Support the use of the STT_COMMON type. (In source and object files only at the moment)

6 files changed, 98 insertions, 19 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index a93c102..09d3a7e 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,15 @@
+2007-10-16  Nick Clifton  <nickc@redhat.com>
+
+	* configure.in (--enable-elf-stt-common): New configure
+	option.  If enabled then the tools can generate symbols with
+	the ELF STT_COMMON type.
+	* config.in: Regenerate.
+	* configure: Regenerate.
+	* elf.c (swap_out_syms): If USE_STT_COMMON is defined then set
+	the type of emitted common symbols to STT_COMMON.
+	* elfcode.h (elf_slurp_symbol_table): Accept STT_COMMON symbol
+	types.
+	
 2007-10-15  Alan Modra  <amodra@bigpond.net.au>
 
 	* coff-arm.c (arm_emit_base_file_entry): Check fwrite return value.
diff --git a/bfd/config.in b/bfd/config.in
index aa91dd6..fd14f82 100644
--- a/bfd/config.in
+++ b/bfd/config.in
@@ -285,6 +285,9 @@
 /* Define if we should default to creating read-only plt entries */
 #undef USE_SECUREPLT
 
+/* Define if we may generate symbols with ELF's STT_COMMON type */
+#undef USE_STT_COMMON
+
 /* Version number of package */
 #undef VERSION
 
diff --git a/bfd/configure b/bfd/configure
index 019bddd9..806ee7e 100755
--- a/bfd/configure
+++ b/bfd/configure
@@ -1012,6 +1012,7 @@ Optional Features:
   --enable-targets        alternative target configurations
   --enable-commonbfdlib   build shared BFD/opcodes/libiberty library
   --enable-secureplt      Default to creating read-only plt entries
+  --enable-elf-stt-common Allow the generation of ELF symbols with the STT_COMMON type
   --enable-werror         treat compile warnings as errors
   --enable-build-warnings enable build-time compiler warnings
   --enable-maintainer-mode  enable make rules and dependencies not useful
@@ -4665,13 +4666,13 @@ if test "${lt_cv_nm_interface+set}" = set; then
 else
   lt_cv_nm_interface="BSD nm"
   echo "int some_variable = 0;" > conftest.$ac_ext
-  (eval echo "\"\$as_me:4668: $ac_compile\"" >&5)
+  (eval echo "\"\$as_me:4669: $ac_compile\"" >&5)
   (eval "$ac_compile" 2>conftest.err)
   cat conftest.err >&5
-  (eval echo "\"\$as_me:4671: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
+  (eval echo "\"\$as_me:4672: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
   (eval "$NM \"conftest.$ac_objext\"" 2>conftest.err > conftest.out)
   cat conftest.err >&5
-  (eval echo "\"\$as_me:4674: output\"" >&5)
+  (eval echo "\"\$as_me:4675: output\"" >&5)
   cat conftest.out >&5
   if $GREP 'External.*some_variable' conftest.out > /dev/null; then
     lt_cv_nm_interface="MS dumpbin"
@@ -5726,7 +5727,7 @@ ia64-*-hpux*)
   ;;
 *-*-irix6*)
   # Find out which ABI we are using.
-  echo '#line 5729 "configure"' > conftest.$ac_ext
+  echo '#line 5730 "configure"' > conftest.$ac_ext
   if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   (eval $ac_compile) 2>&5
   ac_status=$?
@@ -6826,11 +6827,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:6829: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:6830: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:6833: \$? = $ac_status" >&5
+   echo "$as_me:6834: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -7148,11 +7149,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:7151: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:7152: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:7155: \$? = $ac_status" >&5
+   echo "$as_me:7156: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -7253,11 +7254,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:7256: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:7257: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:7260: \$? = $ac_status" >&5
+   echo "$as_me:7261: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -7308,11 +7309,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:7311: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:7312: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:7315: \$? = $ac_status" >&5
+   echo "$as_me:7316: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -10105,7 +10106,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10108 "configure"
+#line 10109 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -10205,7 +10206,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10208 "configure"
+#line 10209 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -10449,7 +10450,8 @@ echo "$as_me: error: bad value ${enableval} for 64-bit-bfd option" >&2;}
 esac
 else
   want64=false
-fi; # Check whether --enable-targets or --disable-targets was given.
+fi;
+# Check whether --enable-targets or --disable-targets was given.
 if test "${enable_targets+set}" = set; then
   enableval="$enable_targets"
   case "${enableval}" in
@@ -10460,7 +10462,8 @@ echo "$as_me: error: enable-targets option must specify target names or 'all'" >
   no)       enable_targets= ;;
   *)        enable_targets=$enableval ;;
 esac
-fi; # Check whether --enable-commonbfdlib or --disable-commonbfdlib was given.
+fi;
+# Check whether --enable-commonbfdlib or --disable-commonbfdlib was given.
 if test "${enable_commonbfdlib+set}" = set; then
   enableval="$enable_commonbfdlib"
   case "${enableval}" in
@@ -10471,6 +10474,7 @@ echo "$as_me: error: bad value ${enableval} for BFD commonbfdlib option" >&2;}
    { (exit 1); exit 1; }; } ;;
 esac
 fi;
+
 # Check whether --with-mmap or --without-mmap was given.
 if test "${with_mmap+set}" = set; then
   withval="$with_mmap"
@@ -10506,7 +10510,6 @@ fi
 
 DEBUGDIR=${libdir}/debug
 
-
 # Check whether --with-separate-debug-dir or --without-separate-debug-dir was given.
 if test "${with_separate_debug_dir+set}" = set; then
   withval="$with_separate_debug_dir"
@@ -10514,6 +10517,37 @@ if test "${with_separate_debug_dir+set}" = set; then
 fi;
 
