From 557cc2b721432775a12fcafa60e9b8b0c320c29d Mon Sep 17 00:00:00 2001
From: Patrick Palka <ppalka@redhat.com>
Date: Sat, 3 Jun 2023 09:17:31 -0400
Subject: [PATCH] c++: replace in_template_function
All uses of in_template_function except for the one in cp_make_fname_decl
seem like they could be generalized to consider any template context.
To that end this patch replaces the predicate with a generalized
in_template_context predicate that returns true if we're inside any
template context. If we legitimately need to consider only function
contexts, as in cp_make_fname_decl, we can just additionally check e.g.
current_function_decl.
One concrete benefit of this, which the adjusted testcase below
demonstrates, is that we no longer instantiate/odr-use entities based on
uses within a non-function template.
gcc/cp/ChangeLog:
* class.cc (build_base_path): Check in_template_context instead
of in_template_function.
(resolves_to_fixed_type_p): Likewise.
* cp-tree.h (in_template_context): Define.
(in_template_function): Remove.
* decl.cc (cp_make_fname_decl): Check current_function_decl
and in_template_context instead of in_template_function.
* decl2.cc (mark_used): Check in_template_context instead of
in_template_function.
* pt.cc (in_template_function): Remove.
* semantics.cc (enforce_access): Check in_template_context
instead of current_template_parms directly.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Waddress-of-packed-member2.C: No longer expect a()
to be marked as odr-used.
---
gcc/cp/class.cc | 4 ++--
gcc/cp/cp-tree.h | 2 +-
gcc/cp/decl.cc | 2 +-
gcc/cp/decl2.cc | 2 +-
gcc/cp/pt.cc | 19 -------------------
gcc/cp/semantics.cc | 2 +-
.../g++.dg/warn/Waddress-of-packed-member2.C | 2 +-
7 files changed, 7 insertions(+), 26 deletions(-)
diff --git a/gcc/cp/class.cc b/gcc/cp/class.cc
index bc84f4f731ac..778759237dc7 100644
--- a/gcc/cp/class.cc
+++ b/gcc/cp/class.cc
@@ -344,7 +344,7 @@ build_base_path (enum tree_code code,
bool uneval = (cp_unevaluated_operand != 0
|| processing_template_decl
- || in_template_function ());
+ || in_template_context);
/* For a non-pointer simple base reference, express it as a COMPONENT_REF
without taking its address (and so causing lambda capture, 91933). */
@@ -8055,7 +8055,7 @@ resolves_to_fixed_type_p (tree instance, int* nonnull)
/* processing_template_decl can be false in a template if we're in
instantiate_non_dependent_expr, but we still want to suppress
this check. */
- if (in_template_function ())
+ if (in_template_context)
{
/* In a template we only care about the type of the result. */
if (nonnull)
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index a1b882f11fed..ce2095c7aaa1 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -1924,6 +1924,7 @@ extern GTY(()) struct saved_scope *scope_chain;
#define current_template_parms scope_chain->template_parms
#define current_template_depth \
(current_template_parms ? TMPL_PARMS_DEPTH (current_template_parms) : 0)
+#define in_template_context (current_template_parms != NULL_TREE)
#define processing_template_decl scope_chain->x_processing_template_decl
#define processing_specialization scope_chain->x_processing_specialization
@@ -7353,7 +7354,6 @@ extern tree lookup_template_variable (tree, tree);
extern bool uses_template_parms (tree);
extern bool uses_template_parms_level (tree, int);
extern bool uses_outer_template_parms_in_constraints (tree);
-extern bool in_template_function (void);
extern bool need_generic_capture (void);
extern tree instantiate_class_template (tree);
extern tree instantiate_template (tree, tree, tsubst_flags_t);
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index a672e4844f1a..3985c6d2d1f1 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -5021,7 +5021,7 @@ cp_make_fname_decl (location_t loc, tree id, int type_dep)
tree domain = NULL_TREE;
tree init = NULL_TREE;
- if (!(type_dep && in_template_function ()))
+ if (!(type_dep && current_function_decl && in_template_context))
{
const char *name = NULL;
bool release_name = false;
diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index b510cdac5541..b402befba6da 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -5782,7 +5782,7 @@ mark_used (tree decl, tsubst_flags_t complain /* = tf_warning_or_error */)
&& DECL_OMP_DECLARE_REDUCTION_P (decl)))
maybe_instantiate_decl (decl);
- if (processing_template_decl || in_template_function ())
+ if (processing_template_decl || in_template_context)
return true;
/* Check this too in case we're within instantiate_non_dependent_expr. */
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 7fb3e75bceb1..244b0b034545 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -10951,25 +10951,6 @@ uses_template_parms (tree t)
return instantiation_dependent_expression_p (t);
}
-/* Returns true iff we're processing an incompletely instantiated function
- template. Useful instead of processing_template_decl because the latter
- is set to 0 during instantiate_non_dependent_expr. */
-
-bool
-in_template_function (void)
-{
- /* Inspect the less volatile cfun->decl instead of current_function_decl;
- the latter might get set for e.g. access checking during satisfaction. */
- tree fn = cfun ? cfun->decl : NULL_TREE;
- bool ret;
- ++processing_template_decl;
- ret = (fn && DECL_LANG_SPECIFIC (fn)
- && DECL_TEMPLATE_INFO (fn)
- && any_dependent_template_arguments_p (DECL_TI_ARGS (fn)));
- --processing_template_decl;
- return ret;
-}
-
/* Returns true if T depends on any template parameter with level LEVEL. */
bool
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 05df62823021..0843b5eae736 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -346,7 +346,7 @@ enforce_access (tree basetype_path, tree decl, tree diag_decl,
}
tree cs = current_scope ();
- if (current_template_parms
+ if (in_template_context
&& (CLASS_TYPE_P (cs) || TREE_CODE (cs) == FUNCTION_DECL))
if (tree template_info = get_template_info (cs))
{
diff --git a/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member2.C b/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member2.C
index e9bf7cac04c9..d619b28cfe1e 100644
--- a/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member2.C
+++ b/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member2.C
@@ -1,7 +1,7 @@
// PR c++/89973
// { dg-do compile { target c++14 } }
-constexpr int a(); // { dg-warning "used but never defined" }
+constexpr int a();
template <typename>
constexpr void *b = a(); // { dg-error "invalid conversion" }
--
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