[better_errors] Refactor more uses of partial_eval.tracing_debug_info…

… (part 1)

We replace those uses with api_util.tracing_debug_info, which means we
have to move the call further upstream. But this is better because we
have the actual args and kwargs, and we can do a better job, especially
for `arg_names`.

This is part 1 of a series, for: cond, switch, while, scan, composite,
custom_dce, saved_residuals.

jax/_src/ad_checkpoint.py

@@ -439,22 +439,23 @@ def _trace_to_jaxpr(fun: Callable,
 
 ### Utilities
 
-def saved_residuals(f, *args, **kwargs) -> list[tuple[core.AbstractValue, str]]:
+def saved_residuals(f: Callable,
+                    *args, **kwargs) -> list[tuple[core.AbstractValue, str]]:
   in_leaves, in_tree = tree_flatten((args, kwargs))
 
   def f_(*args):
     args, kwargs = tree_unflatten(in_tree, args)
     return f(*args, **kwargs)
 
+  debug_info = api_util.tracing_debug_info("saved_residuals", f, args, kwargs)
   out = api.make_jaxpr(lambda *args: api.linearize(f_, *args)[1],
                        return_shape=True)(*in_leaves)
   assert isinstance(out, tuple)
   jaxpr_, out_shape = out
   jaxpr = jaxpr_.jaxpr
   out_tree = lambda: tree_structure(out_shape)
   assert len(jaxpr.invars) == len(in_leaves)
-  dbg = pe.tracing_debug_info(f, in_tree, out_tree, True, "saved_residuals")
-  return _saved_residuals(jaxpr, dbg.arg_names)
+  return _saved_residuals(jaxpr, debug_info.arg_names)
 
 def _saved_residuals(jaxpr: core.Jaxpr,
                      arg_names: tuple[str | None, ...]) -> list[tuple[core.AbstractValue, str]]:

jax/_src/api_util.py

@@ -84,7 +84,8 @@ def apply_flat_fun(fun, io_tree, *py_args):
   return tree_unflatten(out_tree, ans)
 
 @lu.transformation_with_aux2
-def flatten_fun_nokwargs(f, store, in_tree, *args_flat):
+def flatten_fun_nokwargs(f: Callable, store: lu.Store,
+                         in_tree: PyTreeDef, *args_flat):
   py_args = tree_unflatten(in_tree, args_flat)
   ans = f(*py_args)
   ans, out_tree = tree_flatten(ans)

jax/_src/custom_batching.py

@@ -28,6 +28,7 @@
 from jax._src import traceback_util
 from jax._src import tree_util
 from jax._src import util
+from jax._src import api_util
 from jax._src.api_util import flatten_fun_nokwargs, resolve_kwargs
 from jax._src.interpreters import ad
 from jax._src.interpreters import batching
@@ -147,10 +148,12 @@ def __call__(self, *args, **kwargs):
       raise AttributeError(
           f"No batching rule defined for custom_vmap function {fun_name} "
           "using def_vmap.")
+    debug = api_util.tracing_debug_info("custom_vmap", self.fun, args, {})
     args_flat, in_tree = tree_flatten(args)
-    flat_fun, out_tree = flatten_fun_nokwargs(lu.wrap_init(self.fun), in_tree)
+    flat_fun, out_tree = flatten_fun_nokwargs(lu.wrap_init(self.fun,
+                                                           debug_info=debug),
+                                              in_tree)
     in_avals = [core.get_aval(x) for x in args_flat]
-    debug = pe.tracing_debug_info(self.fun, in_tree, out_tree, False, "custom_vmap")
     jaxpr, _, consts, () = pe.trace_to_jaxpr_dynamic(flat_fun, in_avals, debug)
     closed_call = core.ClosedJaxpr(pe.convert_constvars_jaxpr(jaxpr), ())
     in_tree = treedef_tuple((tree_structure(consts), in_tree))

