使用optional代替expected

actboy168 · Apr 25, 2024 · 069f745 · 069f745
1 parent 628dc91
commit 069f745
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Showing 8 changed files with 35 additions and 34 deletions.
diff --git a/bee/sys/path.h b/bee/sys/path.h
@@ -1,10 +1,10 @@
 #pragma once
 
-#include <bee/nonstd/expected.h>
 #include <bee/nonstd/filesystem.h>
 
+#include <optional>
+
 namespace bee::sys {
-    using path_expected = expected<fs::path, std::string>;
-    path_expected exe_path() noexcept;
-    path_expected dll_path() noexcept;
+    std::optional<fs::path> exe_path() noexcept;
+    std::optional<fs::path> dll_path() noexcept;
 }
diff --git a/bee/sys/path_bsd.cpp b/bee/sys/path_bsd.cpp
@@ -11,38 +11,38 @@
 
 namespace bee::sys {
 #if defined(__FreeBSD__)
-    path_expected exe_path() noexcept {
+    std::optional<fs::path> exe_path() noexcept {
         int name[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
         char exe[1024];
         size_t length = 1024;
         int error     = sysctl(name, 4, exe, &length, NULL, 0);
         if (error < 0 || length <= 1) {
-            return unexpected<std::string>(error::sys_errmsg("exe_path"));
+            return std::nullopt;
         }
         return fs::path(exe, exe + length - 1);
     }
 #elif defined(__OpenBSD__)
-    path_expected exe_path() noexcept {
+    std::optional<fs::path> exe_path() noexcept {
         int name[] = { CTL_KERN, KERN_PROC_ARGS, getpid(), KERN_PROC_ARGV };
         size_t argc;
         if (sysctl(name, 4, NULL, &argc, NULL, 0) < 0) {
-            return unexpected<std::string>(error::sys_errmsg("exe_path"));
+            return std::nullopt;
         }
         const char** argv = (const char**)malloc(argc);
         if (!argv) {
-            return unexpected<std::string>(error::sys_errmsg("exe_path"));
+            return std::nullopt;
         }
         if (sysctl(name, 4, argv, &argc, NULL, 0) < 0) {
-            return unexpected<std::string>(error::sys_errmsg("exe_path"));
+            return std::nullopt;
         }
         return fs::path(argv[0]);
     }
 #else
-    path_expected exe_path() noexcept {
+    std::optional<fs::path> exe_path() noexcept {
         std::error_code ec;
         auto res = fs::read_symlink("/proc/self/exe", ec);
         if (ec) {
-            return unexpected<std::string>(error::sys_errmsg("exe_path"));
+            return std::nullopt;
         }
         return res;
     }

diff --git a/bee/sys/path_linux.cpp b/bee/sys/path_linux.cpp
@@ -3,11 +3,11 @@
 #include <unistd.h>
 
 namespace bee::sys {
-    path_expected exe_path() noexcept {
+    std::optional<fs::path> exe_path() noexcept {
         std::error_code ec;
         auto res = fs::read_symlink("/proc/self/exe", ec);
         if (ec) {
-            return unexpected<std::string>(error::sys_errmsg("exe_path"));
+            return std::nullopt;
         }
         return res;
     }

diff --git a/bee/sys/path_osx.cpp b/bee/sys/path_osx.cpp
@@ -2,18 +2,16 @@
 #include <bee/utility/dynarray.h>
 #include <mach-o/dyld.h>
 
+#include <cassert>
+
 namespace bee::sys {
-    path_expected exe_path() noexcept {
+    std::optional<fs::path> exe_path() noexcept {
         uint32_t path_len = 0;
         _NSGetExecutablePath(0, &path_len);
-        if (path_len <= 1) {
-            return unexpected<std::string>("_NSGetExecutablePath failed.");
-        }
+        assert(path_len > 1);
         dynarray<char> buf(path_len);
         int rv = _NSGetExecutablePath(buf.data(), &path_len);
-        if (rv != 0) {
-            return unexpected<std::string>("_NSGetExecutablePath failed.");
-        }
+        assert(rv == 0);
         return fs::path(buf.data(), buf.data() + path_len - 1);
     }
 }
diff --git a/bee/sys/path_posix.cpp b/bee/sys/path_posix.cpp
@@ -2,22 +2,23 @@
 #include <dlfcn.h>
 
