[libc-commits] [libc] f6506ec - [libc] Implement POSIX truncate and ftruncate functions for Linux.
Siva Chandra Reddy via libc-commits
libc-commits at lists.llvm.org
Fri Aug 26 12:27:44 PDT 2022
Author: Siva Chandra Reddy
Date: 2022-08-26T19:27:24Z
New Revision: f6506ec4431341b2d067f2d2fcda846129219695
URL: https://github.com/llvm/llvm-project/commit/f6506ec4431341b2d067f2d2fcda846129219695
DIFF: https://github.com/llvm/llvm-project/commit/f6506ec4431341b2d067f2d2fcda846129219695.diff
LOG: [libc] Implement POSIX truncate and ftruncate functions for Linux.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D132705
Added:
libc/src/unistd/ftruncate.h
libc/src/unistd/linux/ftruncate.cpp
libc/src/unistd/linux/truncate.cpp
libc/src/unistd/truncate.h
libc/test/src/unistd/ftruncate_test.cpp
libc/test/src/unistd/truncate_test.cpp
Modified:
libc/config/linux/aarch64/entrypoints.txt
libc/config/linux/x86_64/entrypoints.txt
libc/spec/posix.td
libc/src/unistd/CMakeLists.txt
libc/src/unistd/linux/CMakeLists.txt
libc/test/src/unistd/CMakeLists.txt
Removed:
################################################################################
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index dcb39ba7fc372..fe56176cdd922 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -115,6 +115,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.unistd.close
libc.src.unistd.fchdir
libc.src.unistd.fsync
+ libc.src.unistd.ftruncate
libc.src.unistd.link
libc.src.unistd.linkat
libc.src.unistd.lseek
@@ -124,6 +125,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.unistd.rmdir
libc.src.unistd.symlink
libc.src.unistd.symlinkat
+ libc.src.unistd.truncate
libc.src.unistd.unlink
libc.src.unistd.unlinkat
libc.src.unistd.write
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 307bdd3efaa72..431730677b033 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -115,6 +115,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.unistd.close
libc.src.unistd.fchdir
libc.src.unistd.fsync
+ libc.src.unistd.ftruncate
libc.src.unistd.link
libc.src.unistd.linkat
libc.src.unistd.lseek
@@ -124,6 +125,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.unistd.rmdir
libc.src.unistd.symlink
libc.src.unistd.symlinkat
+ libc.src.unistd.truncate
libc.src.unistd.unlink
libc.src.unistd.unlinkat
libc.src.unistd.write
diff --git a/libc/spec/posix.td b/libc/spec/posix.td
index a03b04ff25688..4dcf09dda7e0d 100644
--- a/libc/spec/posix.td
+++ b/libc/spec/posix.td
@@ -281,6 +281,11 @@ def POSIX : StandardSpec<"POSIX"> {
RetValSpec<IntType>,
[ArgSpec<IntType>]
>,
+ FunctionSpec<
+ "ftruncate",
+ RetValSpec<IntType>,
+ [ArgSpec<ConstCharPtr>, ArgSpec<OffTType>]
+ >,
FunctionSpec<
"link",
RetValSpec<IntType>,
@@ -326,6 +331,11 @@ def POSIX : StandardSpec<"POSIX"> {
RetValSpec<IntType>,
[ArgSpec<IntType>, ArgSpec<ConstCharPtr>, ArgSpec<IntType>, ArgSpec<ConstCharPtr>]
>,
+ FunctionSpec<
+ "truncate",
+ RetValSpec<IntType>,
+ [ArgSpec<IntType>, ArgSpec<OffTType>]
+ >,
FunctionSpec<
"unlink",
RetValSpec<IntType>,
