gdb: add target_ops::supports_displaced_step

[deliverable/binutils-gdb.git] / config / override.m4

diff --git a/config/override.m4 b/config/override.m4
index fc2d5272d7498a15049d5e273388f98c42af7177..d3e815bb1b40c91f23d9fed7710573f9f2623cb6 100644 (file)
--- a/config/override.m4
+++ b/config/override.m4
@@ -29,7 +29,7 @@ m4_copy_force([_AC_PREREQ], [AC_PREREQ])
 
 dnl Ensure exactly this Autoconf version is used
 m4_ifndef([_GCC_AUTOCONF_VERSION],
-  [m4_define([_GCC_AUTOCONF_VERSION], [2.64])])
+  [m4_define([_GCC_AUTOCONF_VERSION], [2.69])])
 
 dnl Test for the exact version when AC_INIT is expanded.
 dnl This allows to update the tree in steps (for testing)
@@ -48,6 +48,12 @@ _GCC_AUTOCONF_VERSION_CHECK
 ])
 
 
+dnl Ensure we do not use a buggy M4.
+m4_if(m4_index([..wi.d.], [.d.]), [-1],
+  [m4_fatal(m4_do([m4 with buggy strstr detected.  Please install
+GNU M4 1.4.16 or newer and set the M4 environment variable]))])
+
+
 dnl Fix 2.64 cross compile detection for AVR and RTEMS
 dnl by not trying to compile fopen.
 m4_if(m4_defn([m4_PACKAGE_VERSION]), [2.64],
@@ -95,4 +101,16 @@ m4_define([_AC_CHECK_DECLS],
 
 ])
 
+dnl If flex/lex are not found, the top level configure sets LEX to
+dnl "/path_to/missing flex".  When AC_PROG_LEX tries to find the flex
+dnl output file, it calls $LEX to do so, but the current lightweight
+dnl "missing" won't create a file.  This results in an error.
+dnl Avoid calling the bulk of AC_PROG_LEX when $LEX is "missing".
+AC_DEFUN_ONCE([AC_PROG_LEX],
+[AC_CHECK_PROGS(LEX, flex lex, :)
+case "$LEX" in
+  :|*"missing "*) ;;
+  *) _AC_PROG_LEX_YYTEXT_DECL ;;
+esac])
+
 ])