m4/ax_with_curses.m4 needs upgrading

[aspiers]

The compile of lnav.o is currently failing due to undefined reference to symbol. (I guess the preceding warnings are unrelated.)

  CXX      lnav.o
In file included from hist_source.hh:45:0,
                 from lnav.hh:47,
                 from lnav.cc:82:
textview_curses.hh: In member function ‘virtual nonstd::optional_lite::optional<strong_int<int, __vis_line_distinct> > vis_location_history::loc_history_back(vis_line_t)’:
textview_curses.hh:511:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (this->lh_history_position + 1 >= this->vlh_history.size()) {
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from top_status_source.hh:36:0,
                 from lnav.hh:50,
                 from lnav.cc:82:
logfile_sub_source.hh: In member function ‘nonstd::optional_lite::optional<strong_int<int, __vis_line_distinct> > logfile_sub_source::find_from_content(content_line_t)’:
logfile_sub_source.hh:514:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             while (vis_start < this->text_line_count()) {
                    ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
lnav.cc: In function ‘void rebuild_indexes()’:
lnav.cc:583:59: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if ((!scroll_downs[LNV_LOG] || log_view.get_top() > new_count) && force) {
                                        ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
  CXXLD    lnav
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: lnav.o: undefined reference to symbol 'keypad@@NCURSES6_TINFO_5.0.19991023'
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /lib64/libtinfo.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
make[2]: *** [Makefile:841: lnav] Error 1
make[2]: Leaving directory '/home/adam/.GIT/3rd-party/lnav/src'
make[1]: *** [Makefile:701: all] Error 2
make[1]: Leaving directory '/home/adam/.GIT/3rd-party/lnav/src'
make: *** [Makefile:470: all-recursive] Error 1

[tstack]

Hmm, not sure what might be going on. Maybe try running configure with --disable-static.

What distribution are you using?

[aspiers]

I'm using openSUSE Leap 15.0. I didn't used to have this problem, but I haven't tried compiling lnav for quite a while until just now.

I notice that the undefined symbol ref is keypad@@NCURSES6_TINFO_5.0.19991023, and if I grep for keypad in the source I see three calls to that:

src/lnav.cc:        keypad(stdscr, TRUE);
test/drive_readline_curses.cc:    keypad(stdscr, TRUE);
test/rltest.cc:    keypad(stdscr, TRUE);  /* enable keyboard mapping */

Based on the above, presumably it's supposed to come from an ncurses library, right? I have these on my system:

/usr/include/ncurses/cursesw.h:  int            keypad(bool bf) { return ::keypad(w, bf); }
/usr/include/ncurses5/ncurses/cursesw.h:  int            keypad(bool bf) { return ::keypad(w, bf); }
/usr/include/ncurses5/ncursesw/cursesw.h:  int            keypad(bool bf) { return ::keypad(w, bf); }
/usr/include/ncursesw/cursesw.h:  int            keypad(bool bf) { return ::keypad(w, bf); }

but is there supposed to be an #include which brings in that symbol somehow?

[aspiers]

By complete coincidence, I just saw this whilst working on another system on a totally unrelated thing:

# zypper in -f libncurses6
Loading repository data...
Reading installed packages...
Forcing installation of 'libncurses6-5.9-64.1.x86_64' from repository 'Updates'.
Resolving package dependencies...

Problem: mosh-1.3.2-1.34.x86_64 requires libtinfo.so.6(NCURSES6_TINFO_5.0.19991023)(64bit), but this requirement cannot be provided
  deleted providers: libncurses6-6.1-10.4.x86_64
 Solution 1: deinstallation of mosh-1.3.2-1.34.x86_64
 Solution 2: do not install libncurses6-5.9-64.1.x86_64
 Solution 3: break mosh-1.3.2-1.34.x86_64 by ignoring some of its dependencies

Choose from above solutions by number or cancel [1/2/3/c] (c): 

I was trying to downgrade libncurses6, but this shows that mosh depends on libtinfo which is presumably only available in the newer version of the library. So maybe the problem with my compilation is that it was compiled against the newer version which has libtinfo, but it's trying to link against the older version? Or that it wasn't even compiled against the new version, but then I'm not sure how it would even compile.

[aspiers]

I've just seen this again on openSUSE Tumbleweed:

