Collection of fixes needed to compile libelf and other libraries
provided by elfutils for musl targets

error is glibc specific API, so this patch will mostly not accepted
upstream given that elfutils has been closely tied to glibc

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Upstream-Status: Inappropriate [workaround for musl]

--- /dev/null
+++ b/lib/error.h
@@ -0,0 +1,27 @@
+#ifndef _ERROR_H_
+#define _ERROR_H_
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+static unsigned int error_message_count = 0;
+
+static inline void error(int status, int errnum, const char* format, ...)
+{
+	va_list ap;
+	fprintf(stderr, "%s: ", program_invocation_name);
+	va_start(ap, format);
+	vfprintf(stderr, format, ap);
+	va_end(ap);
+	if (errnum)
+		fprintf(stderr, ": %s", strerror(errnum));
+	fprintf(stderr, "\n");
+	error_message_count++;
+	if (status)
+		exit(status);
+}
+
+#endif	/* _ERROR_H_ */
--- a/lib/fixedsizehash.h
+++ b/lib/fixedsizehash.h
@@ -30,7 +30,6 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/cdefs.h>
 
 #include <system.h>
 
--- a/lib/libeu.h
+++ b/lib/libeu.h
@@ -29,6 +29,7 @@
 #ifndef LIBEU_H
 #define LIBEU_H
 
+#include "system.h"
 #include <stddef.h>
 #include <stdint.h>
 
--- a/libdwfl/dwfl_error.c
+++ b/libdwfl/dwfl_error.c
@@ -154,7 +154,16 @@ dwfl_errmsg (int error)
   switch (error &~ 0xffff)
     {
     case OTHER_ERROR (ERRNO):
+#if defined(__GLIBC__)
       return strerror_r (error & 0xffff, "bad", 0);
+#else
+      {
+        static __thread char buf[128] = "";
+        if (strerror_r (error & 0xffff, buf, sizeof(buf)) == 0)
+          return buf;
+      }
+      return "strerror_r() failed";
+#endif
     case OTHER_ERROR (LIBELF):
       return elf_errmsg (error & 0xffff);
     case OTHER_ERROR (LIBDW):
--- a/libdwfl/linux-kernel-modules.c
+++ b/libdwfl/linux-kernel-modules.c
@@ -50,6 +50,7 @@
 #include <sys/utsname.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include "system.h"
 
 /* If fts.h is included before config.h, its indirect inclusions may not
    give us the right LFS aliases of these functions, so map them manually.  */
--- a/libelf/elf.h
+++ b/libelf/elf.h
@@ -21,7 +21,9 @@
 
 #include <features.h>
 
-__BEGIN_DECLS
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /* Standard ELF types.  */
 
@@ -3937,6 +3939,7 @@ enum
 #define R_METAG_TLS_LE_HI16	60
 #define R_METAG_TLS_LE_LO16	61
 
-__END_DECLS
-
+#ifdef __cplusplus
+}
+#endif
 #endif	/* elf.h */