4 files changed, 67 insertions, 0 deletions
diff --git a/tests/serialization/extern/extern-test.slang b/tests/serialization/extern/extern-test.slang
new file mode 100644
index 000000000..0079a3527
--- /dev/null
+++ b/tests/serialization/extern/extern-test.slang
@@ -0,0 +1,26 @@
+// serialized-module-entry-point-test.slang
+
+//TEST:COMPILE: -module-name module -no-codegen tests/serialization/extern/module-a.slang -o tests/serialization/extern/module-a.slang-lib
+//TEST:COMPILE: -module-name module -no-codegen tests/serialization/extern/module-b.slang -o tests/serialization/extern/module-b.slang-lib
+//TEST:COMPARE_COMPUTE_EX: -xslang -module-name -xslang module -slang -compute -xslang -r -xslang tests/serialization/extern/module-a.slang-lib -xslang -r -xslang tests/serialization/extern/module-b.slang-lib 
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0 ], stride=4):dxbinding(0),glbinding(0),out,name outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+// Declare the type exists
+[__extern] struct Thing {};
+// A mechanism to make a Thing without knowing the specific fields.
+[__extern] Thing makeThing(int a, int b);
+
+[__extern] int doSomething(Thing a, Thing b);
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int index = int(dispatchThreadID.x);
+
+    Thing a = makeThing(index + 1, index + 2);
+    Thing b = makeThing(-index , index * 2);
+    
+    outputBuffer[index] = doSomething(a, b);
+}
+\ No newline at end of file
diff --git a/tests/serialization/extern/extern-test.slang.expected.txt b/tests/serialization/extern/extern-test.slang.expected.txt
new file mode 100644
index 000000000..e326b6740
--- /dev/null
+++ b/tests/serialization/extern/extern-test.slang.expected.txt
@@ -0,0 +1,4 @@
+5
+B
+11
+17
diff --git a/tests/serialization/extern/module-a.slang b/tests/serialization/extern/module-a.slang
new file mode 100644
index 000000000..81816a213
--- /dev/null
+++ b/tests/serialization/extern/module-a.slang
@@ -0,0 +1,23 @@
+//TEST_IGNORE_FILE:
+
+// module-a.slang
+
+struct Thing
+{
+    int a; 
+    int b;
+};
+
+Thing makeThing(int a, int b)
+{
+    Thing thing;
+    thing.a = a;
+    thing.b = b;
+    return thing;
+}
+
+int foo(Thing thing) 
+{ 
+    return thing.a + thing.b * 2; 
+}
+
diff --git a/tests/serialization/extern/module-b.slang b/tests/serialization/extern/module-b.slang
new file mode 100644
index 000000000..20371f156
--- /dev/null
+++ b/tests/serialization/extern/module-b.slang
@@ -0,0 +1,14 @@
+//TEST_IGNORE_FILE:
+
+// module-b.slang
+
+// This looks like a definition (and it is) but with [__extern] it's definition will be replaced at link time with a defintion
+[__extern] struct Thing {};
+[__extern] int foo(Thing thing);
+
+int doSomething(Thing a, Thing b)
+{
+    return foo(a) + foo(b);
+}
+
+