Teach syncqt to filter out QT_DEPRECATED_* macros

We already had code that filtered out QT_DEPRECATED_X("text").  But that
isn't enough, because, by now, we have a true cornucopia of
QT_DEPRECATED_* macros.  And only some are called with an argument list.

Move the filtering code into the subroutine filterDeprecationMacros,
because our filtering is slightly more complex now:

- Try to match a QT_DEPRECATED_* macro call.
- Try to match balanced parentheses with a recursive regular expression.
- Check whether the found balanced parentheses are directly behind
  QT_DEPRECATED_*, because only then it is the argument list of that
  macro.
- Filter out what we've found.

With this patch, syncqt doesn't discard deprecated classes anymore.

Task-number: QTBUG-80347
Change-Id: I7872159639be330d5a039c98eac0c5007d9acb93
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

libexec/syncqt.pl

@@ -192,6 +192,33 @@ sub shouldMasterInclude {
     return 1;
 }
 
+######################################################################
+# Syntax:  filterDeprecationMacros(line)
+# Params:  line: a line of C++ source
+#
+# Purpose: Removes occurrences of QT_DEPRECATED_* macro calls.
+#          The calls may have an argument list that is also removed.
+# Returns: The filtered line.
+######################################################################
+sub filterDeprecationMacros {
+    my $line = $_[0];
+    my $rest;
+    if ($line =~ /(.*\s+)QT_DEPRECATED_[[:upper:][:digit:]_]+\s*(.*)/) {
+        $line = $1;
+        $rest = $2;
+
+        # Does the macro call have an argument list? If so, remove it.
+        # The regular expression matches balanced parenthesis anywhere in $rest.
+        # Therefore, we must check whether the match starts at index zero.
+        if ($rest =~ /\((?:[^)(]+|(?R))*+\)/ && $-[0] == 0) {
+            $line .= substr($rest, $+[0]);
+        } else {
+            $line .= $rest;
+        }
+    }
+    return $line;
+}
+
 ######################################################################
 # Syntax:  classNames(iheader, clean, requires)
 # Params:  iheader, string, filename to parse for classname "symlinks"
@@ -298,7 +325,7 @@ sub classNames {
 
         if($definition) {
             $definition =~ s=[\n\r]==g;
-            $definition =~ s/QT_DEPRECATED_X\s*\(\s*".*?"\s*\)//g;
+            $definition = filterDeprecationMacros($definition);
             my @symbols;
             my $post_kw = qr/Q_DECL_FINAL|final|sealed/; # add here macros and keywords that go after the class-name of a class definition
             if($definition =~ m/^ *typedef *.*\(\*([^\)]*)\)\(.*\);$/) {