3 files changed, 430 insertions, 0 deletions
diff --git a/tests/diagnostics/extension-full-name.slang b/tests/diagnostics/extension-full-name.slang
new file mode 100644
index 000000000..292028011
--- /dev/null
+++ b/tests/diagnostics/extension-full-name.slang
@@ -0,0 +1,357 @@
+// extension-full-name.slang
+//DIAGNOSTIC_TEST:SIMPLE:-target hlsl
+
+// Define a generic type with a nested struct
+struct GenericType<T>
+{
+    T value;
+
+    struct InnerType
+    {
+        T innerValue;
+    }
+
+    InnerType inner;
+}
+
+// Define a non-generic type
+struct NonGenericType
+{
+    float value;
+
+    struct InnerType
+    {
+        float innerValue;
+    }
+
+    InnerType inner;
+}
+
+// Add an extension to the generic type
+extension GenericType<half>
+{
+    // Type in extension
+    struct State
+    {
+        half value;
+        half factor;
+    }
+
+    // Function in extension
+    State
+    createState()
+    {
+        State state;
+        state.value = value;
+        state.factor = 1.0h;
+        return state;
+    }
+
+    // Value/field in extension
+    static State defaultState;
+}
+
+// Add an extension to a nested type inside a generic type
+extension GenericType<float>.InnerType
+{
+    struct Options
+    {
+        float min;
+        float max;
+    }
+
+    Options
+    getOptions()
+    {
+        Options opts;
+        opts.min = 0;
+        opts.max = innerValue;
+        return opts;
+    }
+
+    static Options defaultOptions;
+}
+
+// Add an extension to the non-generic type
+extension NonGenericType
+{
+    // Type in extension
+    struct Config
+    {
+        float threshold;
+        float scale;
+    }
+
+    // Function in extension
+    Config
+    createConfig()
+    {
+        Config config;
+        config.threshold = 0.5;
+        config.scale = 2.0;
+        return config;
+    }
+
+    // Value/field in extension
+    static Config defaultConfig;
+}
+
+// Add nested types and extensions
+struct Container
+{
+    struct Nested
+    {
+        float value;
+
+        struct DeepNested
+        {
+            int count;
+        }
+
+        DeepNested deep;
+    }
+
+    Nested nested;
+}
+
+// Extension for deeply nested type
+extension Container.Nested.DeepNested
+{
+    struct Record
+    {
+        int id;
+        float value;
+    }
+
+    Record
+    createRecord(int newId)
+    {
+        Record r;
+        r.id = newId;
+        r.value = 0;
+        return r;
+    }
+
+    static Record defaultRecord;
+}
+
+extension Container.Nested
+{
+    // Type in nested extension
+    struct Settings
+    {
+        float value;
+        float threshold;
+    }
+
+    // Function in nested extension
+    Settings
+    createSettings()
+    {
+        Settings settings;
+        settings.value = value;
+        settings.threshold = 0.1;
+        return settings;
+    }
+
+    // Value/field in nested extension
+    static Settings defaultSettings;
+}
+
+[shader("compute")][numthreads(1, 1, 1)] void main(uint3 dispatchThreadID
+                                                   : SV_DispatchThreadID)
+{
+    // Test array extensions with constraints
+    testArrayExtension();
+
+    // Test namespace extensions
+    testNamespaceExtensions();
+
+    // Type instantiation tests
+    GenericType<half>.State state1;
+    GenericType<float>.InnerType.Options options1;
+    NonGenericType.Config config1;
+    Container.Nested.Settings settings1;
+    Container.Nested.DeepNested.Record record1;
+
+    // Initialize extension types with struct literals
+    state1 = {1.0h, 2.0h};  // Valid struct initialization
+    options1 = {0.0, 1.0};  // Valid struct initialization
