ENH: Add file existence and readability checks for generator inputs

Improve error handling by introducing validation to ensure input files exist and are readable before proceeding, enhancing robustness of the generator.

Author: hjmjohnson

generator/main.cpp

@@ -58,8 +58,17 @@
 
 #include <memory>
 
+#include <QDebug>
+
+static bool fileExistsAndReadable(const QString& filePath) {
+    QFileInfo info(filePath);
+    return info.exists() && info.isFile() &&
+           (QFile(filePath).permissions() & QFileDevice::ReadUser);
+}
+
 void displayHelp(GeneratorSet *generatorSet);
 
+
 namespace
 {
 
@@ -284,8 +293,6 @@ int main(int argc, char *argv[])
     QString default_file = ":/trolltech/generator/qtscript_masterinclude.h";
     QString default_system = ":/trolltech/generator/build_all.txt";
 
-    QString fileName;
-    QString typesystemFileName;
     QString pp_file = ".preprocessed.tmp";
 
     QMap<QString, QString> args;
@@ -353,9 +360,11 @@ int main(int argc, char *argv[])
         }
     }
 
-    fileName = args.value("arg-1");
+    // fileName is a required input file
+    QString fileName = args.value("arg-1");
 
-    typesystemFileName = args.value("arg-2");
+    // typesystemFileName is a required input file
+    QString typesystemFileName = args.value("arg-2");
     if (args.contains("arg-3"))
         displayHelp(&*gs);
 
@@ -368,6 +377,17 @@ int main(int argc, char *argv[])
     if (fileName.isEmpty() || typesystemFileName.isEmpty() )
         displayHelp(&*gs);
 
+    if (!fileExistsAndReadable(fileName))
+    {
+        printf("ERROR: first argument file '%s' does not exist or is not readable.\n", qPrintable(fileName));
+        displayHelp(&*gs);
+    }
+    if (!fileExistsAndReadable(typesystemFileName))
+    {
+        printf("ERROR: second argument file '%s' does not exist or is not readable.\n", qPrintable(typesystemFileName));
+        displayHelp(&*gs);
+    }
+
     if (!gs->readParameters(args))
         displayHelp(&*gs);