[clang] [HLSL] Add static methods for resource initialization (PR #155866)

[Helena Kotas via cfe-commits]

================
@@ -676,6 +774,58 @@ BuiltinTypeDeclBuilder::addHandleConstructorFromImplicitBinding() {
       .finalize();
 }
 
+BuiltinTypeDeclBuilder &BuiltinTypeDeclBuilder::addCreateFromBinding() {
+  if (Record->isCompleteDefinition())
+    return *this;
+
+  using PH = BuiltinTypeMethodBuilder::PlaceHolder;
+  ASTContext &AST = SemaRef.getASTContext();
+  QualType HandleType = getResourceHandleField()->getType();
+  QualType RecordType = AST.getTypeDeclType(cast<TypeDecl>(Record));
+
+  return BuiltinTypeMethodBuilder(*this, "__createFromBinding", RecordType,
+                                  false, false, AS_public, SC_Static)
+      .addParam("registerNo", AST.UnsignedIntTy)
+      .addParam("spaceNo", AST.UnsignedIntTy)
+      .addParam("range", AST.IntTy)
+      .addParam("index", AST.UnsignedIntTy)
+      .addParam("name", AST.getPointerType(AST.CharTy.withConst()))
+      .createLocalVar("tmp", RecordType)
+      .getResourceHandle(PH::LocalVar_0)
+      .callBuiltin("__builtin_hlsl_resource_handlefrombinding", HandleType,
+                   PH::LastStmt, PH::_0, PH::_1, PH::_2, PH::_3, PH::_4)
+      .setHandleFieldOnResource(PH::LocalVar_0, PH::LastStmt)
+      .returnValue(PH::LocalVar_0)
+      .finalize();
+}
+
+BuiltinTypeDeclBuilder &BuiltinTypeDeclBuilder::addCreateFromImplicitBinding() {
+  if (Record->isCompleteDefinition())
+    return *this;
+
+  using PH = BuiltinTypeMethodBuilder::PlaceHolder;
+  ASTContext &AST = SemaRef.getASTContext();
+  QualType HandleType = getResourceHandleField()->getType();
+  QualType RecordType = AST.getTypeDeclType(cast<TypeDecl>(Record));
+
+  return BuiltinTypeMethodBuilder(*this, "__createFromImplicitBinding",
+                                  RecordType, false, false, AS_public,
+                                  SC_Static)
+      .addParam("orderId", AST.UnsignedIntTy)
+      .addParam("spaceNo", AST.UnsignedIntTy)
+      .addParam("range", AST.IntTy)
+      .addParam("index", AST.UnsignedIntTy)
+      .addParam("name", AST.getPointerType(AST.CharTy.withConst()))
+      .createLocalVar("tmp", RecordType)
+      .getResourceHandle(PH::LocalVar_0)
+      .callBuiltin("__builtin_hlsl_resource_handlefromimplicitbinding",
+                   HandleType, PH::LastStmt, PH::_0, PH::_1, PH::_2, PH::_3,
+                   PH::_4)
+      .setHandleFieldOnResource(PH::LocalVar_0, PH::LastStmt)
----------------
hekota wrote:

`setHandleFieldOnResource(PH::LocalVar_0, PH::LastStmt)` is assigning the value of the last statement (=result of the builtin call) to the resource handle field to the first local variable in the method. Then then it is returning the local variable. I will add a comment to the `addCreateFromBinding`/`addCreateFromImplicitBinding` methods explaining how the body looks like.

https://github.com/llvm/llvm-project/pull/155866