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feat: add current_exe in rust env

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yyc12345
2025-10-02 18:06:24 +08:00
parent d69563b5df
commit 5859264eca
3 changed files with 141 additions and 24 deletions
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103
src/yycc/rust/env.cpp
View File

@ -1,6 +1,7 @@
#include "env.hpp"
#include "../macro/os_detector.hpp"
// Environment variable required
#if defined(YYCC_OS_WINDOWS)
#include "../encoding/windows.hpp"
#include "../num/safe_op.hpp"
@ -14,14 +15,25 @@
#include <stdexcept>
#endif
// Path related functions required
#if defined(YYCC_OS_WINDOWS)
#include "../windows/winfct.hpp"
#else
#include <unistd.h>
#include <sys/stat.h>
#endif
#define SAFECAST ::yycc::num::safe_cast
#define SAFEOP ::yycc::num::safe_op
#define ENC ::yycc::encoding::windows
#define REINTERPRET ::yycc::string::reinterpret
#define WINFCT ::yycc::windows::winfct
namespace yycc::rust::env {
EnvResult<std::u8string> get_var(const std::u8string_view &name) {
#pragma region Environment Variable
VarResult<std::u8string> get_var(const std::u8string_view &name) {
#if defined(YYCC_OS_WINDOWS)
// Reference: https://learn.microsoft.com/en-us/windows/win32/api/processenv/nf-processenv-getenvironmentvariablew
// Convert to wchar
@ -38,22 +50,22 @@ namespace yycc::rust::env {
// the size passed to this function must include NULL terminal.
// So we forcely use checked add and sub for this bad behavior.
auto fct_size = SAFEOP::checked_add<size_t>(wvalue.size(), 1);
if (!fct_size.has_value()) return std::unexpected(EnvError::BadArithmetic);
if (!fct_size.has_value()) return std::unexpected(VarError::BadArithmetic);
auto rv = ::GetEnvironmentVariableW(wname.c_str(), wvalue.data(), fct_size.value());
// Check the return value
if (rv == 0) {
// Function failed. Extract error reason.
auto ec = GetLastError();
if (ec == ERROR_ENVVAR_NOT_FOUND) return std::unexpected(EnvError::NoSuchName);
else return std::unexpected(EnvError::BadCall);
if (ec == ERROR_ENVVAR_NOT_FOUND) return std::unexpected(VarError::NoSuchName);
else return std::unexpected(VarError::BadCall);
} else {
// Function okey. Check the size.
// Fetch function expected size.
auto rv_size = SAFECAST::try_to<size_t>(rv);
if (!rv_size.has_value()) return std::unexpected(EnvError::BadArithmetic);
if (!rv_size.has_value()) return std::unexpected(VarError::BadArithmetic);
auto exp_size = SAFEOP::checked_sub<size_t>(rv_size.value(), 1);
if (!exp_size.has_value()) return std::unexpected(EnvError::BadArithmetic);
if (!exp_size.has_value()) return std::unexpected(VarError::BadArithmetic);
// YYC MARK:
// According to Microsoft, the return value of this function is just a bullshit.
@ -75,7 +87,7 @@ namespace yycc::rust::env {
}
// Convert back to UTF8 string and return.
return ENC::to_utf8(wvalue).transform_error([](auto err) { return EnvError::BadEncoding; });
return ENC::to_utf8(wvalue).transform_error([](auto err) { return VarError::BadEncoding; });
#else
// String view is not NULL-terminal-guaranted,
// so we solve this when casting its type.
@ -83,18 +95,18 @@ namespace yycc::rust::env {
// Fetch variable
auto finder = std::getenv(ordinary_name.c_str());
if (finder == nullptr) return std::unexpected(EnvError::NoSuchName);
if (finder == nullptr) return std::unexpected(VarError::NoSuchName);
else return REINTERPRET::as_utf8(finder);
#endif
}
EnvResult<void> set_var(const std::u8string_view &name, const std::u8string_view &value) {
