From 375c25bd1ee445ddf97c5eb3a40f6db753cc2e23 Mon Sep 17 00:00:00 2001
From: mutouyun <orz@orzz.org>
Date: Sun, 6 Nov 2022 17:57:07 +0800
Subject: [PATCH] upd: [imp] improve interface of system

---
 include/libimp/system.h            |  2 +-
 src/libimp/platform/posix/system.h | 17 +++++++++++------
 test/test_imp_system.cpp           |  4 +++-
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/include/libimp/system.h b/include/libimp/system.h
index 0222b2a..dbff599 100644
--- a/include/libimp/system.h
+++ b/include/libimp/system.h
@@ -61,7 +61,7 @@ public:
 enum class info : std::int32_t {
   page_size,
 };
-LIBIMP_EXPORT std::int64_t conf(info) noexcept;
+LIBIMP_EXPORT result<std::int64_t> conf(info) noexcept;
 
 } // namespace sys
 LIBIMP_NAMESPACE_END_
diff --git a/src/libimp/platform/posix/system.h b/src/libimp/platform/posix/system.h
index 3f5f33d..f0e285b 100644
--- a/src/libimp/platform/posix/system.h
+++ b/src/libimp/platform/posix/system.h
@@ -14,13 +14,17 @@
 LIBIMP_NAMESPACE_BEG_
 namespace sys {
 
+#ifndef ENOERR
+#define ENOERR (0)
+#endif
+
 /**
  * @brief Get the system error code
  * https://man7.org/linux/man-pages/man3/errno.3.html
  */
 result_code error_code() noexcept {
   auto err = errno;
-  if (err == 0) return {true};
+  if (err == ENOERR) return {ENOERR};
   return {false, std::uint64_t(err)};
 }
 
@@ -29,7 +33,7 @@ result_code error_code() noexcept {
  * https://man7.org/linux/man-pages/man3/errno.3.html
  */
 void error_code(result_code code) noexcept {
-  errno = code ? 0 : (int)code.value();
+  errno = code ? ENOERR : (int)code.value();
 }
 
 /**
@@ -56,7 +60,7 @@ std::string error_str(result_code code) noexcept {
  * https://man7.org/linux/man-pages/man2/getpagesize.2.html
  * https://man7.org/linux/man-pages/man3/sysconf.3.html
  */
-std::int64_t conf(info r) noexcept {
+result<std::int64_t> conf(info r) noexcept {
   LIBIMP_LOG_();
   switch (r) {
   case info::page_size: {
@@ -66,10 +70,11 @@ std::int64_t conf(info r) noexcept {
   }
   default:
     log.error("invalid info = {}", enum_cast(r));
-    return -1;
+    return {};
   }
-  log.error("info = {}, error = {}", enum_cast(r), error_msg(error_code()));
-  return -1;
+  auto err = sys::error();
+  log.error("info = {}, error = {}", enum_cast(r), err);
+  return {false, (int)err.value()};
 }
 
 } // namespace sys
diff --git a/test/test_imp_system.cpp b/test/test_imp_system.cpp
index ff8832e..d4128ed 100644
--- a/test/test_imp_system.cpp
+++ b/test/test_imp_system.cpp
@@ -67,5 +67,7 @@ TEST(system, error_str) {
 }
 
 TEST(system, conf) {
-  EXPECT_EQ(imp::sys::conf(imp::sys::info::page_size), 4096);
+  auto ret = imp::sys::conf(imp::sys::info::page_size);
+  EXPECT_TRUE(ret);
+  EXPECT_EQ(ret.value(), 4096);
 }
\ No newline at end of file