diff --git a/libc/src/unistd/CMakeLists.txt b/libc/src/unistd/CMakeLists.txt
index 849b83e6d23a6..d55ed7163ca44 100644
--- a/libc/src/unistd/CMakeLists.txt
+++ b/libc/src/unistd/CMakeLists.txt
@@ -30,6 +30,13 @@ add_entrypoint_object(
.${LIBC_TARGET_OS}.fsync
)
+add_entrypoint_object(
+ ftruncate
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.ftruncate
+)
+
add_entrypoint_object(
link
ALIAS
@@ -93,6 +100,13 @@ add_entrypoint_object(
.${LIBC_TARGET_OS}.symlinkat
)
+add_entrypoint_object(
+ truncate
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.truncate
+)
+
add_entrypoint_object(
unlink
ALIAS
diff --git a/libc/src/unistd/ftruncate.h b/libc/src/unistd/ftruncate.h
new file mode 100644
index 0000000000000..1971dc53af2d7
--- /dev/null
+++ b/libc/src/unistd/ftruncate.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for ftruncate ---------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_UNISTD_FTRUNCATE_H
+#define LLVM_LIBC_SRC_UNISTD_FTRUNCATE_H
+
+#include <unistd.h>
+
+namespace __llvm_libc {
+
+int ftruncate(int, off_t);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_UNISTD_FTRUNCATE_H
diff --git a/libc/src/unistd/linux/CMakeLists.txt b/libc/src/unistd/linux/CMakeLists.txt
index 132fd7b78cb75..249b057ca950d 100644
--- a/libc/src/unistd/linux/CMakeLists.txt
+++ b/libc/src/unistd/linux/CMakeLists.txt
@@ -50,6 +50,19 @@ add_entrypoint_object(
libc.src.errno.errno
)
+add_entrypoint_object(
+ ftruncate
+ SRCS
+ ftruncate.cpp
+ HDRS
+ ../ftruncate.h
+ DEPENDS
+ libc.include.unistd
+ libc.include.sys_syscall
+ libc.src.__support.OSUtil.osutil
+ libc.src.errno.errno
+)
+
add_entrypoint_object(
link
SRCS
@@ -174,6 +187,19 @@ add_entrypoint_object(
libc.src.errno.errno
)
+add_entrypoint_object(
+ truncate
+ SRCS
+ truncate.cpp
+ HDRS
+ ../truncate.h
+ DEPENDS
+ libc.include.unistd
+ libc.include.sys_syscall
+ libc.src.__support.OSUtil.osutil
+ libc.src.errno.errno
+)
+
add_entrypoint_object(
unlink
SRCS
diff --git a/libc/src/unistd/linux/ftruncate.cpp b/libc/src/unistd/linux/ftruncate.cpp
new file mode 100644
index 0000000000000..38de44100162a
--- /dev/null
+++ b/libc/src/unistd/linux/ftruncate.cpp
@@ -0,0 +1,29 @@
+//===-- Linux implementation of ftruncate ---------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/unistd/ftruncate.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <sys/syscall.h> // For syscall numbers.
+#include <unistd.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, ftruncate, (int fd, off_t len)) {
+ int ret = __llvm_libc::syscall(SYS_ftruncate, fd, len);
+ if (ret < 0) {
+ errno = -ret;
+ return -1;
+ }
+ return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/unistd/linux/truncate.cpp b/libc/src/unistd/linux/truncate.cpp
new file mode 100644
index 0000000000000..c24bfa8e47b70
--- /dev/null
+++ b/libc/src/unistd/linux/truncate.cpp
@@ -0,0 +1,29 @@
+//===-- Linux implementation of truncate ----------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/unistd/truncate.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <sys/syscall.h> // For syscall numbers.
