[PATCH] Check for binutils .cfi_* advance bug with code alignment factor > 1 (PR target/37610)

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

gas until a few days ago mishandled CFI advances with code alignment factor > 1
(e.g. on ppc*, sparc*, hppa*).  This patch attempts to check for that
bug in configure and not use .cfi_* directives in that case.

Tested on powerpc-linux with both buggy and fixed gas and on x86_64-linux
bootstrapped/regtested (there even buggy gas results in using .cfi_*
directives, as x86_64/i386 etc. use code alignment factor 1, which
was supported correctly).  GAS used to mishandle both .cfi_* directives
and hand written .eh_frame if code alignment factor was bigger than 1,
but while for .cfi_* directives the factor is hardcoded into gas, for
.eh_frame gcc was always using factor 1 (which is less space efficient,
but without correct assembler support is the only possibility).

Ok for trunk?

2008-12-02  Jakub Jelinek  <jakub@redhat.com>

	PR target/37610
	* configure.ac (gcc_cv_readelf): Look for readelf.
	(gcc_cv_as_cfi_advance_working): Check for working
	cfi advances with code alignment factor > 1.
	(HAVE_GAS_CFI_DIRECTIVE): Don't define if cfi advances
	don't work properly.
	* configure: Regenerated.

--- gcc/configure.ac.jj	2008-12-02 14:51:06.000000000 +0100
+++ gcc/configure.ac	2008-12-02 16:08:52.000000000 +0100
@@ -2005,6 +2005,29 @@ else
 	AC_MSG_RESULT($gcc_cv_objdump)
 fi
 
+# Figure out what readelf we will be using.
+AS_VAR_SET_IF(gcc_cv_readelf,, [
+if test -f $gcc_cv_binutils_srcdir/configure.in \
+     && test -f ../binutils/Makefile \
+     && test x$build = x$host; then
+	# Single tree build which includes binutils.
+	gcc_cv_readelf=../binutils/readelf$build_exeext
+elif test -x readelf$build_exeext; then
+	gcc_cv_readelf=./readelf$build_exeext
+else
+        AC_PATH_PROG(gcc_cv_readelf, readelf)
+fi])
+
+AC_MSG_CHECKING(what readelf to use)
+if test "$gcc_cv_readelf" = ../binutils/readelf$build_exeext; then
+	# Single tree build which includes binutils.
+	AC_MSG_RESULT(newly built readelf)
+elif test x$gcc_cv_readelf = x; then
+	AC_MSG_RESULT(not found)
+else
+	AC_MSG_RESULT($gcc_cv_readelf)
+fi
+
 # Figure out what assembler alignment features are present.
 gcc_GAS_CHECK_FEATURE([.balign and .p2align], gcc_cv_as_balign_and_p2align,
  [2,6,0],,
@@ -2234,8 +2257,29 @@ gcc_GAS_CHECK_FEATURE([cfi directives], 
     gcc_cv_as_cfi_directive=yes
     ;;
 esac])
+if test $gcc_cv_as_cfi_directive = yes && test x$gcc_cv_readelf != x; then
+gcc_GAS_CHECK_FEATURE([working cfi advance], gcc_cv_as_cfi_advance_working,
+  ,,
+[	.text
+	.cfi_startproc
+	.cfi_adjust_cfa_offset 64
+	.skip 512, 0
+	.cfi_adjust_cfa_offset 128
+	.cfi_endproc],
+[
+changequote(,)dnl
+if $gcc_cv_readelf -wf conftest.o 2>/dev/null \
+    | grep 'DW_CFA_advance_loc[12]:[ 	][ 	]*512[ 	]' >/dev/null; then
+   gcc_cv_as_cfi_advance_working=yes
+fi
+changequote([,])dnl
+])
+else
+  gcc_cv_as_cfi_advance_working=yes
+fi
 AC_DEFINE_UNQUOTED(HAVE_GAS_CFI_DIRECTIVE,
-  [`if test $gcc_cv_as_cfi_directive = yes; then echo 1; else echo 0; fi`],
+  [`if test $gcc_cv_as_cfi_directive = yes \
+       && test $gcc_cv_as_cfi_advance_working = yes; then echo 1; else echo 0; fi`],
   [Define 0/1 if your assembler supports CFI directives.])
 
