ensure dllexport/public visibility of all aliases we generate

src/libc_override_gcc_and_weak.h

@@ -55,7 +55,7 @@
 # error libc_override_gcc_and_weak.h is for gcc distributions only.
 #endif
 
-#define ALIAS(tc_fn)   __attribute__ ((alias (#tc_fn), used))
+#define ALIAS(tc_fn)   __attribute__ ((alias (#tc_fn), used)) PERFTOOLS_DLL_DECL
 
 void* operator new(size_t size) CPP_BADALLOC  ALIAS(tc_new);
 void operator delete(void* p) CPP_NOTHROW     ALIAS(tc_delete);

src/libc_override_glibc.h

@@ -70,7 +70,7 @@
 // do it inside the gcc #ifdef, since redhat uses gcc.
 // TODO(csilvers): only do this if we detect we're an old enough glibc?
 
-#define ALIAS(tc_fn)   __attribute__ ((alias (#tc_fn)))
+#define ALIAS(tc_fn)   __attribute__ ((alias (#tc_fn))) PERFTOOLS_DLL_DECL
 extern "C" {
   void* __libc_malloc(size_t size)                ALIAS(tc_malloc);
   void __libc_free(void* ptr)                     ALIAS(tc_free);