PL/1 frontend

[Merrick, Thomas]

I would like to resurrect the PL/1 frontend which appears to have stopped development about 3 years ago.  I plan to start with the preprocessor, which is a PL/1 subset interpreter.

First of all, is this the correct list to ask questions about writing a frontend?  I plan on using GCC 4.5.1 and most of the example frontends seem to be made for 4.4.3 or earlier and do not work against 4.5.1.  Is there a good example that works on 4.5.1?  I just need the minimal subset right now as the preprocessor does not output, except for debugging and the input stream for the main PL/1 processor.

When I wrote a minimal frontend program, I get the following during linking:

/a0/staff/tmerrick/gcc-4.5.1/host-i686-pc-linux-gnu/prev-gcc/xgcc -B/a0/staff/tmerrick/gcc-4.5.1/host-i686-pc-linux-gnu/prev-gcc/ -B/usr/local/i686-pc-linux-gnu/bin/ -B/usr/local/i686-pc-linux-gnu/bin/ -B/usr/local/i686-pc-linux-gnu/lib/ -isystem /usr/local/i686-pc-linux-gnu/include -isystem /usr/local/i686-pc-linux-gnu/sys-include     -g -O2 -fomit-frame-pointer -gtoggle -DIN_GCC   -W -Wall -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wmissing-format-attribute -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Wold-style-definition -Wc++-compat   -DHAVE_CONFIG_H  -o pl11 \
        pl1/pl11.o main.o  libbackend.a ../libcpp/libcpp.a ../libdecnumber/libdecnumber.a ../libcpp/libcpp.a   ../libiberty/libiberty.a ../libdecnumber/libdecnumber.a  attribs.o   -L/a0/staff/tmerrick/gcc-4.5.1/host-i686-pc-linux-gnu/gmp/.libs -L/a0/staff/tmerrick/gcc-4.5.1/host-i686-pc-linux-gnu/mpfr/.libs -L/a0/staff/tmerrick/gcc-4.5.1/host-i686-pc-linux-gnu/mpc/src/.libs -lmpc -lmpfr -lgmp -rdynamic -ldl  -L../zlib -lz -lelf
libbackend.a(coverage.o):(.rodata+0x20): undefined reference to `gt_ggc_mx_lang_tree_node'
libbackend.a(coverage.o):(.rodata+0x24): undefined reference to `gt_pch_nx_lang_tree_node'
libbackend.a(dbxout.o):(.rodata+0x180): undefined reference to `gt_ggc_mx_lang_tree_node'
libbackend.a(dbxout.o):(.rodata+0x184): undefined reference to `gt_pch_nx_lang_tree_node'

With the last 4 lines repeated about 100 times for various parts of the backend.  I am not sure if this is for debugging or inline code, but there is obviously something that I am missing.  Any ideas?


Tom Merrick
IT Manager
College of Science & Technology
Texas A&M University
CI 352
6300 Ocean Drive
Corpus Christi, TX 78412-5806
Phone: 361-825-2435
Fax: 361-825-5789