Sync from gcc/

	PR lto/46273
	* configure.ac: Remove libelf tests.  Build lto-plugin on ELF always
	and on other supported platforms whenever LTO is enabled.
	* configure: Rebuild.

1 files changed, 7 insertions, 143 deletions

diff --git a/configure.ac b/configure.ac
index ac44863..c0e7384 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1656,149 +1656,12 @@ AC_ARG_ENABLE(lto,
 enable_lto=$enableval,
 enable_lto=yes; default_enable_lto=yes)
 
-
-ACX_ELF_TARGET_IFELSE([if test x"$enable_lto" = x"yes" ; then
-  # Make sure that libelf.h and gelf.h are available.
-  AC_ARG_WITH(libelf, [  --with-libelf=PATH       Specify prefix directory for the installed libelf package
-                          Equivalent to --with-libelf-include=PATH/include
-                          plus --with-libelf-lib=PATH/lib])
-
-  AC_ARG_WITH(libelf_include, [  --with-libelf-include=PATH Specify directory for installed libelf include files])
-
-  AC_ARG_WITH(libelf_lib, [  --with-libelf-lib=PATH   Specify the directory for the installed libelf library])
-
-  saved_CFLAGS="$CFLAGS"
-  saved_CPPFLAGS="$CPPFLAGS"
-  saved_LIBS="$LIBS"
-
-  case $with_libelf in 
-    "")
-      libelflibs="-lelf"
-      libelfinc="-I/usr/include/libelf"
-      ;;
-    *)
-      libelflibs="-L$with_libelf/lib -lelf"
-      libelfinc="-I$with_libelf/include -I$with_libelf/include/libelf"
-      LIBS="$libelflibs $LIBS"
-      ;;
-  esac
-
-  if test "x$with_libelf_include" != x; then
-    libelfinc="-I$with_libelf_include"
-  fi
-
-  if test "x$with_libelf_lib" != x; then
-    libelflibs="-L$with_libelf_lib -lelf"
-    LIBS="$libelflibs $LIBS"
-  fi
-
-  if test "x$with_libelf$with_libelf_include$with_libelf_lib" = x \
-     && test -d ${srcdir}/libelf; then
-    libelflibs='-L$$r/$(HOST_SUBDIR)/libelf/lib -lelf '
-    libelfinc='-D__LIBELF_INTERNAL__ -I$$r/$(HOST_SUBDIR)/libelf/lib -I$$s/libelf/lib'
-    LIBS="$libelflibs $LIBS"
-
- else
-
-  CFLAGS="$CFLAGS $libelfinc"
-  CPPFLAGS="$CPPFLAGS $libelfinc"
-  LIBS="$LIBS $libelflibs"
-
-  AC_CHECK_HEADERS(libelf.h, [have_libelf_h=yes])
-  AC_CHECK_HEADERS(gelf.h, [have_gelf_h=yes])
-
-  AC_CHECK_HEADERS(libelf/libelf.h, [have_libelf_libelf_h=yes])
-  AC_CHECK_HEADERS(libelf/gelf.h, [have_libelf_gelf_h=yes])
-
-  # If we couldn't find libelf.h and the user forced it, emit an error.
-  if test x"$have_libelf_h" != x"yes" \
-     && test x"$have_libelf_libelf_h" != x"yes" ; then
-    if test x"$default_enable_lto" != x"yes" ; then
-      AC_MSG_ERROR([LTO support requires libelf.h or libelf/libelf.h.])
-    else
-      enable_lto=no
-      libelflibs=
-      libelfinc=
-    fi
-  fi
-
-  # If we couldn't find gelf.h and the user forced it, emit an error.
-  if test x"$have_gelf_h" != x"yes" \
-     && test x"$have_libelf_gelf_h" != x"yes" ; then
-    if test x"$default_enable_lto" != x"yes" ; then
-      AC_MSG_ERROR([LTO support requires gelf.h or libelf/gelf.h.])
