HDR
diff --git a/libc/include/llvm-libc-macros/linux/dirent-macros.h b/libc/include/llvm-libc-macros/linux/dirent-macros.h
new file mode 100644
index 0000000000000..7d9347593a4a2
--- /dev/null
+++ b/libc/include/llvm-libc-macros/linux/dirent-macros.h
@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Definition of macros from dirent.h.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_LINUX_DIRENT_MACROS_H
+#define LLVM_LIBC_MACROS_LINUX_DIRENT_MACROS_H
+
+#define DT_UNKNOWN 0
+#define DT_FIFO 1
+#define DT_CHR 2
+#define DT_DIR 4
+#define DT_BLK 6
+#define DT_REG 8
+#define DT_LNK 10
+#define DT_SOCK 12
+
+#endif // LLVM_LIBC_MACROS_LINUX_DIRENT_MACROS_H
diff --git a/libc/include/llvm-libc-types/CMakeLists.txt b/libc/include/llvm-libc-types/CMakeLists.txt
index 9dd7548aa5126..aae93bd905e36 100644
--- a/libc/include/llvm-libc-types/CMakeLists.txt
+++ b/libc/include/llvm-libc-types/CMakeLists.txt
@@ -11,6 +11,7 @@ add_header(
.size_t
libc.include.llvm-libc-macros.annex_k_macros
)
+add_header(reclen_t HDR reclen_t.h)
add_header(ssize_t HDR ssize_t.h)
add_header(__atfork_callback_t HDR __atfork_callback_t.h)
add_header(__search_compare_t HDR __search_compare_t.h)
@@ -122,7 +123,8 @@ add_header(time_t HDR time_t_64.h DEST_HDR time_t.h)
add_header(sighandler_t HDR sighandler_t.h)
add_header(stack_t HDR stack_t.h DEPENDS .size_t)
add_header(suseconds_t HDR suseconds_t.h)
-add_header(struct_dirent HDR struct_dirent.h DEPENDS .ino_t .off_t)
+add_header(struct_dirent HDR struct_dirent.h DEPENDS .ino_t .off_t .reclen_t)
+add_header(struct_posix_dent HDR struct_posix_dent.h DEPENDS .ino_t .off_t .reclen_t)
add_header(struct_dl_phdr_info HDR struct_dl_phdr_info.h DEPENDS .size_t libc.include.llvm-libc-macros.link_macros)
add_header(dl_info HDR Dl_info.h)
add_header(struct_f_owner_ex HDR struct_f_owner_ex.h DEPENDS .pid_t)
diff --git a/libc/include/llvm-libc-types/reclen_t.h b/libc/include/llvm-libc-types/reclen_t.h
new file mode 100644
index 0000000000000..64a028ee62617
--- /dev/null
+++ b/libc/include/llvm-libc-types/reclen_t.h
@@ -0,0 +1,19 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Definition of reclen_t type.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_RECLEN_T_H
+#define LLVM_LIBC_TYPES_RECLEN_T_H
+
+typedef unsigned short reclen_t;
+
+#endif // LLVM_LIBC_TYPES_RECLEN_T_H
diff --git a/libc/include/llvm-libc-types/struct_dirent.h b/libc/include/llvm-libc-types/struct_dirent.h
index f950869fc77dd..0272e76369d4c 100644
--- a/libc/include/llvm-libc-types/struct_dirent.h
+++ b/libc/include/llvm-libc-types/struct_dirent.h
@@ -11,12 +11,13 @@
#include "ino_t.h"
#include "off_t.h"
+#include "reclen_t.h"
struct dirent {
ino_t d_ino;
#ifdef __linux__
off_t d_off;
- unsigned short d_reclen;
+ reclen_t d_reclen;
#endif
unsigned char d_type;
// The user code should use strlen to determine actual the size of d_name.
diff --git a/libc/include/llvm-libc-types/struct_posix_dent.h b/libc/include/llvm-libc-types/struct_posix_dent.h
new file mode 100644
index 0000000000000..0b46268506fe3
--- /dev/null
+++ b/libc/include/llvm-libc-types/struct_posix_dent.h
@@ -0,0 +1,35 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Definition of struct posix_dent.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_STRUCT_POSIX_DENT_H
+#define LLVM_LIBC_TYPES_STRUCT_POSIX_DENT_H
+
+#include "ino_t.h"
+#include "off_t.h"
+#include "reclen_t.h"
+
+struct posix_dent {
+ ino_t d_ino;
+#ifdef __linux__
+ off_t d_off;
+#endif
+ reclen_t d_reclen;
+ unsigned char d_type;
+ // The user code should use strlen to determine the actual size of d_name.
+ // Likewise, it is incorrect and prohibited by the POSIX standard to determine
+ // the size of struct posix_dent type using sizeof. The size should be got
+ // using a different method, for example, from the d_reclen field.
+ char d_name[1];
+};
+
+#endif // LLVM_LIBC_TYPES_STRUCT_POSIX_DENT_H
diff --git a/libc/test/src/dirent/dirent_test.cpp b/libc/test/src/dirent/dirent_test.cpp
index 2862b140ba8ed..05bcafbcfb403 100644
--- a/libc/test/src/dirent/dirent_test.cpp
+++ b/libc/test/src/dirent/dirent_test.cpp
@@ -34,14 +34,22 @@ TEST_F(LlvmLibcDirentTest, SimpleOpenAndRead) {
struct ::dirent *d = LIBC_NAMESPACE::readdir(dir);
if (d == nullptr)
break;
- if (string_view(&d->d_name[0]) == "file1.txt")
+ if (string_view(&d->d_name[0]) == "file1.txt") {
file1 = d;
- if (string_view(&d->d_name[0]) == "file2.txt")
+ EXPECT_EQ(d->d_type, static_cast<decltype(d->d_type)>(DT_REG));
+ }
+ if (string_view(&d->d_name[0]) == "file2.txt") {
file2 = d;
- if (string_view(&d->d_name[0]) == "dir1")
+ EXPECT_EQ(d->d_type, static_cast<decltype(d->d_type)>(DT_REG));
+ }
+ if (string_view(&d->d_name[0]) == "dir1") {
dir1 = d;
- if (string_view(&d->d_name[0]) == "dir2")
+ EXPECT_EQ(d->d_type, static_cast<decltype(d->d_type)>(DT_DIR));
+ }
+ if (string_view(&d->d_name[0]) == "dir2") {
dir2 = d;
+ EXPECT_EQ(d->d_type, static_cast<decltype(d->d_type)>(DT_DIR));
+ }
}
// Verify that we don't break out of the above loop in error.
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