+    config1 = {0.1, 0.5};   // Valid struct initialization
+    settings1 = {0.2, 0.3}; // Valid struct initialization
+    record1 = {1, 2.5};     // Valid struct initialization
+
+    // Extension type mismatches - assign value type to extension type
+    state1 = 0;    // Error: expected expr of type 'GenericType<half>.State', got 'int'
+    options1 = 0;  // Error: expected expr of type 'GenericType<float>.InnerType.Options', got 'int'
+    config1 = 0;   // Error: expected expr of type 'NonGenericType.Config', got 'int'
+    settings1 = 0; // Error: expected expr of type 'Container.Nested.Settings', got 'int'
+    record1 = 0;   // Error: expected expr of type 'Container.Nested.DeepNested.Record', got 'int'
+
+    // Extension type mismatches - assign wrong extension types
+    GenericType<int>.InnerType intInner;
+    GenericType<float>.InnerType floatInner;
+
+    // This should fail due to different generic parameters
+    floatInner.Options floatOpts =
+        intInner.getOptions(); // This won't compile as intInner doesn't have getOptions
+
+    // Extension member access - valid cases
+    state1.value = 1.0h;       // Valid
+    state1.factor = 2.0h;      // Valid
+    options1.min = 0.0;        // Valid
+    options1.max = 1.0;        // Valid
+    config1.threshold = 0.5;   // Valid
+    config1.scale = 2.0;       // Valid
+    settings1.value = 0.1;     // Valid
+    settings1.threshold = 0.2; // Valid
+    record1.id = 100;          // Valid
+    record1.value = 3.14;      // Valid
+
+    // Extension function calls
+    GenericType<half> halfType;
+    NonGenericType nonGenType;
+    Container.Nested nested;
+    Container.Nested.DeepNested deepNested;
+    GenericType<float>.InnerType floatInnerType;
+
+    state1 = halfType.createState();        // Valid
+    config1 = nonGenType.createConfig();    // Valid
+    settings1 = nested.createSettings();    // Valid
+    record1 = deepNested.createRecord(42);  // Valid
+    options1 = floatInnerType.getOptions(); // Valid
+
+    // Type mismatches - function return values
+    options1 =
+        halfType
+            .createState(); // Error: expected expr of type 'GenericType<float>.InnerType.Options',
+                            // got 'GenericType<half>.State'
+    state1 = nonGenType.createConfig(); // Error: expected expr of type 'GenericType<half>.State',
+                                        // got 'NonGenericType.Config'
+    config1 = nested.createSettings();  // Error: expected expr of type 'NonGenericType.Config', got
+                                        // 'Container.Nested.Settings'
+}
+
+// Define an interface for constraint
+interface IFoo
+{
+    float getValue();
+}
+
+// Struct that implements IFoo
+struct Bar : IFoo
+{
+    float value;
+
+    float getValue() { return value; }
+}
+
+// Struct that doesn't implement IFoo
+struct Baz
+{
+    float value;
+}
+
+// Extension with constrained generic type parameter
+extension<T : IFoo, let N : int> Array<T, N>
+{
+    // Add a struct type inside the extension
+    struct DataStats
+    {
+        float average;
+        float maximum;
+        float minimum;
+    }
+
+    // Add a function that uses the struct type
+    DataStats computeStats()
+    {
+        DataStats stats;
+        stats.average = 0;
+        stats.maximum = -1e38;
+        stats.minimum = 1e38;
+
+        for(int i = 0; i < N; i++)
+        {
+            float val = this[i].getValue();
+            stats.average += val;
+            stats.maximum = max(stats.maximum, val);
+            stats.minimum = min(stats.minimum, val);
+        }
+
+        if(N > 0)
+            stats.average /= float(N);
+
+        return stats;