 
+# Check to see if we should allow the generation of
+# symbols with the ELF standard's STT_COMMON type.
+# Check whether --enable-elf-stt-common or --disable-elf-stt-common was given.
+if test "${enable_elf_stt_common+set}" = set; then
+  enableval="$enable_elf_stt_common"
+  case "${enableval}" in
+  yes) want_elf_stt_common=true ;;
+  no)  want_elf_stt_common=false ;;
+  *)   { { echo "$as_me:$LINENO: error: bad value ${enableval} for ELF STT_COMMON option" >&5
+echo "$as_me: error: bad value ${enableval} for ELF STT_COMMON option" >&2;}
+   { (exit 1); exit 1; }; } ;;
+ esac
+else
+  # We have to choose a default behaviour.  For native builds we could
+# test whether the loader supports the STT_COMMON type.  For cross
+# toolchains we default to assuming that they are not supported.
+if test "$cross_compiling" != yes; then
+  want_elf_stt_common=false
+ else
+ # XXX FIXME: Add code to test the loader here.
+  want_elf_stt_common=false
+ fi
+fi; if test $want_elf_stt_common = true; then
+
+cat >>confdefs.h <<\_ACEOF
+#define USE_STT_COMMON 1
+_ACEOF
+
+fi
+
+
 
 
 # Check whether --with-pkgversion or --without-pkgversion was given.
diff --git a/bfd/configure.in b/bfd/configure.in
index facc1a3..ad8440e 100644
--- a/bfd/configure.in
+++ b/bfd/configure.in
@@ -31,6 +31,7 @@ AC_ARG_ENABLE(64-bit-bfd,
   no)   want64=false ;;
   *)    AC_MSG_ERROR(bad value ${enableval} for 64-bit-bfd option) ;;
 esac],[want64=false])dnl
+
 AC_ARG_ENABLE(targets,
 [  --enable-targets        alternative target configurations],
 [case "${enableval}" in
@@ -39,6 +40,7 @@ AC_ARG_ENABLE(targets,
   no)       enable_targets= ;;
   *)        enable_targets=$enableval ;;
 esac])dnl
+
 AC_ARG_ENABLE(commonbfdlib,
 [  --enable-commonbfdlib   build shared BFD/opcodes/libiberty library],
 [case "${enableval}" in
@@ -46,6 +48,7 @@ AC_ARG_ENABLE(commonbfdlib,
   no)  commonbfdlib=false ;;
   *)   AC_MSG_ERROR([bad value ${enableval} for BFD commonbfdlib option]) ;;
 esac])dnl
+
 AC_ARG_WITH(mmap,
 [  --with-mmap             try using mmap for BFD input files if available],
 [case "${withval}" in
@@ -67,13 +70,32 @@ if test $use_secureplt = true; then
 fi
 
 DEBUGDIR=${libdir}/debug
-	 
 AC_ARG_WITH(separate-debug-dir,
   AS_HELP_STRING([--with-separate-debug-dir=DIR],
                  [Look for global separate debug info in DIR [[default=LIBDIR/debug]]]),
 [DEBUGDIR="${withval}"])
 AC_SUBST(DEBUGDIR)
 
+# Check to see if we should allow the generation of
+# symbols with the ELF standard's STT_COMMON type.
+AC_ARG_ENABLE(elf-stt-common,
+[  --enable-elf-stt-common Allow the generation of ELF symbols with the STT_COMMON type],
+[case "${enableval}" in
+  yes) want_elf_stt_common=true ;;
+  no)  want_elf_stt_common=false ;;
+  *)   AC_MSG_ERROR(bad value ${enableval} for ELF STT_COMMON option) ;;
+ esac],
+# We have to choose a default behaviour.  For native builds we could
+# test whether the loader supports the STT_COMMON type, but that would
+# mean that built binaries could not be exported to older systems where
+# the loader does not support it. So by default we always choose to
+# disable this feature.
+  want_elf_stt_common=false)dnl
+if test $want_elf_stt_common = true; then
+  AC_DEFINE(USE_STT_COMMON, 1,
+    [Define if we may generate symbols with ELF's STT_COMMON type])
+fi
+	 
 ACX_PKGVERSION([GNU Binutils])
 ACX_BUGURL([http://www.sourceware.org/bugzilla/])
 
diff --git a/bfd/elf.c b/bfd/elf.c
index b5b51d0..8aac231 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -6297,7 +6297,11 @@ Unable to find equivalent output section for symbol '%s' from section '%s'"),
 	    sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
 	}
       else if (bfd_is_com_section (syms[idx]->section))
-	sym.st_info = ELF_ST_INFO (STB_GLOBAL, type);
+	sym.st_info = ELF_ST_INFO (STB_GLOBAL,
+#ifdef USE_STT_COMMON
+				   type == STT_OBJECT ? STT_COMMON :
+#endif
+				   type);
       else if (bfd_is_und_section (syms[idx]->section))
 	sym.st_info = ELF_ST_INFO (((flags & BSF_WEAK)
 				    ? STB_WEAK
diff --git a/bfd/elfcode.h b/bfd/elfcode.h
index e1f5801..ea2a6d3 100644
--- a/bfd/elfcode.h
+++ b/bfd/elfcode.h
@@ -1323,6 +1323,10 @@ elf_slurp_symbol_table (bfd *abfd, asymbol **symptrs, bfd_boolean dynamic)
 	    case STT_FUNC:
 	      sym->symbol.flags |= BSF_FUNCTION;
 	      break;
+	    case STT_COMMON:
+	      /* FIXME: Do we have to put the size field into the value field
+		 as we do with symbols in SHN_COMMON sections (see above) ?  */
+	      /* Fall through.  */
 	    case STT_OBJECT:
 	      sym->symbol.flags |= BSF_OBJECT;
 	      break;