--- a/libsanitizer/configure.ac	Thu Oct 25 07:37:49 2018 +0900
+++ b/libsanitizer/configure.ac	Thu Feb 13 11:34:05 2020 +0900
@@ -1,7 +1,6 @@
 #                                               -*- Autoconf -*-
 # Process this file with autoconf to produce a configure script.
 
-AC_PREREQ([2.64])
 AC_INIT(package-unused, version-unused, libsanitizer)
 AC_CONFIG_SRCDIR([include/sanitizer/common_interface_defs.h])
 
@@ -30,6 +29,8 @@
 AM_INIT_AUTOMAKE(foreign no-dist)
 AM_MAINTAINER_MODE
 
+GCC_WITH_TOOLEXECLIBDIR
+
 # Calculate toolexeclibdir
 # Also toolexecdir, though it's only used in toolexeclibdir
 case ${version_specific_libs} in
@@ -45,7 +46,14 @@
        test x"$with_cross_host" != x"no"; then
       # Install a library built with a cross compiler in tooldir, not libdir.
       toolexecdir='$(exec_prefix)/$(target_alias)'
-      toolexeclibdir='$(toolexecdir)/lib'
+      case ${with_toolexeclibdir} in
+	no)
+	  toolexeclibdir='$(toolexecdir)/lib'
+	  ;;
+	*)
+	  toolexeclibdir=${with_toolexeclibdir}
+	  ;;
+      esac
     else
       toolexecdir='$(libdir)/gcc-lib/$(target_alias)'
       toolexeclibdir='$(libdir)'
@@ -253,12 +261,12 @@
   ALLOC_FILE=alloc.lo
 else
   VIEW_FILE=mmapio.lo
-  AC_PREPROC_IFELSE([
+  AC_PREPROC_IFELSE([AC_LANG_SOURCE([
 #include <sys/mman.h>
 #if !defined(MAP_ANONYMOUS) && !defined(MAP_ANON)
   #error no MAP_ANONYMOUS
 #endif
-], [ALLOC_FILE=mmap.lo], [ALLOC_FILE=alloc.lo])
+])], [ALLOC_FILE=mmap.lo], [ALLOC_FILE=alloc.lo])
 fi
 AC_SUBST(VIEW_FILE)
 AC_SUBST(ALLOC_FILE)
@@ -281,12 +289,6 @@
   # When built as a GCC target library, we can't do a link test.
   AC_EGREP_HEADER([dl_iterate_phdr], [link.h], [have_dl_iterate_phdr=yes],
 		  [have_dl_iterate_phdr=no])
-  case "${host}" in
-  *-*-solaris2.10*)
-    # Avoid dl_iterate_phdr on Solaris 10, where it is in the
-    # header file but is only in -ldl.
-    have_dl_iterate_phdr=no ;;
-  esac
 fi
 if test "$have_dl_iterate_phdr" = "yes"; then
   AC_DEFINE(HAVE_DL_ITERATE_PHDR, 1, [Define if dl_iterate_phdr is available.])