Add pointer handling to helper_utils, finish pointer assignment

Author: r41k0u

pythonbpf/expr/__init__.py

@@ -1,4 +1,10 @@
 from .expr_pass import eval_expr, handle_expr
-from .type_normalization import convert_to_bool, get_base_type_and_depth
+from .type_normalization import convert_to_bool, get_base_type_and_depth, deref_to_depth
 
-__all__ = ["eval_expr", "handle_expr", "convert_to_bool", "get_base_type_and_depth"]
+__all__ = [
+    "eval_expr",
+    "handle_expr",
+    "convert_to_bool",
+    "get_base_type_and_depth",
+    "deref_to_depth",
+]

pythonbpf/expr/expr_pass.py

@@ -26,7 +26,7 @@ def _handle_constant_expr(expr: ast.Constant):
     if isinstance(expr.value, int) or isinstance(expr.value, bool):
         return ir.Constant(ir.IntType(64), int(expr.value)), ir.IntType(64)
     else:
-        logger.error("Unsupported constant type")
+        logger.error(f"Unsupported constant type {ast.dump(expr)}")
         return None
 
 

pythonbpf/expr/type_normalization.py

@@ -26,7 +26,7 @@ def get_base_type_and_depth(ir_type):
     return cur_type, depth
 
 
-def _deref_to_depth(func, builder, val, target_depth):
+def deref_to_depth(func, builder, val, target_depth):
     """Dereference a pointer to a certain depth."""
 
     cur_val = val
@@ -92,9 +92,9 @@ def _normalize_types(func, builder, lhs, rhs):
         rhs_base, rhs_depth = get_base_type_and_depth(rhs.type)
         if lhs_base == rhs_base:
             if lhs_depth < rhs_depth:
-                rhs = _deref_to_depth(func, builder, rhs, rhs_depth - lhs_depth)
+                rhs = deref_to_depth(func, builder, rhs, rhs_depth - lhs_depth)
             elif rhs_depth < lhs_depth:
-                lhs = _deref_to_depth(func, builder, lhs, lhs_depth - rhs_depth)
+                lhs = deref_to_depth(func, builder, lhs, lhs_depth - rhs_depth)
             return _normalize_types(func, builder, lhs, rhs)
 
 

pythonbpf/helper/helper_utils.py

@@ -3,7 +3,7 @@
 from collections.abc import Callable
 
 from llvmlite import ir
-from pythonbpf.expr import eval_expr
+from pythonbpf.expr import eval_expr, get_base_type_and_depth, deref_to_depth
 
 logger = logging.getLogger(__name__)
 
@@ -224,10 +224,27 @@ def _populate_fval(ftype, node, fmt_parts, exprs):
             raise NotImplementedError(
                 f"Unsupported integer width in f-string: {ftype.width}"
             )
-    elif ftype == ir.PointerType(ir.IntType(8)):
-        # NOTE: We assume i8* is a string
-        fmt_parts.append("%s")
-        exprs.append(node)
+    elif isinstance(ftype, ir.PointerType):
+        target, depth = get_base_type_and_depth(ftype)
+        if isinstance(target, ir.IntType):
+            if target.width == 64:
+                fmt_parts.append("%lld")
+                exprs.append(node)
+            elif target.width == 32:
+                fmt_parts.append("%d")
+                exprs.append(node)
+            elif target.width == 8 and depth == 1:
+                # NOTE: Assume i8* is a string
+                fmt_parts.append("%s")
+                exprs.append(node)
+            else:
+                raise NotImplementedError(
+                    f"Unsupported pointer target type in f-string: {target}"
+                )
+        else:
+            raise NotImplementedError(
+                f"Unsupported pointer target type in f-string: {target}"
+            )
     else:
         raise NotImplementedError(f"Unsupported field type in f-string: {ftype}")
 
@@ -264,7 +281,20 @@ def _prepare_expr_args(expr, func, module, builder, local_sym_tab, struct_sym_ta
 
     if val:
         if isinstance(val.type, ir.PointerType):
-            val = builder.ptrtoint(val, ir.IntType(64))
+            target, depth = get_base_type_and_depth(val.type)
+            if isinstance(target, ir.IntType):
+                if target.width >= 32:
+                    val = deref_to_depth(func, builder, val, depth)
+                    val = builder.sext(val, ir.IntType(64))
+                elif target.width == 8 and depth == 1:
+                    # NOTE: i8* is string, no need to deref
+                    pass
+
+            else:
+                logger.warning(
+                    "Only int and ptr supported in bpf_printk args. Others default to 0."
+                )
+                val = ir.Constant(ir.IntType(64), 0)
         elif isinstance(val.type, ir.IntType):
             if val.type.width < 64:
                 val = builder.sext(val, ir.IntType(64))