On 03/21/2016 03:47 PM, David Edelsohn wrote:
> On Mon, Mar 21, 2016 at 4:49 AM, Michael Haubenwallner
> <michael.haubenwall...@ssi-schaefer.com> wrote:
>>
>> 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]]'
>
> Sorry, I was confused by the two cases for "aix" and the case for
> "GNU" within AIX.
>
>>
>> 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?
For GNU nm I've identified the "C" (common) symcode to be "weak" as well.
But still I'm unsure about TLS symbols: Always import them as "strong"?
>>> 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) != ".") ..'
>
> Is that in your patch or existing code? Your patch removes the
> current substr($3,1,1).
In current code there is substr($3,1,1) for GNU nm (BSD mode) and
substr($1,1,1) for AIX nm (POSIX mode), both identifying the "dot"
symbols as to be *removed* from the list of exported symbols.
This patch leaves removal of the "dot" symbols up to $global_symbol_pipe,
which does remove them due to not being a valid C symbol name.
>>> 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.
>
> Ah, well, this is turning into a very complex statement. GCC requires
> GNU Awk and most developers use Bash, but does this work correctly
> with AIX awk and AIX Ksh?
This awk program is quite simple and works with AIX awk too. The AWK
variable is not promoted into the final libtool script, and I don't
want to have projects using libtool to require GNU Awk in general.
Most shells do not take [\] within two ['] as escapement,
so I do the escaping of ['] outside any string. Usually,
$ echo '\''
will leave you with a string open to be continued, while
$ echo \'
gives a single ['].
And this one doesn't feel more readable either:
_LT_TAGVAR(...)='$NM ... | awk '"'"'{ ... }'"'"' | sort ...'
What about this one:
_LT_TAGVAR(...)='$NM ... | awk '[\']'{ ... }'[\']' | sort ...'
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
>>>>
