[HLSL] Add more tests to root signature metadata extraction (#127283)

This PR adds a few more tests to validate some error scenarios of root
signature metadata representation.

Closes: #127280

---------

Co-authored-by: joaosaffran <[email protected]>

Author: joaosaffran

llvm/lib/Target/DirectX/DXILRootSignature.cpp

@@ -150,11 +150,17 @@ analyzeModule(Module &M) {
       continue;
     }
 
-    MDNode *RootElementListNode =
-        dyn_cast<MDNode>(RSDefNode->getOperand(1).get());
+    Metadata *RootElementListOperand = RSDefNode->getOperand(1).get();
 
+    if (RootElementListOperand == nullptr) {
+      reportError(Ctx, "Root Element mdnode is null.");
+      continue;
+    }
+
+    MDNode *RootElementListNode = dyn_cast<MDNode>(RootElementListOperand);
     if (RootElementListNode == nullptr) {
-      reportError(Ctx, "Missing Root Element List Metadata node.");
+      reportError(Ctx, "Root Element is not a metadata node.");
+      continue;
     }
 
     mcdxbc::RootSignatureDesc RSD;

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error-is-not-function.ll

@@ -0,0 +1,26 @@
+; RUN: not opt -passes='print<dxil-root-signature>' %s -S -o - 2>&1 | FileCheck %s
+
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+; CHECK: error: First element of root signature is not a Function
+; CHECK-NOT: Root Signature Definitions
+
+define void @main() #0 {
+entry:
+  ret void
+}
+
+define void @anotherMain() #0 {
+entry:
+  ret void
+}
+
+attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
+
+!dx.rootsignatures = !{!2, !5} ; list of function/root signature pairs
+!2 = !{ ptr @main, !3 } ; function, root signature
+!3 = !{ !4 } ; list of root signature elements
+!4 = !{ !"RootFlags", i32 1 } ; 1 = allow_input_assembler_input_layout
+!5 = !{ i32 -1, !6 } ; function, root signature
+!6 = !{ !7 } ; list of root signature elements
+!7 = !{ !"RootFlags", i32 2 } ; 1 = allow_input_assembler_input_layout

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error-is-not-value.ll

@@ -0,0 +1,26 @@
+; RUN: not opt -passes='print<dxil-root-signature>' %s -S -o - 2>&1 | FileCheck %s
+
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+; CHECK: error: First element of root signature is not a Value
+; CHECK-NOT: Root Signature Definitions
+
+define void @main() #0 {
+entry:
+  ret void
+}
+
+define void @anotherMain() #0 {
+entry:
+  ret void
+}
+
+attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
+
+!dx.rootsignatures = !{!2, !5} ; list of function/root signature pairs
+!2 = !{ ptr @main, !3 } ; function, root signature
+!3 = !{ !4 } ; list of root signature elements
+!4 = !{ !"RootFlags", i32 1 } ; 1 = allow_input_assembler_input_layout
+!5 = !{ !3, !6 } ; function, root signature
+!6 = !{ !7 } ; list of root signature elements
+!7 = !{ !"RootFlags", i32 2 } ; 1 = allow_input_assembler_input_layout

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error-no-root-element-list.ll

@@ -0,0 +1,26 @@
+; RUN: not opt -passes='print<dxil-root-signature>' %s -S -o - 2>&1 | FileCheck %s
+
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+; CHECK: error: Root Element mdnode is null.
+; CHECK-NOT: Root Signature Definitions
+
+define void @main() #0 {
+entry:
+  ret void
+}
+
+define void @anotherMain() #0 {
+entry:
+  ret void
+}
+
+attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
+
+!dx.rootsignatures = !{!2, !5} ; list of function/root signature pairs
+!2 = !{ ptr @main, null } ; function, root signature
+!3 = !{ !4 } ; list of root signature elements
+!4 = !{ !"RootFlags", i32 1 } ; 1 = allow_input_assembler_input_layout
+!5 = !{ i32 -1, !6 } ; function, root signature
+!6 = !{ !7 } ; list of root signature elements
+!7 = !{ !"RootFlags", i32 2 } ; 1 = allow_input_assembler_input_layout

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error-root-element-not-mdnode.ll

@@ -0,0 +1,26 @@
+; RUN: not opt -passes='print<dxil-root-signature>' %s -S -o - 2>&1 | FileCheck %s
+
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+; CHECK: error: Root Element is not a metadata node.
+; CHECK-NOT: Root Signature Definitions
+
+define void @main() #0 {
+entry:
+  ret void
+}
+
+define void @anotherMain() #0 {
+entry:
+  ret void
+}
+
+attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
+
+!dx.rootsignatures = !{!2, !5} ; list of function/root signature pairs
+!2 = !{ ptr @main, i32 -1 } ; function, root signature
+!3 = !{ !4 } ; list of root signature elements
+!4 = !{ !"RootFlags", i32 1 } ; 1 = allow_input_assembler_input_layout
+!5 = !{ i32 -1, !6 } ; function, root signature
+!6 = !{ !7 } ; list of root signature elements
+!7 = !{ !"RootFlags", i32 2 } ; 1 = allow_input_assembler_input_layout