#!/bin/sh
# Use Failmalloc to test behaviour in the face of out-of-memory conditions.
# The test runs a binary multiple times while configuring Failmalloc to fail a
# different malloc() call each time, while looking for abnormal program exits
# due to segfaults. See https://www.nongnu.org/failmalloc/
#
# Ideally, it would ensure that the test binary returns an error code on each
# failure, but this often doesn't happen. This is a problem that should be
# rectified, but the API doesn't allow returning an error code in many
# functions that could encounter a problem. The issue could be solve in more
# cases with more judicious use of log calls with EXIF_LOG_CODE_NO_MEMORY
# codes.
. ./check-vars.sh

VERBOSE=
if [ "$1" = "-v" ] ; then
    VERBOSE=1
fi

if [ x"$FAILMALLOC_PATH" = x ]; then
    echo libfailmalloc is not available
    echo SKIPPING
    exit
fi

BINARY_PREFIX=./
if [ -e .libs/lt-test-value ]; then
    # If libtool is in use, the normal "binary" is actually a shell script which
    # would be interfered with by libfailmalloc. Instead, use the special lt-
    # binary which should work properly.
    BINARY_PREFIX=".libs/lt-"
fi

# Usage: failmalloc_binary_test #iterations binary <optional arguments>
# FIXME: auto-determine #iterations by comparing the output of each run
# with the output of a normal run, and exiting when that happens.
failmalloc_binary_test () {
  binary="$BINARY_PREFIX$2"
  iterations="$1"
  shift
  shift
  echo Checking "$binary" for "$iterations" iterations
  for n in $(seq "$iterations"); do
      test "$VERBOSE" = 1 && { echo "$n"; set -x; }
      FAILMALLOC_INTERVAL="$n" LD_PRELOAD="$FAILMALLOC_PATH" "$binary" "$@" >/dev/null
      s=$?
      test "$VERBOSE" = 1 && set +x;
      if test "$s" -ge 128; then
          # Such status codes only happen due to termination due to a signal
          # like SIGSEGV.
          echo "Abnormal binary exit status $s at malloc #$n on $binary"
          echo FAILURE
          exit 1
      fi
  done
}

# The number of iterations is determined empirically to be about twice as
# high as the maximum number of mallocs performed by the test program in order
# to avoid lowering code coverage in the case of future code changes that cause
# more allocations.

failmalloc_binary_test 500 test-value
failmalloc_binary_test 300 test-mem
for f in $SRCDIR/testdata/*jpg; do
    echo "Testing `basename "$f"`"
    failmalloc_binary_test 500 test-parse "$f"
    # N.B., test-parse --swap-byte-order doesn't test any new paths
done

echo PASSED