QLoggingRegistry: cut out the QMap middle-man

In Qt 6, QMap is just a shared pointer to a std::map.

QLoggingRegistry::qtCategoryEnvironmentOverrides is never copied,
though, so the implicit sharing that QMap adds on top of std::map is
useless.

Use the underlying std::map directly.

Yes, the std::map API is a bit raw around the edges (std::pair
value_type), but we're professionals here.

This saves more than 1.1KiB in TEXT size on optimized AMD64 GCC 11
C++20 Linux builds.

Change-Id: Id72b2432ed41a97700cc2d9ecafa902b919efe84
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 5 insertions, 4 deletions

diff --git a/src/corelib/io/qloggingregistry.cpp b/src/corelib/io/qloggingregistry.cpp
index f9728f9b72..8c9216ff62 100644
--- a/src/corelib/io/qloggingregistry.cpp
+++ b/src/corelib/io/qloggingregistry.cpp
@@ -350,7 +350,7 @@ void QLoggingRegistry::unregisterCategory(QLoggingCategory *cat)
 void QLoggingRegistry::registerEnvironmentOverrideForCategory(const char *categoryName,
                                                               const char *environment)
 {
-    qtCategoryEnvironmentOverrides.insert(categoryName, environment);
+    qtCategoryEnvironmentOverrides.insert_or_assign(categoryName, environment);
 }
 
 /*!
@@ -442,7 +442,7 @@ void QLoggingRegistry::defaultCategoryFilter(QLoggingCategory *cat)
             if (it == reg->qtCategoryEnvironmentOverrides.end())
                 debug = false;
             else
-                debug = qEnvironmentVariableIntValue(it.value());
+                debug = qEnvironmentVariableIntValue(it->second);
         }
     }
 
diff --git a/src/corelib/io/qloggingregistry_p.h b/src/corelib/io/qloggingregistry_p.h
index aa38ed895b..0c378499f3 100644
--- a/src/corelib/io/qloggingregistry_p.h
+++ b/src/corelib/io/qloggingregistry_p.h
@@ -19,11 +19,12 @@
 #include <QtCore/qloggingcategory.h>
 #include <QtCore/qlist.h>
 #include <QtCore/qhash.h>
-#include <QtCore/qmap.h>
 #include <QtCore/qmutex.h>
 #include <QtCore/qstring.h>
 #include <QtCore/qtextstream.h>
 
+#include <map>
+
 class tst_QLoggingRegistry;
 
 QT_BEGIN_NAMESPACE
@@ -127,7 +128,7 @@ private:
     QList<QLoggingRule> ruleSets[NumRuleSets];
     QHash<QLoggingCategory *, QtMsgType> categories;
     QLoggingCategory::CategoryFilter categoryFilter;
-    QMap<QByteArrayView, const char *> qtCategoryEnvironmentOverrides;
+    std::map<QByteArrayView, const char *> qtCategoryEnvironmentOverrides;
 
     friend class ::tst_QLoggingRegistry;
 };