From 21614cd30d0f23f2535a6e7ffa8dce6dd008eaff Mon Sep 17 00:00:00 2001
From: Vern Paxson <vern@icir.org>
Date: Wed, 20 Jun 2018 09:49:29 -0700
Subject: [PATCH] basic code implemented, but there's a memory problem
 somehwere :-(

---
 src/Expr.cc | 47 ++++++++++++++++++++++++++++-------------------
 src/Expr.h  |  3 +++
 src/parse.y | 36 ++++++++++--------------------------
 3 files changed, 41 insertions(+), 45 deletions(-)

diff --git a/src/Expr.cc b/src/Expr.cc
index f5c8e66b50..d895e811ab 100644
--- a/src/Expr.cc
+++ b/src/Expr.cc
@@ -665,6 +665,9 @@ Val* BinaryExpr::Fold(Val* v1, Val* v2) const
 	if ( it == TYPE_INTERNAL_STRING )
 		return StringFold(v1, v2);
 
+	if ( v1->Type()->Tag() == TYPE_PATTERN )
+		return PatternFold(v1, v2);
+
 	if ( it == TYPE_INTERNAL_ADDR )
 		return AddrFold(v1, v2);
 
@@ -851,6 +854,21 @@ Val* BinaryExpr::StringFold(Val* v1, Val* v2) const
 	return new Val(result, TYPE_BOOL);
 	}
 
+Val* BinaryExpr::PatternFold(Val* v1, Val* v2) const
+	{
+	const RE_Matcher* re1 = v1->AsPattern();
+	const RE_Matcher* re2 = v2->AsPattern();
+
+	if ( tag != EXPR_AND && tag != EXPR_OR )
+		BadTag("BinaryExpr::PatternFold");
+
+	RE_Matcher* res = tag == EXPR_AND ?
+		RE_Matcher_conjunction(re1, re2) :
+		RE_Matcher_disjunction(re1, re2);
+
+	return new PatternVal(res);
+	}
+
 Val* BinaryExpr::AddrFold(Val* v1, Val* v2) const
 	{
 	IPAddr a1 = v1->AsAddr();
@@ -1696,9 +1714,6 @@ BoolExpr::BoolExpr(BroExprTag arg_tag, Expr* arg_op1, Expr* arg_op2)
 			SetType(base_type(TYPE_BOOL));
 		}
 
-	else if ( bt1 == TYPE_PATTERN && bt2 == bt1 )
-		SetType(base_type(TYPE_PATTERN));
-
 	else
 		ExprError("requires boolean operands");
 	}
@@ -1708,22 +1723,6 @@ Val* BoolExpr::DoSingleEval(Frame* f, Val* v1, Expr* op2) const
 	if ( ! v1 )
 		return 0;
 
-	if ( Type()->Tag() == TYPE_PATTERN )
-		{
-		Val* v2 = op2->Eval(f);
-		if ( ! v2 )
-			return 0;
-
-		RE_Matcher* re1 = v1->AsPattern();
-		RE_Matcher* re2 = v2->AsPattern();
-
-		RE_Matcher* res = tag == EXPR_AND_AND ?
-			RE_Matcher_conjunction(re1, re2) :
-			RE_Matcher_disjunction(re1, re2);
-
-		return new PatternVal(res);
-		}
-
 	if ( tag == EXPR_AND_AND )
 		{
 		if ( v1->IsZero() )
@@ -1885,6 +1884,16 @@ BitExpr::BitExpr(BroExprTag arg_tag, Expr* arg_op1, Expr* arg_op2)
 			SetType(base_type(TYPE_COUNT));
 		}
 
+	if ( bt1 == TYPE_PATTERN )
+		{
+		if ( bt2 != TYPE_PATTERN )
+			ExprError("cannot mix pattern and non-pattern operands");
+		else if ( tag == EXPR_XOR )
+			ExprError("'^' operator does not apply to patterns");
+		else
+			SetType(base_type(TYPE_PATTERN));
+		}
+
 	else
 		ExprError("requires \"count\" operands");
 	}
diff --git a/src/Expr.h b/src/Expr.h
index 8e8b6cc96b..4229750fb1 100644
--- a/src/Expr.h
+++ b/src/Expr.h
@@ -327,6 +327,9 @@ protected:
 	// Same for when the constants are strings.
 	virtual Val* StringFold(Val* v1, Val* v2) const;
 
+	// Same for when the constants are patterns.
+	virtual Val* PatternFold(Val* v1, Val* v2) const;
+
 	// Same for when the constants are addresses or subnets.
 	virtual Val* AddrFold(Val* v1, Val* v2) const;
 	virtual Val* SubNetFold(Val* v1, Val* v2) const;
diff --git a/src/parse.y b/src/parse.y
index 6f7a43ae7f..b8f82aa1fb 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -2,7 +2,7 @@
 // See the file "COPYING" in the main distribution directory for copyright.
 %}
 
-%expect 78
+%expect 77
 
 %token TOK_ADD TOK_ADD_TO TOK_ADDR TOK_ANY
 %token TOK_ATENDIF TOK_ATELSE TOK_ATIF TOK_ATIFDEF TOK_ATIFNDEF
@@ -49,13 +49,12 @@
 %left '$' '[' ']' '(' ')' TOK_HAS_FIELD TOK_HAS_ATTR
 
 %type <b> opt_no_test opt_no_test_block opt_deprecated
-%type <str> TOK_ID TOK_PATTERN_TEXT single_pattern
+%type <str> TOK_ID TOK_PATTERN_TEXT
 %type <id> local_id global_id def_global_id event_id global_or_event_id resolve_id begin_func
 %type <id_l> local_id_list
 %type <ic> init_class
 %type <expr> opt_init
 %type <val> TOK_CONSTANT
-%type <re> pattern
 %type <expr> expr opt_expr init anonymous_function
 %type <event_expr> event
 %type <stmt> stmt stmt_list func_body for_head
@@ -720,11 +719,15 @@ expr:
 			$$ = new ConstExpr($1);
 			}
 
-	|	pattern
+	|	'/' { begin_RE(); } TOK_PATTERN_TEXT { end_RE(); } '/'
 			{
-			set_location(@1);
-			$1->Compile();
-			$$ = new ConstExpr(new PatternVal($1));
+			set_location(@3);
+
+			RE_Matcher* re = new RE_Matcher($3);
+			delete [] $3;
+
+			re->Compile();
+			$$ = new ConstExpr(new PatternVal(re));
 			}
 
 	|       '|' expr '|'	%prec '('
@@ -754,25 +757,6 @@ opt_expr_list:
 		{ $$ = new ListExpr(); }
 	;
 
-pattern:
-		pattern '|' single_pattern
-			{
-			$1->AddPat($3);
-			delete [] $3;
-			}
-
-	|	single_pattern
-			{
-			$$ = new RE_Matcher($1);
-			delete [] $1;
-			}
-	;
-
-single_pattern:
-		'/' { begin_RE(); } TOK_PATTERN_TEXT { end_RE(); } '/'
-			{ $$ = $3; }
-	;
-
 enum_body:
 		enum_body_list
 			{