jax/_src/custom_dce.py

@@ -127,14 +127,16 @@ def __call__(self, *args, **kwargs):
           "def_dce."
       )
     rule_name = util.fun_name(self.dce_rule)
+    debug = api_util.tracing_debug_info("custom_dce", self.fun,
+                                        args, {}, static_argnums=self.static_argnums)
     args = api_util.resolve_kwargs(self.fun, args, kwargs)
     if self.static_argnums:
       static_argnums = set(self.static_argnums)
       for i in static_argnums:
         check_for_tracers(args[i])
       dyn_argnums = [i for i in range(len(args)) if i not in static_argnums]
       fun, dyn_args = api_util.argnums_partial(
-          lu.wrap_init(self.fun),
+          lu.wrap_init(self.fun, debug_info=debug),
           dyn_argnums,
           args,
           require_static_args_hashable=False,
@@ -144,7 +146,7 @@ def __call__(self, *args, **kwargs):
           lu.wrap_init(self.dce_rule), static_args
       )
     else:
-      fun = lu.wrap_init(self.fun)
+      fun = lu.wrap_init(self.fun, debug_info=debug)
       dce_rule = lu.wrap_init(self.dce_rule)
       dyn_args = args
 
@@ -188,9 +190,6 @@ def dce_jaxpr_thunk(
 
       return core.ClosedJaxpr(dce_jaxpr, dce_consts), used_ins
 
-    debug = pe.tracing_debug_info(
-        self.fun, in_tree, out_tree, False, "custom_dce"
-    )
     jaxpr, _, consts, () = pe.trace_to_jaxpr_dynamic(flat_fun, in_avals, debug)
     closed_call = pe.close_jaxpr(pe.convert_constvars_jaxpr(jaxpr))
     out_avals = closed_call.out_avals

jax/_src/interpreters/batching.py

@@ -32,7 +32,7 @@
 from jax._src.core import Trace, Tracer, TraceTag, AxisName
 from jax._src.interpreters import partial_eval as pe
 from jax._src.tree_util import (tree_unflatten, tree_flatten,
-                                register_pytree_node)
+                                register_pytree_node, PyTreeDef)
 from jax._src.typing import Array
 from jax._src.util import (unzip2, safe_map, safe_zip, split_list,
                            canonicalize_axis, moveaxis, as_hashable_function,
@@ -328,7 +328,8 @@ def is_vmappable(x: Any) -> bool:
   return type(x) is Jumble or type(x) in vmappables
 
 @lu.transformation_with_aux2
-def flatten_fun_for_vmap(f, store, in_tree, *args_flat):
+def flatten_fun_for_vmap(f: Callable,
+                         store: lu.Store, in_tree: PyTreeDef, *args_flat):
   py_args, py_kwargs = tree_unflatten(in_tree, args_flat)
   ans = f(*py_args, **py_kwargs)
   ans, out_tree = tree_flatten(ans, is_leaf=is_vmappable)
@@ -591,7 +592,7 @@ def _batch_outer(f, axis_data, in_dims, *in_vals):
   return outs
 
 @lu.transformation2
-def _batch_inner(f, axis_data, out_dim_dests, tag, in_dims, *in_vals):
+def _batch_inner(f: Callable, axis_data, out_dim_dests, tag, in_dims, *in_vals):
   in_dims = in_dims() if callable(in_dims) else in_dims
   with core.take_current_trace() as parent_trace:
     trace = BatchTrace(parent_trace, tag, axis_data)

jax/_src/lax/control_flow/common.py

@@ -20,6 +20,7 @@
 from functools import partial
 from typing import Any
 
+from jax._src import api_util
 from jax._src import core
 from jax._src import linear_util as lu
 from jax._src.lax import lax
@@ -28,9 +29,8 @@
 from jax._src import state
 from jax._src import util
 from jax._src.util import weakref_lru_cache, safe_map, partition_list
-from jax.api_util import flatten_fun_nokwargs
 from jax._src.interpreters import partial_eval as pe
-from jax.tree_util import tree_map, tree_unflatten, keystr
+from jax.tree_util import tree_map, tree_unflatten, keystr, PyTreeDef
 from jax._src.tree_util import equality_errors_pytreedef
 
 map, unsafe_map = safe_map, map
@@ -50,41 +50,52 @@ def _typecheck_param(prim, param, name, msg_required, pred):
     raise core.JaxprTypeError(msg)
 
