Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk?
-- >8 -- r14-2655-g92d1425ca78040 made instantiate_template avoid redundantly performing a specialization lookup when instantiating a function or alias template. This patch applies the same optimization to tsubst_template_decl when (partially) instantiating a function template, which allows us to remove a check from register_specialization since tsubst_function_decl no longer calls register_specialization for a function template partial instantiation. gcc/cp/ChangeLog: * pt.cc (register_specialization): Remove now-unnecessary early exit for FUNCTION_DECL partial instantiation. (tsubst_template_decl): Pass use_spec_table=false to tsubst_function_decl. Set DECL_TI_ARGS of a non-lambda FUNCTION_DECL specialization to the full set of arguments. Simplify register_specialization call accordingly. gcc/testsuite/ChangeLog: * g++.dg/template/nontype12.C: Expect two instead of three duplicate diagnostics for A<double>::bar() specialization. --- gcc/cp/pt.cc | 29 +++++++---------------- gcc/testsuite/g++.dg/template/nontype12.C | 1 - 2 files changed, 9 insertions(+), 21 deletions(-) diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index c311a6b88f5..a0296a1ea16 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -1507,21 +1507,6 @@ register_specialization (tree spec, tree tmpl, tree args, bool is_friend, || (TREE_CODE (tmpl) == FIELD_DECL && TREE_CODE (spec) == NONTYPE_ARGUMENT_PACK)); - if (TREE_CODE (spec) == FUNCTION_DECL - && uses_template_parms (DECL_TI_ARGS (spec))) - /* This is the FUNCTION_DECL for a partial instantiation. Don't - register it; we want the corresponding TEMPLATE_DECL instead. - We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than - the more obvious `uses_template_parms (spec)' to avoid problems - with default function arguments. In particular, given - something like this: - - template <class T> void f(T t1, T t = T()) - - the default argument expression is not substituted for in an - instantiation unless and until it is actually needed. */ - return spec; - spec_entry elt; elt.tmpl = tmpl; elt.args = args; @@ -14663,7 +14648,7 @@ tsubst_template_decl (tree t, tree args, tsubst_flags_t complain, tree in_decl = t; tree spec; tree tmpl_args; - tree full_args; + tree full_args = NULL_TREE; tree r; hashval_t hash = 0; @@ -14754,7 +14739,8 @@ tsubst_template_decl (tree t, tree args, tsubst_flags_t complain, tree inner = decl; ++processing_template_decl; if (TREE_CODE (inner) == FUNCTION_DECL) - inner = tsubst_function_decl (inner, args, complain, lambda_fntype); + inner = tsubst_function_decl (inner, args, complain, lambda_fntype, + /*use_spec_table=*/false); else { if (TREE_CODE (inner) == TYPE_DECL && !TYPE_DECL_ALIAS_P (inner)) @@ -14792,6 +14778,11 @@ tsubst_template_decl (tree t, tree args, tsubst_flags_t complain, } else { + if (TREE_CODE (inner) == FUNCTION_DECL) + /* Set DECL_TI_ARGS to the full set of template arguments, which + tsubst_function_decl didn't do due to use_spec_table=false. */ + DECL_TI_ARGS (inner) = full_args; + DECL_TI_TEMPLATE (inner) = r; DECL_TI_ARGS (r) = DECL_TI_ARGS (inner); } @@ -14822,9 +14813,7 @@ tsubst_template_decl (tree t, tree args, tsubst_flags_t complain, if (TREE_CODE (decl) == FUNCTION_DECL && !lambda_fntype) /* Record this non-type partial instantiation. */ - register_specialization (r, t, - DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)), - false, hash); + register_specialization (r, t, full_args, false, hash); return r; } diff --git a/gcc/testsuite/g++.dg/template/nontype12.C b/gcc/testsuite/g++.dg/template/nontype12.C index 9a9c3ac1e66..e36a9f16f94 100644 --- a/gcc/testsuite/g++.dg/template/nontype12.C +++ b/gcc/testsuite/g++.dg/template/nontype12.C @@ -5,7 +5,6 @@ template<typename T> struct A { template<T> int foo(); // { dg-error "double" "" { target c++17_down } } template<template<T> class> int bar(); // { dg-bogus {double[^\n]*\n[^\n]*C:7:[^\n]*double} "" { xfail c++17_down } } - // { dg-error "double" "" { target c++17_down } .-1 } template<T> struct X; // { dg-error "double" "" { target c++17_down } } }; -- 2.42.0.216.gbda494f404