Fix for issue with user attribute lookup (#2437)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Add handling for root paths.

* Fixes around absolute paths.

* Add SimplifyStyle

* Remove unrequire include.

* Fix some details around RelativeFileSystem canonical paths.

* For MemoryFileSystem make sure "/a" and "a" maps to same canonical path.

* Add test for canonicalPath.

* Improve comment.

* More testing around canonical paths.

* Fix for user attribute lookup issue.

* Add a test.

* Small improvements in test.

* Improve the comments around lookup workaround.

5 files changed, 74 insertions, 0 deletions

diff --git a/source/slang/slang-check-impl.h b/source/slang/slang-check-impl.h
index 433c6ca70..c15428877 100644
--- a/source/slang/slang-check-impl.h
+++ b/source/slang/slang-check-impl.h
@@ -237,6 +237,11 @@ namespace Slang
         Dictionary<LookupRequestKey, LookupResult> lookupCache;
     };
 
+
+        /// Give a cache and a name, will remove all entries associated with a name
+        /// Might be useful/necessary if a new name is introduced
+    void removeLookupForName(TypeCheckingCache* cache, Name* name);
+
         /// Shared state for a semantics-checking session.
     struct SharedSemanticsContext
     {
diff --git a/source/slang/slang-check-modifier.cpp b/source/slang/slang-check-modifier.cpp
index a7fb641a2..a2b411c22 100644
--- a/source/slang/slang-check-modifier.cpp
+++ b/source/slang/slang-check-modifier.cpp
@@ -226,6 +226,19 @@ namespace Slang
         attrDecl->parentDecl = parentDecl;
         parentDecl->members.add(attrDecl);
         
+        SLANG_ASSERT(!parentDecl->isMemberDictionaryValid());
+
+        // TODO(JS): A bit of a work around(!)
+        // 
+        // To get to this point we must have already have performed a lookup for attributeName, 
+        // and it failed. That lookup used the TypeCheckingCache, and 
+        // so we know there is a cache entry that will be *wrong*, now we have created and 
+        // added the AttributeDecl with the attributeName.
+        // 
+        // To work around, we remove all cached lookups around the name, such that when a subsequent 
+        // lookup is made, the cache will not return the old (wrong) result.
+        removeLookupForName(getLinkage()->getTypeCheckingCache(), attributeName);
+
         // Finally, we perform any required semantic checks on
         // the newly constructed attribute decl.
         //
diff --git a/source/slang/slang-check.cpp b/source/slang/slang-check.cpp
index bcc74a6d0..8c6cddbfe 100644
--- a/source/slang/slang-check.cpp
+++ b/source/slang/slang-check.cpp
@@ -210,4 +210,24 @@ namespace Slang
             throw;
         }
     }
+
+    void removeLookupForName(TypeCheckingCache* cache, Name* name)
+    {
+        auto& lookupCache = cache->lookupCache;
+
+        List<LookupRequestKey> keys;
+
+        for (const auto& pairs : lookupCache)
+        {
+            const auto& key = pairs.Key;
+            if (key.name == name)
+            {
+                keys.add(key);
+            }
+        }
+        for (auto& key : keys)
+        {
+            lookupCache.Remove(key);
+        }
+    }
 }
diff --git a/tests/bugs/user-attribute-lookup.slang b/tests/bugs/user-attribute-lookup.slang
new file mode 100644
index 000000000..96cd3ad19
--- /dev/null
+++ b/tests/bugs/user-attribute-lookup.slang
@@ -0,0 +1,32 @@
+//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;
+
+// To test for a bug where a user attribute, gets incorrectly looked up
+// as a cached lookup made before creation will make it multiply defined.
+
+// Define an attribute that will appear in reflection
+[__AttributeUsage(_AttributeTargets.Var)]
+struct StaticSamplerAttribute {};
+
+struct Thing
+{
+    [StaticSampler] SamplerState samplerState1;
+    [StaticSampler] SamplerState samplerState2;
+}
+
+[StaticSampler] SamplerState samplerState;
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+	uint tid = dispatchThreadID.x;
+
+	float inVal = float(tid);
+
+	outputBuffer[tid] = int(inVal);
+}
+
+
diff --git a/tests/bugs/user-attribute-lookup.slang.expected.txt b/tests/bugs/user-attribute-lookup.slang.expected.txt
new file mode 100644
index 000000000..bc856dafa
--- /dev/null
+++ b/tests/bugs/user-attribute-lookup.slang.expected.txt
@@ -0,0 +1,4 @@
+0
+1
+2
+3