Bug fix: partially specialized non-static generic invoke missing `this` argument. (#2536)

* Fix non-static generic func call issue.

* Add test case.

* Revert unnecessary change.

* Update test comment.

Co-authored-by: Yong He <yhe@nvidia.com>

4 files changed, 65 insertions, 1 deletions

diff --git a/source/slang/slang-check-expr.cpp b/source/slang/slang-check-expr.cpp
index 2c6899269..1f0e1a2dc 100644
--- a/source/slang/slang-check-expr.cpp
+++ b/source/slang/slang-check-expr.cpp
@@ -1054,6 +1054,14 @@ namespace Slang
         {
             return overloadedExpr2->base;
         }
+        else if (auto genApp = as<GenericAppExpr>(expr))
+        {
+            return GetBaseExpr(genApp->functionExpr);
+        }
+        else if (auto partiallyApplied = as<PartiallyAppliedGenericExpr>(expr))
+        {
+            return GetBaseExpr(partiallyApplied->originalExpr);
+        }
         return nullptr;
     }
 
diff --git a/source/slang/slang-check-overload.cpp b/source/slang/slang-check-overload.cpp
index 3867dda03..911587fd5 100644
--- a/source/slang/slang-check-overload.cpp
+++ b/source/slang/slang-check-overload.cpp
@@ -729,7 +729,7 @@ namespace Slang
                 {
                     auto expr = m_astBuilder->create<PartiallyAppliedGenericExpr>();
                     expr->loc = context.loc;
-                    expr->originalExpr = originalAppExpr;
+                    expr->originalExpr = baseExpr;
                     expr->baseGenericDeclRef = as<DeclRefExpr>(baseExpr)->declRef.as<GenericDecl>();
                     expr->substWithKnownGenericArgs = (GenericSubstitution*)candidate.subst;
                     return expr;
diff --git a/tests/bugs/generic-member-method.slang b/tests/bugs/generic-member-method.slang
new file mode 100644
index 000000000..06e80cd0c
--- /dev/null
+++ b/tests/bugs/generic-member-method.slang
@@ -0,0 +1,52 @@
+// Test calling a generic member method with partially specified generic arguments.
+
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -shaderobj
+//TEST(compute,vulkan):COMPARE_COMPUTE_EX:-vk -slang -compute -shaderobj
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+interface INothing
+{
+    int getVal();
+}
+
+struct Nothing : INothing
+{
+    int getVal() { return 0; }
+}
+
+interface IImpl
+{
+    int computeAdd<TNothing : INothing, TNothing2 : INothing>(TNothing nothingArg, TNothing2 nothing, int otherVal);
+}
+
+struct Impl : IImpl
+{
+    int thisVal;
+    __init()
+    {
+        thisVal = 1;
+    }
+    // Introduce two generic parameters so we can construct a partially specialized invoke.
+    int computeAdd<TNothing : INothing, TNothing2 : INothing>(TNothing nothingArg, TNothing2 nothing, int otherVal)
+    {
+        return thisVal + otherVal + nothingArg.getVal();
+    }
+    int doThing(int otherVal)
+    {
+        Nothing nothing;
+        // Partially specialize the invoke.
+        // This will result in construction of `PartiallySpecializedInvokeExpr`.
+        // We need to make sure the baseExpr is persisted during this step.
+        return computeAdd<Nothing>(nothing, nothing, otherVal);
+    }
+}
+
+[numthreads(1, 1, 1)]
+void computeMain(int3 dispatchThreadID: SV_DispatchThreadID)
+{
+    Impl impl;
+    Nothing nothing;
+    outputBuffer[0] = impl.doThing(2);
+}
\ No newline at end of file
diff --git a/tests/bugs/generic-member-method.slang.expected.txt b/tests/bugs/generic-member-method.slang.expected.txt
new file mode 100644
index 000000000..8a673e262
--- /dev/null
+++ b/tests/bugs/generic-member-method.slang.expected.txt
@@ -0,0 +1,4 @@
+3
+0
+0
+0