SWAT-352: when loading lleventhost, call apr_dso_error() function.

In addition to its usual apr_sterror() function, APR defines a special
function specifically for errors relating to the apr_dso_*() functions.
Introduce ll_apr_warn_status() and ll_apr_assert_status() overloads accepting
apr_dso_handle_t* to call apr_dso_error() as well as apr_strerror() and log
its output. Use new ll_apr_warn_status() in LLAppViewer::loadEventHostModule()
for apr_dso_load() and apr_dso_sym() calls. Instead of shorthand
ll_apr_assert_status(), use with llassert_always() so check is still performed
even in Release build.
Add more lleventhost-related debugging output, e.g. full pathname of the DLL.
On Mac and Linux, call 'file' command to report nature of the DLL too.

indra/llcommon/llapr.cpp

@@ -28,6 +28,7 @@
 
 #include "linden_common.h"
 #include "llapr.h"
+#include "apr_dso.h"
 
 apr_pool_t *gAPRPoolp = NULL; // Global APR memory pool
 LLVolatileAPRPool *LLAPRFile::sAPRFilePoolp = NULL ; //global volatile APR memory pool.
@@ -279,14 +280,31 @@ bool ll_apr_warn_status(apr_status_t status)
 {
 	if(APR_SUCCESS == status) return false;
 	char buf[MAX_STRING];	/* Flawfinder: ignore */
-	apr_strerror(status, buf, MAX_STRING);
+	apr_strerror(status, buf, sizeof(buf));
 	LL_WARNS("APR") << "APR: " << buf << LL_ENDL;
 	return true;
 }
 
+bool ll_apr_warn_status(apr_status_t status, apr_dso_handle_t *handle)
+{
+    bool result = ll_apr_warn_status(status);
+    // Despite observed truncation of actual Mac dylib load errors, increasing
+    // this buffer to more than MAX_STRING doesn't help: it appears that APR
+    // stores the output in a fixed 255-character internal buffer. (*sigh*)
+    char buf[MAX_STRING];           /* Flawfinder: ignore */
+    apr_dso_error(handle, buf, sizeof(buf));
+    LL_WARNS("APR") << "APR: " << buf << LL_ENDL;
+    return result;
+}
+
 void ll_apr_assert_status(apr_status_t status)
 {
-	llassert(ll_apr_warn_status(status) == false);
+	llassert(! ll_apr_warn_status(status));
+}
+
+void ll_apr_assert_status(apr_status_t status, apr_dso_handle_t *handle)
+{
+    llassert(! ll_apr_warn_status(status, handle));
 }
 
 //---------------------------------------------------------------------

indra/llcommon/llapr.h

@@ -53,6 +53,8 @@
 extern LL_COMMON_API apr_thread_mutex_t* gLogMutexp;
 extern apr_thread_mutex_t* gCallStacksLogMutexp;
 
+struct apr_dso_handle_t;
+
 /** 
  * @brief initialize the common apr constructs -- apr itself, the
  * global pool, and a mutex.
@@ -259,8 +261,11 @@ public:
  * @return Returns <code>true</code> if status is an error condition.
  */
 bool LL_COMMON_API ll_apr_warn_status(apr_status_t status);
+/// There's a whole other APR error-message function if you pass a DSO handle.
+bool LL_COMMON_API ll_apr_warn_status(apr_status_t status, apr_dso_handle_t* handle);
 
 void LL_COMMON_API ll_apr_assert_status(apr_status_t status);
+void LL_COMMON_API ll_apr_assert_status(apr_status_t status, apr_dso_handle_t* handle);
 
 extern "C" LL_COMMON_API apr_pool_t* gAPRPoolp; // Global APR memory pool
 

indra/newview/llappviewer.cpp

@@ -4622,6 +4622,35 @@ void LLAppViewer::loadEventHostModule(S32 listen_port)
 		return;
 	}
 
+	LL_INFOS("eventhost") << "Found lleventhost at '" << dso_path << "'" << LL_ENDL;
+#if ! defined(LL_WINDOWS)
+	{
+		std::string outfile("/tmp/lleventhost.file.out");
+		std::string command("file '" + dso_path + "' > '" + outfile + "' 2>&1");
+		int rc = system(command.c_str());
+		if (rc != 0)
+		{
+			LL_WARNS("eventhost") << command << " ==> " << rc << ':' << LL_ENDL;
+		}
+		else
+		{
+			LL_INFOS("eventhost") << command << ':' << LL_ENDL;
+		}
+		{
+			std::ifstream reader(outfile.c_str());
+			std::string line;
+			while (std::getline(reader, line))
+			{
+				size_t len = line.length();
+				if (len && line[len-1] == '\n')
+					line.erase(len-1);
+				LL_INFOS("eventhost") << line << LL_ENDL;
+			}
+		}
+		remove(outfile.c_str());
+	}
+#endif // LL_WINDOWS
+
 	apr_dso_handle_t * eventhost_dso_handle = NULL;
 	apr_pool_t * eventhost_dso_memory_pool = NULL;
 
@@ -4630,13 +4659,13 @@ void LLAppViewer::loadEventHostModule(S32 listen_port)
 	apr_status_t rv = apr_dso_load(&eventhost_dso_handle,
 		dso_path.c_str(),
 		eventhost_dso_memory_pool);
-	ll_apr_assert_status(rv);
+	llassert_always(! ll_apr_warn_status(rv, eventhost_dso_handle));
 	llassert_always(eventhost_dso_handle != NULL);
 
 	int (*ll_plugin_start_func)(LLSD const &) = NULL;
 	rv = apr_dso_sym((apr_dso_handle_sym_t*)&ll_plugin_start_func, eventhost_dso_handle, "ll_plugin_start");
 
-	ll_apr_assert_status(rv);
+	llassert_always(! ll_apr_warn_status(rv, eventhost_dso_handle));
 	llassert_always(ll_plugin_start_func != NULL);
 
 	LLSD args;