Merge "Fix genantlr() to support buck caching"

.gitignore

@@ -9,5 +9,6 @@
 /gerrit-package-plugins
 /.buckconfig.local
 /.buckd
+/buck-cache
 /buck-out
 /local.properties

Documentation/asciidoc.defs

@@ -46,7 +46,7 @@ def genasciidoc(
     )
   genrule(
     name = name,
-    cmd = '',
+    cmd = ':>$OUT',
     srcs = [],
     deps = [':' + o for o in outs],
     out = name + '__done',

Documentation/dev-buck.txt

@@ -216,6 +216,23 @@ being built, or in `~/.gerritcodereview/`.  The file in the root of the gerrit
 repository has precedence.
 
 
+Caching Build Results
+~~~~~~~~~~~~~~~~~~~~~
+
+Build results can be locally cached, saving rebuild time when
+switching between Git branches. Buck's documentation covers
+caching in link:http://facebook.github.io/buck/concept/buckconfig.html[buckconfig].
+The trivial case using a local directory is:
+
+----
+  cat >.buckconfig.local <<EOF
+  [cache]
+    mode = dir
+    dir = buck-cache
+  EOF
+----
+
+
 Build Process Switch Exit Criteria
 ----------------------------------
 

gerrit-antlr/BUCK

@@ -3,7 +3,6 @@ ANTLR_OUTS = [
   'QueryParser.java',
 ]
 PARSER_DEPS = [
-  ':query_antlr',
   ':query_exception',
   '//lib/antlr:java_runtime',
 ]
@@ -24,7 +23,7 @@ genantlr(
 java_library(
   name = 'lib',
   srcs = [genfile(f) for f in ANTLR_OUTS],
-  deps = PARSER_DEPS,
+  deps = PARSER_DEPS + [':' + f for f in ANTLR_OUTS],
 )
 
 genrule(

tools/DEFS

@@ -16,13 +16,25 @@ def genantlr(
     name,
     srcs,
     outs):
+  tmp = name + '.srcjar'
   genrule(
     name = name,
     srcs = srcs,
-    cmd = '${//lib/antlr:antlr-tool} -o $(dirname $OUT) $SRCS',
+    cmd = '${//lib/antlr:antlr-tool} -o $TMP $SRCS;' +
+      'cd $TMP;' +
+      'zip -qr $OUT .',
     deps = ['//lib/antlr:antlr-tool'],
-    out = outs[0],
+    out = tmp,
   )
+  for o in outs:
+    genrule(
+      name = o,
+      cmd = 'unzip -qp $SRCS %s >$OUT' % o,
+      srcs = [genfile(tmp)],
+      deps = [':' + name],
+      out = o,
+    )
+
 
 def gwt_module(
     name,