Add regression tests for HLSLParser parenthesized expressions

Covers the fix for issue #940 with tests for:
- Parenthesized constructor with binary operators
- Double-nested parentheses
- Both operands parenthesized
- Chained operators after parens

tests/libprojectM/CMakeLists.txt

@@ -27,6 +27,7 @@ test_api_headers(TestMainAPIHeaders
         )
 
 add_executable(projectM-unittest
+        HLSLParserTest.cpp
         LoggingTest.cpp
         PresetFileParserTest.cpp
         WaveformAlignerTest.cpp
@@ -50,6 +51,7 @@ target_include_directories(projectM-unittest
         PRIVATE
         "${PROJECTM_SOURCE_DIR}/src/libprojectM"
         "${PROJECTM_SOURCE_DIR}"
+        "${PROJECTM_SOURCE_DIR}/vendor/hlslparser/src"
         )
 
 target_link_libraries(projectM-unittest

tests/libprojectM/HLSLParserTest.cpp

@@ -0,0 +1,64 @@
+#include <gtest/gtest.h>
+
+#include <HLSLParser.h>
+#include <HLSLTree.h>
+
+#include <cstring>
+
+namespace {
+
+bool ParseHLSL(const char* code)
+{
+    M4::Allocator allocator;
+    M4::HLSLTree tree(&allocator);
+    M4::HLSLParser parser(&allocator, &tree);
+    return parser.Parse("test.hlsl", code, strlen(code));
+}
+
+} // namespace
+
+// Regression test for issue #940: parenthesized constructor with binary operator
+// was rejected with "expected ';'" error.
+TEST(HLSLParser, ParenthesizedConstructorWithMultiply)
+{
+    EXPECT_TRUE(ParseHLSL(
+        "float scalar = 2.0;\n"
+        "float2 var = (float2(1.0, 2.0)) * scalar;\n"
+    ));
+}
+
+TEST(HLSLParser, ParenthesizedConstructorWithAdd)
+{
+    EXPECT_TRUE(ParseHLSL(
+        "float2 var = (float2(1.0, 2.0)) + float2(3.0, 4.0);\n"
+    ));
+}
+
+TEST(HLSLParser, DoubleNestedParensWithOperator)
+{
+    EXPECT_TRUE(ParseHLSL(
+        "float2 var = ((float2(1.0, 2.0))) * 2.0;\n"
+    ));
+}
+
+TEST(HLSLParser, BothOperandsParenthesized)
+{
+    EXPECT_TRUE(ParseHLSL(
+        "float2 var = (float2(1.0, 2.0)) * (float2(3.0, 4.0));\n"
+    ));
+}
+
+TEST(HLSLParser, ChainedOperatorsAfterParens)
+{
+    EXPECT_TRUE(ParseHLSL(
+        "float a = 1.0; float b = 2.0; float c = 3.0;\n"
+        "float x = (a) * b + c;\n"
+    ));
+}
+
+TEST(HLSLParser, ConstructorWithoutParensStillWorks)
+{
+    EXPECT_TRUE(ParseHLSL(
+        "float2 var = float2(1.0, 2.0) * 2.0;\n"
+    ));
+}