[PATCH 3/4] Use POSIX nm to simplify AIX export_symbols_cmds.

* m4/libtool.m4 (LT_PATH_NM): Detect POSIX-compatible nm for AIX.  In
BSD mode, the AIX nm does not tell whether a symbol is weak, need to use
POSIX mode instead.
(_LT_CMD_GLOBAL_SYMBOLS): Support POSIX-compatible nm.  Reorder to allow
for platform specific hooks during transformation of global_symbol_pipe
into C source code.  For AIX, set hook to transform even weak text
symbols as text symbols.
(_LT_LINKER_SHLIBS): Use global_symbol_pipe to simplify forming the
export_symbols_cmds for AIX.
---
 m4/libtool.m4 | 101 ++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 55 insertions(+), 46 deletions(-)

diff --git a/m4/libtool.m4 b/m4/libtool.m4
index 2c0e657..6134522 100644
--- a/m4/libtool.m4
+++ b/m4/libtool.m4
@@ -3755,10 +3755,10 @@ _LT_DECL([], [want_nocaseglob], [1],
 
 # LT_PATH_NM
 # ----------
-# find the pathname to a BSD- or MS-compatible name lister
+# find the pathname to a BSD-, POSIX- or MS-compatible name lister
 AC_DEFUN([LT_PATH_NM],
 [AC_REQUIRE([AC_PROG_CC])dnl
-AC_CACHE_CHECK([for BSD- or MS-compatible name lister (nm)], lt_cv_path_NM,
+AC_CACHE_CHECK([for BSD-, POSIX- or MS-compatible name lister (nm)], lt_cv_path_NM,
 [if test -n "$NM"; then
   # Let the user override the test.
   lt_cv_path_NM=$NM
@@ -3808,6 +3808,26 @@ else
   : ${lt_cv_path_NM=no}
 fi])
 if test no != "$lt_cv_path_NM"; then
+  case $host_os in
+  aix[[4-9]]*)
+    # With AIX nm we need the '-l' flag to get the "weak" information
+    # for the Import File, but '-l' is ignored with the '-B' flag.  So
+    # we use the '-P' (POSIX) flag instead.  As users often provide the
+    # '-B' flag, which conflicts with '-P', we drop any provided flag.
+    # AIX nm needs the '-C' flag to disable demangling.  For both GNU
+    # and AIX nm, the '-g' flag shows public (global) symbols only,
+    # and the '-p' flag disables sorting to improve performance.
+    set dummy $lt_cv_path_NM
+    case `@S|@2 -V 2>&1` in
+    *GNU* | *'with BFD'*)
+      lt_cv_path_NM="@S|@2 -Bgp"
+      ;;
+    *)
+      lt_cv_path_NM="@S|@2 -PlCgp"
+      ;;
+    esac
+    ;;
+  esac
   NM=$lt_cv_path_NM
 else
   # Didn't find any BSD compatible name lister, look for dumpbin.
@@ -3832,7 +3852,7 @@ fi
 test -z "$NM" && NM=nm
 _LT_SET_TOOL_ABI_FLAG([NM])
 AC_SUBST([NM])
-_LT_DECL([], [NM], [1], [A BSD- or MS-compatible name lister])dnl
+_LT_DECL([], [NM], [1], [A BSD-, POSIX- or MS-compatible name lister])dnl
 
 AC_CACHE_CHECK([the name lister ($NM) interface], [lt_cv_nm_interface],
   [lt_cv_nm_interface="BSD nm"
@@ -3847,6 +3867,8 @@ AC_CACHE_CHECK([the name lister ($NM) interface], [lt_cv_nm_interface],
   cat conftest.out >&AS_MESSAGE_LOG_FD
   if $GREP 'External.*some_variable' conftest.out > /dev/null; then
     lt_cv_nm_interface="MS dumpbin"
+  elif $GREP '^[[	 ]]*_*some_variable' conftest.out > /dev/null; then
+    lt_cv_nm_interface="POSIX nm"
   fi
   rm -f conftest*])
 ])# LT_PATH_NM
@@ -4012,8 +4034,33 @@ symcode='[[BCDEGRST]]'
 # Regexp to match symbols that can be accessed directly from C.
 sympat='\([[_A-Za-z]][[_A-Za-z0-9]]*\)'
 
