Moc: assert size of registered strings list is within INT_MAX range

Assert generator.strings.size() < INT_MAX after all strings have been
registered.

Parts of the public API, e.g. QMetaMethod::methodIndex and similar
functions return int, and other parts of the code expect int values, at
least for Qt6 this can't be changed, so use qsizetype internally and
assert the values fit in an int.

Change-Id: Ib226e9c19a578bbeaeb9bb767d756a9569fe57b3
Reviewed-by: Fabian Kosmale <[email protected]>
Reviewed-by: Thiago Macieira <[email protected]>

3 files changed, 10 insertions, 2 deletions

diff --git a/src/tools/moc/generator.cpp b/src/tools/moc/generator.cpp
index 097d0021428..625e1e6733e 100644
--- a/src/tools/moc/generator.cpp
+++ b/src/tools/moc/generator.cpp
@@ -122,7 +122,7 @@ void Generator::strreg(const QByteArray &s)
 
 int Generator::stridx(const QByteArray &s)
 {
-    int i = strings.indexOf(s);
+    int i = int(strings.indexOf(s));
     Q_ASSERT_X(i != -1, Q_FUNC_INFO, "We forgot to register some strings");
     return i;
 }
@@ -841,7 +841,7 @@ void Generator::generateProperties()
         int notifyId = p.notifyId;
         if (p.notifyId < -1) {
             // signal is in parent class
-            const int indexInStrings = strings.indexOf(p.notify);
+            const int indexInStrings = int(strings.indexOf(p.notify));
             notifyId = indexInStrings | IsUnresolvedSignal;
         }
         fprintf(out, ", 0x%.8x, uint(%d), %d,\n", flags, notifyId, p.revision);
diff --git a/src/tools/moc/generator.h b/src/tools/moc/generator.h
index fa651f04a0a..ac295577692 100644
--- a/src/tools/moc/generator.h
+++ b/src/tools/moc/generator.h
@@ -20,6 +20,8 @@ public:
               const QHash<QByteArray, QByteArray> &knownGadgets, FILE *outfile = nullptr,
               bool requireCompleteTypes = false);
     void generateCode();
+    qsizetype registeredStringsCount() { return strings.size(); };
+
 private:
     bool registerableMetaType(const QByteArray &propertyType);
     void registerClassInfoStrings();
diff --git a/src/tools/moc/moc.cpp b/src/tools/moc/moc.cpp
index 4a9e3463ac8..d04f2d079ee 100644
--- a/src/tools/moc/moc.cpp
+++ b/src/tools/moc/moc.cpp
@@ -1138,6 +1138,12 @@ void Moc::generate(FILE *out, FILE *jsonOutput)
     for (int i = 0; i < classList.size(); ++i) {
         Generator generator(&classList[i], metaTypes, knownQObjectClasses, knownGadgets, out, requireCompleteTypes);
         generator.generateCode();
+
+        // generator.generateCode() should have already registered all strings
+        if (Q_UNLIKELY(generator.registeredStringsCount() >= std::numeric_limits<int>::max())) {
+            error("internal limit exceeded: number of parsed strings is too big.");
+            exit(EXIT_FAILURE);
+        }
     }
     fputs("", out);