Cupid: A Smart Development Environment for Earth System Models

1. Cupid:A Smart Development Environment for Earth System Models Rocky Dunlap research sponsored by NASA/ROSES

2. ESMF/NUOPC • A framework for constructing earth system models from components • Hierarchical architecture • Functions for coupling and data exchange, including representing numerical grids and interpolation • A layer on top of ESMF • Standardized way of using ESMF to promote a common model architecture • Generic components that can be specialized

3. Adopting a Scientific Framework • Scientific frameworks provide: • an overall structure for the application • reusable, domain-specific functionality • Adopting a scientific framework requires: • understanding the framework API • writing framework completion code to implement framework concepts • respecting framework constraints

4. Framework SpecificModeling Languages • Explicit encoding of domain-specific concepts provided by a framework API • Framework concepts are mapped to code patterns • Two-way mapping: • Reverse engineering of existing code • Forward engineering - code generation Antkiewicz, Michał, and Krzysztof Czarnecki. "Framework-specific modeling languages with round-trip engineering." Model Driven Engineering Languages and Systems (2006): 692-706.

5. source code editor framework-specific model

6. Framework Completion Code Framework Specific Modeling Language NUOPC Model Implements Set Services Name Calls Generic Set Services Registers Init Phase 1 Registers Init Phase 2 Implements Init Phase 1

7. Structural Mapping Types

8. Structural Mapping Types (cont)

9. Mappings NUOPC Model module Implements Set Services subroutine: “*(type(ESMF_GridComp), integer)” Name subroutineName Calls Generic Set Services call: “routine_SetServices” definedInModule: “NUOPC_Model” Registers Init Phase 0 call: “ESMF_GridCompSetEntryPoint” Registers Init Phase 1 call: “ESMF_GridCompSetEntryPoint” Registers Init Phase 2 call: “ESMF_GridCompSetEntryPoint” subroutine: “*(type(ESMF_GridComp), type(ESMF_State), type(ESMF_State), type(ESMF_Clock), integer)” Implements Init Phase 0 subroutine: “*(type(ESMF_GridComp), type(ESMF_State), type(ESMF_State), type(ESMF_Clock), integer)” Implements Init Phase 1 ...

10. Constraints NUOPC Model module [1] Implements Set Services subroutine: “*(type(ESMF_GridComp), integer)” [1] Name subroutineName required by framework (violations allowed during development) ![1] Calls Generic Set Services call: “routine_SetServices” definedInModule: “NUOPC_Model” required by framework AND essential to match set services (never violated) [0..1] Registers Init Phase 0 call: “ESMF_GridCompSetEntryPoint” [1] Registers Init Phase 1 call: “ESMF_GridCompSetEntryPoint” optional by framework [1] Registers Init Phase 2 call: “ESMF_GridCompSetEntryPoint” subroutine: “*(type(ESMF_GridComp), type(ESMF_State), type(ESMF_State), type(ESMF_Clock), integer)” [0..1] Implements Init Phase 0 subroutine: “*(type(ESMF_GridComp), type(ESMF_State), type(ESMF_State), type(ESMF_Clock), integer)” [1] Implements Init Phase 1 ...

11. Another Part of the FSML Implements Init Phase 1 subroutine: “*(type(ESMF_GridComp), type(ESMF_State), type(ESMF_State), type(ESMF_Clock), integer)” [1] importStateParam formalParam: 2 [1] exportStateParam formalParam: 3 [0..*] advertisesImportField call: NUOPC_StateAdvertiseField [1] addsToState argValByIndex: 1 essential OCL: self.addsToState == self.parent.importStateParam ![1] addsToImportState [1] standardName argValByKeyword: “StandardName” derived path expression

12. Partial Code for Init Phase 1

13. Making the FSML More Concise Implements Init Phase 1 subroutine: “*(type(ESMF_GridComp), type(ESMF_State), type(ESMF_State), type(ESMF_Clock), integer)” [1] importStateParam formalParam: 2 [1] exportStateParam formalParam: 3 [0..*] advertisesImportField call: NUOPC_StateAdvertiseField [1] addsToState argValByIndex: 1 ![1] argValByIndex: 1 sameAs: (../../ formalParam: 2) addsToImportState [1] standardName argValByKeyword: “StandardName” embedded path expression

14. Realize Bi-directional Mappings code queries code transformations module atm use ESMF use NUOPC use NUOPC_Model subroutine setservices(gcomp, rc) .... end subroutine subroutine advance(gcomp, rc) .... end subroutine .... end module Virtual Program Graph & Abstract Syntax Tree parse rewrite Photran Eclipse Plugin

15. Status • FSML concepts: • NUOPC Model, Set Services, Init Phase 1, Init Phase 2, Advertise Import/Export Field, Realize Import/Export Field, Attach Model Advance method • Mappings: defined on as “as needed” basis • Code queries for every mapping (reverse dir.) • Only a few code transformations (forward dir.)

