Add support for [noinline] attribute (#1650)

This adds the `[noinline]` attribute to the front-end, and passes it through when generating HLSL output.

Notes:

* This change doesn't include a test since the dxc version I have locally parses `[noinline]` but then generates DXIL that fails validation.

* This change doesn't include logic to handle `[noinline]` for other targets. Notably, SPIR-V has decorations that convey the same intention, but we don't yet take advantage of the GLSL extension(s) that would let us generate those decorations.

* By necesstiy, `[noinline]` is only a "strong suggestion" and not actually something the compiler can ever guarantee/enforce.

1 files changed, 12 insertions, 0 deletions

diff --git a/source/slang/slang-ast-modifier.h b/source/slang/slang-ast-modifier.h
index 55b62483b..3d0c3c6c1 100644
--- a/source/slang/slang-ast-modifier.h
+++ b/source/slang/slang-ast-modifier.h
@@ -937,4 +937,16 @@ class NVAPISlotModifier : public Modifier
     String spaceName;
 };
 
+    /// A `[noinline]` attribute represents a request by the application that,
+    /// to the extent possible, a function should not be inlined into call sites.
+    ///
+    /// Note that due to various limitations of different targets, it is entirely
+    /// possible for such functions to be inlined or specialized to call sites.
+    ///
+class NoInlineAttribute : public Attribute
+{
+    SLANG_AST_CLASS(NoInlineAttribute)
+};
+
+
 } // namespace Slang