Better support for multiple multiplexing switches

pkg/dbc/def.go

@@ -1,6 +1,7 @@
 package dbc
 
 import (
+	"fmt"
 	"strconv"
 	"text/scanner"
 )
@@ -308,17 +309,22 @@ func (d *SignalDef) parseFrom(p *Parser) {
 		if tok.typ != scanner.Ident {
 			p.failf(tok.pos, "expected ident")
 		}
-		switch {
-		case tok.txt == "M":
-			d.IsMultiplexerSwitch = true
-		case tok.txt[0] == 'm' && len(tok.txt) > 1:
+		rem := tok.txt
+		if len(rem) > 1 && rem[0] == 'm' {
 			d.IsMultiplexed = true
-			i, err := strconv.Atoi(tok.txt[1:])
-			if err != nil || i < 0 {
+			var i uint64
+			n, err := fmt.Sscanf(rem[1:], "%d", &i)
+			if err != nil || n < 0 {
 				p.failf(tok.pos, "invalid multiplexer value")
 			}
 			d.MultiplexerSwitch = uint64(i)
-		default:
+			rem = rem[1+len(strconv.FormatUint(i, 10)):]
+		}
+		if len(rem) > 0 && rem[0] == 'M' {
+			d.IsMultiplexerSwitch = true
+			rem = rem[1:]
+		}
+		if rem != "" {
 			p.failf(tok.pos, "expected multiplexer")
 		}
 	}
@@ -353,6 +359,45 @@ func (d *SignalDef) Position() scanner.Position {
 	return d.Pos
 }
 
+// SignalMultiplexValueDef defines a signal multiplex value within a message.
+type SignalMultiplexValueDef struct {
+	// Pos is the position of the definition.
+	Pos scanner.Position
+
+	// MessageID contains the message CAN ID associated with the signal multiplex value.
+	MessageID MessageID
+
+	// Signal in the message that is multiplexed.
+	Signal Identifier
+
+	// MultiplexerSwitch in the message.
+	MultiplexerSwitch Identifier
+
+	// RangeStart of the values of the MultiplexerSwitch that will trigger Signal.
+	RangeStart uint64
+
+	// RangeEnd of the values of the MultiplexerSwitch that will trigger Signal.
+	RangeEnd uint64
+}
+
+var _ Def = &SignalMultiplexValueDef{}
+
+func (d *SignalMultiplexValueDef) parseFrom(p *Parser) {
+	d.Pos = p.keyword(KeywordSignalMultiplexValue).pos
+	d.MessageID = p.messageID()
+	d.Signal = p.identifier()
+	d.MultiplexerSwitch = p.identifier()
+	d.RangeStart = p.uint()
+	p.token('-')
+	d.RangeEnd = p.uint()
+	p.token(';')
+}
+
+// Position returns the position of the definition.
+func (d *SignalMultiplexValueDef) Position() scanner.Position {
+	return d.Pos
+}
+
 // SignalValueTypeDef defines an extended type definition for a signal.
 type SignalValueTypeDef struct {
 	Pos             scanner.Position

pkg/dbc/keyword.go

@@ -16,6 +16,7 @@ const (
 	KeywordNewSymbols              Keyword = "NS_"
 	KeywordNodes                   Keyword = "BU_"
 	KeywordSignal                  Keyword = "SG_"
+	KeywordSignalMultiplexValue    Keyword = "SG_MUL_VAL_"
 	KeywordSignalGroup             Keyword = "SIG_GROUP_"
 	KeywordSignalType              Keyword = "SGTYPE_"
 	KeywordSignalValueType         Keyword = "SIG_VALTYPE_"

pkg/dbc/parser.go

@@ -83,6 +83,8 @@ func (p *Parser) Parse() (err Error) {
 			def = &MessageDef{}
 		case KeywordSignal:
 			def = &SignalDef{}
+		case KeywordSignalMultiplexValue:
+			def = &SignalMultiplexValueDef{}
 		case KeywordEnvironmentVariable:
 			def = &EnvironmentVariableDef{}
 		case KeywordComment:

pkg/dbc/parser_test.go

@@ -244,6 +244,52 @@ func TestParser_Parse(t *testing.T) {
 			},
 		},
 
+		{
+			name: "CSS-Electronics-OBD2-v1.4.dbc",
+			text: `SG_ ParameterID_Service02 m2M : 23|8@0+ (1,0) [0|255] "" Vector__XXX`,
+			defs: []Def{
+				&SignalDef{
+					Pos: scanner.Position{
+						Filename: "CSS-Electronics-OBD2-v1.4.dbc",
+						Line:     1,
+						Column:   1,
+					},
+					Name:                "ParameterID_Service02",
+					IsBigEndian:         true,
+					StartBit:            23,
+					Size:                8,
+					Factor:              1,
+					Offset:              0,
+					Minimum:             0,
+					Maximum:             255,
+					Unit:                "",
+					Receivers:           []Identifier{"Vector__XXX"},
+					IsMultiplexerSwitch: true,
+					IsMultiplexed:       true,
+					MultiplexerSwitch:   2,
+				},
+			},
+		},
+
+		{
+			name: "CSS-Electronics-OBD2-v1.4.dbc",
+			text: `SG_MUL_VAL_ 2024 S1_PID_5B_HybrBatPackRemLife ParameterID_Service01 91-91;`,
+			defs: []Def{
+				&SignalMultiplexValueDef{
+					Pos: scanner.Position{
+						Filename: "CSS-Electronics-OBD2-v1.4.dbc",
+						Line:     1,
+						Column:   1,
+					},
+					MessageID:         2024,
+					Signal:            "S1_PID_5B_HybrBatPackRemLife",
+					MultiplexerSwitch: "ParameterID_Service01",
+					RangeStart:        91,
+					RangeEnd:          91,
+				},
+			},
+		},
+
 		{
 			name: "comment.dbc",
 			text: `CM_ "comment";`,