SQL: Move `sql:server` to `plugin:sql` (elastic/x-pack-elasticsearch#3604)

This moves SQL's server project into `plugin:sql` without modifying how the integration is performed. I know that it is not correct with regards to the x-pack modularization but I think it is a good first step.

Original commit: elastic/x-pack-elasticsearch@2f40d02e4d

dev-tools/checkstyle_suppressions.xml

@@ -6,7 +6,7 @@
 <suppressions>
   <!-- On Windows, Checkstyle matches files using \ path separator -->
   <!-- These files are generated by ANTLR so its silly to hold them to our rules. -->
-  <suppress files="sql[/\\]server[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]xpack[/\\]sql[/\\]parser[/\\]SqlBase(Base(Listener|Visitor)|Lexer|Listener|Parser|Visitor).java" checks="." />
+  <suppress files="plugin[/\\]sql[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]xpack[/\\]sql[/\\]parser[/\\]SqlBase(Base(Listener|Visitor)|Lexer|Listener|Parser|Visitor).java" checks="." />
 
   <suppress files="plugin[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]xpack[/\\]common[/\\]action[/\\]XPackDeleteByQueryAction.java" checks="LineLength" />
   <suppress files="plugin[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]xpack[/\\]ml[/\\]action[/\\]StopDatafeedAction.java" checks="LineLength" />

plugin/build.gradle

@@ -33,7 +33,7 @@ dependencyLicenses {
   mapping from: /elasticsearch-rest-client.*/, to: 'elasticsearch'
   mapping from: /server.*/, to: 'elasticsearch'
   mapping from: /rest-proto.*/, to: 'elasticsearch'
-  mapping from: /aggs-matrix-stats.*/, to: 'elasticsearch' //pulled in by sql:server
+  mapping from: /x-pack-sql.*/, to: 'elasticsearch'
   mapping from: /http.*/, to: 'httpclient' // pulled in by rest client
   mapping from: /commons-.*/, to: 'commons' // pulled in by rest client
   ignoreSha 'elasticsearch-rest-client'
@@ -42,8 +42,8 @@ dependencyLicenses {
   ignoreSha 'server'
   ignoreSha 'rest-proto'
   ignoreSha 'elasticsearch-rest-client-sniffer'
-  ignoreSha 'aggs-matrix-stats'
   ignoreSha 'x-pack-core'
+  ignoreSha 'x-pack-sql'
 }
 
 licenseHeaders {
@@ -99,8 +99,8 @@ dependencies {
   nativeBundle "org.elasticsearch.ml:ml-cpp:${project.version}@zip"
   testCompile 'org.ini4j:ini4j:0.5.2'
 
-  // sql's server components and its transitive dependencies
-  compile project(':x-pack-elasticsearch:sql:server')
+  // sql's plugin and its cli
+  compile project(':x-pack-elasticsearch:plugin:sql')
   bundledBin(project(':x-pack-elasticsearch:sql:cli')) {
     transitive = false
   }

plugin/sql/build.gradle

@@ -1,27 +1,90 @@
+description = 'The Elasticsearch plugin that powers SQL for Elasticsearch'
+
 apply plugin: 'elasticsearch.build'
 
 archivesBaseName = 'x-pack-sql'
 
-// TODO: enable this once we have tests
-test.enabled=false
-licenseHeaders.enabled = false
+dependencies {
+    provided "org.elasticsearch:elasticsearch:${version}"
+    compile project(':x-pack-elasticsearch:sql:rest-proto')
+    compile "org.elasticsearch.plugin:x-pack-core:${version}"
+    compile 'org.antlr:antlr4-runtime:4.5.3'
+    testCompile "org.elasticsearch.test:framework:${version}"
+}
 
 dependencyLicenses {
     mapping from: /server.*/, to: 'elasticsearch'
-    mapping from: /aggs-matrix-stats.*/, to: 'elasticsearch' //pulled in by sql:server
+    mapping from: /rest-proto.*/, to: 'elasticsearch'
+
     ignoreSha 'x-pack-core'
+    ignoreSha 'rest-proto'
+}
+
+/**********************************************
+ *          SQL Parser regeneration           *
+ **********************************************/
+
+configurations {
+    regenerate
 }
 
 dependencies {
-    provided "org.elasticsearch:elasticsearch:${version}"
-
-    compile "org.elasticsearch.plugin:x-pack-core:${version}"
-
-    // sql's server components and its transitive dependencies
-    // TODO: what to do about this dependency, is it still needed?
-    // compile project(':x-pack-elasticsearch:sql:server')
+    regenerate 'org.antlr:antlr4:4.5.3'
 }
 
-parent.bundlePlugin {
-    from jar
+String grammarPath = 'src/main/antlr'
+String outputPath = 'src/main/java/org/elasticsearch/xpack/sql/parser'
+
+task cleanGenerated(type: Delete) {
+    delete fileTree(grammarPath) {
+        include '*.tokens'
+    }
+    delete fileTree(outputPath) {
+        include 'SqlBase*.java'
+    }
+}
+
+task regenParser(type: JavaExec) {
+    dependsOn cleanGenerated
+    main = 'org.antlr.v4.Tool'
+    classpath = configurations.regenerate
+    systemProperty 'file.encoding', 'UTF-8'
+    systemProperty 'user.language', 'en'
+    systemProperty 'user.country', 'US'
+    systemProperty 'user.variant', ''
+    args '-Werror',
+         '-package', 'org.elasticsearch.xpack.sql.parser',
+         '-listener',
+         '-visitor',
+         '-o', outputPath,
+         "${file(grammarPath)}/SqlBase.g4"
+}
+
+task regen {
+    dependsOn regenParser
+    doLast {
+        // moves token files to grammar directory for use with IDE's
+        ant.move(file: "${outputPath}/SqlBase.tokens", toDir: grammarPath)
+        ant.move(file: "${outputPath}/SqlBaseLexer.tokens", toDir: grammarPath)
+        // make the generated classes package private
+        ant.replaceregexp(match: 'public ((interface|class) \\QSqlBase\\E\\w+)',
+                          replace: '\\1',
+                          encoding: 'UTF-8') {
+            fileset(dir: outputPath, includes: 'SqlBase*.java')
+        }
+        // nuke timestamps/filenames in generated files
+        ant.replaceregexp(match: '\\Q// Generated from \\E.*',
+                          replace: '\\/\\/ ANTLR GENERATED CODE: DO NOT EDIT',
+                          encoding: 'UTF-8') {
+            fileset(dir: outputPath, includes: 'SqlBase*.java')
+        }
+        // remove tabs in antlr generated files
+        ant.replaceregexp(match: '\t', flags: 'g', replace: '  ', encoding: 'UTF-8') {
+            fileset(dir: outputPath, includes: 'SqlBase*.java')
+        }
+        // fix line endings
+        ant.fixcrlf(srcdir: outputPath, eol: 'lf') {
+            patternset(includes: 'SqlBase*.java')
+        }
+    }
 }