iassert

A better invariant assertion library with gdb support

This is a C++ library to improve over the default assert in C++. The main advantages:

• Guarded assert support. GI(cond1,cond2) The cond2 triggers a failure only if cond1 is true.

• Release vs Debug spurious messages. The default C assert will result in warnings if a variable is just used in asserts. This source of warnings is removed in iassert.

• GDB support. If you define I_GDB=1 before launch the program, it waits for a GBD connection to remotely debug the program.

• Shorter syntax I(cond) for invariant or always true, GI(cond1,cond2) for guarded asserts

• Allows for messages in asserts, I(cond,"bad bad case") or GI(true,false,"Not again")

• Intercepts segfaults and prints call trace

• Segfault can be intercepted with GDB too.

Bazel ready:

bazel build -c dbg //...

To import in your project:

bazel_dep(name = "iassert", version = "0.1.1")

archive_override(
    module_name = "iassert",
    integrity = "sha256-Z9PIn1Fvbo8rE5RhStEvuRA0h39CcRK+536PzJKH/UU=",
    strip_prefix = "iassert-db67db81bc7708fae78d1d667c9a085e5c0e123c",
    urls = [
        "https://github.com/masc-ucsc/iassert/archive/db67db81bc7708fae78d1d667c9a085e5c0e123c.zip",
    ],
)

Example usage:

#include <stdio.h>

#include "iassert.hpp"

int main() {
  int i=0;
  int j = 1;

  (void)(i);

  I(false);
  I(true,"this works");
  GI(true,true, "jeje");
  GI(true,true);

  printf("Hello %d\n",j);
}

To support segfault call I_setup:

#include <stdio.h>

#include "iassert.hpp"

int main() {

  I_setup();

  int bad[10];
  bad[100000] = 0; // Trigger segfault

}

To breakpoint with gdb. Write a failing assertion anywhere. Connect with gdb, set a breakpoint in I_gdb_continuation, now the assertion will continue inside gdb.

>b I_gdb_continuation
>c

If you want to avoid typing this every time, you can set it in the ~/.gdbinit

# $(HOME)/.gdbinit setup for iassert
set breakpoint pending on
break I_gdb_continuation
set breakpoint pending auto