VarResult<void> set_var(const std::u8string_view &name, const std::u8string_view &value) {
#if defined(YYCC_OS_WINDOWS)
// Reference: https://learn.microsoft.com/en-us/windows/win32/api/processenv/nf-processenv-setenvironmentvariablew
// Convert to wchar, set variable, and check result.
auto rv = ::SetEnvironmentVariableW(ENC::to_wchar(name).value().c_str(), ENC::to_wchar(value).value().c_str());
if (!rv) return std::unexpected(EnvError::BadCall);
if (!rv) return std::unexpected(VarError::BadCall);
else return {};
#else
// Reference: https://pubs.opengroup.org/onlinepubs/9699919799/functions/setenv.html
@ -106,19 +118,19 @@ namespace yycc::rust::env {
if (rv == 0) return {};
// Check error type
if (errno == EINVAL) return std::unexpected(EnvError::BadName);
else if (errno == ENOMEM) return std::unexpected(EnvError::NoMemory);
if (errno == EINVAL) return std::unexpected(VarError::BadName);
else if (errno == ENOMEM) return std::unexpected(VarError::NoMemory);
else throw std::runtime_error("impossible errno");
#endif
}
EnvResult<void> del_var(const std::u8string_view &name) {
VarResult<void> del_var(const std::u8string_view &name) {
#if defined(YYCC_OS_WINDOWS)
// Reference: https://learn.microsoft.com/en-us/windows/win32/api/processenv/nf-processenv-setenvironmentvariablew
// Convert to wchar, delete variable, and check result.
auto rv = ::SetEnvironmentVariableW(ENC::to_wchar(name).value().c_str(), NULL);
if (!rv) return std::unexpected(EnvError::BadCall);
if (!rv) return std::unexpected(VarError::BadCall);
else return {};
#else
// Reference: https://pubs.opengroup.org/onlinepubs/9699919799/functions/unsetenv.html
@ -129,9 +141,70 @@ namespace yycc::rust::env {
if (rv == 0) return {};
// Check error type
if (errno == EINVAL) return std::unexpected(EnvError::BadName);
if (errno == EINVAL) return std::unexpected(VarError::BadName);
else throw std::runtime_error("impossible errno");
#endif
}
#pragma endregion
#pragma region Environment
PathResult<std::u8string> current_exe() {
#if defined(YYCC_OS_WINDOWS)
return WINFCT::get_module_file_name(NULL).transform_error([](auto e) { return PathError::Win32; });
#else
// TODO:
// "/proc/self/exe" is Linux specific, not in POSIX standard.
// This method may need further patch when running on macOS.
// Reference: https://www.man7.org/linux/man-pages/man2/readlink.2.html
// specify the path
constexpr char path[] = "/proc/self/exe";
// get the expected size
struct stat sb;
if (lstat(path, &sb) != 0) {
}
auto expected_size = SAFECAST::try_to<size_t>(sb.st_size);
if (!expected_size.has_value()) {
return std::unexpected(PathError::BadCast);
}
auto buf_size = expected_size.value();
// Some magic symlinks under (for example) /proc and /sys report 'st_size' as zero.
// In that case, take PATH_MAX as a "good enough" estimate.
if (buf_size == 0) {
buf_size = PATH_MAX;
}
// prepare buffer and resize it;
std::u8string rv(u8'\0', buf_size);
// write data
auto passed_size = SAFEOP::checked_add<size_t>(buf_size, 1);
if (!passed_size.has_value()) {
return std::unexpected(PathError::Overflow);
}
ssize_t nbytes = readlink(path, REINTERPRET::as_ordinary(rv.data()), passed_size.value());
if (nbytes < 0) {
return std::unexpected(PathError::Posix);
}
// check written size
auto written_size = SAFECAST::try_to<size_t>(nbytes);
if (!written_size.has_value()) {
return std::unexpected(PathError::BadCast);
}
if (written_size.value() != buf_size) {
return std::unexpected(PathError::BadSize);
}
// okey
return rv;
#endif
}
#pragma endregion
} // namespace yycc::rust::env