 @weakref_lru_cache
-def _initial_style_open_jaxpr(fun: Callable, in_tree, in_avals,
-                              primitive_name: str | None = None):
-  wrapped_fun, out_tree = flatten_fun_nokwargs(lu.wrap_init(fun), in_tree)
-  debug = pe.tracing_debug_info(fun, in_tree, out_tree, False,
-                                primitive_name or "<unknown>")
+def _initial_style_open_jaxpr(fun: Callable,
+                              in_tree: PyTreeDef,
+                              in_avals: Sequence[core.AbstractValue],
+                              debug_info: api_util.TracingDebugInfo | None = None):
+  wrapped_fun, out_tree = api_util.flatten_fun_nokwargs(
+      lu.wrap_init(fun, debug_info=debug_info),
+      in_tree)
   jaxpr, _, consts, attrs_tracked = pe.trace_to_jaxpr_dynamic(
-      wrapped_fun, in_avals, debug)
+      wrapped_fun, in_avals, debug_info)
   return jaxpr, consts, out_tree(), attrs_tracked
 
 @weakref_lru_cache
-def _initial_style_jaxpr(fun: Callable, in_tree, in_avals,
-                         primitive_name: str | None = None):
+def _initial_style_jaxpr(fun: Callable,
+                         in_tree: PyTreeDef,
+                         in_avals: Sequence[core.AbstractValue],
+                         # TODO(necula): remove primitive_name
+                         primitive_name: str | None = None,
+                         # TODO(necula): remove the None from below
+                         debug_info: api_util.TracingDebugInfo | None = None):
   jaxpr, consts, out_tree, () = _initial_style_open_jaxpr(
-      fun, in_tree, in_avals, primitive_name)
+      fun, in_tree, in_avals, debug_info)
   closed_jaxpr = pe.close_jaxpr(pe.convert_constvars_jaxpr(jaxpr))
   return closed_jaxpr, consts, out_tree
 
-def _initial_style_jaxpr_attrs(fun: Callable, in_tree, in_avals,
-                               primitive_name: str | None = None):
+def _initial_style_jaxpr_attrs(fun: Callable,
+                               in_tree: PyTreeDef,
+                               in_avals: Sequence[core.AbstractValue],
+                               debug_info: api_util.TracingDebugInfo):
   jaxpr, consts, out_tree, attrs_tracked = _initial_style_open_jaxpr(
-      fun, in_tree, in_avals, primitive_name)
+      fun, in_tree, in_avals, debug_info)
   closed_jaxpr = pe.close_jaxpr(pe.convert_constvars_jaxpr(jaxpr))
   return closed_jaxpr, consts, out_tree, attrs_tracked
 
 def _initial_style_jaxprs_with_common_consts(
-    funs: Sequence[Callable], in_tree, in_avals, primitive_name: str):
+    funs: Sequence[Callable],
+    in_tree: PyTreeDef, in_avals: Sequence[core.AbstractValue], *,
+    debug_infos: Sequence[api_util.TracingDebugInfo]):
   # When staging the branches of a conditional into jaxprs, constants are
   # extracted from each branch and converted to jaxpr arguments. To use the
   # staged jaxprs as the branches to a conditional *primitive*, we need for
   # their (input) signatures to match. This function "joins" the staged jaxprs:
   # for each one, it makes another that accepts *all* constants, but only uses
   # those that it needs (dropping the rest).
-
-  jaxpr_data = [_initial_style_open_jaxpr(fn, in_tree, in_avals, primitive_name)
-                for fn in funs]
+  jaxpr_data = [_initial_style_open_jaxpr(fn, in_tree, in_avals,
+                                          debug_info)
+                for fn, debug_info in zip(funs, debug_infos)]
   if not jaxpr_data:
     return [], [], []
 

jax/_src/lax/control_flow/conditionals.py

@@ -25,8 +25,7 @@
 
 from jax.tree_util import tree_flatten, tree_unflatten
 from jax._src import ad_util
-from jax._src.api_util import (
-    _check_no_aliased_ref_args, _check_no_aliased_closed_over_refs)
+from jax._src import api_util
 from jax._src import config
 from jax._src import core
 from jax._src import dispatch
@@ -135,17 +134,18 @@ def switch(index, branches, *operands):
   if (config.disable_jit.value and core.is_concrete(index)):
     return branches[int(index)](*operands)
 