+    }
+
+    // Add a field
+    static DataStats defaultStats;
+}
+
+void testArrayExtension()
+{
+    // Create an array of a type that implements IFoo
+    Bar barArray[3] = { {1.0}, {2.0}, {3.0} };
+
+    // Create an array of a type that doesn't implement IFoo
+    Baz bazArray[3] = { {1.0}, {2.0}, {3.0} };
+
+    // This should work - using the extension on a valid type
+    Array<Bar, 3>.DataStats barStats;
+    barStats = barArray.computeStats(); // Valid
+
+    // Type mismatch errors
+    barStats = 0; // Error: expected expr of type 'Bar[3].DataStats', got 'int'
+
+    // This won't compile - Baz doesn't implement IFoo
+    //Array<Baz, 3>.DataStats bazStats;  // This should fail because Baz doesn't implement IFoo
+    //bazStats = bazArray.computeStats(); // This also won't compile
+
+    // Type mismatch between different extension instantiations
+    Array<Bar, 2>.DataStats bar2Stats;
+    bar2Stats = barArray.computeStats(); // Error: expected expr of type 'Bar[2].DataStats', got 'Bar[3].DataStats'
+}
+
+// Test namespace extensions
+// Define a simple base struct
+struct SimpleBase
+{
+    float value;
+}
+
+// Define a namespace with an extension
+namespace TestNamespace
+{
+    extension SimpleBase
+    {
+        struct NamedConfig
+        {
+            float factor;
+        }
+
+        NamedConfig createConfig()
+        {
+            NamedConfig config;
+            config.factor = value * 2.0;
+            return config;
+        }
+    }
+}
+
+// Test function for namespace extensions
+void testNamespaceExtensions()
+{
+    // Need to use the namespace to access the extension methods
+    using namespace TestNamespace;
+
+    SimpleBase base;
+    base.value = 5.0;
+
+    // The type is just "SimpleBase.NamedConfig", not "TestNamespace.SimpleBase.NamedConfig"
+    SimpleBase.NamedConfig config;
+    config.factor = 2.0;
+
+    // Generate a type error to check the output format
+    config = 0; // Error: expected expr of type 'SimpleBase.NamedConfig', got 'int'
+}
diff --git a/tests/diagnostics/extension-full-name.slang.actual b/tests/diagnostics/extension-full-name.slang.actual
new file mode 100644
index 000000000..0d53a90ce
--- /dev/null
+++ b/tests/diagnostics/extension-full-name.slang.actual
@@ -0,0 +1,32 @@
+result code = -1
+standard error = {
+tests/diagnostics/extension-full-name.slang(179): error 30019: expected an expression of type 'GenericType<half>.State', got 'int'
+    state1 = 0;    // Error: expected expr of type 'GenericType<half>.State', got 'int'
+             ^
+tests/diagnostics/extension-full-name.slang(180): error 30019: expected an expression of type 'GenericType<float>.InnerType.Options', got 'int'
+    options1 = 0;  // Error: expected expr of type 'GenericType<float>.InnerType.Options', got 'int'
+               ^
+tests/diagnostics/extension-full-name.slang(181): error 30019: expected an expression of type 'NonGenericType.Config', got 'int'
+    config1 = 0;   // Error: expected expr of type 'NonGenericType.Config', got 'int'
+              ^
+tests/diagnostics/extension-full-name.slang(182): error 30019: expected an expression of type 'Container.Nested.Settings', got 'int'
+    settings1 = 0; // Error: expected expr of type 'Container.Nested.Settings', got 'int'
+                ^
+tests/diagnostics/extension-full-name.slang(183): error 30019: expected an expression of type 'Container.Nested.DeepNested.Record', got 'int'
+    record1 = 0;   // Error: expected expr of type 'Container.Nested.DeepNested.Record', got 'int'
+              ^
+tests/diagnostics/extension-full-name.slang(191): error 30027: 'getOptions' is not a member of 'GenericType<int>.InnerType'.