+if test "$lt_cv_nm_interface" = "MS dumpbin"; then
+  # Gets list of data symbols to import.
+  lt_cv_sys_global_symbol_to_import="sed -n -e 's/^I .* \(.*\)$/\1/p'"
+  # Adjust the below global symbol transforms to fixup imported variables.
+  lt_cdecl_hook=" -e 's/^I .* \(.*\)$/extern __declspec(dllimport) char \1;/p'"
+  lt_c_name_hook=" -e 's/^I .* \(.*\)$/  {\"\1\", (void *) 0},/p'"
+  lt_c_name_lib_hook="\
+  -e 's/^I .* \(lib.*\)$/  {\"\1\", (void *) 0},/p'\
+  -e 's/^I .* \(.*\)$/  {\"lib\1\", (void *) 0},/p'"
+else
+  # Disable hooks by default.
+  lt_cv_sys_global_symbol_to_import=
+  lt_cdecl_hook=
+  lt_c_name_hook=
+  lt_c_name_lib_hook=
+fi
+
 # Define system-specific variables.
 case $host_os in
+aix[[4-9]]*)
+  case `$NM -V 2>&1` in
+  *GNU* | *'with BFD'*) ;;
+  *)
+    symcode='[[BDLTVWZ]]'
+    lt_cdecl_hook=" -e 's/^W/T/p'" # weak text symbol
+  esac
+  ;;
 aix*)
   symcode='[[BCDT]]'
   ;;
@@ -4054,23 +4101,6 @@ case `$NM -V 2>&1` in
   symcode='[[ABCDGIRSTW]]' ;;
 esac
 