+  dbgs = [api_util.tracing_debug_info("switch", branch, operands, {})
+          for branch in branches]
   ops, ops_tree = tree_flatten(operands)
   ops_avals = tuple(map(core.get_aval, ops))
 
   if config.mutable_array_checks.value:
-    dbg = pe.tracing_debug_info(branches[0], ops_tree, None, False, 'switch')  # type: ignore
-    _check_no_aliased_ref_args(dbg, ops_avals, ops)
+    api_util._check_no_aliased_ref_args(dbgs[0], ops_avals, ops)
 
   jaxprs, consts, out_trees = _initial_style_jaxprs_with_common_consts(
-      branches, ops_tree, ops_avals, primitive_name='switch')
+      branches, ops_tree, ops_avals, debug_infos=dbgs)
   if config.mutable_array_checks.value:
-    _check_no_aliased_closed_over_refs(dbg, (*jaxprs[0].consts, *consts), ops)
+    api_util._check_no_aliased_closed_over_refs(dbgs[0], (*jaxprs[0].consts, *consts), ops)
   for i, (out_tree, jaxpr) in enumerate(zip(out_trees[1:], jaxprs[1:])):
     _check_tree_and_avals("branch 0 output",
                           out_trees[0], jaxprs[0].out_avals,
@@ -237,14 +237,16 @@ def cond(pred, true_fun, false_fun, *operands):
   ops, ops_tree = tree_flatten(operands)
   ops_avals = tuple(map(core.get_aval, ops))
 
+  dbg_true_fun = api_util.tracing_debug_info("cond", true_fun, operands, {})
   if config.mutable_array_checks.value:
-    dbg = pe.tracing_debug_info(true_fun, ops_tree, None, False, 'cond')  # type: ignore
-    _check_no_aliased_ref_args(dbg, ops_avals, ops)
+    api_util._check_no_aliased_ref_args(dbg_true_fun, ops_avals, ops)
+  dbg_false_fun = api_util.tracing_debug_info("cond", false_fun, operands, {})
   jaxprs, consts, out_trees = _initial_style_jaxprs_with_common_consts(
-      (true_fun, false_fun), ops_tree, ops_avals, 'cond')
+      (true_fun, false_fun), ops_tree, ops_avals,
+      debug_infos=[dbg_true_fun, dbg_false_fun])
   true_jaxpr, false_jaxpr = jaxprs
   if config.mutable_array_checks.value:
-    _check_no_aliased_closed_over_refs(dbg, (*true_jaxpr.consts, *consts), ops)
+    api_util._check_no_aliased_closed_over_refs(dbg_true_fun, (*true_jaxpr.consts, *consts), ops)
 
   out_tree, false_out_tree = out_trees
   if any(isinstance(out_aval, AbstractRef) for out_aval in

jax/_src/lax/control_flow/for_loop.py

@@ -21,7 +21,7 @@
 from typing import Any, Generic, TypeVar
 
 from jax import lax
-from jax.api_util import flatten_fun_nokwargs
+from jax._src import api_util
 from jax._src.interpreters import ad
 from jax._src.interpreters import batching
 from jax._src.interpreters import mlir
@@ -73,7 +73,7 @@ class Ref(Generic[T]): pass
 def _trace_to_jaxpr_with_refs(f, state_tree: PyTreeDef,
                               state_avals: Sequence[core.AbstractValue]
                               ) -> tuple[core.Jaxpr, list[Any], PyTreeDef]:
-  f, out_tree_thunk = flatten_fun_nokwargs(
+  f, out_tree_thunk = api_util.flatten_fun_nokwargs(
       lu.wrap_init(f), treedef_tuple((tree_structure(0), state_tree)))
   jaxpr, _, consts, () = pe.trace_to_jaxpr_dynamic(
       f, state_avals)
@@ -195,10 +195,10 @@ def scan(f: Callable[[Carry, X], tuple[Carry, Y]],
   def _create_jaxpr(init):
     init_flat = tree_leaves(init)
     _, in_tree = tree_flatten((init, xs))
-
+    dbg = api_util.tracing_debug_info("scan", f, (init, xs), {})
     carry_avals = tuple(map(core.get_aval, init_flat))
     jaxpr, _, out_tree = _initial_style_jaxpr(
-        f, in_tree, carry_avals + x_avals, "scan")
+        f, in_tree, carry_avals + x_avals, "scan", debug_info=dbg)
     return jaxpr, out_tree
   jaxpr, out_tree = _create_jaxpr(init)
   _, ys_avals = tree_unflatten(out_tree, jaxpr.out_avals)

jax/_src/lax/control_flow/loops.py

@@ -272,21 +272,21 @@ def scan(f, init, xs, length=None):
 
