Fix an autoconf bug: The second argument to AC_LANG_PROGRAM is code that

gets placed inside a main function, and should not itself be a main
function. This is silently hidden in GCC-hosted builds because the
inner main looks like a nested function declaration, which GCC supports.
In builds with compilers which do not support nested functions (by default),
this was causing an error, which caused these autoconf checks to fail,
leaving their options disabled.

This fixes test/Feature/load_module.ll on x86_64-unknown-linux-gnu
llvm-gcc selfhost builds, among other things.

This also includes a regenerated configure, as the diff is small and telling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102288 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/autoconf/m4/link_options.m4 b/autoconf/m4/link_options.m4
index 3442e46567406182516a9eb70f060b752d2a89bc..697abab07d4d47347ff9b26a2c69b7fd2d768abb 100644 (file)
--- a/autoconf/m4/link_options.m4
+++ b/autoconf/m4/link_options.m4
@@ -8,7 +8,7 @@ AC_DEFUN([AC_LINK_USE_R],
 [ AC_LANG_PUSH([C])
   oldcflags="$CFLAGS"
   CFLAGS="$CFLAGS -Wl,-R."
-  AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[int main() { return 0; }]])],
+  AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
     [llvm_cv_link_use_r=yes],[llvm_cv_link_use_r=no])
   CFLAGS="$oldcflags"
   AC_LANG_POP([C])
@@ -29,7 +29,7 @@ AC_DEFUN([AC_LINK_EXPORT_DYNAMIC],
 [ AC_LANG_PUSH([C])
   oldcflags="$CFLAGS"
   CFLAGS="$CFLAGS -Wl,-export-dynamic"
-  AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[int main() { return 0; }]])],
+  AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
     [llvm_cv_link_use_export_dynamic=yes],[llvm_cv_link_use_export_dynamic=no])
   CFLAGS="$oldcflags"
   AC_LANG_POP([C])
@@ -70,7 +70,7 @@ AC_DEFUN([AC_LINK_RETAIN_SYMBOLS_FILE],
   echo "main" > "$tmp/exports"
 
   CFLAGS="$CFLAGS -Wl,-retain-symbols-file=$tmp/exports"
-  AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[int main() { return 0; }]])],
+  AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
     [llvm_cv_link_use_retain_symbols_file=yes],[llvm_cv_link_use_retain_symbols_file=no])
   rm "$tmp/exports"
   rmdir "$tmp"

diff --git a/configure b/configure
index 84bf2e2d58b55f4014651d6bac0516dae2c0f8dd..9f35b4196a0713ce459acf4b46b2b07782672224 100755 (executable)
--- a/configure
+++ b/configure
@@ -8634,7 +8634,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 int
 main ()
 {
-int main() { return 0; }
+
   ;
   return 0;
 }
@@ -8726,7 +8726,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 int
 main ()
 {
-int main() { return 0; }
+
   ;
   return 0;
 }
@@ -8837,7 +8837,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 int
 main ()
 {
-int main() { return 0; }
+
   ;
   return 0;
 }