 gcc_GAS_CHECK_FEATURE([cfi personality directive],
--- gcc/configure.jj	2008-11-27 17:14:20.000000000 +0100
+++ gcc/configure	2008-12-02 16:09:18.000000000 +0100
@@ -458,7 +458,7 @@ ac_includes_default="\
 # include <unistd.h>
 #endif"
 
-ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS build build_cpu build_vendor build_os host host_cpu host_vendor host_os target target_cpu target_vendor target_os target_noncanonical build_libsubdir build_subdir host_subdir target_subdir GENINSRC CC CFLAGS LDFLAGS CPPFLAGS ac_ct_CC EXEEXT OBJEXT GNATBIND ac_ct_GNATBIND GNATMAKE ac_ct_GNATMAKE NO_MINUS_C_MINUS_O OUTPUT_OPTION CPP EGREP loose_warn strict_warn warn_cflags nocommon_flag TREEBROWSER valgrind_path valgrind_path_defines valgrind_command coverage_flags enable_multilib enable_decimal_float enable_fixed_point enable_shared TARGET_SYSTEM_ROOT TARGET_SYSTEM_ROOT_DEFINE CROSS_SYSTEM_HEADER_DIR onestep PKGVERSION REPORT_BUGS_TO REPORT_BUGS_TEXI datarootdir docdir htmldir SET_MAKE AWK LN_S LN RANLIB ac_ct_RANLIB ranlib_flags INSTALL INSTALL_PROGRAM INSTALL_DATA make_compare_target have_mktemp_command MAKEINFO BUILD_INFO GENERATED_MANPAGES FLEX BISON NM AR COLLECT2_LIBS GNAT_LIBEXC LDEXP_LIB TARGET_GETGROUPS_T LIBICONV LTLIBICONV LIBICONV_DEP manext objext gthread_flags extra_modes_file extra_opt_files USE_NLS LIBINTL LIBINTL_DEP INCINTL XGETTEXT GMSGFMT POSUB CATALOGS DATADIRNAME INSTOBJEXT GENCAT CATOBJEXT CROSS ALL SYSTEM_HEADER_DIR inhibit_libc CC_FOR_BUILD BUILD_CFLAGS BUILD_LDFLAGS STMP_FIXINC STMP_FIXPROTO collect2 LIBTOOL SED FGREP GREP LD DUMPBIN ac_ct_DUMPBIN OBJDUMP ac_ct_OBJDUMP ac_ct_AR STRIP ac_ct_STRIP lt_ECHO DSYMUTIL ac_ct_DSYMUTIL NMEDIT ac_ct_NMEDIT LIPO ac_ct_LIPO OTOOL ac_ct_OTOOL OTOOL64 ac_ct_OTOOL64 objdir enable_fast_install gcc_cv_as ORIGINAL_AS_FOR_TARGET gcc_cv_ld ORIGINAL_LD_FOR_TARGET gcc_cv_nm ORIGINAL_NM_FOR_TARGET gcc_cv_objdump libgcc_visibility GGC zlibdir zlibinc MAINT gcc_tooldir dollar slibdir subdirs srcdir all_compilers all_gtfiles all_lang_makefrags all_lang_makefiles all_languages all_selected_languages build_exeext build_install_headers_dir build_xm_file_list build_xm_include_list build_xm_defines build_file_translate check_languages cpp_install_dir xmake_file tmake_file extra_gcc_objs extra_headers_list extra_objs extra_parts extra_passes extra_programs float_h_file gcc_config_arguments gcc_gxx_include_dir host_exeext host_xm_file_list host_xm_include_list host_xm_defines out_host_hook_obj install lang_opt_files lang_specs_files lang_tree_files local_prefix md_file objc_boehm_gc out_file out_object_file thread_file tm_file_list tm_include_list tm_defines tm_p_file_list tm_p_include_list xm_file_list xm_include_list xm_defines c_target_objs cxx_target_objs fortran_target_objs target_cpu_default GMPLIBS GMPINC PPLLIBS PPLINC CLOOGLIBS CLOOGINC LIBOBJS LTLIBOBJS'
+ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS build build_cpu build_vendor build_os host host_cpu host_vendor host_os target target_cpu target_vendor target_os target_noncanonical build_libsubdir build_subdir host_subdir target_subdir GENINSRC CC CFLAGS LDFLAGS CPPFLAGS ac_ct_CC EXEEXT OBJEXT GNATBIND ac_ct_GNATBIND GNATMAKE ac_ct_GNATMAKE NO_MINUS_C_MINUS_O OUTPUT_OPTION CPP EGREP loose_warn strict_warn warn_cflags nocommon_flag TREEBROWSER valgrind_path valgrind_path_defines valgrind_command coverage_flags enable_multilib enable_decimal_float enable_fixed_point enable_shared TARGET_SYSTEM_ROOT TARGET_SYSTEM_ROOT_DEFINE CROSS_SYSTEM_HEADER_DIR onestep PKGVERSION REPORT_BUGS_TO REPORT_BUGS_TEXI datarootdir docdir htmldir SET_MAKE AWK LN_S LN RANLIB ac_ct_RANLIB ranlib_flags INSTALL INSTALL_PROGRAM INSTALL_DATA make_compare_target have_mktemp_command MAKEINFO BUILD_INFO GENERATED_MANPAGES FLEX BISON NM AR COLLECT2_LIBS GNAT_LIBEXC LDEXP_LIB TARGET_GETGROUPS_T LIBICONV LTLIBICONV LIBICONV_DEP manext objext gthread_flags extra_modes_file extra_opt_files USE_NLS LIBINTL LIBINTL_DEP INCINTL XGETTEXT GMSGFMT POSUB CATALOGS DATADIRNAME INSTOBJEXT GENCAT CATOBJEXT CROSS ALL SYSTEM_HEADER_DIR inhibit_libc CC_FOR_BUILD BUILD_CFLAGS BUILD_LDFLAGS STMP_FIXINC STMP_FIXPROTO collect2 LIBTOOL SED FGREP GREP LD DUMPBIN ac_ct_DUMPBIN OBJDUMP ac_ct_OBJDUMP ac_ct_AR STRIP ac_ct_STRIP lt_ECHO DSYMUTIL ac_ct_DSYMUTIL NMEDIT ac_ct_NMEDIT LIPO ac_ct_LIPO OTOOL ac_ct_OTOOL OTOOL64 ac_ct_OTOOL64 objdir enable_fast_install gcc_cv_as ORIGINAL_AS_FOR_TARGET gcc_cv_ld ORIGINAL_LD_FOR_TARGET gcc_cv_nm ORIGINAL_NM_FOR_TARGET gcc_cv_objdump gcc_cv_readelf libgcc_visibility GGC zlibdir zlibinc MAINT gcc_tooldir dollar slibdir subdirs srcdir all_compilers all_gtfiles all_lang_makefrags all_lang_makefiles all_languages all_selected_languages build_exeext build_install_headers_dir build_xm_file_list build_xm_include_list build_xm_defines build_file_translate check_languages cpp_install_dir xmake_file tmake_file extra_gcc_objs extra_headers_list extra_objs extra_parts extra_passes extra_programs float_h_file gcc_config_arguments gcc_gxx_include_dir host_exeext host_xm_file_list host_xm_include_list host_xm_defines out_host_hook_obj install lang_opt_files lang_specs_files lang_tree_files local_prefix md_file objc_boehm_gc out_file out_object_file thread_file tm_file_list tm_include_list tm_defines tm_p_file_list tm_p_include_list xm_file_list xm_include_list xm_defines c_target_objs cxx_target_objs fortran_target_objs target_cpu_default GMPLIBS GMPINC PPLLIBS PPLINC CLOOGLIBS CLOOGINC LIBOBJS LTLIBOBJS'
 ac_subst_files='language_hooks'
 ac_pwd=`pwd`
 