-if test "$lt_cv_nm_interface" = "MS dumpbin"; then
-  # Gets list of data symbols to import.
-  lt_cv_sys_global_symbol_to_import="sed -n -e 's/^I .* \(.*\)$/\1/p'"
-  # Adjust the below global symbol transforms to fixup imported variables.
-  lt_cdecl_hook=" -e 's/^I .* \(.*\)$/extern __declspec(dllimport) char \1;/p'"
-  lt_c_name_hook=" -e 's/^I .* \(.*\)$/  {\"\1\", (void *) 0},/p'"
-  lt_c_name_lib_hook="\
-  -e 's/^I .* \(lib.*\)$/  {\"\1\", (void *) 0},/p'\
-  -e 's/^I .* \(.*\)$/  {\"lib\1\", (void *) 0},/p'"
-else
-  # Disable hooks by default.
-  lt_cv_sys_global_symbol_to_import=
-  lt_cdecl_hook=
-  lt_c_name_hook=
-  lt_c_name_lib_hook=
-fi
-
 # Transform an extracted symbol line into a proper C declaration.
 # Some systems (esp. on ia64) link data and code symbols differently,
 # so use this general approach.
@@ -4128,6 +4158,9 @@ for ac_symprfx in "" "_"; do
 "     s[1]~/^[@?]/{print f,s[1],s[1]; next};"\
 "     s[1]~prfx {split(s[1],t,\"@\"); print f,t[1],substr(t[1],length(prfx))}"\
 "     ' prfx=^$ac_symprfx]"
+  elif test "$lt_cv_nm_interface" = "POSIX nm"; then
+    symxfrm="\\2 $ac_symprfx\\1 \\1"
+    lt_cv_sys_global_symbol_pipe="sed -n -e 's/^[[	 ]]*$ac_symprfx$sympat[[	 ]][[	 ]]*\($symcode$symcode*\)[[	 ]][[	 ]]*.*$opt_cr$/$symxfrm/p'"
   else
     lt_cv_sys_global_symbol_pipe="sed -n -e 's/^.*[[	 ]]\($symcode$symcode*\)[[	 ]][[	 ]]*$ac_symprfx$sympat$opt_cr$/$symxfrm/p'"
   fi
@@ -5009,19 +5042,7 @@ m4_if([$1], [CXX], [
   _LT_TAGVAR(exclude_expsyms, $1)=['_GLOBAL_OFFSET_TABLE_|_GLOBAL__F[ID]_.*']
   case $host_os in
   aix[[4-9]]*)
-    # If we're using GNU nm, then we don't want the "-C" option.
-    # -C means demangle to GNU nm, but means don't demangle to AIX nm.
-    # Without the "-l" option, or with the "-B" option, AIX nm treats
-    # weak defined symbols like other global defined symbols, whereas
-    # GNU nm marks them as "W".
-    # While the 'weak' keyword is ignored in the Export File, we need
-    # it in the Import File for the 'aix-soname' feature, so we have
-    # to replace the "-B" option with "-P" for AIX nm.
-    if $NM -V 2>&1 | $GREP 'GNU' > /dev/null; then
-      _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "W")) && ([substr](\$ 3,1,1) != ".")) { if (\$ 2 == "W") { print \$ 3 " weak" } else { print \$ 3 } } }'\'' | sort -u > $export_symbols'
-    else
-      _LT_TAGVAR(export_symbols_cmds, $1)='`func_echo_all $NM | $SED -e '\''s/B\([[^B]]*\)$/P\1/'\''` -PCpgl $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "L") || (\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) && ([substr](\$ 1,1,1) != ".")) { if ((\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) { print \$ 1 " weak" } else { print \$ 1 } } }'\'' | sort -u > $export_symbols'
-    fi
+    _LT_TAGVAR(export_symbols_cmds, $1)='$NM $libobjs $convenience | $global_symbol_pipe | $EGREP -v " ($exclude_expsyms)$" | awk '\''{ kw = "" } /^[[VWZ]] / { kw = " weak" } { print $ 3 kw }'\'' | sort -u > $export_symbols'
     ;;
   pw32*)
     _LT_TAGVAR(export_symbols_cmds, $1)=$ltdll_cmds
@@ -5464,19 +5485,7 @@ _LT_EOF
 	exp_sym_flag='-Bexport'
 	no_entry_flag=
       else
-	# If we're using GNU nm, then we don't want the "-C" option.
-	# -C means demangle to GNU nm, but means don't demangle to AIX nm.
-	# Without the "-l" option, or with the "-B" option, AIX nm treats
-	# weak defined symbols like other global defined symbols, whereas
-	# GNU nm marks them as "W".
-	# While the 'weak' keyword is ignored in the Export File, we need
-	# it in the Import File for the 'aix-soname' feature, so we have
-	# to replace the "-B" option with "-P" for AIX nm.
-	if $NM -V 2>&1 | $GREP 'GNU' > /dev/null; then
-	  _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "W")) && ([substr](\$ 3,1,1) != ".")) { if (\$ 2 == "W") { print \$ 3 " weak" } else { print \$ 3 } } }'\'' | sort -u > $export_symbols'
-	else
-	  _LT_TAGVAR(export_symbols_cmds, $1)='`func_echo_all $NM | $SED -e '\''s/B\([[^B]]*\)$/P\1/'\''` -PCpgl $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "L") || (\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) && ([substr](\$ 1,1,1) != ".")) { if ((\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) { print \$ 1 " weak" } else { print \$ 1 } } }'\'' | sort -u > $export_symbols'
-	fi
+	_LT_TAGVAR(export_symbols_cmds, $1)='$NM $libobjs $convenience | $global_symbol_pipe | $EGREP -v " ($exclude_expsyms)$" | awk '\''{ kw = "" } /^[[VWZ]] / { kw = " weak" } { print $ 3 kw }'\'' | sort -u > $export_symbols'
 	aix_use_runtimelinking=no
 
 	# Test if we are trying to use run time linking or normal
-- 
2.4.6