Prefix variables with "ac_zmq_"

 - Added a macro for checking clang compiler
 - Moved basic compiler checks to a macro
 - Added a macro for checking if compiler supports a flag
 - Added --enable-debug flag
 - Added a macro for running normal autoconf check with compiler flags
 - Added a macro for checking for verbose flag for different compilers (-Wall)
 - Added a macro for turning on strict standards compliance
 - Added a macro for turning warnings to errors
 - Added a macro for checking if compiler supports given pragma
 - Most of the flags now go through checks if the compilers supports them
   rather than enumerating different compilers
 - Added DSO symbol visibility for sun compiler
 - Enabled verbose mode for sun compiler
 - Fixed build for ICC 12.x by adding -wd279 to size_t checks
 - Removed pkg-config checks as those don't seem to be used anywhere
Signed-off-by: Mikko Koppanen <mkoppanen@php.net>

autogen.sh

@@ -18,12 +18,6 @@
 
 # Script to generate all required files from fresh git checkout.
 
-command -v pkg-config >/dev/null 2>&1
-if  [ $? -ne 0 ]; then
-    echo "autogen.sh: error: could not find pkg-config.  pkg-config is required to run autogen.sh." 1>&2
-    exit 1
-fi
-
 command -v libtool >/dev/null 2>&1
 if  [ $? -ne 0 ]; then
     echo "autogen.sh: error: could not find libtool.  libtool is required to run autogen.sh." 1>&2

include/zmq.h

@@ -30,7 +30,7 @@ extern "C" {
 #include "winsock2.h"
 #endif
 
-/*  Win32 needs special handling for DLL exports                              */
+/*  Handle DSO symbol visibility                                             */
 #if defined _WIN32
 #   if defined DLL_EXPORT
 #       define ZMQ_EXPORT __declspec(dllexport)
@@ -38,9 +38,12 @@ extern "C" {
 #       define ZMQ_EXPORT __declspec(dllimport)
 #   endif
 #else
-#   define ZMQ_EXPORT
-#   if defined __GNUC__ && __GNUC__ >= 4
-#       pragma GCC visibility push(default)
+#   if defined __SUNPRO_C  || defined __SUNPRO_CC
+#       define ZMQ_EXPORT __global
+#   elif (defined __GNUC__ && __GNUC__ >= 4) || defined __INTEL_COMPILER
+#       define ZMQ_EXPORT __attribute__ ((visibility("default")))
+#   else
+#       define ZMQ_EXPORT
 #   endif
 #endif
 
@@ -246,9 +249,6 @@ ZMQ_EXPORT int zmq_poll (zmq_pollitem_t *items, int nitems, long timeout);
 ZMQ_EXPORT int zmq_device (int device, void * insocket, void* outsocket);
 
 #undef ZMQ_EXPORT
-#if defined __GNUC__ && __GNUC__ >= 4 && !defined _WIN32
-#    pragma GCC visibility pop
-#endif
 
 #ifdef __cplusplus
 }

include/zmq_utils.h

@@ -24,7 +24,7 @@
 extern "C" {
 #endif
 
-/*  Win32 needs special handling for DLL exports                              */
+/*  Handle DSO symbol visibility                                             */
 #if defined _WIN32
 #   if defined DLL_EXPORT
 #       define ZMQ_EXPORT __declspec(dllexport)
@@ -32,9 +32,12 @@ extern "C" {
 #       define ZMQ_EXPORT __declspec(dllimport)
 #   endif
 #else
-#   define ZMQ_EXPORT
-#   if defined __GNUC__ && __GNUC__ >= 4
-#       pragma GCC visibility push(default)
+#   if defined __SUNPRO_C  || defined __SUNPRO_CC
+#       define ZMQ_EXPORT __global
+#   elif (defined __GNUC__ && __GNUC__ >= 4) || defined __INTEL_COMPILER
+#       define ZMQ_EXPORT __attribute__ ((visibility("default")))
+#   else
+#       define ZMQ_EXPORT
 #   endif
 #endif
 
@@ -52,9 +55,6 @@ ZMQ_EXPORT unsigned long zmq_stopwatch_stop (void *watch_);
 ZMQ_EXPORT void zmq_sleep (int seconds_);
 
 #undef ZMQ_EXPORT
-#if defined __GNUC__ && __GNUC__ >= 4 && !defined _WIN32
-#    pragma GCC visibility pop
-#endif
 
 #ifdef __cplusplus
 }