Fixed -reflect-function when a definition is found but the fwd declare is missing

Author: Nielsbishere

tools/clang/test/HLSLFileCheck/dxreflector/fwd_declare_test2.hlsl

@@ -0,0 +1,55 @@
+// RUN: %dxreflector -reflect-functions %s | FileCheck %s
+
+struct PSInput {
+	float4 color : COLOR;
+};
+
+struct Test;
+
+struct A {
+	float a;
+	float t(Test t);  
+};
+
+struct Test {
+	float a;  
+};
+
+float A::t(Test t) {
+	return 2;
+}
+
+[[oxc::stage("pixel")]]
+float4 PSMain(PSInput input) : SV_TARGET
+{
+	A a;
+	Test t;
+	return input.color * a.t(t);
+}
+
+// CHECK: {
+// CHECK:         "Features": [
+// CHECK:                 "Functions",
+// CHECK:                 "Symbols"
+// CHECK:         ],
+// CHECK:         "Children": [
+// CHECK:                 {
+// CHECK:                         "Name": "PSMain",
+// CHECK:                         "NodeType": "Function",
+// CHECK:                         "Semantic": "SV_TARGET",
+// CHECK:                         "Annotations": [
+// CHECK:                                 {{"\[\[oxc::stage\(\\\"pixel\\\"\)\]\]"}}
+// CHECK:                         ],
+// CHECK:                         "Function": {
+// CHECK:                                 "Params": {
+// CHECK:                                         "input": {
+// CHECK:                                                 "TypeName": "PSInput"
+// CHECK:                                         }
+// CHECK:                                 },
+// CHECK:                                 "ReturnType": {
+// CHECK:                                         "TypeName": "float4"
+// CHECK:                                 }
+// CHECK:                         }
+// CHECK:                 }
+// CHECK:         ]
+// CHECK: }

tools/clang/tools/dxcreflection/dxcreflection_from_ast.cpp

@@ -97,6 +97,48 @@ PushNextNodeId(uint32_t &NodeId, ReflectionData &Refl, const SourceManager &SM,
   if (LocalId >= (1u << 24))
     return HLSL_REFL_ERR("LocalId overflow");
 
+  bool isFwdDeclare = false;
+  bool canHaveFwdDeclare = false;
+  const Decl *fwdDeclare = nullptr;
+
+  if (DeclSelf) {
+
+    if (const FunctionDecl *func = dyn_cast<FunctionDecl>(DeclSelf)) {
+      isFwdDeclare = !func->doesThisDeclarationHaveABody();
+      fwdDeclare = func->getCanonicalDecl();
+      canHaveFwdDeclare = true;
+    }
+
+    else if (const EnumDecl *enm = dyn_cast<EnumDecl>(DeclSelf)) {
+      isFwdDeclare = !enm->isCompleteDefinition();
+      fwdDeclare = enm->getCanonicalDecl();
+      canHaveFwdDeclare = true;
+    }
+
+    else if (const RecordDecl *rec = dyn_cast<RecordDecl>(DeclSelf)) {
+
+      isFwdDeclare = !rec->isThisDeclarationADefinition();
+      fwdDeclare = rec->getCanonicalDecl();
+      canHaveFwdDeclare = true;
+
+      if (isFwdDeclare && rec->isImplicit()) { // Inner ghost node
+        NodeId = uint32_t(-1);
+        return ReflectionErrorSuccess;
+      }
+    }
+  }
+
+  //There is a forward declare, but we haven't seen it before.
+  //This happens for example if we have a fwd func declare in a struct, but define it in global namespace.
+  //(only) -reflect-function will hide this struct from us, but will still find a function in the global scope.
+  //This fixes that problem.
+
+  if (!isFwdDeclare && fwdDeclare && fwdDeclare != DeclSelf &&
+      FwdDecls->find(fwdDeclare) == FwdDecls->end()) {
+    NodeId = uint32_t(-1);
+    return ReflectionErrorSuccess;
+  }
+
   uint32_t nodeId = Refl.Nodes.size();
 
   uint16_t annotationStart = uint16_t(Refl.Annotations.size());
@@ -179,37 +221,6 @@ PushNextNodeId(uint32_t &NodeId, ReflectionData &Refl, const SourceManager &SM,
 
   D3D_INTERPOLATION_MODE interpolationMode = GetInterpolationMode(DeclSelf);
 
-  bool isFwdDeclare = false;
-  bool canHaveFwdDeclare = false;
-  const Decl *fwdDeclare = nullptr;
-
-  if (DeclSelf) {
-
-    if (const FunctionDecl *func = dyn_cast<FunctionDecl>(DeclSelf)) {
-      isFwdDeclare = !func->doesThisDeclarationHaveABody();
-      fwdDeclare = func->getCanonicalDecl();
-      canHaveFwdDeclare = true;
-    }
-
-    else if (const EnumDecl *enm = dyn_cast<EnumDecl>(DeclSelf)) {
-      isFwdDeclare = !enm->isCompleteDefinition();
-      fwdDeclare = enm->getCanonicalDecl();
-      canHaveFwdDeclare = true;
-    }
-
-    else if (const RecordDecl *rec = dyn_cast<RecordDecl>(DeclSelf)) {
-
-      isFwdDeclare = !rec->isThisDeclarationADefinition();
-      fwdDeclare = rec->getCanonicalDecl();
-      canHaveFwdDeclare = true;
-
-      if (isFwdDeclare && rec->isImplicit()) { // Inner ghost node
-        NodeId = uint32_t(-1);
-        return ReflectionErrorSuccess;
-      }
-    }
-  }
-
   uint32_t currId = uint32_t(Refl.Nodes.size());
 
   if (canHaveFwdDeclare) {