#!/bin/bash
set -eu

src="$1"
dst="$2"

extern_anchor='extern void _tx_timer_interrupt(void);'
call_anchor='_tx_timer_interrupt();'

mkdir -p "$(dirname "$dst")"
tmp1="${dst}.tmp1"

line=$(grep -n -F "$extern_anchor" "$src" | head -n 1 | cut -d: -f1)
if [ -z "$line" ]; then
    echo "failed to find _tx_timer_interrupt declaration anchor in input source" >&2
    exit 1
fi
sed "${line}a\\
void test_interrupt_dispatch(void) __attribute__((weak));\nvoid test_interrupt_dispatch(void) {}" "$src" > "$tmp1"

line=$(grep -n -F "$call_anchor" "$tmp1" | head -n 1 | cut -d: -f1)
if [ -z "$line" ]; then
    echo "failed to find _tx_timer_interrupt call anchor in input source" >&2
    rm -f "$tmp1"
    exit 1
fi
sed "${line}i\\
                test_interrupt_dispatch();" "$tmp1" > "$dst"
rm -f "$tmp1"