-    else
-      enable_lto=no
-      libelflibs=
-      libelfinc=
-    fi
-  fi
-
-  # Check that the detected libelf has the functions we need.  We cannot
-  # rely on just detecting the headers since they do not include 
-  # versioning information.  Add functions, if needed.
-  if test x"$enable_lto" = x"yes" ; then
-    AC_MSG_CHECKING([for the correct version of libelf])
-    AC_TRY_LINK(
-      [#include <libelf.h>],[
-      elf_errmsg (0);
-      elf_getscn (0, 0);
-      elf_nextscn (0, 0);
-      elf_strptr (0, 0, 0);
-      elf_getident (0, 0);
-      elf_begin (0, 0, 0);
-      elf_ndxscn (0);
-      elf_end (0);
-      ],
-      [AC_MSG_RESULT([yes]);],
-      [AC_MSG_RESULT([no]); enable_lto=no; libelflibs= ; libelfinc= ]
-    )
-
-    # Check for elf_getshdrstrndx or elf_getshstrndx.  The latter's flavor
-    # is determined in gcc/configure.ac.
-    if test x"$enable_lto" = x"yes" ; then
-      AC_MSG_CHECKING([for elf_getshdrstrndx])
-      AC_TRY_LINK(
-        [#include <libelf.h>],[
-	elf_getshdrstrndx (0, 0);
-        ],
-        [AC_MSG_RESULT([yes]);],
-        [AC_MSG_RESULT([no]);
-	 AC_MSG_CHECKING([for elf_getshstrndx])
-         AC_TRY_LINK(
-           [#include <libelf.h>],[
-	   elf_getshstrndx (0, 0);
-           ],
-           [AC_MSG_RESULT([yes]);],
-           [AC_MSG_RESULT([no]); enable_lto=no; libelflibs= ; libelfinc= ]
-         )]
-      )
-    fi
-
-    # If we couldn't enable LTO and the user forced it, emit an error.
-    if test x"$enable_lto" = x"no" \
-       && test x"$default_enable_lto" != x"yes" ; then
-      AC_MSG_ERROR([To enable LTO, GCC requires libelf v0.8.12+.
-Try the --with-libelf, --with-libelf-include and --with-libelf-lib options
-to specify its location.])
-    fi
-  fi
-
-  CFLAGS="$saved_CFLAGS"
-  CPPFLAGS="$saved_CPPFLAGS"
-  LIBS="$saved_LIBS"
-
- fi
-
-  # Flags needed for libelf.
-  AC_SUBST(libelflibs)
-  AC_SUBST(libelfinc)
-  # ELF platforms build the lto-plugin when GOLD is in use.
-  build_lto_plugin=${ENABLE_GOLD}
-fi],[if test x"$default_enable_lto" = x"yes" ; then
+ACX_ELF_TARGET_IFELSE([# ELF platforms build the lto-plugin always.
+  build_lto_plugin=yes
+],[if test x"$default_enable_lto" = x"yes" ; then
     case $target in
       *-apple-darwin* | *-cygwin* | *-mingw*) ;;
-      # On other non-ELF platforms, LTO must be explicitly enabled.
+      # On other non-ELF platforms, LTO has yet to be validated.
       *) enable_lto=no ;;
     esac
   else
@@ -1816,11 +1679,12 @@ fi],[if test x"$default_enable_lto" = x"yes" ; then
     esac
   fi
   # Among non-ELF, only Windows platforms support the lto-plugin so far.
+  # Build it unless LTO was explicitly disabled.
   case $target in
-    *-cygwin* | *-mingw*) build_lto_plugin=yes ;;
+    *-cygwin* | *-mingw*) build_lto_plugin=$enable_lto ;;
     *) ;;
   esac
-  default_enable_lto=no])
+])
 
 
 # By default, C is the only stage 1 language.