On 03/20/2016 01:04 AM, David Edelsohn wrote:
> I agree with this in principle, but I'm not convinced that the patch
> itself is correct.
Thanks!
> I also would have split the MS-compatible part of the patch as a
> separate step. It is not listed in the ChangeLog and just confuses
> the patch.
This is just a reordering of existing code - these lines are removed
below, and the ChangeLog part is "Reorder to allow for platform specific
hooks during transformation of global_symbol_pipe into C source code."
> I don't see that this emits TLS symbols. Global TLS symbols are not
> in the symcode list.
Isn't the "L" for TLS symbols?
+ symcode='[[BDLTVWZ]]'
But indeed I've failed to identify the symcode of "weak TLS" symbols,
except for "L*" with AIX nm in unspecified mode (nm -l, no -B or -P)
Neither AIX nm nor GNU nm docs explicitly tell about weak TLS symbols.
Is it possible for TLS symbols to be weak at all?
> Global symbol pipe and exclude symbols somehow restricts the symbols
> to the non "dot" symbols?
Yes - but this is what the existing code does as well:
'... && ([substr](\$ 1,1,1) != ".") ..'
> The export_symbols_cmds awk command does not have matching quotes, so
> I don't know what is going on.
>
> awk '\''{ kw = "" } /^[[VWZ]] / { kw = " weak" } { print $ 3 kw }'\''
>
> you're starting and ending with '\" which seems odd. why aren't these
> complementary?
The awk argument is passed between ['], as it contains ["].
Escaping [\] the ['] is done outside any other string. Read as:
_LT_TAGVAR(...)=['$NM ... | awk '][\']['{ ... }'][\'][' | sort ...']
Indeed I can add [] here if you like.
Thanks!
/haubi/
>
> Thanks, David
>
> On Wed, Mar 2, 2016 at 11:19 AM, Michael Haubenwallner
> <michael.haubenwall...@ssi-schaefer.com> wrote:
>> * m4/libtool.m4 (LT_PATH_NM): Detect POSIX-compatible nm for AIX. In
>> BSD mode, the AIX nm does not tell whether a symbol is weak, need to use
>> POSIX mode instead.
>> (_LT_CMD_GLOBAL_SYMBOLS): Support POSIX-compatible nm. Reorder to allow
>> for platform specific hooks during transformation of global_symbol_pipe
>> into C source code. For AIX, set hook to transform even weak text
>> symbols as text symbols.
>> (_LT_LINKER_SHLIBS): Use global_symbol_pipe to simplify forming the
>> export_symbols_cmds for AIX.
>> ---
>> m4/libtool.m4 | 101
>> ++++++++++++++++++++++++++++++++--------------------------
>> 1 file changed, 55 insertions(+), 46 deletions(-)
>>
>> diff --git a/m4/libtool.m4 b/m4/libtool.m4
>> index 2c0e657..6134522 100644
>> --- a/m4/libtool.m4
>> +++ b/m4/libtool.m4
>> @@ -3755,10 +3755,10 @@ _LT_DECL([], [want_nocaseglob], [1],
>>
>> # LT_PATH_NM
>> # ----------
>> -# find the pathname to a BSD- or MS-compatible name lister
>> +# find the pathname to a BSD-, POSIX- or MS-compatible name lister
>> AC_DEFUN([LT_PATH_NM],
>> [AC_REQUIRE([AC_PROG_CC])dnl
>> -AC_CACHE_CHECK([for BSD- or MS-compatible name lister (nm)], lt_cv_path_NM,
>> +AC_CACHE_CHECK([for BSD-, POSIX- or MS-compatible name lister (nm)],
>> lt_cv_path_NM,
>> [if test -n "$NM"; the
>> # 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
>>