+#include <unistd.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, truncate, (const char *path, off_t len)) {
+ int ret = __llvm_libc::syscall(SYS_truncate, path, len);
+ if (ret < 0) {
+ errno = -ret;
+ return -1;
+ }
+ return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/unistd/truncate.h b/libc/src/unistd/truncate.h
new file mode 100644
index 0000000000000..a6ef92146008c
--- /dev/null
+++ b/libc/src/unistd/truncate.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for truncate ----------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_UNISTD_TRUNCATE_H
+#define LLVM_LIBC_SRC_UNISTD_TRUNCATE_H
+
+#include <unistd.h>
+
+namespace __llvm_libc {
+
+int truncate(const char *, off_t);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_UNISTD_TRUNCATE_H
diff --git a/libc/test/src/unistd/CMakeLists.txt b/libc/test/src/unistd/CMakeLists.txt
index 2c9369cbd51ed..1ea5fcfbbebc7 100644
--- a/libc/test/src/unistd/CMakeLists.txt
+++ b/libc/test/src/unistd/CMakeLists.txt
@@ -32,6 +32,24 @@ add_libc_unittest(
libc.test.errno_setter_matcher
)
+add_libc_unittest(
+ ftruncate_test
+ SUITE
+ libc_unistd_unittests
+ SRCS
+ ftruncate_test.cpp
+ DEPENDS
+ libc.include.errno
+ libc.include.unistd
+ libc.src.fcntl.open
+ libc.src.unistd.close
+ libc.src.unistd.read
+ libc.src.unistd.ftruncate
+ libc.src.unistd.unlink
+ libc.src.unistd.write
+ libc.src.__support.CPP.string_view
+)
+
add_libc_unittest(
read_write_test
SUITE
@@ -169,6 +187,24 @@ add_libc_unittest(
libc.src.unistd.unlink
)
+add_libc_unittest(
+ truncate_test
+ SUITE
+ libc_unistd_unittests
+ SRCS
+ truncate_test.cpp
+ DEPENDS
+ libc.include.errno
+ libc.include.unistd
+ libc.src.fcntl.open
+ libc.src.unistd.close
+ libc.src.unistd.read
+ libc.src.unistd.truncate
+ libc.src.unistd.unlink
+ libc.src.unistd.write
+ libc.src.__support.CPP.string_view
+)
+
add_libc_unittest(
unlink_test
SUITE
diff --git a/libc/test/src/unistd/ftruncate_test.cpp b/libc/test/src/unistd/ftruncate_test.cpp
new file mode 100644
index 0000000000000..c0bb37689cfd0
--- /dev/null
+++ b/libc/test/src/unistd/ftruncate_test.cpp
@@ -0,0 +1,71 @@
+//===-- Unittests for ftruncate -------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/CPP/string_view.h"
+#include "src/fcntl/open.h"
+#include "src/unistd/close.h"
+#include "src/unistd/ftruncate.h"
+#include "src/unistd/read.h"
+#include "src/unistd/unlink.h"
+#include "src/unistd/write.h"
+#include "test/ErrnoSetterMatcher.h"
+#include "utils/UnitTest/Test.h"
+
+#include <errno.h>
+
+namespace cpp = __llvm_libc::cpp;
+
+TEST(LlvmLibcFtruncateTest, CreateAndTruncate) {
+ using __llvm_libc::testing::ErrnoSetterMatcher::Succeeds;
+ constexpr const char TEST_FILE[] = "testdata/ftruncate.test";
+ constexpr const char WRITE_DATA[] = "hello, ftruncate";
+ constexpr size_t WRITE_SIZE = sizeof(WRITE_DATA);
+ char buf[WRITE_SIZE];
+
+ // The test strategy is as follows:
+ // 1. Create a normal file with some data in it.
+ // 2. Read it to make sure what was written is actually in the file.
+ // 3. Truncate to 1 byte.
+ // 4. Try to read more than 1 byte and fail.
+ errno = 0;
+ int fd = __llvm_libc::open(TEST_FILE, O_WRONLY | O_CREAT, S_IRWXU);
+ ASSERT_EQ(errno, 0);
+ ASSERT_GT(fd, 0);
+ ASSERT_EQ(ssize_t(WRITE_SIZE),
+ __llvm_libc::write(fd, WRITE_DATA, WRITE_SIZE));
+ ASSERT_THAT(__llvm_libc::close(fd), Succeeds(0));
+
+ fd = __llvm_libc::open(TEST_FILE, O_RDONLY);
+ ASSERT_EQ(errno, 0);
+ ASSERT_GT(fd, 0);
+ ASSERT_EQ(ssize_t(WRITE_SIZE), __llvm_libc::read(fd, buf, WRITE_SIZE));
+ ASSERT_EQ(cpp::string_view(buf), cpp::string_view(WRITE_DATA));
+ ASSERT_THAT(__llvm_libc::close(fd), Succeeds(0));
+
+ // For ftruncate operation to succeed, the file should be opened for
+ // writing.
