Add JSON parsing support to qmake.

Add qjson* implementation files from corelib/json
to the qmake build. Add a read-only compile mode,
enabled by defining QT_JSON_READONLY.

Add qmake built-in function parseJson(file, into)
which parses a json file into the given variable.

qmake uses a flat key -> value-list implementation
for storing variables, which means that some hackery
is need to represent arbitrarily nested JSON. Use a
special "_KEYS_" variable for arrays and objects:

Arrays:
["item1", "item2"]
$${array._KEYS_} -> 0 1 2
$${array.0} -> "item1"
$${array.1} -> "item2"

Objects:
{ "key1" : "value1", "key2" : "value2" }
$${object._KEYS_} -> key1 key2
$${object.key1} -> value1
$${object.key2} -> value2

Change-Id: I0aa2e4e4ae14fa25be8242bc16d3cffce32504d2
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

8 files changed, 13 insertions, 9 deletions

diff --git a/src/corelib/json/qjsonarray.cpp b/src/corelib/json/qjsonarray.cpp
index 8dd7f6092f..d81de89628 100644
--- a/src/corelib/json/qjsonarray.cpp
+++ b/src/corelib/json/qjsonarray.cpp
@@ -1089,7 +1089,7 @@ void QJsonArray::compact()
 }
 
 
-#ifndef QT_NO_DEBUG_STREAM
+#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
 QDebug operator<<(QDebug dbg, const QJsonArray &a)
 {
     if (!a.a) {
diff --git a/src/corelib/json/qjsonarray.h b/src/corelib/json/qjsonarray.h
index 1474ccae41..562e6accd7 100644
--- a/src/corelib/json/qjsonarray.h
+++ b/src/corelib/json/qjsonarray.h
@@ -211,7 +211,7 @@ private:
     QJsonPrivate::Array *a;
 };
 
-#ifndef QT_NO_DEBUG_STREAM
+#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QJsonArray &);
 #endif
 
diff --git a/src/corelib/json/qjsondocument.cpp b/src/corelib/json/qjsondocument.cpp
index 4806ac68d6..6e257df39d 100644
--- a/src/corelib/json/qjsondocument.cpp
+++ b/src/corelib/json/qjsondocument.cpp
@@ -303,10 +303,12 @@ QVariant QJsonDocument::toVariant() const
 
  \sa fromJson()
  */
+#ifndef QT_JSON_READONLY
 QByteArray QJsonDocument::toJson() const
 {
     return toJson(Indented);
 }
+#endif
 
 /*!
     \enum QJsonDocument::JsonFormat
@@ -338,6 +340,7 @@ QByteArray QJsonDocument::toJson() const
 
     \sa fromJson(), JsonFormat
  */
+#ifndef QT_JSON_READONLY
 QByteArray QJsonDocument::toJson(JsonFormat format) const
 {
     if (!d)
@@ -352,6 +355,7 @@ QByteArray QJsonDocument::toJson(JsonFormat format) const
 
     return json;
 }
+#endif
 
 /*!
  Parses a UTF-8 encoded JSON document and creates a QJsonDocument
@@ -562,7 +566,7 @@ bool QJsonDocument::isNull() const
     return (d == 0);
 }
 
-#ifndef QT_NO_DEBUG_STREAM
+#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
 QDebug operator<<(QDebug dbg, const QJsonDocument &o)
 {
     if (!o.d) {
diff --git a/src/corelib/json/qjsondocument.h b/src/corelib/json/qjsondocument.h
index 0354262e2c..ea42d76b20 100644
--- a/src/corelib/json/qjsondocument.h
+++ b/src/corelib/json/qjsondocument.h
@@ -117,7 +117,7 @@ public:
 
 #ifdef Q_QDOC
     QByteArray toJson(JsonFormat format = Indented) const;
-#else
+#elif !defined(QT_JSON_READONLY)
     QByteArray toJson() const; //### Merge in Qt6
     QByteArray toJson(JsonFormat format) const;
 #endif
@@ -148,7 +148,7 @@ private:
     QJsonPrivate::Data *d;
 };
 
-#ifndef QT_NO_DEBUG_STREAM
+#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QJsonDocument &);
 #endif
 
diff --git a/src/corelib/json/qjsonobject.cpp b/src/corelib/json/qjsonobject.cpp
index 362d01384e..afc0d5f71f 100644
--- a/src/corelib/json/qjsonobject.cpp
+++ b/src/corelib/json/qjsonobject.cpp
@@ -1036,7 +1036,7 @@ void QJsonObject::setValueAt(int i, const QJsonValue &val)
     insert(e->key(), val);
 }
 
-#ifndef QT_NO_DEBUG_STREAM
+#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
 QDebug operator<<(QDebug dbg, const QJsonObject &o)
 {
     if (!o.o) {
diff --git a/src/corelib/json/qjsonobject.h b/src/corelib/json/qjsonobject.h
index 8226b614b4..ad3184b1f2 100644
--- a/src/corelib/json/qjsonobject.h
+++ b/src/corelib/json/qjsonobject.h
@@ -206,7 +206,7 @@ private:
     QJsonPrivate::Object *o;
 };
 
-#ifndef QT_NO_DEBUG_STREAM
+#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QJsonObject &);
 #endif
 
diff --git a/src/corelib/json/qjsonvalue.cpp b/src/corelib/json/qjsonvalue.cpp
index 8aa1f654c6..0a603b958a 100644
--- a/src/corelib/json/qjsonvalue.cpp
+++ b/src/corelib/json/qjsonvalue.cpp
@@ -661,7 +661,7 @@ QJsonValue QJsonValueRef::toValue() const
     return o->valueAt(index);
 }
 
-#ifndef QT_NO_DEBUG_STREAM
+#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
 QDebug operator<<(QDebug dbg, const QJsonValue &o)
 {
     switch (o.t) {
diff --git a/src/corelib/json/qjsonvalue.h b/src/corelib/json/qjsonvalue.h
index b18bbde0f7..c0ecdd2b61 100644
--- a/src/corelib/json/qjsonvalue.h
+++ b/src/corelib/json/qjsonvalue.h
@@ -179,7 +179,7 @@ private:
     uint index : 31;
 };
 
-#ifndef QT_NO_DEBUG_STREAM
+#if !defined(QT_NO_DEBUG_STREAM) && !defined(QT_JSON_READONLY)
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QJsonValue &);
 #endif