Add stdlib.h to pb_syshdr.h for dynamic allocation

extra/pb_syshdr.h

@@ -53,6 +53,16 @@ typedef int bool;
 
 #endif
 
+/* stdlib.h subset */
+#ifdef PB_ENABLE_MALLOC
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#else
+void *realloc(void *ptr, size_t size);
+void free(void *ptr);
+#endif
+#endif
+
 /* string.h subset */
 #ifdef HAVE_STRING_H
 #include <string.h>

tests/SConstruct

@@ -50,6 +50,7 @@ if not env.GetOption('clean'):
     stdint = conf.CheckCHeader('stdint.h')
     stddef = conf.CheckCHeader('stddef.h')
     string = conf.CheckCHeader('string.h')
+    stdlib = conf.CheckCHeader('stdlib.h')
     if not stdbool or not stdint or not stddef or not string:
         conf.env.Append(CPPDEFINES = {'PB_SYSTEM_HEADER': '\\"pb_syshdr.h\\"'})
         conf.env.Append(CPPPATH = "#../extra")
@@ -58,6 +59,7 @@ if not env.GetOption('clean'):
         if stdint: conf.env.Append(CPPDEFINES = {'HAVE_STDINT_H': 1})
         if stddef: conf.env.Append(CPPDEFINES = {'HAVE_STDDEF_H': 1})
         if string: conf.env.Append(CPPDEFINES = {'HAVE_STRING_H': 1})
+        if stdlib: conf.env.Append(CPPDEFINES = {'HAVE_STDLIB_H': 1})
     
     # Check if we can use pkg-config to find protobuf include path
     status, output = conf.TryAction('pkg-config protobuf --variable=includedir > $TARGET')