oracle.sh

#!/usr/bin/env bash

# Usage:
#
#     ./oracle.sh <bindgen> <test case>
#
# <bindgen> is the path to the bindgen executable.
#
# <test case> is the path to a C or C++ header file to test.
#
# Exits 0 if the test case triggers a bindgen bug.
#
# Exits 1 if the test case is not interesting.
#
# Assumes that rustc, clang++, and libclang >= 3.9 are available.

# Exit the script with a nonzero exit code if:
# * any individual command finishes with a nonzero exit code, or
# * we access any undefined variable.
# * a process in a pipe fails
set -eu
set -o pipefail

# Print out the stack when Rust code panics.
export RUST_BACKTRACE=1

BINDGEN=$1
TEST_CASE=$2

# Make sure that the test case is valid C++ by compiling it.
clang++ --std=c++14 -c "$HEADER" || {
    echo "Not interesting: bindgen can only process valid C and C++ header"
    echo "files."
    exit 1
}

BINDINGS=$(mktemp -t "bindings-XXXXXX.rs")

# Use bindgen to emit Rust bindings and FFI glue to the types and functions
# defined in the test case.
"$BINDGEN" "$TEST_CASE" -o "$BINDINGS" -- -x c++ -std=c++14 || {
    echo "Interesting: bindgen failed to generate bindings for the test case!"
    exit 0
}

TEST_BIN=$(mktemp -t "test-bindings-XXXXXX")

# Use rustc to compile the bindings and their unit tests that assert that the
# Rust layout of a type matches what libclang told us was the C/C++ layout of
# the type.
rustc --test "$BINDINGS" -o "$TEST_BIN" || {
    echo "Interesting: bindgen emitted Rust code that won't compile!"
    exit 0
}

# Finally, run the layout unit tests.
"$TEST_BIN" || {
    echo "Interesting: bindgen emitted type definitions that are failing their"
    echo "layout unit tests!"
    exit 0
}

echo "Not interesting: bindgen emitted Rust bindings, they compiled, and the"
echo "layout unit tests passed."
exit 1