cabana(DBCFile): handle escaped quotes (commaai#31889)

* cabana(DBCFile): VAL_ allow empty description

Even though this doesn't make much sense, we should still be able to
parse it.

* cabana(DBCFile): allow escaped quotemarks in signal comment

* also message comments

* escape/unescape quotes

* test empty val desc

* test generating DBC with escaped quotes in comment

* seperate test case

* fix trailing space

* remove empty val

* trailing whitespace again

tools/cabana/dbc/dbcfile.cc

@@ -80,8 +80,8 @@ void DBCFile::parse(const QString &content) {
   static QRegularExpression bo_regexp(R"(^BO_ (\w+) (\w+) *: (\w+) (\w+))");
   static QRegularExpression sg_regexp(R"(^SG_ (\w+) : (\d+)\|(\d+)@(\d+)([\+|\-]) \(([0-9.+\-eE]+),([0-9.+\-eE]+)\) \[([0-9.+\-eE]+)\|([0-9.+\-eE]+)\] \"(.*)\" (.*))");
   static QRegularExpression sgm_regexp(R"(^SG_ (\w+) (\w+) *: (\d+)\|(\d+)@(\d+)([\+|\-]) \(([0-9.+\-eE]+),([0-9.+\-eE]+)\) \[([0-9.+\-eE]+)\|([0-9.+\-eE]+)\] \"(.*)\" (.*))");
-  static QRegularExpression msg_comment_regexp(R"(^CM_ BO_ *(\w+) *\"([^"]*)\"\s*;)");
-  static QRegularExpression sg_comment_regexp(R"(^CM_ SG_ *(\w+) *(\w+) *\"([^"]*)\"\s*;)");
+  static QRegularExpression msg_comment_regexp(R"(^CM_ BO_ *(\w+) *\"((?:[^"\\]|\\.)*)\"\s*;)");
+  static QRegularExpression sg_comment_regexp(R"(^CM_ SG_ *(\w+) *(\w+) *\"((?:[^"\\]|\\.)*)\"\s*;)");
   static QRegularExpression val_regexp(R"(VAL_ (\w+) (\w+) (\s*[-+]?[0-9]+\s+\".+?\"[^;]*))");
 
   int line_num = 0;
@@ -173,7 +173,7 @@ void DBCFile::parse(const QString &content) {
       auto match = msg_comment_regexp.match(line);
       dbc_assert(match.hasMatch());
       if (auto m = (cabana::Msg *)msg(match.captured(1).toUInt())) {
-        m->comment = match.captured(2).trimmed();
+        m->comment = match.captured(2).trimmed().replace("\\\"", "\"");
       }
     } else if (line.startsWith("CM_ SG_ ")) {
       if (!line.endsWith("\";")) {
@@ -183,7 +183,7 @@ void DBCFile::parse(const QString &content) {
       auto match = sg_comment_regexp.match(line);
       dbc_assert(match.hasMatch());
       if (auto s = get_sig(match.captured(1).toUInt(), match.captured(2))) {
-        s->comment = match.captured(3).trimmed();
+        s->comment = match.captured(3).trimmed().replace("\\\"", "\"");
       }
     } else {
       seen = false;
@@ -207,7 +207,7 @@ QString DBCFile::generateDBC() {
     const QString transmitter = m.transmitter.isEmpty() ? DEFAULT_NODE_NAME : m.transmitter;
     dbc_string += QString("BO_ %1 %2: %3 %4\n").arg(address).arg(m.name).arg(m.size).arg(transmitter);
     if (!m.comment.isEmpty()) {
-      comment += QString("CM_ BO_ %1 \"%2\";\n").arg(address).arg(m.comment);
+      comment += QString("CM_ BO_ %1 \"%2\";\n").arg(address).arg(QString(m.comment).replace("\"", "\\\""));
     }
     for (auto sig : m.getSignals()) {
       QString multiplexer_indicator;
@@ -230,7 +230,7 @@ QString DBCFile::generateDBC() {
                         .arg(sig->unit)
                         .arg(sig->receiver_name.isEmpty() ? DEFAULT_NODE_NAME : sig->receiver_name);
       if (!sig->comment.isEmpty()) {
-        comment += QString("CM_ SG_ %1 %2 \"%3\";\n").arg(address).arg(sig->name).arg(sig->comment);
+        comment += QString("CM_ SG_ %1 %2 \"%3\";\n").arg(address).arg(sig->name).arg(QString(sig->comment).replace("\"", "\\\""));
       }
       if (!sig->val_desc.empty()) {
         QStringList text;

tools/cabana/tests/test_cabana.cc

@@ -65,6 +65,17 @@ CM_ SG_ 160 signal_1 "signal comment";
   REQUIRE(dbc.generateDBC() == content);
 }
 
+TEST_CASE("DBCFile::generateDBC - escaped quotes") {
+  QString content = R"(BO_ 160 message_1: 8 EON
+ SG_ signal_1 : 0|12@1+ (1,0) [0|4095] "unit" XXX
+
+CM_ BO_ 160 "message comment with \"escaped quotes\"";
+CM_ SG_ 160 signal_1 "signal comment with \"escaped quotes\"";
+)";
+  DBCFile dbc("", content);
+  REQUIRE(dbc.generateDBC() == content);
+}
+
 TEST_CASE("parse_dbc") {
   QString content = R"(
 BO_ 160 message_1: 8 EON
@@ -82,7 +93,11 @@ CM_ SG_ 160 signal_1 "signal comment";
 CM_ SG_ 160 signal_2 "multiple line comment 
 1
 2
-";)";
+";
+
+CM_ BO_ 162 "message comment with \"escaped quotes\"";
+CM_ SG_ 162 signal_1 "signal comment with \"escaped quotes\"";
+)";
 
   DBCFile file("", content);
   auto msg = file.msg(160);
@@ -121,6 +136,10 @@ CM_ SG_ 160 signal_2 "multiple line comment
   REQUIRE(msg->sigs[1]->start_bit == 12);
   REQUIRE(msg->sigs[1]->size == 1);
   REQUIRE(msg->sigs[1]->receiver_name == "XXX");
+
+  // escaped quotes
+  REQUIRE(msg->comment == "message comment with \"escaped quotes\"");
+  REQUIRE(msg->sigs[0]->comment == "signal comment with \"escaped quotes\"");
 }
 
 TEST_CASE("parse_opendbc") {