Initial support for immutable lambda expressions. (#6914)

* Initial support for immutable lambda expressions.

* More diagnostics, and langauge server fix.

* Language server fix.

* Fix bug identified in review.

* Add expected result.

* Update expected result.

5 files changed, 136 insertions, 0 deletions

diff --git a/tests/language-feature/lambda/lambda-0.slang b/tests/language-feature/lambda/lambda-0.slang
new file mode 100644
index 000000000..2a660a114
--- /dev/null
+++ b/tests/language-feature/lambda/lambda-0.slang
@@ -0,0 +1,30 @@
+
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHECK):-vk -output-using-type
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHECK):-cpu -output-using-type
+
+//TEST_INPUT: set outputBuffer = out ubuffer(data=[0 0 0 0], stride=4)
+RWStructuredBuffer<float> outputBuffer;
+
+struct Matrix
+{
+    float data[16];
+
+    [mutating]
+    void map(IFunc<float, float> f)
+    {
+        for (int i = 0; i < 16; ++i)
+        {
+            data[i] = f(data[i]);
+        }
+    }
+}
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    Matrix m = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
+    int c = 2;
+    m.map((float x) => (float)(x * c));
+    outputBuffer[0] = m.data[3];
+    // CHECK: 8.0
+}
\ No newline at end of file
diff --git a/tests/language-feature/lambda/lambda-1.slang b/tests/language-feature/lambda/lambda-1.slang
new file mode 100644
index 000000000..66f68d334
--- /dev/null
+++ b/tests/language-feature/lambda/lambda-1.slang
@@ -0,0 +1,47 @@
+
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHECK):-vk -output-using-type
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHECK):-cpu -output-using-type
+
+//TEST_INPUT: set outputBuffer = out ubuffer(data=[0 0 0 0], stride=4)
+RWStructuredBuffer<float> outputBuffer;
+
+struct Matrix
+{
+    float data[16];
+
+    [mutating]
+    void map(IFunc<float, float> f)
+    {
+        for (int i = 0; i < 16; ++i)
+        {
+            data[i] = f(data[i]);
+        }
+    }
+}
+
+struct Applier
+{
+    float c;
+    void apply(inout Matrix m)
+    {
+        m.map((float x) =>
+        {
+            if (x > 2.5)
+                return x * c;
+            else
+                return x + c;
+        });
+    }
+}
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    Matrix m = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
+    Applier applier = { 1.5 };
+    applier.apply(m);
+    outputBuffer[0] = m.data[1];
+    // CHECK: 3.5
+    outputBuffer[1] = m.data[3];
+    // CHECK: 6.0
+}
\ No newline at end of file
diff --git a/tests/language-feature/lambda/lambda-2.slang b/tests/language-feature/lambda/lambda-2.slang
new file mode 100644
index 000000000..b731f1855
--- /dev/null
+++ b/tests/language-feature/lambda/lambda-2.slang
@@ -0,0 +1,20 @@
+
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHECK):-vk -output-using-type
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHECK):-cpu -output-using-type
+
+//TEST_INPUT: set outputBuffer = out ubuffer(data=[0 0 0 0], stride=4)
+RWStructuredBuffer<float> outputBuffer;
+
+IFunc<float, float> createFunc(int c)
+{
+    return (float x) => (float)(x * 2 + c);
+}
+
+
+[numthreads(1, 1, 1)]
+void computeMain()
+{
+    let func = createFunc(2);
+    // CHECK: 8.0
+    outputBuffer[0] = func(3.0);
+}
diff --git a/tests/language-feature/lambda/lambda-diagnostics.slang b/tests/language-feature/lambda/lambda-diagnostics.slang
new file mode 100644
index 000000000..951df093b
--- /dev/null
+++ b/tests/language-feature/lambda/lambda-diagnostics.slang
@@ -0,0 +1,23 @@
+//TEST:SIMPLE(filecheck=CHECK): -target spirv
+
+[numthreads(1,1,1)]
+void test()
+{
+    int c = 0;
+    let lam = (int a) => {
+        //CHECK:([[# @LINE+1]]): error 30011:
+        c = a + 1;
+    };
+    let lam1 = (int a) => {
+        if (a > 0)
+            return 1;
+        else
+            //CHECK:([[# @LINE+1]]): error 30111:
+            return 3.0;
+    };
+    RayQuery q;
+    let lam2 = (int a) => {
+        //CHECK:([[# @LINE+1]]): error 30112:
+        q.Abort();
+    };
+}
\ No newline at end of file
diff --git a/tests/language-feature/lambda/lambda-simple.slang b/tests/language-feature/lambda/lambda-simple.slang
new file mode 100644
index 000000000..abb7b1a99
--- /dev/null
+++ b/tests/language-feature/lambda/lambda-simple.slang
@@ -0,0 +1,16 @@
+
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHECK):-vk -output-using-type
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHECK):-cpu -output-using-type
+
+//TEST_INPUT: set outputBuffer = out ubuffer(data=[0 0 0 0], stride=4)
+RWStructuredBuffer<uint> outputBuffer;
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    int c = 1;
+    let lambda = (int x, int y) => x + y + c;
+    let result = lambda(3, 4);
+    outputBuffer[0] = result; // Expecting outputBuffer[0] to be 8
+    // CHECK: 8
+}
\ No newline at end of file