+ fd = __llvm_libc::open(TEST_FILE, O_WRONLY);
+ ASSERT_GT(fd, 0);
+ ASSERT_EQ(errno, 0);
+ ASSERT_THAT(__llvm_libc::ftruncate(fd, off_t(1)), Succeeds(0));
+ ASSERT_THAT(__llvm_libc::close(fd), Succeeds(0));
+
+ fd = __llvm_libc::open(TEST_FILE, O_RDONLY);
+ ASSERT_EQ(errno, 0);
+ ASSERT_GT(fd, 0);
+ ASSERT_EQ(ssize_t(1), __llvm_libc::read(fd, buf, WRITE_SIZE));
+ ASSERT_EQ(buf[0], WRITE_DATA[0]);
+ ASSERT_THAT(__llvm_libc::close(fd), Succeeds(0));
+
+ ASSERT_THAT(__llvm_libc::unlink(TEST_FILE), Succeeds(0));
+}
+
+TEST(LlvmLibcFtruncateTest, TruncateBadFD) {
+ using __llvm_libc::testing::ErrnoSetterMatcher::Fails;
+ ASSERT_THAT(__llvm_libc::ftruncate(1, off_t(1)), Fails(EINVAL));
+}
diff --git a/libc/test/src/unistd/truncate_test.cpp b/libc/test/src/unistd/truncate_test.cpp
new file mode 100644
index 0000000000000..ae7765ec6b557
--- /dev/null
+++ b/libc/test/src/unistd/truncate_test.cpp
@@ -0,0 +1,67 @@
+//===-- Unittests for truncate --------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/CPP/string_view.h"
+#include "src/fcntl/open.h"
+#include "src/unistd/close.h"
+#include "src/unistd/read.h"
+#include "src/unistd/truncate.h"
+#include "src/unistd/unlink.h"
+#include "src/unistd/write.h"
+#include "test/ErrnoSetterMatcher.h"
+#include "utils/UnitTest/Test.h"
+
+#include <errno.h>
+
+namespace cpp = __llvm_libc::cpp;
+
+TEST(LlvmLibcTruncateTest, CreateAndTruncate) {
+ using __llvm_libc::testing::ErrnoSetterMatcher::Succeeds;
+ constexpr const char TEST_FILE[] = "testdata/truncate.test";
+ constexpr const char WRITE_DATA[] = "hello, truncate";
+ constexpr size_t WRITE_SIZE = sizeof(WRITE_DATA);
+ char buf[WRITE_SIZE];
+
+ // The test strategy is as follows:
+ // 1. Create a normal file with some data in it.
+ // 2. Read it to make sure what was written is actually in the file.
+ // 3. Truncate to 1 byte.
+ // 4. Try to read more than 1 byte and fail.
+ errno = 0;
+ int fd = __llvm_libc::open(TEST_FILE, O_WRONLY | O_CREAT, S_IRWXU);
+ ASSERT_EQ(errno, 0);
+ ASSERT_GT(fd, 0);
+ ASSERT_EQ(ssize_t(WRITE_SIZE),
+ __llvm_libc::write(fd, WRITE_DATA, WRITE_SIZE));
+ ASSERT_THAT(__llvm_libc::close(fd), Succeeds(0));
+
+ fd = __llvm_libc::open(TEST_FILE, O_RDONLY);
+ ASSERT_EQ(errno, 0);
+ ASSERT_GT(fd, 0);
+ ASSERT_EQ(ssize_t(WRITE_SIZE), __llvm_libc::read(fd, buf, WRITE_SIZE));
+ ASSERT_EQ(cpp::string_view(buf), cpp::string_view(WRITE_DATA));
+ ASSERT_THAT(__llvm_libc::close(fd), Succeeds(0));
+
+ ASSERT_THAT(__llvm_libc::truncate(TEST_FILE, off_t(1)), Succeeds(0));
+
+ fd = __llvm_libc::open(TEST_FILE, O_RDONLY);
+ ASSERT_EQ(errno, 0);
+ ASSERT_GT(fd, 0);
+ ASSERT_EQ(ssize_t(1), __llvm_libc::read(fd, buf, WRITE_SIZE));
+ ASSERT_EQ(buf[0], WRITE_DATA[0]);
+ ASSERT_THAT(__llvm_libc::close(fd), Succeeds(0));
+
+ ASSERT_THAT(__llvm_libc::unlink(TEST_FILE), Succeeds(0));
+}
+
+TEST(LlvmLibcTruncateTest, TruncateNonExistentFile) {
+ using __llvm_libc::testing::ErrnoSetterMatcher::Fails;
+ ASSERT_THAT(
+ __llvm_libc::truncate("non-existent-dir/non-existent-file", off_t(1)),
+ Fails(ENOENT));
+}
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