From fb3cfece9c6973499e0045f77d84612a959626f1 Mon Sep 17 00:00:00 2001
From: Eric Tune <etune@google.com>
Date: Thu, 17 Dec 2015 10:07:30 -0800
Subject: [PATCH] Nice error message if no types.generated.go files.

Explains how to fix problem, instead of
saying "index" is an unbound reference.

Problem happens when previous run of codecgen deleted all the outputs
and then failed midway.
---
 hack/update-codecgen.sh | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/hack/update-codecgen.sh b/hack/update-codecgen.sh
index 80310785b0b..ff717db1958 100755
--- a/hack/update-codecgen.sh
+++ b/hack/update-codecgen.sh
@@ -84,6 +84,14 @@ for (( i=0; i<number; i++ )); do
 done
 index=(${result})
 
+haveindex=${index:-}
+if [[ -z ${haveindex} ]]; then
+  echo No files found for $0
+  echo A previous run of $0 may have deleted all the files and then crashed.
+  echo Use 'touch' to create files named 'types.generated.go' listed as deleted in 'git status'
+  exit 1
+fi
+
 CODECGEN="${PWD}/codecgen_binary"
 godep go build -o "${CODECGEN}" github.com/ugorji/go/codec/codecgen
 
@@ -95,11 +103,13 @@ for (( i=0; i < number; i++ )); do
   rm -f "${generated_files[${i}]}"
 done
 
+
 # Generate files in the dependency order.
 for current in "${index[@]}"; do
   generated_file=${generated_files[${current}]}
   initial_dir=${PWD}
   file=${generated_file//\.generated\.go/.go}
+  echo "codecgen processing ${file}"
   # codecgen work only if invoked from directory where the file
   # is located.
   pushd "$(dirname ${file})" > /dev/null
@@ -107,6 +117,7 @@ for current in "${index[@]}"; do
   base_generated_file=$(basename "${generated_file}")
   # We use '-d 1234' flag to have a deterministic output everytime.
   # The constant was just randomly chosen.
+  echo Running ${CODECGEN} -d 1234 -o  "${base_generated_file}" "${base_file}"
   ${CODECGEN} -d 1234 -o "${base_generated_file}" "${base_file}"
   # Add boilerplate at the begining of the generated file.
   sed 's/YEAR/2015/' "${initial_dir}/hack/boilerplate/boilerplate.go.txt" > "${base_generated_file}.tmp"