16. Issues & Opportunities • Dealing with different versions of the framework, API releases, etc. • FSML: Should we take a coarse-grained or fine-grained approach? • coarse-grained: Full architecture of NUOPC application; Models, Mediators, Connectors, etc. • fine-grained: Focus on NUOPC Model with high detail • Limitations of static analysis • How far will it take us? • Inclusion of control flow hints for the user: conditionals and loops • How would this tool work in a dynamic environment?

17. Old Slides

18. Constraints NUOPC Model [1] required by framework (violations allowed during development) Implements Set Services [1] Name required by framework AND essential in order to match parent feature (never violated) ![1] Calls Generic Set Services [0..1] Registers Init Phase 0 [1] Registers Init Phase 1 [1] Registers Init Phase 2 optional by framework [0..1] Implements Init Phase 0 [1] Implements Init Phase 1 ...

20. Image taken from Figure 2 of: Antkiewicz, Michał, and Krzysztof Czarnecki. "Framework-specific modeling languages with round-trip engineering." Model Driven Engineering Languages and Systems (2006): 692-706. http://gp.uwaterloo.ca/sites/default/files/models06.pdf

21. Synchronization States and Reconciliation (Antkiewicz) • synchronization state: forward addition • a feature added to the asserted model • e.g., a new import field is advertised • reconciliation decision: enforce • make code consistent with asserted model • e.g., adds calls to NUOPC_StateAdvertiseField()

22. Synchronization States and Reconciliation (Antkiewicz) • synchronization state: reverse removal • a feature removed from code • e.g., call to NUOPC_StateRealizeField() removed • reconciliation decision: update • make asserted model consistent with code • e.g., remove realize field feature from asserted model • key features used to match concepts between code and model • e.g., use field short name because they are unique

23. Forward Engineering (Antkiewicz) • Example feature (variation point): • advertise import field “sea_surface_temperature” • Code transformations • need to add a call to: NUOPC_StateAdvertiseField(importState, StandardName=“sea_surface_temperature”, rc=rc) • where to add the call (initialize phase 1) • how to determine which subroutine? (e.g., look at SetServices?) • what if it doesn’t exist? (e.g., add it automatically?) • name of import state parameter (second parameter of subroutine) • add error checking calls? (need to know name of rc parameter)

24. Reverse Engineering (Antkiewicz) • Start with existing source code (e.g., a Fortran module) • Code queries used to build model • Question: Is the Fortran module a NUOPC Model? • Does it use ESMF, NUOPC, and NUOPC_Model? • Is this enough? • Does it have a SetServices that calls the generic NUOPC_Modelroutine_SetServices() • Keep it mind it could have an alias, e.g., model_routine_SetServices() • Support for partial concepts • e.g., this is a NUOPC_Model but it fails to call the generic routine_setServices() method • required because we are helping the user to build up implementation incrementally

25. Partial Framework Specific Modeling Language for NUOPC Maps to a Fortran module Name of model True if module uses ESMF, NUOPC, NUOPC_Model Reference Maps to subroutine True if has correct parameter types (gcomp, rc) True if calls routine_SetServices in NUOPC_Model True if sets entry point for init phase 1, 2

26. Code Queries

27. Candidates / False Positives • Goal: Given code for a (partial) NUOPC Model, find the SetServices routine • Initially ALL subroutines in the module are candidates • Look for clues: • parameter types (ESMF_GridComp, Integer) • calls to routine_SetServices() in NUOPC_Model • calls to ESMF_GridCompSetServices() • calls to ESMF_MethodAdd()

28. Has 2 parameters of type ESMF_Grid and Integer Calls routine_SetServices() If there is ONE subroutine here, it is likely the right one. BUT, if there are ZERO subroutines, then we have to consider other CANDIDATES. Calls ESMF_GridCompSetServices()