qmllint: Add ability to ignore individual warnings

Allows users to ignore individual warnings by adding a "// qmllint disable" comment in the line that triggers the warning.
This feature is especially useful for use in pre-commit / CI tests as it allows to add exceptions for individual warnings that cannot be fixed immediately.

[ChangeLog][qmllint][New Feature] You can now ignore individual warnings by adding "// qmllint disable"
in the line causing it. You may also specify one or more warning type to ignore ("// qmllint disable warningtype1 warningtype2...") which is preferable. This can also be done for entire blocks of code by using "// qmllint disable" in an empty line and ending it with "// qmllint enable"

Change-Id: Iea6c29132d6b51ecfb5e5d8a19a43446a7286c24
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

3 files changed, 87 insertions, 7 deletions

diff --git a/tools/qmllint/findwarnings.cpp b/tools/qmllint/findwarnings.cpp
index bc228fa8e1..31ecb9a03a 100644
--- a/tools/qmllint/findwarnings.cpp
+++ b/tools/qmllint/findwarnings.cpp
@@ -421,9 +421,9 @@ bool FindWarningVisitor::visit(QQmlJS::AST::IdentifierExpression *idexp)
     return true;
 }
 
-FindWarningVisitor::FindWarningVisitor(
-        QQmlJSImporter *importer, QStringList qmltypesFiles, QString code, QString fileName,
-        bool silent)
+FindWarningVisitor::FindWarningVisitor(QQmlJSImporter *importer, QStringList qmltypesFiles,
+                                       QString code, QList<QQmlJS::SourceLocation> comments,
+                                       QString fileName, bool silent)
     : QQmlJSImportVisitor(importer,
                           implicitImportDirectory(fileName, importer->resourceFileMapper()),
                           qmltypesFiles, fileName, code, silent),
@@ -457,6 +457,83 @@ FindWarningVisitor::FindWarningVisitor(
     }
     for (const auto& jsGlobVar: jsGlobVars)
         m_currentScope->insertJSIdentifier(jsGlobVar, globalJavaScript);
+
+    parseComments(comments);
+}
+
+void FindWarningVisitor::parseComments(const QList<QQmlJS::SourceLocation> &comments)
+{
+    QHash<int, QSet<QQmlJSLoggerCategory>> disablesPerLine;
+    QHash<int, QSet<QQmlJSLoggerCategory>> enablesPerLine;
+    QHash<int, QSet<QQmlJSLoggerCategory>> oneLineDisablesPerLine;
+
+    const QStringList lines = m_code.split(u'\n');
+
+    for (const auto &loc : comments) {
+        const QString comment = m_code.mid(loc.offset, loc.length);
+        if (!comment.startsWith(u" qmllint ") && !comment.startsWith(u"qmllint "))
+            continue;
+
+        QStringList words = comment.split(u' ');
+        if (words.constFirst().isEmpty())
+            words.removeFirst();
+
+        const QString command = words.at(1);
+
+        QSet<QQmlJSLoggerCategory> categories;
+        for (qsizetype i = 2; i < words.size(); i++) {
+            const QString category = words.at(i);
+            const auto option = m_logger.options().constFind(category);
+            if (option != m_logger.options().constEnd())
+                categories << option->m_category;
+            else
+                m_logger.log(u"qmllint directive on unknown category \"%1\""_qs.arg(category),
+                             Log_Syntax, loc);
+        }
+
+        if (categories.isEmpty()) {
+            for (const auto &option : m_logger.options())
+                categories << option.m_category;
+        }
+
+        if (command == u"disable"_qs) {
+            const QString line = lines[loc.startLine - 1];
+            const QString preComment = line.left(line.indexOf(comment) - 2);
+
+            bool lineHasContent = false;
+            for (qsizetype i = 0; i < preComment.size(); i++) {
+                if (!preComment[i].isSpace()) {
+                    lineHasContent = true;
+                    break;
+                }
+            }
+
+            if (lineHasContent)
+                oneLineDisablesPerLine[loc.startLine] |= categories;
+            else
+                disablesPerLine[loc.startLine] |= categories;
+        } else if (command == u"enable"_qs) {
+            enablesPerLine[loc.startLine + 1] |= categories;
+        } else {
+            m_logger.log(u"Invalid qmllint directive \"%1\" provided"_qs.arg(command), Log_Syntax,
+                         loc);
+        }
+    }
+
+    if (disablesPerLine.isEmpty() && oneLineDisablesPerLine.isEmpty())
+        return;
+
+    QSet<QQmlJSLoggerCategory> currentlyDisabled;
+    for (qsizetype i = 1; i <= lines.length(); i++) {
+        currentlyDisabled.unite(disablesPerLine[i]).subtract(enablesPerLine[i]);
+
+        currentlyDisabled.unite(oneLineDisablesPerLine[i]);
+
+        if (!currentlyDisabled.isEmpty())
+            m_logger.ignoreWarnings(i, currentlyDisabled);
+
+        currentlyDisabled.subtract(oneLineDisablesPerLine[i]);
+    }
 }
 
 bool FindWarningVisitor::check()
diff --git a/tools/qmllint/findwarnings.h b/tools/qmllint/findwarnings.h
index b6c5f19c76..e2538fe5b8 100644
--- a/tools/qmllint/findwarnings.h
+++ b/tools/qmllint/findwarnings.h
@@ -57,9 +57,9 @@ class FindWarningVisitor : public QQmlJSImportVisitor
 {
     Q_DISABLE_COPY_MOVE(FindWarningVisitor)
 public:
-    explicit FindWarningVisitor(
-            QQmlJSImporter *importer, QStringList qmltypesFiles, QString code, QString fileName,
-            bool silent);
+    explicit FindWarningVisitor(QQmlJSImporter *importer, QStringList qmltypesFiles, QString code,
+                                QList<QQmlJS::SourceLocation> comments, QString fileName,
+                                bool silent);
     ~FindWarningVisitor() override = default;
     bool check();
 
@@ -88,6 +88,8 @@ private:
     // correctness, the scope that defines the default property acts as a key
     QHash<const QQmlJSScope *, bool> m_scopeHasDefaultPropertyAssignment;
 
+    void parseComments(const QList<QQmlJS::SourceLocation> &comments);
+
     void checkInheritanceCycle(QQmlJSScope::ConstPtr scope);
     void checkGroupedAndAttachedScopes(QQmlJSScope::ConstPtr scope);
     void flushPendingSignalParameters();
diff --git a/tools/qmllint/main.cpp b/tools/qmllint/main.cpp
index 7e3962fe0b..7f4c63439f 100644
--- a/tools/qmllint/main.cpp
+++ b/tools/qmllint/main.cpp
@@ -168,7 +168,8 @@ static bool lint_file(const QString &filename, const bool silent, QJsonArray *js
 
             importer.setResourceFileMapper(mapper);
 
-            FindWarningVisitor v { &importer, qmltypesFiles, code, filename, silent || json };
+            FindWarningVisitor v { &importer,         qmltypesFiles, code,
+                                   engine.comments(), filename,      silent || json };
 
             for (auto it = options.cbegin(); it != options.cend(); ++it) {
                 v.logger().setCategoryDisabled(it.value().m_category, it.value().m_disabled);