On Wed, Apr 27, 2022 at 08:24:54AM -0400, Patrick Palka wrote:
> On Tue, 26 Apr 2022, Marek Polacek via Gcc-patches wrote:
>
> > We crash compiling this test since r11-7993 which changed
> > lookup_template_class_1 so that we only call tsubst_enum when
> >
> > !uses_template_parms (current_nonlambda_scope ())
> >
> > But here current_nonlambda_scope () is the global NAMESPACE_DECL ::, which
> > doesn't have a type, therefore is considered type-dependent. So we don't
> > call tsubst_enum, and crash in tsubst_copy/CONST_DECL because we didn't
> > find the e1 enumerator.
> >
> > I don't think any namespace can depend on any template parameter, so
> > this patch tweaks uses_template_parms.
> >
> > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/11?
> >
> > PR c++/105398
> >
> > gcc/cp/ChangeLog:
> >
> > * pt.cc (uses_template_parms): Return false for any NAMESPACE_DECL.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * g++.dg/cpp1y/lambda-generic-enum2.C: New test.
> > ---
> > gcc/cp/pt.cc | 2 +-
> > gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum2.C | 15 +++++++++++++++
> > 2 files changed, 16 insertions(+), 1 deletion(-)
> > create mode 100644 gcc/testsuite/g++.dg/cpp1y/lambda-generic-enum2.C
> >
> > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> > index 3cf1d7af8d2..e785c5db142 100644
> > --- a/gcc/cp/pt.cc
> > +++ b/gcc/cp/pt.cc
> > @@ -10905,7 +10905,7 @@ uses_template_parms (tree t)
> > || uses_template_parms (TREE_CHAIN (t)));
> > else if (TREE_CODE (t) == TYPE_DECL)
> > dependent_p = dependent_type_p (TREE_TYPE (t));
> > - else if (t == error_mark_node)
> > + else if (t == error_mark_node || TREE_CODE (t) == NAMESPACE_DECL)
>
> LGTM. In passing, perhaps we should move this t == error_mark_node test
> to the beginning of the function alongside the t == NULL_TREE test?
Thanks, yeah, maybe. I also don't like the separate declaration of
saved_processing_template_decl, the return type, but I've resisted cleaning
that up, otherwise I never know when to stop. But here's a version with more
cleanups:
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index e9a3d09ac4c..d0ebbb7a196 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7311,7 +7311,7 @@ extern tree lookup_template_class (tree, tree,
tree, tree,
int, tsubst_flags_t);
extern tree lookup_template_function (tree, tree);
extern tree lookup_template_variable (tree, tree);
-extern int uses_template_parms (tree);
+extern bool uses_template_parms (tree);
extern bool uses_template_parms_level (tree, int);
extern bool in_template_function (void);
extern bool need_generic_capture (void);
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 3cf1d7af8d2..dc5b9938f2c 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -10884,35 +10884,30 @@ find_template_parameters (tree t, tree ctx_parms)
/* Returns true if T depends on any template parameter. */
-int
+bool
uses_template_parms (tree t)
{
- if (t == NULL_TREE)
+ if (t == NULL_TREE || t == error_mark_node)
return false;
- bool dependent_p;
- int saved_processing_template_decl;
+ /* Namespaces can't depend on any template parameters. */
+ if (TREE_CODE (t) == NAMESPACE_DECL)
+ return false;
+
+ processing_template_decl_sentinel ptds (/*reset*/false);
+ ++processing_template_decl;
- saved_processing_template_decl = processing_template_decl;
- if (!saved_processing_template_decl)
- processing_template_decl = 1;
if (TYPE_P (t))
- dependent_p = dependent_type_p (t);
+ return dependent_type_p (t);
else if (TREE_CODE (t) == TREE_VEC)
- dependent_p = any_dependent_template_arguments_p (t);
+ return any_dependent_template_arguments_p (t);
else if (TREE_CODE (t) == TREE_LIST)
- dependent_p = (uses_template_parms (TREE_VALUE (t))
- || uses_template_parms (TREE_CHAIN (t)));
+ return (uses_template_parms (TREE_VALUE (t))
+ || uses_template_parms (TREE_CHAIN (t)));
else if (TREE_CODE (t) == TYPE_DECL)
- dependent_p = dependent_type_p (TREE_TYPE (t));
- else if (t == error_mark_node)
- dependent_p = false;
+ return dependent_type_p (TREE_TYPE (t));
else
- dependent_p = instantiation_dependent_expression_p (t);
-
- processing_template_decl = saved_processing_template_decl;
-
- return dependent_p;
+ return instantiation_dependent_expression_p (t);
}
/* Returns true iff we're processing an incompletely instantiated function
Maybe go with the original patch for GCC 12 and leave the cleanups for GCC 13?
Marek
