#!/bin/bash
# Run tests for a single compiler variation.

set -euo pipefail

if [ $# != 3 ]; then
   echo "$0 <encoder.c> <gcc|clang> <c90|c99|c11>"
   exit 1
fi
SOURCE=$1
CC=$2
STD=$3

if [[ "$CC" == "gcc" ]]; then
   # Need an extra flag to silence one warning for GCC, due to:
   # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89549
   CFLAGS="-O3 -Wall -Werror -pedantic -Wno-misleading-indentation"
else
   CFLAGS="-O3 -Wall -Werror -pedantic"
fi

# Output executable names.
#
# $OUTPUT_PREFIX matches what Makefile expected for "make clean".
# $CC-$STD-$$ suffix produces different output files for each compiler
# variation, so that this script can be run in parallel.
#
# The ".exe" suffix is needed for cygwin, otherwise we may get both
# "prog" and "prog.exe" output files, and cygwin has a tendency to run
# the wrong one.
OUTPUT_PREFIX=test_output
ENCODER_BIN="./$OUTPUT_PREFIX-$CC-$STD-$$.exe"
OUTPUT_BIN="./$OUTPUT_PREFIX-verify-$CC-$STD-$$.exe"
OUTPUT_SOURCE="$OUTPUT_PREFIX-$CC-$STD-$$.c"

function die() {
   echo "Failed for $CC/$STD: $1"

   # Exit with failure status, and leave temporary files behind for debugging.
   exit 1
}

function run_tests() {
   DATA=$1

   # Build encoder.
   rm -f "$ENCODER_BIN"
   $CC -std=$STD $CFLAGS "$SOURCE" -o "$ENCODER_BIN"

   # Encode data to C output.
   #
   # The "sed" patch below is to workaround this clang bug:
   # https://bugs.llvm.org/show_bug.cgi?id=44480
   echo "$DATA" \
      | "$ENCODER_BIN" 65535 \
      | sed -e "s/__FILE__/\"$OUTPUT_SOURCE\"/" \
      > "$OUTPUT_SOURCE"

   # Verify that #error is reached if we didn't define PIN.
   ( $CC "$OUTPUT_SOURCE" > /dev/null 2>&1 ) && die "#error test failed"

   # Verify correct PIN.
   rm -f "$OUTPUT_BIN"
   $CC -std=$STD $CFLAGS -DPIN=65535 "$OUTPUT_SOURCE" -o "$OUTPUT_BIN"
   "$OUTPUT_BIN" | grep -qF "$DATA" || die "Correct PIN test failed"

   # Verify incorrect PIN.
   rm -f "$OUTPUT_BIN"
   $CC -std=$STD $CFLAGS -DPIN=65534 "$OUTPUT_SOURCE" -o "$OUTPUT_BIN"
   "$OUTPUT_BIN" | grep -qF "$DATA" && die "Incorrect PIN test failed"

   return 0
}

# Run tests with short readable text data.  Note that we use
# different data for each run, so that we are not going to
# accidentally pass due to leftover binaries from previous run.
run_tests "$$ $RANDOM $(date) OK"

# Cleanup temporary output files before exiting with success status.
rm -f "$ENCODER_BIN" "$OUTPUT_SOURCE" "$OUTPUT_BIN"
exit 0