gdbsource() eats GDB errors

[lentinj]

Description:

When using gdbsource(..., interactive = TRUE), GDB errors are getting eaten somewhere.

Reproducible Steps:

Run the following script:

library(TMB)

writeLines(con = "/tmp/gdb_woes.cpp", "
#include <TMB.hpp>
template<class Type>
Type objective_function<Type>::operator() () {
    PARAMETER(p);
    Type x = 1;
    abort();
    return p + x;
}
")

TMB::compile("/tmp/gdb_woes.cpp", flags = "-g0 -O0")
dyn.load(TMB::dynlib("/tmp/gdb_woes"))

writeLines(con = '/tmp/gdb_woes_testcase.R', '
dyn.load(TMB::dynlib("/tmp/gdb_woes"))
TMB::MakeADFun(data = list(), parameters = list(p=1), DLL = "gdb_woes")
')
gdbsource('/tmp/gdb_woes_testcase.R', interactive = TRUE)

Current Output:

Program received signal SIGABRT, Aborted.
0x00007ffff79567bb in raise () from /lib/x86_64-linux-gnu/libc.so.6
#0  0x00007ffff79567bb in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007ffff7941535 in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007ffff2c41718 in objective_function<double>::operator()() () from /tmp/gdb_woes.so
 . . . snip . . .
(gdb) up
#1  0x00007ffff7941535 in abort () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) up
#2  0x00007ffff2c41718 in objective_function<double>::operator()() () from /tmp/gdb_woes.so
(gdb) print p
(gdb) print x
(gdb) argh
(gdb) help print
Print value of expression EXP.
Variables accessible are those of the lexical environment of the selected
 . . . snip . . .

Expected Output:

Running outside of gdbsource():-

$ R -d gdb
(gdb) run --vanilla < /tmp/gdb_woes_testcase.R
Program received signal SIGABRT, Aborted.
0x00007ffff79567bb in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) up
#1  0x00007ffff7941535 in abort () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) up
#2  0x00007ffff2c41718 in objective_function<double>::operator()() () from /tmp/gdb_woes.so
(gdb) print p
No symbol table is loaded.  Use the "file" command.
(gdb) print x
No symbol table is loaded.  Use the "file" command.
(gdb) argh
Undefined command: "argh".  Try "help".
(gdb) file /tmp/gdb_woes.so
A program is being debugged already.
Are you sure you want to change the file? (y or n) y
Reading symbols from /tmp/gdb_woes.so...(no debugging symbols found)...done.

Aha, that's because I turned debugging off when using TMB::compile(). Fixing flags so I get debug symbols I can see output when my print commands are valid:

(gdb) print p
$1 = 1
(gdb) pritn x
(gdb) print x
$2 = 1

TMB Version:

> packageVersion("TMB")
[1] ‘1.7.18’

R Version:

> R.version.string
[1] "R version 3.6.3 (2020-02-29)"

... and ...

> R.version.string
[1] "R version 4.0.3 (2020-10-10)"

Operating System:

Debian 5.10.5-1

[lentinj]

Replacing the system call in gdbsource with system2 seems to solve this, at least on Linux:

        system2('R', c(
            "-d", "gdb",
            paste("--debugger-args=\"-x", gdbscript, "\"")))