Update the ObjC version checks to support a min and current version.

- Capture the version used to generated.
- Check at compile time and runtime that generated code isn't from a newer
  version, also check that the min version required is also supported.
- Keep the old constants/macros/functions to special case the last version
  that was working so those generated sources still work until we decide
  otherwise.

1 files changed, 33 insertions, 34 deletions

diff --git a/objectivec/DevTools/check_version_stamps.sh b/objectivec/DevTools/check_version_stamps.sh
index 325b71dd..1acbe2a2 100755
--- a/objectivec/DevTools/check_version_stamps.sh
+++ b/objectivec/DevTools/check_version_stamps.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/bash -eu
 
 # This script checks that the runtime version number constant in the compiler
 # source and in the runtime source is the same.
@@ -8,8 +8,6 @@
 # builds would break. At the same time, we don't want the runtime source
 # depending on the compiler sources; so two copies of the constant are needed.
 
-set -eu
-
 readonly ScriptDir=$(dirname "$(echo $0 | sed -e "s,^\([^/]\),$(pwd)/\1,")")
 readonly ProtoRootDir="${ScriptDir}/../.."
 
@@ -18,39 +16,40 @@ die() {
     exit 1
 }
 
-readonly ConstantName=GOOGLE_PROTOBUF_OBJC_GEN_VERSION
-
-# Collect version from plugin sources.
-
-readonly PluginSrc="${ProtoRootDir}/src/google/protobuf/compiler/objectivec/objectivec_file.cc"
-readonly PluginVersion=$( \
-    cat "${PluginSrc}" \
-        | sed -n -e "s:const int32 ${ConstantName} = \([0-9]*\);:\1:p"
-)
-
-if [[ -z "${PluginVersion}" ]] ; then
-    die "Failed to find ${ConstantName} in the plugin source (${PluginSrc})."
-fi
-
-# Collect version from runtime sources.
-
+readonly GeneratorSrc="${ProtoRootDir}/src/google/protobuf/compiler/objectivec/objectivec_file.cc"
 readonly RuntimeSrc="${ProtoRootDir}/objectivec/GPBBootstrap.h"
-readonly RuntimeVersion=$( \
-    cat "${RuntimeSrc}" \
-        | sed -n -e "s:#define ${ConstantName} \([0-9]*\):\1:p"
-)
-
-if [[ -z "${RuntimeVersion}" ]] ; then
-    die "Failed to find ${ConstantName} in the runtime source (${RuntimeSrc})."
-fi
-
-# Compare them.
 
-if [[ "${PluginVersion}" != "${RuntimeVersion}" ]] ; then
-    die "Versions don't match!
-   Plugin: ${PluginVersion} from ${PluginSrc}
-  Runtime: ${RuntimeVersion} from ${RuntimeSrc}
+check_constant() {
+  local ConstantName="$1"
+
+  # Collect version from generator sources.
+  local GeneratorVersion=$( \
+      cat "${GeneratorSrc}" \
+          | sed -n -e "s:const int32 ${ConstantName} = \([0-9]*\);:\1:p"
+  )
+  if [[ -z "${GeneratorVersion}" ]] ; then
+      die "Failed to find ${ConstantName} in the generator source (${GeneratorSrc})."
+  fi
+
+  # Collect version from runtime sources.
+  local RuntimeVersion=$( \
+      cat "${RuntimeSrc}" \
+          | sed -n -e "s:#define ${ConstantName} \([0-9]*\):\1:p"
+  )
+  if [[ -z "${RuntimeVersion}" ]] ; then
+      die "Failed to find ${ConstantName} in the runtime source (${RuntimeSrc})."
+  fi
+
+  # Compare them.
+  if [[ "${GeneratorVersion}" != "${RuntimeVersion}" ]] ; then
+      die "${ConstantName} values don't match!
+  Generator: ${GeneratorVersion} from ${GeneratorSrc}
+    Runtime: ${RuntimeVersion} from ${RuntimeSrc}
 "
-fi
+  fi
+}
+
+# Do the check.
+check_constant GOOGLE_PROTOBUF_OBJC_VERSION
 
 # Success