Fix highlighting of debugger disassembly view

The disassembly view uses a custom MIME type that derives from x-asm,
but that didn't trigger highlighting.

Make the generic highlighter look at the parent MIME types if no
highlighting was found for the MIME type itself.

Generalize this "go breadth-first through the parents" that was already
used for resolving editor factories.

Change-Id: Ia054058a8c06b9d8849384e79ee3b83fbc12279c
Reviewed-by: David Schulz <david.schulz@qt.io>

src/libs/utils/mimetypes2/mimeutils.cpp

@@ -100,4 +100,34 @@ void setMagicRulesForMimeType(const MimeType &mimeType, const QMap<int, QList<Mi
     d->setMagicRulesForMimeType(mimeType, rules);
 }
 
+void visitMimeParents(const MimeType &mimeType,
+                      const std::function<bool(const MimeType &mimeType)> &visitor)
+{
+    // search breadth-first through parent hierarchy, e.g. for hierarchy
+    // * application/x-ruby
+    //     * application/x-executable
+    //         * application/octet-stream
+    //     * text/plain
+    QList<MimeType> queue;
+    QSet<QString> seen;
+    queue.append(mimeType);
+    seen.insert(mimeType.name());
+    while (!queue.isEmpty()) {
+        const MimeType mt = queue.takeFirst();
+        if (!visitor(mt))
+            break;
+        // add parent mime types
+        const QStringList parentNames = mt.parentMimeTypes();
+        for (const QString &parentName : parentNames) {
+            const MimeType parent = mimeTypeForName(parentName);
+            if (parent.isValid()) {
+                int seenSize = seen.size();
+                seen.insert(parent.name());
+                if (seen.size() != seenSize) // not seen before, so add
+                    queue.append(parent);
+            }
+        }
+    }
+}
+
 } // namespace Utils

src/libs/utils/mimeutils.h

@@ -8,6 +8,8 @@
 #include <mimemagicrule_p.h>
 #include <mimetype.h>
 
+#include <functional>
+
 namespace Utils {
 
 class FilePath;
@@ -49,4 +51,8 @@ QTCREATOR_UTILS_EXPORT void setGlobPatternsForMimeType(const MimeType &mimeType,
 QTCREATOR_UTILS_EXPORT void setMagicRulesForMimeType(
     const MimeType &mimeType, const QMap<int, QList<MimeMagicRule>> &rules); // priority -> rules
 
+// visits all parents breadth-first
+// visitor should return false to break the loop, true to continue
+QTCREATOR_UTILS_EXPORT void visitMimeParents(
+    const MimeType &mimeType, const std::function<bool(const MimeType &mimeType)> &visitor);
 } // namespace Utils

src/plugins/coreplugin/editormanager/ieditorfactory_p.h

@@ -25,17 +25,7 @@ static void mimeTypeFactoryLookup(const Utils::MimeType &mimeType,
                                   QList<EditorTypeLike *> *list)
 {
     QSet<EditorTypeLike *> matches;
-    // search breadth-first through parent hierarchy, e.g. for hierarchy
-    // * application/x-ruby
-    //     * application/x-executable
-    //         * application/octet-stream
-    //     * text/plain
-    QList<Utils::MimeType> queue;
-    QSet<QString> seen;
-    queue.append(mimeType);
-    seen.insert(mimeType.name());
-    while (!queue.isEmpty()) {
-        Utils::MimeType mt = queue.takeFirst();
+    Utils::visitMimeParents(mimeType, [&](const Utils::MimeType &mt) -> bool {
         // check for matching factories
         for (EditorTypeLike *factory : allFactories) {
             if (!matches.contains(factory)) {
@@ -48,18 +38,8 @@ static void mimeTypeFactoryLookup(const Utils::MimeType &mimeType,
                 }
             }
         }
-        // add parent mime types
-        const QStringList parentNames = mt.parentMimeTypes();
-        for (const QString &parentName : parentNames) {
-            const Utils::MimeType parent = Utils::mimeTypeForName(parentName);
-            if (parent.isValid()) {
-                int seenSize = seen.size();
-                seen.insert(parent.name());
-                if (seen.size() != seenSize) // not seen before, so add
-                    queue.append(parent);
-            }
-        }
-    }
+        return true; // continue
+    });
 }
 
 } // Internal

src/plugins/texteditor/highlighter.cpp

@@ -120,13 +120,16 @@ Highlighter::Definitions Highlighter::definitionsForDocument(const TextDocument
     if (definitions.isEmpty()) {
         const MimeType &mimeType = Utils::mimeTypeForName(document->mimeType());
         if (mimeType.isValid()) {
-            // highlight definitions might not use the canonical name but an alias
-            const QStringList names = QStringList(mimeType.name()) + mimeType.aliases();
-            for (const QString &name : names) {
-                definitions = definitionsForMimeType(name);
-                if (!definitions.isEmpty())
-                    break;
-            }
+            Utils::visitMimeParents(mimeType, [&](const MimeType &mt) -> bool {
+                // highlight definitions might not use the canonical name but an alias
+                const QStringList names = QStringList(mt.name()) + mt.aliases();
+                for (const QString &name : names) {
+                    definitions = definitionsForMimeType(name);
+                    if (!definitions.isEmpty())
+                        return false; // stop
+                }
+                return true; // continue
+            });
         }
     }