From 3fbac8e2b7867611a2136d127fb83da768c731bc Mon Sep 17 00:00:00 2001
From: JamesReynolds <JamesReynolds>
Date: Fri, 1 Jun 2018 11:51:08 +0100
Subject: [PATCH 1/3] Closes #717

Failure to compile to systems that don't have a valid definition
of strerror_r.
---
 include/spdlog/details/os.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/spdlog/details/os.h b/include/spdlog/details/os.h
index a9246de2..08adca5d 100644
--- a/include/spdlog/details/os.h
+++ b/include/spdlog/details/os.h
@@ -397,6 +397,11 @@ inline std::string errno_to_string(char buf[256], int res)
     return "Unknown error";
 }
 
+inline std::string errno_to_string(char buf[256], const fmt::internal::Null<> &/*tag*/)
+{
+    return errno_to_string(buf, -1);
+}
+
 // Return errno string (thread safe)
 inline std::string errno_str(int err_num)
 {

From aa9012fa07a732711097f32e4ea56ca5dedba264 Mon Sep 17 00:00:00 2001
From: JamesReynolds <JamesReynolds>
Date: Fri, 1 Jun 2018 12:14:17 +0100
Subject: [PATCH 2/3] Fixes #717

This fix uses the fmt::safe_strerror instead of the underlying
strerror_r functionality. I think this is better - but I'm not
sure if there is a reason for avoiding the use of this function.
---
 include/spdlog/details/os.h | 49 +++----------------------------------
 1 file changed, 4 insertions(+), 45 deletions(-)

diff --git a/include/spdlog/details/os.h b/include/spdlog/details/os.h
index 08adca5d..04e0d712 100644
--- a/include/spdlog/details/os.h
+++ b/include/spdlog/details/os.h
@@ -383,57 +383,16 @@ inline std::string filename_to_str(const filename_t &filename)
 }
 #endif
 
-inline std::string errno_to_string(char[256], char *res)
-{
-    return std::string(res);
-}
-
-inline std::string errno_to_string(char buf[256], int res)
-{
-    if (res == 0)
-    {
-        return std::string(buf);
-    }
-    return "Unknown error";
-}
-
-inline std::string errno_to_string(char buf[256], const fmt::internal::Null<> &/*tag*/)
-{
-    return errno_to_string(buf, -1);
-}
-
 // Return errno string (thread safe)
 inline std::string errno_str(int err_num)
 {
-    char buf[256];
+    char buf[256], *buf_ptr = buf;
     SPDLOG_CONSTEXPR auto buf_size = sizeof(buf);
-
-#ifdef _WIN32
-    if (strerror_s(buf, buf_size, err_num) == 0)
+    if (fmt::safe_strerror(err_num, buf_ptr, buf_size) == 0)
     {
-        return std::string(buf);
+        return std::string(buf_ptr);
     }
-    else
-    {
-        return "Unknown error";
-    }
-
-#elif defined(__FreeBSD__) || defined(__APPLE__) || defined(ANDROID) || defined(__SUNPRO_CC) ||                                            \
-    ((_POSIX_C_SOURCE >= 200112L) && !defined(_GNU_SOURCE)) // posix version
-
-    if (strerror_r(err_num, buf, buf_size) == 0)
-    {
-        return std::string(buf);
-    }
-    else
-    {
-        return "Unknown error";
-    }
-
-#else // gnu version (might not use the given buf, so its retval pointer must be used)
-    auto err = strerror_r(err_num, buf, buf_size); // let compiler choose type
-    return errno_to_string(buf, err);              // use overloading to select correct stringify function
-#endif
+    return "Unknown error";
 }
 
 inline int pid()

From 7bc598c9b587b8aef405c9af4ddff417fc26df30 Mon Sep 17 00:00:00 2001
From: JamesReynolds <JamesReynolds>
Date: Fri, 1 Jun 2018 14:32:33 +0100
Subject: [PATCH 3/3] Move errno code into common

errno code is no longer OS specific. Moving to common.
---
 include/spdlog/common.h     | 15 +++++++++------
 include/spdlog/details/os.h | 12 ------------
 2 files changed, 9 insertions(+), 18 deletions(-)

diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index e7f47fd2..e6d9a557 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -143,11 +143,6 @@ enum class pattern_time_type
 //
 // Log exception
 //
-namespace details {
-namespace os {
-std::string errno_str(int err_num);
-}
-} // namespace details
 class spdlog_ex : public std::exception
 {
 public:
@@ -158,7 +153,15 @@ public:
 
     spdlog_ex(const std::string &msg, int last_errno)
     {
-        _msg = msg + ": " + details::os::errno_str(last_errno);
+        char buf[256], *buf_ptr = buf;
+        SPDLOG_CONSTEXPR auto buf_size = sizeof(buf);
+        if (fmt::safe_strerror(last_errno, buf_ptr, buf_size) != 0)
+        {
+            buf_ptr = buf;
+            char unknown[] = "Unknown error";
+            std::copy(unknown, unknown + sizeof(unknown), buf_ptr);
+        }
+        _msg = msg + ": " + std::string(buf_ptr);
     }
 
     const char *what() const SPDLOG_NOEXCEPT override
diff --git a/include/spdlog/details/os.h b/include/spdlog/details/os.h
index 04e0d712..28eb53c3 100644
--- a/include/spdlog/details/os.h
+++ b/include/spdlog/details/os.h
@@ -383,18 +383,6 @@ inline std::string filename_to_str(const filename_t &filename)
 }
 #endif
 
-// Return errno string (thread safe)
-inline std::string errno_str(int err_num)
-{
-    char buf[256], *buf_ptr = buf;
-    SPDLOG_CONSTEXPR auto buf_size = sizeof(buf);
-    if (fmt::safe_strerror(err_num, buf_ptr, buf_size) == 0)
-    {
-        return std::string(buf_ptr);
-    }
-    return "Unknown error";
-}
-
 inline int pid()
 {