  TIMEFMT  time_fmts.cc
  CXX      time_fmts.o
  AR       libdiag.a
  CXXLD    lnav-test
  CXXLD    lnav
/usr/lib64/gcc/x86_64-suse-linux/10/../../../../x86_64-suse-linux/bin/ld: lnav.o: undefined reference to symbol 'keypad@@NCURSES6_TINFO_5.0.19991023'
/usr/lib64/gcc/x86_64-suse-linux/10/../../../../x86_64-suse-linux/bin/ld: /lib64/libtinfo.so.6: error adding symbols: DSO missing from command line
/usr/lib64/gcc/x86_64-suse-linux/10/../../../../x86_64-suse-linux/bin/ld: lnav.o: undefined reference to symbol 'keypad@@NCURSES6_TINFO_5.0.19991023'
/usr/lib64/gcc/x86_64-suse-linux/10/../../../../x86_64-suse-linux/bin/ld: /lib64/libtinfo.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
make[2]: *** [Makefile:1024: lnav] Error 1
make[2]: *** Waiting for unfinished jobs....
collect2: error: ld returned 1 exit status
make[2]: *** [Makefile:1028: lnav-test] Error 1
make[2]: Leaving directory '/home/adam/.GIT/3rd-party/lnav/src'
make[1]: *** [Makefile:1188: install-recursive] Error 1
make[1]: Leaving directory '/home/adam/.GIT/3rd-party/lnav/src'
make: *** [Makefile:486: install-recursive] Error 1

[aspiers]

OK I figured out from this that the problem is that -ltinfo is missing from the linking command. Using V=1 confirms that:

make[2]: Entering directory '/home/adam/.GIT/3rd-party/lnav/src'
g++-10  -fmessage-length=0 -grecord-gcc-switches -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables -fasynchronous-unwind-tables -g -static-libgcc -L/home/adam/.GIT/3rd-party/lnav/src/static-libs -static-libstdc++    -L/usr/local/lib64 -L/usr/local/lib -L/usr/lib64 -L/usr/lib -L//lib64 -L//lib -o lnav lnav.o libdiag.a base/libbase.a fmtlib/libcppfmt.a pcrepp/libpcrepp.a yajl/libyajl.a yajlpp/libyajlpp.a -lreadline -lncursesw -lsqlite3  -lpcrecpp -lpcrecpp -lpcre -lgpm -ldl -lbz2 -lz -lutil -lpthread 
/usr/lib64/gcc/x86_64-suse-linux/10/../../../../x86_64-suse-linux/bin/ld: lnav.o: undefined reference to symbol 'keypad@@NCURSES6_TINFO_5.0.19991023'
/usr/lib64/gcc/x86_64-suse-linux/10/../../../../x86_64-suse-linux/bin/ld: /lib64/libtinfo.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

and sure enough, adding it in fixes the issue.

This led me to question the method by which lnav is currently calculating the linker flags for ncursesw (and presumably it's the same issue for ncurses. The above link suggests that pkg-config should be used, and on my system, running pkg-config --libs ncursesw outputs:

-Wl,-O2 -Wl,-Bsymbolic-functions -Wl,--as-needed -lncursesw -ltinfo 

However, I see that lnav uses m4/ax_with_curses.m4 from autoconf-archive, and I also see that it has #serial 13 which means that it's more than 5 years out of date. This explains why it's missing any reference to tinfo, which was first introduced in 2016, and later updated.

So the summary is that m4/ax_with_curses.m4 in lnav is way out of date and should be updated. It would be worth checking if any other m4 macros are also out of date.

[aspiers]

I just copied in the latest m4/ax_with_curses.m4 from autoconf-archive, did a full distclean / reconfigure / build, and it still didn't work. At this point I realised that even though src/Makefile now correctly contains:

CURSES_LIBS = -Wl,-O2 -Wl,-Bsymbolic-functions -Wl,--as-needed -lncursesw -ltinfo

lnav's other Makefile rules are not consuming it, because they're still using CURSES_LIB (N.B. singular, not plural). And indeed, part of the diff of the updated m4 file is:

-#   The following output variable is defined by this macro; it is precious
-#   and may be overridden on the ./configure command line:
+#   The following output variables are defined by this macro; they are
+#   precious and may be overridden on the ./configure command line:
 #
-#     CURSES_LIB  - library to add to xxx_LDADD
+#     CURSES_LIBS  - library to add to xxx_LDADD
+#     CURSES_CFLAGS  - include paths to add to xxx_CPPFLAGS
 #
-#   The library listed in CURSES_LIB is NOT added to LIBS by default. You
-#   need to add CURSES_LIB to the appropriate xxx_LDADD line in your
-#   Makefile.am.  For example:
+#   In previous versions of this macro, the flags CURSES_LIB and
+#   CURSES_CPPFLAGS were defined. These have been renamed, in keeping with
+#   AX_WITH_CURSES's close bigger brother, PKG_CHECK_MODULES, which should
+#   eventually supersede the use of AX_WITH_CURSES. Neither the library
+#   listed in CURSES_LIBS, nor the flags in CURSES_CFLAGS are added to LIBS,
+#   respectively CPPFLAGS, by default. You need to add both to the
+#   appropriate xxx_LDADD/xxx_CPPFLAGS line in your Makefile.am. For
+#   example:
 #
-#     prog_LDADD = @CURSES_LIB@
+#     prog_LDADD = @CURSES_LIBS@

Changing LDADD in src/Makefile.am to refer to $(CURSES_LIBS) instead of $(CURSES_LIB) finally fixed the compilation, but I still see several other references to the old $(CURSES_LIB) which presumably need to be fixed.