Simplify _ELFUTILS_PREREQ checking

We were jumping through a few hoops to deal with elfutils < 0.138 that
did not have the _ELFUTILS_PREREQ macro.  I've added an always-false
dummy macro to take its place when it doesn't exit.  All of the other
"#ifdef _ELFUTILS_PREREQ" ugliness can now go away.

1 files changed, 13 insertions, 0 deletions

diff --git a/dwarf_wrappers.h b/dwarf_wrappers.h
index 959ece92..9233fc1d 100644
--- a/dwarf_wrappers.h
+++ b/dwarf_wrappers.h
@@ -8,10 +8,23 @@
 
 #ifndef DWARF_WRAPPERS_H
 #define DWARF_WRAPPERS_H 1
+
+#include "config.h"
+
+extern "C" {
 #include <elfutils/libdw.h>
+#ifdef HAVE_ELFUTILS_VERSION_H
+#include <elfutils/version.h>
+#endif
+}
 
 #include <string>
 
+#if !defined(_ELFUTILS_PREREQ)
+// make a dummy PREREQ check for elfutils < 0.138
+#define _ELFUTILS_PREREQ(major, minor) (0 >= 1)
+#endif
+
 // NB: "rc == 0" means OK in this case
 void dwfl_assert(const std::string& desc, int rc);