#!/bin/sh
set -eu
base="${TMPDIR-/tmp}/mcpu-cpp-dep-side-effects-$$"
mkdir -p "$base/src" "$base/user" "$base/sys" "$base/out" "$base/stdin"
trap 'rm -rf "$base"' EXIT HUP INT TERM

cat > "$base/src/main.c" <<'EOT'
#include "user.h"
#include <system.h>
MAIN_BODY
EOT
cat > "$base/user/user.h" <<'EOT'
USER_BODY
EOT
cat > "$base/sys/system.h" <<'EOT'
#include "system-child.h"
SYSTEM_BODY
EOT
cat > "$base/sys/system-child.h" <<'EOT'
SYSTEM_CHILD_BODY
EOT

# -MD keeps preprocessing output and writes basename.d in the current
# directory when no -o/-MF is present.  The input directory is not copied to
# the default dependency filename.
(
  cd "$base"
  "$MCPU_CPP" --no-config -I "$base/user" -isystem "$base/sys" \
    -MD "$base/src/main.c" > md.out
)
test -s "$base/md.out"
grep 'MAIN_BODY' "$base/md.out" >/dev/null
test -s "$base/main.d"
grep '^main\.o:' "$base/main.d" >/dev/null
for f in "$base/src/main.c" "$base/user/user.h" \
         "$base/sys/system.h" "$base/sys/system-child.h"
do
  grep -F "$f" "$base/main.d" >/dev/null || {
    echo "-MD omitted dependency: $f" >&2
    exit 1
  }
done

# -MMD has the same side-effect behavior but applies the already established
# -MM user-dependency filter.
rm -f "$base/main.d"
(
  cd "$base"
  "$MCPU_CPP" --no-config -I "$base/user" -isystem "$base/sys" \
    -MMD "$base/src/main.c" > mmd.out
)
test -s "$base/mmd.out"
grep 'MAIN_BODY' "$base/mmd.out" >/dev/null
test -s "$base/main.d"
grep -F "$base/src/main.c" "$base/main.d" >/dev/null
grep -F "$base/user/user.h" "$base/main.d" >/dev/null
! grep -F "$base/sys/system.h" "$base/main.d" >/dev/null
! grep -F "$base/sys/system-child.h" "$base/main.d" >/dev/null

# With ordinary -o, preprocessing goes to that file and the automatic
# dependency filename is obtained by replacing its suffix with .d.
rm -f "$base/main.d" "$base/out/result.i" "$base/out/result.d"
"$MCPU_CPP" --no-config -I "$base/user" -isystem "$base/sys" \
  -MD "$base/src/main.c" -o "$base/out/result.i"
test -s "$base/out/result.i"
grep 'MAIN_BODY' "$base/out/result.i" >/dev/null
test -s "$base/out/result.d"
grep '^main\.o:' "$base/out/result.d" >/dev/null
test ! -e "$base/main.d"

# -MF overrides automatic dependency naming while leaving normal preprocessing
# output semantics untouched.
rm -f "$base/custom.d" "$base/main.d"
(
  cd "$base"
  "$MCPU_CPP" --no-config -I "$base/user" -isystem "$base/sys" \
    -MD -MF custom.d "$base/src/main.c" > mf.out
)
test -s "$base/mf.out"
grep 'MAIN_BODY' "$base/mf.out" >/dev/null
test -s "$base/custom.d"
test ! -e "$base/main.d"

# Attached -MFfile spelling is accepted as by GNU cpp.
rm -f "$base/attached.d"
(
  cd "$base"
  "$MCPU_CPP" --no-config -I "$base/user" -isystem "$base/sys" \
    -MMD -MFattached.d "$base/src/main.c" > attached.out
)
test -s "$base/attached.d"
! grep -F "$base/sys/system.h" "$base/attached.d" >/dev/null

# -MF also redirects the already implemented dependency-only -M/-MM modes.
rm -f "$base/only.d" "$base/only.out"
"$MCPU_CPP" --no-config -I "$base/user" -isystem "$base/sys" \
  -M -MF "$base/only.d" "$base/src/main.c" > "$base/only.out"
test ! -s "$base/only.out"
test -s "$base/only.d"
grep -F "$base/sys/system.h" "$base/only.d" >/dev/null

rm -f "$base/only-user.d" "$base/only-user.out"
"$MCPU_CPP" --no-config -I "$base/user" -isystem "$base/sys" \
  -MM -MF "$base/only-user.d" "$base/src/main.c" > "$base/only-user.out"
test ! -s "$base/only-user.out"
test -s "$base/only-user.d"
! grep -F "$base/sys/system.h" "$base/only-user.d" >/dev/null

# -MF - means dependency stdout.  Put normal preprocessing in a regular -o
# file so the two streams are easy to verify independently.
rm -f "$base/out/stdout.i" "$base/out/stdout.d"
"$MCPU_CPP" --no-config -I "$base/user" -isystem "$base/sys" \
  -MMD -MF - "$base/src/main.c" -o "$base/out/stdout.i" \
  > "$base/mf-dash.out"
test -s "$base/out/stdout.i"
grep 'MAIN_BODY' "$base/out/stdout.i" >/dev/null
grep '^main\.o:' "$base/mf-dash.out" >/dev/null
test ! -e "$base/out/stdout.d"

# stdin follows the existing '-' target convention and gets '-.d' when -MD
# needs an automatic dependency filename.
(
  cd "$base/stdin"
  printf 'STDIN_BODY\n' | "$MCPU_CPP" --no-config -MD > stdout.i
)
test -s "$base/stdin/stdout.i"
grep 'STDIN_BODY' "$base/stdin/stdout.i" >/dev/null
test -s "$base/stdin/-.d"
grep '^-: -$' "$base/stdin/-.d" >/dev/null

# -MF alone is a command-line error: there is no dependency mode to redirect.
if "$MCPU_CPP" --no-config -MF "$base/orphan.d" "$base/src/main.c" \
     > /dev/null 2>&1; then
  echo "-MF without a dependency mode unexpectedly succeeded" >&2
  exit 1
fi