[flang-commits] [flang] [flang][runtime] Add ACCESS library procedure (PR #88517)
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Fri Apr 12 07:15:59 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-runtime
Author: Tom Eccles (tblah)
<details>
<summary>Changes</summary>
Re-land https://github.com/llvm/llvm-project/pull/88395
Two build-bots were broken by the old version:
- https://lab.llvm.org/buildbot/#/builders/285/builds/245
- https://lab.llvm.org/buildbot/#/builders/21/builds/96988
The problem in both cases was that the compiler did not support `std::filesystem` (which I use in the unit test).
I believe that flang already requires a compiler capable of c++ 17 so this should be okay. I have adjusted CMake in 66f32b59f70f15a9155d5106b2490de56a7c5077 so that hopefully `std::filesystem` will be linked for those compilers. However, I am worried that linking `stdc++fs`, could break some other platform. CMake does not appear to have any built in magic to do the right thing [1].
Another alternative would be to rewrite the unit test not to use `std::filesystem`. I would prefer to avoid this so that I don't have to add a manual implementation of `std::filesystem::temp_directory_path()`, as that might be a pain point when porting flang to new systems.
[1] https://gitlab.kitware.com/cmake/cmake/-/issues/17834
---
This is a GNU extension:
https://gcc.gnu.org/onlinedocs/gfortran/ACCESS.html
Used in SALMON:
https://salmon-tddft.jp/download.html
Unfortunately the intrinsic takes a file path to operate on so there isn't an easy way to make the test robust. The unit test expects to be able to create, set read write and execute permissions, and delete files called
std::filesystem::temp_directory_path() / <test_name>.<pid>
The test will fail if a file already exists with that name.
I have not implemented the intrinsic on Windows because this is wrapping a POSIX system call and Windows doesn't support all of the permission bits tested by the intrinsic. I don't have a Windows machine easily available to check if Gfortran implements this intrinsic on Windows.
---
Full diff: https://github.com/llvm/llvm-project/pull/88517.diff
5 Files Affected:
- (modified) flang/docs/Intrinsics.md (+8)
- (modified) flang/include/flang/Runtime/extensions.h (+7)
- (modified) flang/runtime/extensions.cpp (+73)
- (added) flang/unittests/Runtime/AccessTest.cpp (+390)
- (modified) flang/unittests/Runtime/CMakeLists.txt (+4)
``````````diff
diff --git a/flang/docs/Intrinsics.md b/flang/docs/Intrinsics.md
index ccb93e104dab65..848619cb65d909 100644
--- a/flang/docs/Intrinsics.md
+++ b/flang/docs/Intrinsics.md
@@ -657,6 +657,14 @@ CALL CO_REDUCE
CALL CO_SUM
```
+### Inquiry Functions
+ACCESS (GNU extension) is not supported on Windows. Otherwise:
+```
+CHARACTER(LEN=*) :: path = 'path/to/file'
+IF (ACCESS(path, 'rwx')) &
+ ...
+```
+
## Non-standard intrinsics
### PGI
```
diff --git a/flang/include/flang/Runtime/extensions.h b/flang/include/flang/Runtime/extensions.h
index 7d0952206fc195..fef651f3b2eedb 100644
--- a/flang/include/flang/Runtime/extensions.h
+++ b/flang/include/flang/Runtime/extensions.h
@@ -44,5 +44,12 @@ std::int64_t RTNAME(Signal)(std::int64_t number, void (*handler)(int));
// GNU extension subroutine SLEEP(SECONDS)
void RTNAME(Sleep)(std::int64_t seconds);
+// GNU extension function ACCESS(NAME, MODE)
+// TODO: not supported on Windows
+#ifndef _WIN32
