MOC: pass the erroneous Symbol as an arg to Parser::error() overload

We already know the Symbol while parsing, passing a reference to it to
error() makes it simpler to construct the error message.

This fixes an issue where reporting an error about "NONSENSE" in e.g.:
Q_PROPERTY(Foo* foo NONSENSE foo)

would be off-by-one and the error message would say:
path/to/file.h:11:1: error: Parse error at "foo"

instead of 'at "NONSENSE"', which is where the parser actually found an
unexpected attribute.

Fixes: QTBUG-36367
Pick-to: 6.5
Change-Id: Ief70e544af41f7575fbeea9b936fa8197c3ef43d
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/tools/moc/moc.cpp

@@ -1300,7 +1300,8 @@ void Moc::parsePropertyAttributes(PropertyDef &propDef)
     };
 
     while (test(IDENTIFIER)) {
-        const QByteArray l = lexem();
+        const Symbol &lsym = symbol();
+        const QByteArray l = lsym.lexem();
         if (l[0] == 'C' && l == "CONSTANT") {
             propDef.constant = true;
             continue;
@@ -1327,11 +1328,11 @@ void Moc::parsePropertyAttributes(PropertyDef &propDef)
         } else if (test(INTEGER_LITERAL)) {
             v = lexem();
             if (l != "REVISION")
-                error(1);
+                error(lsym);
         } else if (test(DEFAULT)) {
             v = lexem();
             if (l != "READ" && l != "WRITE")
-                error(1);
+                error(lsym);
         } else {
             next(IDENTIFIER);
             v = lexem();
@@ -1345,7 +1346,7 @@ void Moc::parsePropertyAttributes(PropertyDef &propDef)
             if (l == "MEMBER")
                 propDef.member = v;
             else
-                error(2);
+                error(lsym);
             break;
         case 'R':
             if (l == "READ")
@@ -1356,10 +1357,10 @@ void Moc::parsePropertyAttributes(PropertyDef &propDef)
                 bool ok = false;
                 const int minor = v.toInt(&ok);
                 if (!ok || !QTypeRevision::isValidSegment(minor))
-                    error(1);
+                    error(lsym);
                 propDef.revision = QTypeRevision::fromMinorVersion(minor).toEncodedVersion<int>();
             } else
-                error(2);
+                error(lsym);
             break;
         case 'S':
             if (l == "SCRIPTABLE") {
@@ -1369,27 +1370,27 @@ void Moc::parsePropertyAttributes(PropertyDef &propDef)
                 propDef.stored = v + v2;
                 checkIsFunction(propDef.stored, "STORED");
             } else
-                error(2);
+                error(lsym);
             break;
-        case 'W': if (l != "WRITE") error(2);
+        case 'W': if (l != "WRITE") error(lsym);
             propDef.write = v;
             break;
-        case 'B': if (l != "BINDABLE") error(2);
+        case 'B': if (l != "BINDABLE") error(lsym);
             propDef.bind = v;
             break;
-        case 'D': if (l != "DESIGNABLE") error(2);
+        case 'D': if (l != "DESIGNABLE") error(lsym);
             propDef.designable = v + v2;
             checkIsFunction(propDef.designable, "DESIGNABLE");
             break;
-        case 'N': if (l != "NOTIFY") error(2);
+        case 'N': if (l != "NOTIFY") error(lsym);
             propDef.notify = v;
             break;
-        case 'U': if (l != "USER") error(2);
+        case 'U': if (l != "USER") error(lsym);
             propDef.user = v + v2;
             checkIsFunction(propDef.user, "USER");
             break;
         default:
-            error(2);
+            error(lsym);
         }
     }
     if (propDef.constant && !propDef.write.isNull()) {

src/tools/moc/parser.cpp

@@ -20,17 +20,24 @@ static const char *error_msg = nullptr;
 #define ErrorFormatString "%s:%d:%d: "
 #endif
 
-void Parser::error(int rollback) {
+static void defaultErrorMsg(const QByteArray &fileName, const Symbol &sym)
-    index -= rollback;
+{
-    error();
+    fprintf(stderr, ErrorFormatString "error: Parse error at \"%s\"\n",
+            fileName.constData(), sym.lineNum, 1, sym.lexem().data());
 }
+
+void Parser::error(const Symbol &sym)
+{
+    defaultErrorMsg(currentFilenames.top(), sym);
+    exit(EXIT_FAILURE);
+}
+
 void Parser::error(const char *msg) {
     if (msg || error_msg)
         fprintf(stderr, ErrorFormatString "error: %s\n",
                  currentFilenames.top().constData(), symbol().lineNum, 1, msg?msg:error_msg);
     else
-        fprintf(stderr, ErrorFormatString "error: Parse error at \"%s\"\n",
+        defaultErrorMsg(currentFilenames.top(), symbol());
-                 currentFilenames.top().constData(), symbol().lineNum, 1, symbol().lexem().data());
     exit(EXIT_FAILURE);
 }
 

src/tools/moc/parser.h

@@ -44,7 +44,7 @@ public:
     inline QByteArray unquotedLexem() { return symbols.at(index-1).unquotedLexem();}
     inline const Symbol &symbol() { return symbols.at(index-1);}
 
-    Q_NORETURN void error(int rollback);
+    Q_NORETURN void error(const Symbol &symbol);
     Q_NORETURN void error(const char *msg = nullptr);
     void warning(const char * = nullptr);
     void note(const char * = nullptr);

tests/auto/tools/moc/tst_moc.cpp

@@ -62,6 +62,8 @@
 
 #include "qmlmacro.h"
 
+using namespace Qt::StringLiterals;
+
 #ifdef Q_MOC_RUN
 // check that moc can parse these constructs, they are being used in Windows winsock2.h header
 #define STRING_HASH_HASH(x) ("foo" ## x ## "bar")
@@ -2371,6 +2373,13 @@ void tst_Moc::warnings_data()
         << QString()
         << QString("standard input:3:1: error: Parse error at \"decltype\"");
 
+    QTest::newRow("QTBUG-36367: report correct error location")
+        << "class X { \n Q_PROPERTY(Foo* foo NONSENSE foo) \n };"_ba
+        << QStringList()
+        << 1
+        << QString()
+        << u"standard input:2:1: error: Parse error at \"NONSENSE\""_s;
+
 #ifdef Q_OS_UNIX  // Limit to Unix because the error message is platform-dependent
     QTest::newRow("Q_PLUGIN_METADATA: unreadable file")
         << QByteArray("class X { \n Q_PLUGIN_METADATA(FILE \".\") \n };")