@@ -20966,6 +20966,76 @@ else
 echo "${ECHO_T}$gcc_cv_objdump" >&6
 fi
 
+# Figure out what readelf we will be using.
+if test "${gcc_cv_readelf+set}" = set; then
+  :
+else
+
+if test -f $gcc_cv_binutils_srcdir/configure.in \
+     && test -f ../binutils/Makefile \
+     && test x$build = x$host; then
+	# Single tree build which includes binutils.
+	gcc_cv_readelf=../binutils/readelf$build_exeext
+elif test -x readelf$build_exeext; then
+	gcc_cv_readelf=./readelf$build_exeext
+else
+        # Extract the first word of "readelf", so it can be a program name with args.
+set dummy readelf; ac_word=$2
+echo "$as_me:$LINENO: checking for $ac_word" >&5
+echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6
+if test "${ac_cv_path_gcc_cv_readelf+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  case $gcc_cv_readelf in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_gcc_cv_readelf="$gcc_cv_readelf" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+  for ac_exec_ext in '' $ac_executable_extensions; do
+  if $as_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_gcc_cv_readelf="$as_dir/$ac_word$ac_exec_ext"
+    echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+done
+
+  ;;
+esac
+fi
+gcc_cv_readelf=$ac_cv_path_gcc_cv_readelf
+
+if test -n "$gcc_cv_readelf"; then
+  echo "$as_me:$LINENO: result: $gcc_cv_readelf" >&5
+echo "${ECHO_T}$gcc_cv_readelf" >&6
+else
+  echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6
+fi
+
+fi
+fi
+
+
+echo "$as_me:$LINENO: checking what readelf to use" >&5
+echo $ECHO_N "checking what readelf to use... $ECHO_C" >&6
+if test "$gcc_cv_readelf" = ../binutils/readelf$build_exeext; then
+	# Single tree build which includes binutils.
+	echo "$as_me:$LINENO: result: newly built readelf" >&5
+echo "${ECHO_T}newly built readelf" >&6
+elif test x$gcc_cv_readelf = x; then
+	echo "$as_me:$LINENO: result: not found" >&5
+echo "${ECHO_T}not found" >&6
+else
+	echo "$as_me:$LINENO: result: $gcc_cv_readelf" >&5
+echo "${ECHO_T}$gcc_cv_readelf" >&6
+fi
+
 # Figure out what assembler alignment features are present.
 echo "$as_me:$LINENO: checking assembler for .balign and .p2align" >&5
 echo $ECHO_N "checking assembler for .balign and .p2align... $ECHO_C" >&6
@@ -21502,9 +21572,50 @@ fi
 echo "$as_me:$LINENO: result: $gcc_cv_as_cfi_directive" >&5
 echo "${ECHO_T}$gcc_cv_as_cfi_directive" >&6
 
+if test $gcc_cv_as_cfi_directive = yes && test x$gcc_cv_readelf != x; then
+echo "$as_me:$LINENO: checking assembler for working cfi advance" >&5
+echo $ECHO_N "checking assembler for working cfi advance... $ECHO_C" >&6
+if test "${gcc_cv_as_cfi_advance_working+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  gcc_cv_as_cfi_advance_working=no
+  if test x$gcc_cv_as != x; then
+    echo '	.text
+	.cfi_startproc
+	.cfi_adjust_cfa_offset 64
+	.skip 512, 0
+	.cfi_adjust_cfa_offset 128
+	.cfi_endproc' > conftest.s
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }
+    then
+
+if $gcc_cv_readelf -wf conftest.o 2>/dev/null \
+    | grep 'DW_CFA_advance_loc[12]:[ 	][ 	]*512[ 	]' >/dev/null; then
+   gcc_cv_as_cfi_advance_working=yes
+fi
+
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+echo "$as_me:$LINENO: result: $gcc_cv_as_cfi_advance_working" >&5
+echo "${ECHO_T}$gcc_cv_as_cfi_advance_working" >&6
+
+else
+  gcc_cv_as_cfi_advance_working=yes
+fi
 
 cat >>confdefs.h <<_ACEOF
-#define HAVE_GAS_CFI_DIRECTIVE `if test $gcc_cv_as_cfi_directive = yes; then echo 1; else echo 0; fi`
+#define HAVE_GAS_CFI_DIRECTIVE `if test $gcc_cv_as_cfi_directive = yes \
+       && test $gcc_cv_as_cfi_advance_working = yes; then echo 1; else echo 0; fi`
 _ACEOF
 
 
@@ -25432,6 +25543,7 @@ s,@ORIGINAL_LD_FOR_TARGET@,$ORIGINAL_LD_
 s,@gcc_cv_nm@,$gcc_cv_nm,;t t
 s,@ORIGINAL_NM_FOR_TARGET@,$ORIGINAL_NM_FOR_TARGET,;t t
 s,@gcc_cv_objdump@,$gcc_cv_objdump,;t t
+s,@gcc_cv_readelf@,$gcc_cv_readelf,;t t
 s,@libgcc_visibility@,$libgcc_visibility,;t t
 s,@GGC@,$GGC,;t t
 s,@zlibdir@,$zlibdir,;t t

	Jakub