On 02/22/2013 02:14 PM, Jason Merrill wrote:
When we go to tsubst with explicit_args, we should put them in the tinst
level.
OK, that minimal change wasn't enough; we need to delay pushing until we
know what arguments we have to work with.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit 1e712888d97aee95b315f4a2c90f19e412d9dbd3
Author: Jason Merrill <ja...@redhat.com>
Date: Mon Feb 25 16:26:04 2013 -0500
PR c++/56377
* pt.c (fn_type_unification): Wait to call push_tinst_level until
we know what args we're looking at.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 5ff0821..9b7fc3a 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -14900,19 +14900,6 @@ fn_type_unification (tree fn,
tree tinst;
tree r = error_mark_node;
- /* Adjust any explicit template arguments before entering the
- substitution context. */
- if (explicit_targs)
- {
- explicit_targs
- = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
- complain,
- /*require_all_args=*/false,
- /*use_default_args=*/false));
- if (explicit_targs == error_mark_node)
- return error_mark_node;
- }
-
/* In C++0x, it's possible to have a function template whose type depends
on itself recursively. This is most obvious with decltype, but can also
occur with enumeration scope (c++/48969). So we need to catch infinite
@@ -14926,13 +14913,7 @@ fn_type_unification (tree fn,
This is, of course, not reentrant. */
if (excessive_deduction_depth)
return error_mark_node;
- tinst = build_tree_list (fn, targs);
- if (!push_tinst_level (tinst))
- {
- excessive_deduction_depth = true;
- ggc_free (tinst);
- return error_mark_node;
- }
+ tinst = build_tree_list (fn, NULL_TREE);
++deduction_depth;
push_deferring_access_checks (dk_deferred);
@@ -14962,6 +14943,16 @@ fn_type_unification (tree fn,
location_t loc = input_location;
bool incomplete = false;
+ /* Adjust any explicit template arguments before entering the
+ substitution context. */
+ explicit_targs
+ = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
+ complain,
+ /*require_all_args=*/false,
+ /*use_default_args=*/false));
+ if (explicit_targs == error_mark_node)
+ goto fail;
+
/* Substitute the explicit args into the function type. This is
necessary so that, for instance, explicitly declared function
arguments can match null pointed constants. If we were given
@@ -15008,14 +14999,19 @@ fn_type_unification (tree fn,
}
}
+ TREE_VALUE (tinst) = explicit_targs;
+ if (!push_tinst_level (tinst))
+ {
+ excessive_deduction_depth = true;
+ goto fail;
+ }
processing_template_decl += incomplete;
input_location = DECL_SOURCE_LOCATION (fn);
- TREE_VALUE (tinst) = explicit_targs;
fntype = tsubst (TREE_TYPE (fn), explicit_targs,
complain | tf_partial, NULL_TREE);
- TREE_VALUE (tinst) = targs;
input_location = loc;
processing_template_decl -= incomplete;
+ pop_tinst_level ();
if (fntype == error_mark_node)
goto fail;
@@ -15051,11 +15047,9 @@ fn_type_unification (tree fn,
callers must be ready to deal with unification failures in any
event. */
- pop_tinst_level ();
ok = !type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
targs, parms, args, nargs, /*subr=*/0,
strict, flags, explain_p);
- push_tinst_level (tinst);
if (!ok)
goto fail;
@@ -15096,7 +15090,15 @@ fn_type_unification (tree fn,
the corresponding deduced argument values. If the
substitution results in an invalid type, as described above,
type deduction fails. */
+ TREE_VALUE (tinst) = targs;
+ if (!push_tinst_level (tinst))
+ {
+ excessive_deduction_depth = true;
+ goto fail;
+ }
decl = instantiate_template (fn, targs, complain);
+ pop_tinst_level ();
+
if (decl == error_mark_node)
goto fail;
@@ -15141,7 +15143,6 @@ fn_type_unification (tree fn,
excessive_deduction_depth = false;
}
- pop_tinst_level ();
/* We can't free this if a pending_template entry or last_error_tinst_level
is pointing at it. */
if (last_pending_template == old_last_pend
