Port to new Q_UNREACHABLE_RETURN()

This is a semantic patch using ClangTidyTransformator to convert
sequences of Q_UNREACHABLE() + return into Q_UNREACHABLE_RETURN(),
newly added to qtbase.

    const std::string unr = "unr", val = "val", ret = "ret";
    auto makeUnreachableReturn = cat("Q_UNREACHABLE_RETURN(",
                                    ifBound(val, cat(node(val)), cat("")),
                                    ")");
    auto ignoringSwitchCases = [](auto stmt) {
        return anyOf(stmt, switchCase(subStmt(stmt)));
    };

    makeRule(stmt(ignoringSwitchCases(stmt(isExpandedFromMacro("Q_UNREACHABLE")).bind(unr)),
                  nextStmt(returnStmt(optionally(hasReturnValue(expr().bind(val)))).bind(ret))),
             {changeTo(node(unr), cat(makeUnreachableReturn,
                                      ";")), // TODO: why is the ; lost w/o this?
              changeTo(node(ret), cat(""))},
             cat("use ", makeUnreachableReturn));

a.k.a qt-use-unreachable-return.

subStmt() and nextStmt() are non-standard matchers.

There was one false positive, suppressed it with NOLINTNEXTLINE.

It's not really a false positiive, it's just that Clang sees the world
in one way and if conditonal compilation (#if) differs for other
compilers, Clang doesn't know better. This is an artifact of matching
two consecutive statements.

Change-Id: I3855b2dc8523db1ea860f72ad9818738162495c6
Reviewed-by: Qt CI Bot <[email protected]>
Reviewed-by: Fabian Kosmale <[email protected]>

1 files changed, 1 insertions, 2 deletions

diff --git a/tools/qmljsrootgen/main.cpp b/tools/qmljsrootgen/main.cpp
index 77abd1be54..2bd54692d1 100644
--- a/tools/qmljsrootgen/main.cpp
+++ b/tools/qmljsrootgen/main.cpp
@@ -86,8 +86,7 @@ static QString findClassName(const QJSManagedValue &value)
     if (QV4::ScopedValue scoped(scope, asManaged(value)); scoped->isManaged())
         return scoped->managed()->vtable()->className;
 
-    Q_UNREACHABLE();
-    return QString();
+    Q_UNREACHABLE_RETURN(QString());
 }
 
 static QString buildClass(const QJSManagedValue &value, QJsonArray *classes,