Add LLVM IR codegen for `StructDefStmt` (struct type definitions)

[omsherikar]

Description

Implement the translation of astx.StructDefStmt to LLVM IR identified struct types. This is the foundation for struct support in IRx.

Background

• astx already provides StructDefStmt for defining structs
• IRx needs to translate this to LLVM's IdentifiedStructType
• Inspired by LLVM's CodeGenTypes.cpp

Tasks

• Add struct_types: dict[str, ir.IdentifiedStructType] in LLVMLiteIRVisitor to track struct name → LLVM type mapping
• Add struct_defs: dict[str, astx.StructDefStmt] to store struct definitions for field lookup
• Implement visit(node: astx.StructDefStmt) visitor method:
  • Create LLVM IdentifiedStructType using module.context.get_identified_type(name)
  • Map each field's astx type to LLVM type using get_data_type()
  • Set struct body with struct_type.set_body(*field_types)

Example Input (Python)

struct_def = astx.StructDefStmt(
    name="Point",
    attributes=[
        astx.VariableDeclaration(name="x", type_=astx.Int32()),
        astx.VariableDeclaration(name="y", type_=astx.Int32()),
    ],
)

Expected LLVM IR Output

%"Point" = type {i32, i32}

Files to Modify

• src/irx/builders/llvmliteir.py

Acceptance Criteria

• StructDefStmt translates to LLVM IdentifiedStructType
• Struct types are registered and can be looked up by name
• Unit test test_struct_definition passes

[omsherikar]

@xmnlab I have created a issue regarding defining the struct , Can you please have a look into it

[m-akhil-reddy]

Hi @omsherikar @yuvimittal @xmnlab ,
I was reviewing Issue #143 and noticed that a PR #150 was already opened by @Om sherikar. Since Om mentioned being busy and unable to complete the remaining parts (especially adding the test file), I took permission from om to continue and finish the work so that dependent issues (#152 and #159) can also move forward.

My plan is to extend the existing implementation and make a few improvements:

• Add the missing unit test (test_struct_definition) to verify that StructDefStmt correctly generates an LLVM IdentifiedStructType.
• Track struct information using struct_types and struct_defs dictionaries inside LLVMLiteIRVisitor.
• Simplify field type handling by passing attr.type_ directly to get_data_type() instead of converting it to a string.
• Keep the implementation consistent with the existing @dispatch visitor pattern.

Example expected LLVM IR:
%"Point" = type { i32, i32 }

Please let me know if there are any suggestions or preferred changes before I open the PR.

[m-akhil-reddy]

Status :- PR #201