*: adding trace syntax support (pingcap#6644)

ast/misc.go

@@ -90,6 +90,29 @@ type AuthOption struct {
 	// TODO: support auth_plugin
 }
 
+// TraceStmt is a statement to trace what sql actually does at background.
+type TraceStmt struct {
+	stmtNode
+
+	Stmt   StmtNode
+	Format string
+}
+
+// Accept implements Node Accept interface.
+func (n *TraceStmt) Accept(v Visitor) (Node, bool) {
+	newNode, skipChildren := v.Enter(n)
+	if skipChildren {
+		return v.Leave(newNode)
+	}
+	n = newNode.(*TraceStmt)
+	node, ok := n.Stmt.Accept(v)
+	if !ok {
+		return n, false
+	}
+	n.Stmt = node.(DMLNode)
+	return v.Leave(n)
+}
+
 // ExplainStmt is a statement to provide information about how is SQL statement executed
 // or get columns information in a table.
 // See https://dev.mysql.com/doc/refman/5.7/en/explain.html

parser/consistent_test.go

@@ -59,13 +59,13 @@ func (s *testConsistentSuite) TestKeywordConsistent(c *C) {
 	keywordCount := len(reservedKeywords) + len(unreservedKeywords) + len(notKeywordTokens) + len(tidbKeywords)
 	c.Assert(len(tokenMap)-len(aliases), Equals, keywordCount)
 
-	unreservedCollectionDef := extratKeywordsFromCollectionDef(content, "\nUnReservedKeyword:")
+	unreservedCollectionDef := extractKeywordsFromCollectionDef(content, "\nUnReservedKeyword:")
 	c.Assert(unreservedKeywords, DeepEquals, unreservedCollectionDef)
 
-	notKeywordTokensCollectionDef := extratKeywordsFromCollectionDef(content, "\nNotKeywordToken:")
+	notKeywordTokensCollectionDef := extractKeywordsFromCollectionDef(content, "\nNotKeywordToken:")
 	c.Assert(notKeywordTokens, DeepEquals, notKeywordTokensCollectionDef)
 
-	tidbKeywordsCollectionDef := extratKeywordsFromCollectionDef(content, "\nTiDBKeyword:")
+	tidbKeywordsCollectionDef := extractKeywordsFromCollectionDef(content, "\nTiDBKeyword:")
 	c.Assert(tidbKeywords, DeepEquals, tidbKeywordsCollectionDef)
 }
 
@@ -101,7 +101,7 @@ func extractKeywords(content, startMarker, endMarker string) []string {
 	return extractQuotedWords(lines)
 }
 
-func extratKeywordsFromCollectionDef(content, startMarker string) []string {
+func extractKeywordsFromCollectionDef(content, startMarker string) []string {
 	keywordSection := extractMiddle(content, startMarker, "\n\n")
 	words := strings.Split(keywordSection, "|")
 	return extractQuotedWords(words)

parser/misc.go

@@ -466,6 +466,7 @@ var tokenMap = map[string]int{
 	"TINYINT":                  tinyIntType,
 	"TINYTEXT":                 tinytextType,
 	"TO":                       to,
+	"TRACE":                    trace,
 	"TRAILING":                 trailing,
 	"TRANSACTION":              transaction,
 	"TRIGGER":                  trigger,

parser/parser.y

@@ -385,6 +385,7 @@ import (
 	than		"THAN"
 	timeType	"TIME"
 	timestampType	"TIMESTAMP"
+	trace		"TRACE"
 	transaction	"TRANSACTION"
 	triggers	"TRIGGERS"
 	truncate	"TRUNCATE"
@@ -541,6 +542,7 @@ import (
 	EmptyStmt			"empty statement"
 	ExecuteStmt			"Execute statement"
 	ExplainStmt			"EXPLAIN statement"
+	ExplainableStmt			"explainable statement"
 	FlushStmt			"Flush statement"
 	GrantStmt			"Grant statement"
 	InsertIntoStmt			"INSERT INTO statement"
@@ -557,7 +559,8 @@ import (
 	SetStmt				"Set variable statement"
 	ShowStmt			"Show engines/databases/tables/columns/warnings/status statement"
 	Statement			"statement"
-	ExplainableStmt			"explainable statement"
+	TraceStmt			"TRACE statement"
+	TraceableStmt			"traceable statment"
 	TruncateTableStmt		"TRUNCATE TABLE statement"
 	UnlockTablesStmt		"Unlock tables statement"
 	UpdateStmt			"UPDATE statement"
@@ -2129,6 +2132,15 @@ EmptyStmt:
 		$$ = nil
 	}
 
