sim: require a C11 compiler

With GDB requiring a C++11 compiler now, this hopefully shouldn't
be a big deal.  It's been 10 years since C11 came out, so should
be plenty of time to upgrade.

This will allow us to start cleaning up random header logic and
many of our non-standard custom types.

1 files changed, 53 insertions, 13 deletions

diff --git a/sim/avr/configure b/sim/avr/configure
index 99ef833..7cc3478 100755
--- a/sim/avr/configure
+++ b/sim/avr/configure
@@ -678,6 +678,7 @@ CCDEPMODE
 DEPDIR
 am__leading_dot
 PACKAGE
+C_DIALECT
 RANLIB
 AR
 HDEFINES
@@ -8648,6 +8649,55 @@ else
 fi
 
 
+# Require C11 or newer.  Autoconf-2.70 provides ac_cv_prog_cc_c11 when using
+# AC_PROG_CC, but we're still using Autoconf-2.69, and the newest it understands
+# is C99.  So handle it ourselves.
+:
+C_DIALECT=
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C11 is supported by default" >&5
+$as_echo_n "checking whether C11 is supported by default... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#if !defined __STDC_VERSION__ || __STDC_VERSION__ < 201112L
+# error "C11 support not found"
+#endif
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for -std=c11 support" >&5
+$as_echo_n "checking for -std=c11 support... " >&6; }
+  ac_save_CC="$CC"
+  CC="$CC -std=c11"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#if !defined __STDC_VERSION__ || __STDC_VERSION__ < 201112L
+# error "C11 support not found"
+#endif
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+  CC="$ac_save_CC"
+  C_DIALECT="-std=c11"
+
+else
+  as_fn_error $? "C11 is required" "$LINENO" 5
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+
 # Some of the common include files depend on bfd.h, and bfd.h checks
 # that config.h is included first by testing that the PACKAGE macro
 # is defined.
@@ -12064,16 +12114,6 @@ freebsd* | dragonfly*)
   esac
   ;;
 
-gnu*)
-  version_type=linux
-  need_lib_prefix=no
-  need_version=no
-  library_names_spec='${libname}${release}${shared_ext}$versuffix ${libname}${release}${shared_ext}${major} ${libname}${shared_ext}'
-  soname_spec='${libname}${release}${shared_ext}$major'
-  shlibpath_var=LD_LIBRARY_PATH
-  hardcode_into_libs=yes
-  ;;
-
 haiku*)
   version_type=linux
   need_lib_prefix=no
@@ -12190,7 +12230,7 @@ linux*oldld* | linux*aout* | linux*coff*)
   ;;
 
 # This must be Linux ELF.
-linux* | k*bsd*-gnu | kopensolaris*-gnu)
+linux* | k*bsd*-gnu | kopensolaris*-gnu | gnu*)
   version_type=linux
   need_lib_prefix=no
   need_version=no
@@ -12879,7 +12919,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12882 "configure"
+#line 12922 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12985,7 +13025,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12988 "configure"
+#line 13028 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H