 namespace bee::sys {
-    static path_expected dll_path(void* module_handle) noexcept {
+    static std::optional<fs::path> dll_path(void* module_handle) noexcept {
         ::Dl_info dl_info;
         dl_info.dli_fname = 0;
         const int ret     = ::dladdr(module_handle, &dl_info);
         if (0 != ret && dl_info.dli_fname != NULL) {
             std::error_code ec;
             auto path = fs::absolute(dl_info.dli_fname, ec);
             if (ec) {
-                return unexpected<std::string>(ec.message());
+                return std::nullopt;
             }
             return path.lexically_normal();
         }
-        return unexpected<std::string>("::dladdr failed.");
+        errno = EFAULT;
+        return std::nullopt;
     }
 
-    path_expected dll_path() noexcept {
+    std::optional<fs::path> dll_path() noexcept {
         return dll_path((void*)&exe_path);
     }
 }
diff --git a/bee/sys/path_win.cpp b/bee/sys/path_win.cpp
@@ -8,11 +8,11 @@
 extern "C" IMAGE_DOS_HEADER __ImageBase;
 
 namespace bee::sys {
-    static path_expected dll_path(HMODULE module_handle) noexcept {
+    static std::optional<fs::path> dll_path(HMODULE module_handle) noexcept {
         wchar_t buffer[MAX_PATH];
         DWORD path_len = ::GetModuleFileNameW(module_handle, buffer, _countof(buffer));
         if (path_len == 0) {
-            return unexpected<std::string>(error::sys_errmsg("GetModuleFileNameW"));
+            return std::nullopt;
         }
         if (path_len < _countof(buffer)) {
             return fs::path(buffer, buffer + path_len);
@@ -21,20 +21,21 @@ namespace bee::sys {
             dynarray<wchar_t> buf(buf_len);
             path_len = ::GetModuleFileNameW(module_handle, buf.data(), buf_len);
             if (path_len == 0) {
-                return unexpected<std::string>(error::sys_errmsg("GetModuleFileNameW"));
+                return std::nullopt;
             }
             if (path_len < _countof(buffer)) {
                 return fs::path(buf.data(), buf.data() + path_len);
             }
         }
-        return unexpected<std::string>("::GetModuleFileNameW return too long.");
+        SetLastError(ERROR_NOT_ENOUGH_MEMORY);
+        return std::nullopt;
     }
 
-    path_expected exe_path() noexcept {
+    std::optional<fs::path> exe_path() noexcept {
         return dll_path(NULL);
     }
 
-    path_expected dll_path() noexcept {
+    std::optional<fs::path> dll_path() noexcept {
         return dll_path(reinterpret_cast<HMODULE>(&__ImageBase));
     }
 }
diff --git a/binding/lua_filesystem.cpp b/binding/lua_filesystem.cpp
@@ -928,7 +928,7 @@ namespace bee::lua_filesystem {
     static int exe_path(lua_State* L) {
         auto r = sys::exe_path();
         if (!r) {
-            return lua::push_error(L, r.error());
+            return lua::push_error(L, error::sys_errmsg("exe_path"));
         }
         lua::newudata<fs::path>(L, r.value());
         return 1;
@@ -937,7 +937,7 @@ namespace bee::lua_filesystem {
     static int dll_path(lua_State* L) {
         auto r = sys::dll_path();
         if (!r) {
-            return lua::push_error(L, r.error());
+            return lua::push_error(L, error::sys_errmsg("dll_path"));
         }
         lua::newudata<fs::path>(L, r.value());
         return 1;

diff --git a/bootstrap/main.cpp b/bootstrap/main.cpp
@@ -7,6 +7,7 @@
 #    include <bee/win/wtf8.h>
 #endif
 
+#include <bee/error.h>
 #include <bee/lua/module.h>
 #include <bee/nonstd/filesystem.h>
 #include <bee/nonstd/unreachable.h>
@@ -138,7 +139,7 @@ static int pushargs(lua_State *L) {
 static fs::path getprogdir(lua_State *L) {
     auto r = bee::sys::exe_path();
     if (!r) {
-        luaL_error(L, "unable to get progdir: %s\n", r.error().c_str());
+        luaL_error(L, "unable to get progdir: %s\n", bee::error::sys_errmsg("exe_path").c_str());
         std::unreachable();
     }
     return r.value().remove_filename();