   xs_avals = [core.get_aval(x) for x in xs_flat]
   x_avals = [core.mapped_aval(length, 0, aval) for aval in xs_avals]
+  dbg_body = api_util.tracing_debug_info("scan", f, (init, xs), {})
 
   if config.mutable_array_checks.value:
     in_flat, in_tree = tree_flatten((init, xs))
-    dbg = pe.tracing_debug_info(f, in_tree, None, False, 'scan')  # type: ignore
     in_avals = tuple(_map(core.get_aval, in_flat))
-    _check_no_aliased_ref_args(dbg, in_avals, in_flat)
+    _check_no_aliased_ref_args(dbg_body, in_avals, in_flat)
 
   def _create_jaxpr(init):
     init_flat, init_tree = tree_flatten(init)
     in_flat, in_tree = tree_flatten((init, xs))
     carry_avals = tuple(_map(core.get_aval, init_flat))
     jaxpr, consts, out_tree, attrs_tracked = _initial_style_jaxpr_attrs(
-        f, in_tree, (*carry_avals, *x_avals), "scan")
+        f, in_tree, (*carry_avals, *x_avals), debug_info=dbg_body)
     if config.mutable_array_checks.value:
-      _check_no_aliased_closed_over_refs(dbg, (*jaxpr.consts, *consts), in_flat)
+      _check_no_aliased_closed_over_refs(dbg_body, (*jaxpr.consts, *consts), in_flat)
     out_tree_children = out_tree.children()
     if len(out_tree_children) != 2:
       msg = "scan body output must be a pair, got {}."
@@ -1355,10 +1355,12 @@ def while_loop(cond_fun, body_fun, init_val):
   def _create_jaxpr(init_val):
     init_vals, in_tree = tree_flatten((init_val,))
     init_avals = tuple(_map(core.get_aval, init_vals))
+    cond_dbg = api_util.tracing_debug_info("while_cond", cond_fun, (init_val,), {})
     cond_jaxpr, cond_consts, cond_tree = _initial_style_jaxpr(
-        cond_fun, in_tree, init_avals, "while_cond")
+        cond_fun, in_tree, init_avals, "while_cond", debug_info=cond_dbg)
+    body_dbg = api_util.tracing_debug_info("while_body", body_fun, (init_val,), {})
     body_jaxpr, body_consts, body_tree = _initial_style_jaxpr(
-        body_fun, in_tree, init_avals, "while_loop")
+        body_fun, in_tree, init_avals, "while_body", debug_info=body_dbg)
     if not treedef_is_leaf(cond_tree) or len(cond_jaxpr.out_avals) != 1:
       msg = "cond_fun must return a boolean scalar, but got pytree {}."
       raise TypeError(msg.format(cond_tree))

jax/_src/lax/lax.py

@@ -658,9 +658,12 @@ def clamp(min: ArrayLike, x: ArrayLike, max: ArrayLike) -> Array:
 
 
 @weakref_lru_cache
-def _trace_composite_to_jaxpr(fun, in_tree, in_avals, name: str):
+def _trace_composite_to_jaxpr(fun: Callable,
+                              in_tree: tree_util.PyTreeDef,
+                              in_avals: Sequence[core.AbstractValue],
+                              name: str,
+                              debug_info: api_util.TracingDebugInfo):
   flat_fun, out_tree = api_util.flatten_fun_nokwargs(lu.wrap_init(fun), in_tree)
-  debug_info = pe.tracing_debug_info(fun, in_tree, out_tree, False, "composite")
   jaxpr, _, consts, _ = pe.trace_to_jaxpr_dynamic(flat_fun, in_avals, debug_info)
   if any(isinstance(c, core.Tracer) for c in consts):
     raise UnexpectedTracerError(
@@ -736,10 +739,12 @@ def composite(
   """
   @functools.wraps(decomposition)
   def _decorator(*args, **kwargs):
+    debug_info = api_util.tracing_debug_info("composite", decomposition,
+                                             args, kwargs)
     flat_args, in_tree = tree_util.tree_flatten(args)
     in_avals = tuple(core.get_aval(x) for x in flat_args)
     closed_jaxpr, out_tree = _trace_composite_to_jaxpr(
-        partial(decomposition, **kwargs), in_tree, in_avals, name
+        partial(decomposition, **kwargs), in_tree, in_avals, name, debug_info
     )
     out_flat = composite_p.bind(
         *flat_args,