From bef9f6d6412d6c2491610c0735e384f22a2a0d8f Mon Sep 17 00:00:00 2001
From: Steven Murray <steven.murray@cern.ch>
Date: Mon, 24 Mar 2014 11:00:04 +0100
Subject: [PATCH] Improved the comments surrounding strerror_r_wrapper()
---
mediachanger/castorrmc/common/strerror_r_wrapper.cpp | 10 ++++++++++
mediachanger/castorrmc/h/strerror_r_wrapper.h | 10 ++++++++++
2 files changed, 20 insertions(+)
diff --git a/mediachanger/castorrmc/common/strerror_r_wrapper.cpp b/mediachanger/castorrmc/common/strerror_r_wrapper.cpp
index 09273390d9..1a149b2269 100644
--- a/mediachanger/castorrmc/common/strerror_r_wrapper.cpp
+++ b/mediachanger/castorrmc/common/strerror_r_wrapper.cpp
@@ -39,5 +39,15 @@
* strerror_r_wrapper
******************************************************************************/
extern "C" int strerror_r_wrapper(int errnum, char *buf, size_t buflen) {
+ /* This function should be compiled using a C++ compiler and not a C compiler.
+ *
+ * C++ compilers are better at spotting whether the GNU version or the
+ * XSI complicant version of sterror_() is being used. This is because the
+ * difference between the two versions is their return types. The GNU
+ * version returns a 'char *' whereas the XSI compliant version returns an
+ * 'int'. A C compiler may allow the strerror_r() function to return a
+ * 'char *' and have that 'char *' assigned to an 'int'. A C++ compiler
+ * usually gives an error if this is tried.
+ */
return strerror_r(errnum, buf, buflen);
}
diff --git a/mediachanger/castorrmc/h/strerror_r_wrapper.h b/mediachanger/castorrmc/h/strerror_r_wrapper.h
index 059bd065ef..aa474841a1 100644
--- a/mediachanger/castorrmc/h/strerror_r_wrapper.h
+++ b/mediachanger/castorrmc/h/strerror_r_wrapper.h
@@ -44,6 +44,16 @@
* This function wraps the XSI compliant version of strerror_r() and therefore
* writes the string representation of the specified error number to the
* specified buffer.
+ *
+ * This function should be compiled using a C++ compiler and not a C compiler.
+ *
+ * C++ compilers are better at spotting whether the GNU version or the
+ * XSI complicant version of sterror_() is being used. This is because the
+ * difference between the two versions is their return types. The GNU
+ * version returns a 'char *' whereas the XSI compliant version returns an
+ * 'int'. A C compiler may allow the strerror_r() function to return a
+ * 'char *' and have that 'char *' assigned to an 'int'. A C++ compiler
+ * usually gives an error if this is tried.
*
* @param errnum The error number.
* @param buf The buffer.
--
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