GH-219: fix |x| operator int overflow / floating point type inconsistency

When 'x' is an integral arithmetic expression, it's now coerced to
yield a signed integer before taking the absolute value of it to
prevent the common issue of unsigned integer overflow/wraparound for
values below zero.

Using a time or interval value/expression for 'x' now also yields a
time or interval, respective, from the |x| operation instead of
a double.

src/Expr.cc

@@ -1360,6 +1360,9 @@ SizeExpr::SizeExpr(Expr* arg_op) : UnaryExpr(EXPR_SIZE, arg_op)
 	if ( IsError() )
 		return;
 
+	if ( op->Type()->InternalType() == TYPE_INTERNAL_DOUBLE )
+		SetType(op->Type()->Ref());
+	else
 		SetType(base_type(TYPE_COUNT));
 	}
 

src/Val.cc

@@ -425,7 +425,7 @@ Val* Val::SizeVal() const
 		return val_mgr->GetCount(val.uint_val);
 
 	case TYPE_INTERNAL_DOUBLE:
-		return new Val(fabs(val.double_val), TYPE_DOUBLE);
+		return new Val(fabs(val.double_val), type->Tag());
 
 	case TYPE_INTERNAL_OTHER:
 		if ( type->Tag() == TYPE_FUNC )

src/parse.y

@@ -728,7 +728,12 @@ expr:
 	|       '|' expr '|'	%prec '('
 			{
 			set_location(@1, @3);
-			$$ = new SizeExpr($2);
+			auto e = $2;
+
+			if ( IsIntegral(e->Type()->Tag()) )
+				e = new ArithCoerceExpr(e, TYPE_INT);
+
+			$$ = new SizeExpr(e);
 			}
 
 	|       expr TOK_AS type

testing/btest/Baseline/language.interval/out

@@ -15,6 +15,7 @@ add different time units (PASS)
 subtract different time units (PASS)
 absolute value (PASS)
 absolute value (PASS)
+absolute value (PASS)
 assignment operator (PASS)
 assignment operator (PASS)
 multiplication operator (PASS)

testing/btest/Baseline/language.sizeof/output

@@ -2,6 +2,7 @@ IPv4 Address 1.2.3.4: 32
 IPv6 Address ::1: 128
 Boolean T: 1
 Count 10: 10
+Expr: 4
 Double -1.23: 1.230000
 Enum ENUM3: 2
 File 21.000000

testing/btest/language/interval.bro

@@ -70,8 +70,9 @@ event bro_init()
 	test_case( "compare different time units", in13 >= in35 );
 	test_case( "add different time units", in13 + in14 == 4min );
 	test_case( "subtract different time units", in24 - in23 == 0sec );
-	test_case( "absolute value", |in25| == 2.0*3600 );
+	test_case( "absolute value", |in25| == 2hr );
-	test_case( "absolute value", |in36| == 2.5*86400 );
+	test_case( "absolute value", |in36| == 2.5day );
+	test_case( "absolute value", |5sec - 9sec| == 4sec );
 	in34 += 2hr;
 	test_case( "assignment operator", in34 == 122min );
 	in34 -= 2hr;

testing/btest/language/sizeof.bro

@@ -64,6 +64,10 @@ print fmt("Boolean %s: %d", b, |b|);
 # Size of count: identity.
 print fmt("Count %s: %d", c, |c|);
 
+# Size of integral arithmetic expression should coerce to int before absolute
+# value operation to help prevent common unsigned int overflow situations.
+print fmt("Expr: %d", |5 - 9|);
+
 # Size of double: returns absolute value.
 print fmt("Double %s: %f", d, |d|);
 

testing/btest/language/time.bro

@@ -27,7 +27,7 @@ event bro_init()
 	test_case( "inequality", t1 != t3 );
 	test_case( "equality", t1 == t4 );
 	test_case( "subtract time", t2 - t1 == 3sec);
-	test_case( "size operator", |t5| == 1234567890.0 );
+	test_case( "size operator", |t5| == t5 );
 
 }