+        intInner.getOptions(); // This won't compile as intInner doesn't have getOptions
+                 ^~~~~~~~~~
+tests/diagnostics/extension-full-name.slang(221): error 30019: expected an expression of type 'GenericType<float>.InnerType.Options', got 'GenericType<half>.State'
+            .createState(); // Error: expected expr of type 'GenericType<float>.InnerType.Options',
+                        ^
+tests/diagnostics/extension-full-name.slang(223): error 30019: expected an expression of type 'GenericType<half>.State', got 'NonGenericType.Config'
+    state1 = nonGenType.createConfig(); // Error: expected expr of type 'GenericType<half>.State',
+                                    ^
+tests/diagnostics/extension-full-name.slang(225): error 30019: expected an expression of type 'NonGenericType.Config', got 'Container.Nested.Settings'
+    config1 = nested.createSettings();  // Error: expected expr of type 'NonGenericType.Config', got
+                                   ^
+}
+standard output = {
+}
diff --git a/tests/diagnostics/extension-full-name.slang.expected b/tests/diagnostics/extension-full-name.slang.expected
new file mode 100644
index 000000000..8001298c1
--- /dev/null
+++ b/tests/diagnostics/extension-full-name.slang.expected
@@ -0,0 +1,41 @@
+result code = -1
+standard error = {
+tests/diagnostics/extension-full-name.slang(184): error 30019: expected an expression of type 'GenericType<half>.State', got 'int'
+    state1 = 0;    // Error: expected expr of type 'GenericType<half>.State', got 'int'
+             ^
+tests/diagnostics/extension-full-name.slang(185): error 30019: expected an expression of type 'GenericType<float>.InnerType.Options', got 'int'
+    options1 = 0;  // Error: expected expr of type 'GenericType<float>.InnerType.Options', got 'int'
+               ^
+tests/diagnostics/extension-full-name.slang(186): error 30019: expected an expression of type 'NonGenericType.Config', got 'int'
+    config1 = 0;   // Error: expected expr of type 'NonGenericType.Config', got 'int'
+              ^
+tests/diagnostics/extension-full-name.slang(187): error 30019: expected an expression of type 'Container.Nested.Settings', got 'int'
+    settings1 = 0; // Error: expected expr of type 'Container.Nested.Settings', got 'int'
+                ^
+tests/diagnostics/extension-full-name.slang(188): error 30019: expected an expression of type 'Container.Nested.DeepNested.Record', got 'int'
+    record1 = 0;   // Error: expected expr of type 'Container.Nested.DeepNested.Record', got 'int'
+              ^
+tests/diagnostics/extension-full-name.slang(196): error 30027: 'getOptions' is not a member of 'GenericType<int>.InnerType'.
+        intInner.getOptions(); // This won't compile as intInner doesn't have getOptions
+                 ^~~~~~~~~~
+tests/diagnostics/extension-full-name.slang(226): error 30019: expected an expression of type 'GenericType<float>.InnerType.Options', got 'GenericType<half>.State'
+            .createState(); // Error: expected expr of type 'GenericType<float>.InnerType.Options',
+                        ^
+tests/diagnostics/extension-full-name.slang(228): error 30019: expected an expression of type 'GenericType<half>.State', got 'NonGenericType.Config'
+    state1 = nonGenType.createConfig(); // Error: expected expr of type 'GenericType<half>.State',
+                                    ^
+tests/diagnostics/extension-full-name.slang(230): error 30019: expected an expression of type 'NonGenericType.Config', got 'Container.Nested.Settings'
+    config1 = nested.createSettings();  // Error: expected expr of type 'NonGenericType.Config', got
+                                   ^
+tests/diagnostics/extension-full-name.slang(304): error 30019: expected an expression of type 'Bar[3].DataStats', got 'int'
+    barStats = 0; // Error: expected expr of type 'Bar[3].DataStats', got 'int'
+               ^
+tests/diagnostics/extension-full-name.slang(312): error 30019: expected an expression of type 'Bar[2].DataStats', got 'Bar[3].DataStats'
+    bar2Stats = barArray.computeStats(); // Error: expected expr of type 'Bar[2].DataStats', got 'Bar[3].DataStats'
+                                     ^
+tests/diagnostics/extension-full-name.slang(355): error 30019: expected an expression of type 'SimpleBase.NamedConfig', got 'int'
+    config = 0; // Error: expected expr of type 'SimpleBase.NamedConfig', got 'int'
+             ^
+}
+standard output = {
+}