+std::int64_t FORTRAN_PROCEDURE_NAME(access)(const char *name,
+ std::int64_t nameLength, const char *mode, std::int64_t modeLength);
+#endif
+
} // extern "C"
#endif // FORTRAN_RUNTIME_EXTENSIONS_H_
diff --git a/flang/runtime/extensions.cpp b/flang/runtime/extensions.cpp
index 3ac98000335d7d..12498b502ae1cf 100644
--- a/flang/runtime/extensions.cpp
+++ b/flang/runtime/extensions.cpp
@@ -17,6 +17,7 @@
#include "flang/Runtime/entry-names.h"
#include "flang/Runtime/io-api.h"
#include <chrono>
+#include <cstring>
#include <ctime>
#include <signal.h>
#include <thread>
@@ -138,5 +139,77 @@ void RTNAME(Sleep)(std::int64_t seconds) {
std::this_thread::sleep_for(std::chrono::seconds(seconds));
}
+// TODO: not supported on Windows
+#ifndef _WIN32
+std::int64_t FORTRAN_PROCEDURE_NAME(access)(const char *name,
+ std::int64_t nameLength, const char *mode, std::int64_t modeLength) {
+ std::int64_t ret{-1};
+ if (nameLength <= 0 || modeLength <= 0 || !name || !mode) {
+ return ret;
+ }
+
+ // ensure name is null terminated
+ char *newName{nullptr};
+ if (name[nameLength - 1] != '\0') {
+ newName = static_cast<char *>(std::malloc(nameLength + 1));
+ std::memcpy(newName, name, nameLength);
+ newName[nameLength] = '\0';
+ name = newName;
+ }
+
+ // calculate mode
+ bool read{false};
+ bool write{false};
+ bool execute{false};
+ bool exists{false};
+ int imode{0};
+
+ for (std::int64_t i = 0; i < modeLength; ++i) {
+ switch (mode[i]) {
+ case 'r':
+ read = true;
+ break;
+ case 'w':
+ write = true;
+ break;
+ case 'x':
+ execute = true;
+ break;
+ case ' ':
+ exists = true;
+ break;
+ default:
+ // invalid mode
+ goto cleanup;
+ }
+ }
+ if (!read && !write && !execute && !exists) {
+ // invalid mode
+ goto cleanup;
+ }
+
+ if (!read && !write && !execute) {
+ imode = F_OK;
+ } else {
+ if (read) {
+ imode |= R_OK;
+ }
+ if (write) {
+ imode |= W_OK;
+ }
+ if (execute) {
+ imode |= X_OK;
+ }
+ }
+ ret = access(name, imode);
+
+cleanup:
+ if (newName) {
+ free(newName);
+ }
+ return ret;
+}
+#endif
+
} // namespace Fortran::runtime
} // extern "C"
diff --git a/flang/unittests/Runtime/AccessTest.cpp b/flang/unittests/Runtime/AccessTest.cpp
new file mode 100644
index 00000000000000..5c8a634192d92b
--- /dev/null
+++ b/flang/unittests/Runtime/AccessTest.cpp
@@ -0,0 +1,390 @@
+//===-- flang/unittests/Runtime/AccessTest.cpp ----------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// TODO: ACCESS is not yet implemented on Windows
+#ifndef _WIN32
+
+#include "CrashHandlerFixture.h"
+#include "gtest/gtest.h"
+#include "flang/Runtime/extensions.h"
+
+#include <fcntl.h>
+#include <filesystem>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+namespace {
+
+struct AccessTests : public CrashHandlerFixture {};
+
+struct AccessType {
+ bool read{false};
+ bool write{false};
+ bool execute{false};
+ bool exists{false};
+};
+
+} // namespace
+
+static std::string addPIDSuffix(const char *name) {
+ std::stringstream ss;
+ ss << name;
+ ss << '.';
+
+ ss << getpid();
+
+ return ss.str();
+}
+
+static std::filesystem::path createTemporaryFile(
+ const char *name, const AccessType &accessType) {
+ std::filesystem::path path{
+ std::filesystem::temp_directory_path() / addPIDSuffix(name)};
+
+ // O_CREAT | O_EXCL enforces that this file is newly created by this call.
+ // This feels risky. If we don't have permission to create files in the
+ // temporary directory or if the files already exist, the test will fail.
