From 1fb3c1536587d6ed085f13af78101cbfb3481dca Mon Sep 17 00:00:00 2001
From: Sai Praveen Bangaru <31557731+saipraveenb25@users.noreply.github.com>
Date: Thu, 27 Feb 2025 10:28:13 -0800
Subject: Fix overload resolution for `ModuleDeclarationDecl` (#6483)

* Fix overload resolution for `MemberExp`r's base expression

Also fixed an issue where `ModuleDeclarationDecl` priority during overload resolution was inverted.

* Made the fix slightly simpler..

* Update overload-resolve.slang
---
 source/slang/slang-check-expr.cpp                  |  6 +++++-
 source/slang/slang-check-overload.cpp              |  2 +-
 .../namespace-import/overload-resolve.slang        | 25 ++++++++++++++++++++++
 3 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 tests/language-feature/namespaces/namespace-import/overload-resolve.slang

diff --git a/source/slang/slang-check-expr.cpp b/source/slang/slang-check-expr.cpp
index 1fb2b336f..b249bb343 100644
--- a/source/slang/slang-check-expr.cpp
+++ b/source/slang/slang-check-expr.cpp
@@ -4848,17 +4848,21 @@ Expr* SemanticsVisitor::maybeInsertImplicitOpForMemberBase(
     //
     baseExpr = maybeOpenExistential(baseExpr);
 
+    // In case our base expressin is still overloaded, we can perform
+    // some more refinement.
+    //
     // Handle the case of an overloaded base expression
     // here, in case we can use the name of the member to
     // disambiguate which of the candidates is meant, or if
     // we can return an overloaded result.
+    //
     if (auto overloadedExpr = as<OverloadedExpr>(baseExpr))
     {
         // If a member (dynamic or static) lookup result contains both the actual definition
         // and the interface definition obtained from inheritance, we want to filter out
         // the interface definitions.
         LookupResult filteredLookupResult;
-        for (auto lookupResult : overloadedExpr->lookupResult2)
+        for (auto lookupResult : overloadedExpr->lookupResult2.items)
         {
             bool shouldRemove = false;
             if (lookupResult.declRef.getParent().as<InterfaceDecl>())
diff --git a/source/slang/slang-check-overload.cpp b/source/slang/slang-check-overload.cpp
index 01cd303c7..5e55eb70f 100644
--- a/source/slang/slang-check-overload.cpp
+++ b/source/slang/slang-check-overload.cpp
@@ -1345,7 +1345,7 @@ int SemanticsVisitor::CompareLookupResultItems(
     bool leftIsModule = (as<ModuleDeclarationDecl>(left.declRef) != nullptr);
     bool rightIsModule = (as<ModuleDeclarationDecl>(right.declRef) != nullptr);
     if (leftIsModule != rightIsModule)
-        return int(rightIsModule) - int(leftIsModule);
+        return int(leftIsModule) - int(rightIsModule);
 
     // If both are interface requirements, prefer the more derived interface.
     if (leftIsInterfaceRequirement && rightIsInterfaceRequirement)
diff --git a/tests/language-feature/namespaces/namespace-import/overload-resolve.slang b/tests/language-feature/namespaces/namespace-import/overload-resolve.slang
new file mode 100644
index 000000000..0b483d916
--- /dev/null
+++ b/tests/language-feature/namespaces/namespace-import/overload-resolve.slang
@@ -0,0 +1,25 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -shaderobj
+
+module test;
+
+namespace test
+{
+    vector<uint, N> f<int N>(vector<uint, N> x)
+    {
+        return x;
+    }
+}
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+[numthreads(1, 1, 1)]
+void computeMain(int3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int tid = dispatchThreadID.x;
+    int inVal = tid;
+    // Should be able to resolve 'test' properly (and not get confused by the module declaration with the same name)
+    int outVal = test.f<3>(vector<uint, 3>(1, 2, 3)).y;
+    outputBuffer[tid] = outVal;
+    // CHECK: 2
+}
-- 
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