+TraceStmt:
+	"TRACE" TraceableStmt
+	{
+		$$ = &ast.TraceStmt{
+			Stmt:	$2,
+			Format: "row",
+		}
+	}
+
 ExplainSym:
 "EXPLAIN" | "DESCRIBE" | "DESC"
 
@@ -2668,7 +2680,7 @@ UnReservedKeyword:
 | "DYNAMIC"| "END" | "ENGINE" | "ENGINES" | "ENUM" | "ESCAPE" | "EXECUTE" | "FIELDS" | "FIRST" | "FIXED" | "FLUSH" | "FORMAT" | "FULL" |"GLOBAL"
 | "HASH" | "HOUR" | "LESS" | "LOCAL" | "NAMES" | "OFFSET" | "PASSWORD" %prec lowerThanEq | "PREPARE" | "QUICK" | "REDUNDANT"
 | "ROLLBACK" | "SESSION" | "SIGNED" | "SNAPSHOT" | "START" | "STATUS" | "TABLES" | "TEXT" | "THAN" | "TIME" %prec lowerThanStringLitToken | "TIMESTAMP" %prec lowerThanStringLitToken
-| "TRANSACTION" | "TRUNCATE" | "UNKNOWN" | "VALUE" | "WARNINGS" | "YEAR" | "MODE"  | "WEEK"  | "ANY" | "SOME" | "USER" | "IDENTIFIED"
+| "TRACE" | "TRANSACTION" | "TRUNCATE" | "UNKNOWN" | "VALUE" | "WARNINGS" | "YEAR" | "MODE"  | "WEEK"  | "ANY" | "SOME" | "USER" | "IDENTIFIED"
 | "COLLATION" | "COMMENT" | "AVG_ROW_LENGTH" | "CONNECTION" | "CHECKSUM" | "COMPRESSION" | "KEY_BLOCK_SIZE" | "MAX_ROWS"
 | "MIN_ROWS" | "NATIONAL" | "ROW" | "ROW_FORMAT" | "QUARTER" | "GRANTS" | "TRIGGERS" | "DELAY_KEY_WRITE" | "ISOLATION" | "JSON"
 | "REPEATABLE" | "COMMITTED" | "UNCOMMITTED" | "ONLY" | "SERIALIZABLE" | "LEVEL" | "VARIABLES" | "SQL_CACHE" | "INDEXES" | "PROCESSLIST"
@@ -5478,12 +5490,21 @@ Statement:
 		// TODO: This is used to fix issue #320. There may be a better solution.
 		$$ = $1.(*ast.SubqueryExpr).Query.(ast.StmtNode)
 	}
+|	TraceStmt
 |	TruncateTableStmt
 |	UpdateStmt
 |	UseStmt
 |	UnlockTablesStmt
 |	LockTablesStmt
 
+TraceableStmt:
+	SelectStmt
+|	DeleteFromStmt
+|	UpdateStmt
+|	InsertIntoStmt
+|	ReplaceIntoStmt
+|	UnionStmt
+
 ExplainableStmt:
 	SelectStmt
 |	DeleteFromStmt

parser/parser_test.go

@@ -2066,6 +2066,19 @@ func (s *testParserSuite) TestExplain(c *C) {
 	s.RunTest(c, table)
 }
 
+func (s *testParserSuite) TestTrace(c *C) {
+	defer testleak.AfterTest(c)()
+	table := []testCase{
+		{"trace select c1 from t1", true},
+		{"trace delete t1, t2 from t1 inner join t2 inner join t3 where t1.id=t2.id and t2.id=t3.id;", true},
+		{"trace insert into t values (1), (2), (3)", true},
+		{"trace replace into foo values (1 || 2)", true},
+		{"trace update t set id = id + 1 order by id desc;", true},
+		{"trace select c1 from t1 union (select c2 from t2) limit 1, 1", true},
+	}
+	s.RunTest(c, table)
+}
+
 func (s *testParserSuite) TestView(c *C) {
 	defer testleak.AfterTest(c)()
 	table := []testCase{