QShaderGenerator: Allow more expressions in input nodes

Currently QShaderGenerator will crash when encountering some expressions
in input nodes.

For example, this node prototype would make it crash:
"VERTEX_COLOR": {
  "outputs": ["color", "alpha"],
  "rules": [
    "headerSnippets": ["in vec4 vertexColor;"],
    "substitution": "vec3 $color = vertexColor.rgb;
                     float $alpha = vertexColor.a;"
  ]
}

Change-Id: I37abb8099d376843a4cb13228140467dc1b8f60c
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/src/gui/util/qshadergenerator.cpp b/src/gui/util/qshadergenerator.cpp
index 244b95605b..1d47f51e84 100644
--- a/src/gui/util/qshadergenerator.cpp
+++ b/src/gui/util/qshadergenerator.cpp
@@ -346,10 +346,9 @@ QByteArray QShaderGenerator::createShaderCode(const QStringList &enabledLayers)
     code << QByteArrayLiteral("void main()");
     code << QByteArrayLiteral("{");
 
-    const QRegularExpression localToGlobalRegExp(QStringLiteral("[^;]*\\s+(\\w+)\\s*=\\s*((?:\\w+\\(.*\\))|(?:\\w+))[^;]*;"));
     const QRegularExpression temporaryVariableToAssignmentRegExp(QStringLiteral("([^;]*\\s+(v\\d+))\\s*=\\s*([^;]*);"));
     const QRegularExpression temporaryVariableInAssignmentRegExp(QStringLiteral("\\W*(v\\d+)\\W*"));
-    const QRegularExpression outputToTemporaryAssignmentRegExp(QStringLiteral("\\s*(\\w+)\\s*=\\s*([^;]*);"));
+    const QRegularExpression statementRegExp(QStringLiteral("\\s*(\\w+)\\s*=\\s*([^;]*);"));
 
     struct Variable;
 
@@ -521,14 +520,12 @@ QByteArray QShaderGenerator::createShaderCode(const QStringList &enabledLayers)
 
         switch (node.type()) {
         case QShaderNode::Input:
-            matches = localToGlobalRegExp.globalMatch(QString::fromUtf8(substitutionedLine));
+        case QShaderNode::Output:
+            matches = statementRegExp.globalMatch(QString::fromUtf8(substitutionedLine));
             break;
         case QShaderNode::Function:
             matches = temporaryVariableToAssignmentRegExp.globalMatch(QString::fromUtf8(substitutionedLine));
             break;
-        case QShaderNode::Output:
-            matches = outputToTemporaryAssignmentRegExp.globalMatch(QString::fromUtf8(substitutionedLine));
-            break;
         case QShaderNode::Invalid:
             break;
         }