2 files changed, 84 insertions, 0 deletions
diff --git a/tests/diagnostics/illegal-func-decl-module.slang b/tests/diagnostics/illegal-func-decl-module.slang
new file mode 100644
index 000000000..97b66d129
--- /dev/null
+++ b/tests/diagnostics/illegal-func-decl-module.slang
@@ -0,0 +1,26 @@
+//TEST_IGNORE_FILE:
+
+export float libraryFunction(float a)
+{
+    a = a + a;
+    return a;
+}
+
+export float libraryFunction1(inout float a)
+{
+    a = a * a;
+    return a;
+}
+
+export float libraryFunction2(inout float a, in float b, out float c)
+{
+    a = a * a;
+    a = a + b;
+    return a;
+}
+
+export float libraryFunction3(in float a)
+{
+    a = a + a;
+    return a;
+}
diff --git a/tests/diagnostics/illegal-func-decl.slang b/tests/diagnostics/illegal-func-decl.slang
new file mode 100644
index 000000000..0ec73dc27
--- /dev/null
+++ b/tests/diagnostics/illegal-func-decl.slang
@@ -0,0 +1,58 @@
+// illegal-func-decl.slang
+
+// This test checks that the in/out/inout modifiers in function declarations must
+// be consistent with the function's definition, and slang can diagnose the inconsistency.
+
+//TEST:COMPILE: tests/diagnostics/illegal-func-decl-module.slang -o tests/diagnostics/illegal-func-decl-module.slang-module
+
+//DIAGNOSTIC_TEST:SIMPLE(filecheck=CHECK1): -r tests/diagnostics/illegal-func-decl-module.slang-module -DTEST1 -target spirv -o illegal-func-decl.spv
+//DIAGNOSTIC_TEST:SIMPLE(filecheck=CHECK2): -r tests/diagnostics/illegal-func-decl-module.slang-module -DTEST2 -target spirv -o illegal-func-decl.spv
+//DIAGNOSTIC_TEST:SIMPLE(filecheck=CHECK3): -r tests/diagnostics/illegal-func-decl-module.slang-module -DTEST3 -target spirv -o illegal-func-decl.spv
+//DIAGNOSTIC_TEST:SIMPLE(filecheck=CHECK4): -r tests/diagnostics/illegal-func-decl-module.slang-module -DTEST4 -target spirv -o illegal-func-decl.spv
+
+#ifdef TEST1
+// CHECK1: ([[# @LINE+1]]): error 45001: unresolved external symbol 'libraryFunction'.
+extern float libraryFunction(inout float a);    // invalid: 'a' is 'in'
+#endif
+
+#ifdef TEST2
+// CHECK2-NOT: ([[# @LINE+1]]): error 45001: unresolved external symbol 'libraryFunction1'.
+extern float libraryFunction1(inout float b);   // valid
+#endif
+
+#ifdef TEST3
+// CHECK3: ([[# @LINE+1]]): error 45001: unresolved external symbol 'libraryFunction2'.
+extern float libraryFunction2(inout float a, in float b, float c);   // valid: 'c' is 'inout'
+#endif
+
+#ifdef TEST4
+// CHECK4-NOT: ([[# @LINE+1]]): error 45001: unresolved external symbol 'libraryFunction3'.
+export float libraryFunction3(float a);         // valid: 'in' is the default is not specified
+#endif
+
+[shader("compute")]
+[numthreads(1, 1, 1)]
+void main(out float4 col : SV_Target0, bool isFrontHit)
+{
+    float a = 5;
+    float b = 7;
+    float c = 7;
+
+#ifdef TEST1
+    col.x = libraryFunction(a);
+#endif
+
+#ifdef TEST2
+    col.y = libraryFunction1(b);
+#endif
+
+#ifdef TEST3
+    col.z = libraryFunction2(a, b, c);
+#endif
+
+#ifdef TEST4
+    col.w = libraryFunction3(a);
+#endif
+}
+
+