+ // But we can't use std::tmpfile() because we need a path to the file and
+ // to control the filesystem permissions
+ mode_t mode{0};
+ if (accessType.read) {
+ mode |= S_IRUSR;
+ }
+ if (accessType.write) {
+ mode |= S_IWUSR;
+ }
+ if (accessType.execute) {
+ mode |= S_IXUSR;
+ }
+
+ int file = open(path.c_str(), O_CREAT | O_EXCL, mode);
+ if (file == -1) {
+ return {};
+ }
+
+ close(file);
+
+ return path;
+}
+
+static std::int64_t callAccess(
+ const std::filesystem::path &path, const AccessType &accessType) {
+ const char *cpath{path.c_str()};
+ std::int64_t pathlen = std::strlen(cpath);
+
+ std::string mode;
+ if (accessType.read) {
+ mode += 'r';
+ }
+ if (accessType.write) {
+ mode += 'w';
+ }
+ if (accessType.execute) {
+ mode += 'x';
+ }
+ if (accessType.exists) {
+ mode += ' ';
+ }
+
+ const char *cmode = mode.c_str();
+ std::int64_t modelen = std::strlen(cmode);
+
+ return FORTRAN_PROCEDURE_NAME(access)(cpath, pathlen, cmode, modelen);
+}
+
+TEST(AccessTests, TestExists) {
+ AccessType accessType;
+ accessType.exists = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_EQ(res, 0);
+}
+
+TEST(AccessTests, TestNotExists) {
+ std::filesystem::path nonExistant{addPIDSuffix(__func__)};
+ ASSERT_FALSE(std::filesystem::exists(nonExistant));
+
+ AccessType accessType;
+ accessType.exists = true;
+ std::int64_t res = callAccess(nonExistant, accessType);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestRead) {
+ AccessType accessType;
+ accessType.read = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_EQ(res, 0);
+}
+
+TEST(AccessTests, TestNotRead) {
+ AccessType accessType;
+ accessType.read = false;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestWrite) {
+ AccessType accessType;
+ accessType.write = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_EQ(res, 0);
+}
+
+TEST(AccessTests, TestNotWrite) {
+ AccessType accessType;
+ accessType.write = false;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.write = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestReadWrite) {
+ AccessType accessType;
+ accessType.read = true;
+ accessType.write = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_EQ(res, 0);
+}
+
+TEST(AccessTests, TestNotReadWrite0) {
+ AccessType accessType;
+ accessType.read = false;
+ accessType.write = false;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ accessType.write = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestNotReadWrite1) {
+ AccessType accessType;
+ accessType.read = true;
+ accessType.write = false;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ accessType.write = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestNotReadWrite2) {
+ AccessType accessType;
+ accessType.read = false;
+ accessType.write = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ accessType.write = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestExecute) {
+ AccessType accessType;
+ accessType.execute = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_EQ(res, 0);
+}
+
+TEST(AccessTests, TestNotExecute) {
+ AccessType accessType;
+ accessType.execute = false;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.execute = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestRWX) {
+ AccessType accessType;
+ accessType.read = true;
+ accessType.write = true;
+ accessType.execute = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_EQ(res, 0);
+}
+
+TEST(AccessTests, TestNotRWX0) {
+ AccessType accessType;
+ accessType.read = false;
+ accessType.write = false;
+ accessType.execute = false;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ accessType.write = true;
+ accessType.execute = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestNotRWX1) {
+ AccessType accessType;
+ accessType.read = true;
+ accessType.write = false;
+ accessType.execute = false;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ accessType.write = true;
+ accessType.execute = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestNotRWX2) {
+ AccessType accessType;
+ accessType.read = true;
+ accessType.write = true;
+ accessType.execute = false;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ accessType.write = true;
+ accessType.execute = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestNotRWX3) {
+ AccessType accessType;
+ accessType.read = true;
+ accessType.write = false;
+ accessType.execute = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ accessType.write = true;
+ accessType.execute = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+TEST(AccessTests, TestNotRWX4) {
+ AccessType accessType;
+ accessType.read = false;
+ accessType.write = true;
+ accessType.execute = true;
+
+ std::filesystem::path path = createTemporaryFile(__func__, accessType);
+ ASSERT_FALSE(path.empty());
+
+ accessType.read = true;
+ accessType.write = true;
+ accessType.execute = true;
+ std::int64_t res = callAccess(path, accessType);
+
+ std::filesystem::remove(path);
+
+ ASSERT_NE(res, 0);
+}
+
+#endif // !_WIN32
diff --git a/flang/unittests/Runtime/CMakeLists.txt b/flang/unittests/Runtime/CMakeLists.txt
index 23f02aa751246b..10d48b2bf26168 100644
--- a/flang/unittests/Runtime/CMakeLists.txt
+++ b/flang/unittests/Runtime/CMakeLists.txt
@@ -1,4 +1,5 @@
add_flang_unittest(FlangRuntimeTests
+ AccessTest.cpp
Allocatable.cpp
ArrayConstructor.cpp
BufferTest.cpp
@@ -32,4 +33,7 @@ add_flang_unittest(FlangRuntimeTests
target_link_libraries(FlangRuntimeTests
PRIVATE
FortranRuntime
+ stdc++fs
)
+
+set_property(TARGET FlangRuntimeTests PROPERTY CXX_STANDARD 17)
``````````
</details>
https://github.com/llvm/llvm-project/pull/88517
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