41
src/yycc/rust/env.hpp
View File

@ -16,8 +16,10 @@
*/
namespace yycc::rust::env {
/// @brief The error occurs in this module.
enum class EnvError {
#pragma region Environment Variable
/// @brief The error occurs in environment variable operations.
enum class VarError {
NoSuchName, ///< The variable with given name is not presented.
BadEncoding, ///< Error when performing encoding convertion.
BadArithmetic, ///< Error when performing arithmetic operations.
@ -26,16 +28,16 @@ namespace yycc::rust::env {
NoMemory, ///< No enough memory to finish this operation.
};
/// @brief The result type in this module.
/// @brief The result type in environment variable operations.
template<typename T>
using EnvResult = std::expected<T, EnvError>;
using VarResult = std::expected<T, VarError>;
/**
* @brief Get the value of given environment variable name.
* @param[in] name The name of environment variable
* @return Gotten value, or error occurs.
*/
EnvResult<std::u8string> get_var(const std::u8string_view& name);
VarResult<std::u8string> get_var(const std::u8string_view& name);
/**
* @brief Set the value of given environment variable name.
@ -47,7 +49,7 @@ namespace yycc::rust::env {
* @param[in] value The value to be written into.
* @return Nothing or error occurs.
*/
EnvResult<void> set_var(const std::u8string_view& name, const std::u8string_view& value);
VarResult<void> set_var(const std::u8string_view& name, const std::u8string_view& value);
/**
* @brief Delete environment variable with given name.
@ -57,6 +59,31 @@ namespace yycc::rust::env {
* @param[in] name The name of environment variable
* @return Nothing, or error occurs.
*/
EnvResult<void> del_var(const std::u8string_view& name);
VarResult<void> del_var(const std::u8string_view& name);
#pragma endregion
#pragma region Environment Path
/// @brief Error occurs when operating path related functions.
enum class PathError {
Win32, ///< Underlying Win32 function error.
Posix, ///< Underlying POSIX failed.
BadSize, ///< Written size if not matched with expected size.
BadCast, ///< Error occurs when casting values.
Overflow, ///< Some arithmetic operation overflow.
};
/// @brief The result type used for path related functions;
template<typename T>
using PathResult = std::expected<T, PathError>;
/**
* @brief Get the path of the current running executable.
* @return Gotten path (no absolute path guaranteed) or error occurs.
*/
PathResult<std::u8string> current_exe();
#pragma endregion
} // namespace yycc::rust::env

19
test/yycc/rust/env.cpp
View File

@ -1,6 +1,8 @@
#include <gtest/gtest.h>
#include <yycc.hpp>
#include <yycc/rust/env.hpp>
#include <yycc/macro/os_detector.hpp>
#include <filesystem>
#define ENV ::yycc::rust::env
@ -9,7 +11,7 @@ namespace yycctest::rust::env {
constexpr char8_t VAR_NAME[] = u8"HOMER";
constexpr char8_t VAR_VALUE[] = u8"doh";
TEST(RustEnv, All) {
TEST(RustEnv, EnvVar) {
// Write a new variable should okey
{
auto rv = ENV::set_var(VAR_NAME, VAR_VALUE);
@ -42,4 +44,19 @@ namespace yycctest::rust::env {
}
}
TEST(RustEnv, CurrentExe) {
auto rv = ENV::current_exe();
ASSERT_TRUE(rv.has_value());
std::filesystem::path p(rv.value());
auto filename = p.filename().u8string();
#if defined(YYCC_OS_WINDOWS)
// Only Windows has special ext.
EXPECT_EQ(filename, u8"YYCCTest.exe");
#else
// Executable in other system are all in plain name.
EXPECT_EQ(filename, u8"YYCCTest");
#endif
}
} // namespace yycctest::rust::env