Message ID | CA+C-WL9B1Be6NdmAXXbzhsY4Zu=o_6yz-qpiM-NFbdQ+yBdRKw@mail.gmail.com |
---|---|
State | New |
Headers | show |
On 03/06/2016 09:30 AM, Patrick Palka wrote: > On Sun, Mar 6, 2016 at 1:42 AM, Jason Merrill <jason@redhat.com> wrote: >> On 02/08/2016 12:19 AM, Patrick Palka wrote: >>> >>> Here, we are calling template_class_depth on a FIELD_DECL corresponding >>> to a lambda that is used inside variable template. template_class_depth >>> however does not see that this FIELD_DECL is used inside a variable >>> template binding because its chain of DECL_CONTEXTs does not include the >>> corresponding VAR_DECL. So template_class_depth returns the wrong >>> template nesting level which causes its callers to malfunction. In >>> particular we strip a template argument level in >>> tsubst_copy [FIELD_DECL] when we shouldn't have. >>> >>> This patch makes template_class_depth look at a lambda type's >>> LAMBDA_TYPE_EXTRA_SCOPE field instead of its TYPE_CONTEXT, so that it >>> can iterate into an enclosing variable template, if applicable. >>> >>> Tested on x86_64-pc-linux gnu, no new regressions. Also tested against >>> Boost. Is this OK to commit? >> >> >> This is breaking several lambda testcases with -fconcepts on; >> LAMBDA_TYPE_EXTRA_SCOPE can also be a FIELD_DECL or PARM_DECL. Let's just >> check DECL_P. > > Sorry about that. > > In the case of LAMBDA_TYPE_EXTRA_SCOPE being a PARM_DECL, could there > be a chance that this PARM_DECL has a non-null DECL_LANG_SPECIFIC? If > so it looks like we could still later ICE in get_template_info (called > from template_class_depth) when we try to get at its > DECL_TEMPLATE_INFO, an accessor that cannot be used on PARM_DECLs. So > I wonder if maybe get_template_info() should also be adjusted to > handle the case of being given a PARM_DECL which may have a non-null > DECL_LANG_SPECIFIC: Looks good. Jason
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 823e2f0..f68b1f6 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -330,7 +330,8 @@ get_template_info (const_tree t) if (!t || t == error_mark_node) return NULL; - if (TREE_CODE (t) == NAMESPACE_DECL) + if (TREE_CODE (t) == NAMESPACE_DECL + || TREE_CODE (t) == PARM_DECL) return NULL; if (DECL_P (t) && DECL_LANG_SPECIFIC (t)) @@ -378,7 +379,7 @@ template_class_depth (tree type) && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo)))) ++depth; - if (VAR_OR_FUNCTION_DECL_P (type)) + if (DECL_P (type)) type = CP_DECL_CONTEXT (type); else if (LAMBDA_TYPE_P (type)) type = LAMBDA_TYPE_EXTRA_SCOPE (type);