On Wed, Dec 02, 2020 at 01:13:26PM +0100, Jakub Jelinek via Gcc-patches wrote:
> On Tue, Dec 01, 2020 at 04:05:22PM -0500, Jason Merrill via Gcc-patches wrote:
> > Or simpler might be to always defer immediate evaluation of
> > source_location::current() until genericize time.
>
> That works.
> I had to change constexpr.c too so that it temporarily adjusts
> current_function_decl from the constexpr evaluation context, but we do the
> same already from __builtin_FUNCTION ().
>
> Tested on x86_64-linux and i686-linux, ok for trunk if it passes full
> bootstrap/regtest?
I have a few comments, but only minor things; please feel free to ignore
them.
> --- gcc/cp/tree.c.jj 2020-12-01 16:13:01.717818429 +0100
> +++ gcc/cp/tree.c 2020-12-02 11:53:19.032696933 +0100
> @@ -2968,6 +2968,37 @@ array_type_nelts_total (tree type)
> return sz;
> }
>
> +/* Return true if FNDECL is std::source_location::current () method. */
> +
> +bool
> +source_location_current_p (tree fndecl)
> +{
> + gcc_checking_assert (TREE_CODE (fndecl) == FUNCTION_DECL
> + && DECL_IMMEDIATE_FUNCTION_P (fndecl));
> + if (DECL_NAME (fndecl) == NULL_TREE
> + || TREE_CODE (TREE_TYPE (fndecl)) != FUNCTION_TYPE
> + || TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != RECORD_TYPE
> + || DECL_CONTEXT (fndecl) != TREE_TYPE (TREE_TYPE (fndecl)))
> + return false;
> +
> + if (strcmp (IDENTIFIER_POINTER (DECL_NAME (fndecl)), "current") != 0)
> + return false;
You could use id_equal.
> + tree source_location = DECL_CONTEXT (fndecl);
> + if (TYPE_NAME (source_location) == NULL_TREE
> + || TREE_CODE (TYPE_NAME (source_location)) != TYPE_DECL
> + || DECL_NAME (TYPE_NAME (source_location)) == NULL_TREE
> + || strcmp (IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME
> (source_location))),
> + "source_location") != 0)
> + return false;
And here too.
> + tree decl
> + = lookup_qualified_name (std_node,
> + DECL_NAME (TYPE_NAME (source_location)),
> + LOOK_want::TYPE, tf_none);
> + return TYPE_NAME (source_location) == decl;
Can this be decl_in_std_namespace_p?
> --- gcc/cp/constexpr.c.jj 2020-11-26 16:22:24.250407040 +0100
> +++ gcc/cp/constexpr.c 2020-12-02 12:35:11.458852298 +0100
> @@ -1332,7 +1332,14 @@ cxx_eval_builtin_function_call (const co
> }
>
> if (fndecl_built_in_p (fun, CP_BUILT_IN_SOURCE_LOCATION,
> BUILT_IN_FRONTEND))
> - return fold_builtin_source_location (EXPR_LOCATION (t));
> + {
> + tree save_cur_fn = current_function_decl;
You could use
temp_override<tree> ovr (current_function_decl);
to avoid having to restore c_f_d manually.
> + if (ctx->call && ctx->call->fundef)
> + current_function_decl = ctx->call->fundef->decl;
> + t = fold_builtin_source_location (EXPR_LOCATION (t));
> + current_function_decl = save_cur_fn;
> + return t;
> + }
>
> int strops = 0;
> int strret = 0;
> --- gcc/cp/cp-gimplify.c.jj 2020-11-26 16:22:24.250407040 +0100
> +++ gcc/cp/cp-gimplify.c 2020-12-02 12:26:21.596922205 +0100
> @@ -1374,6 +1374,15 @@ cp_genericize_r (tree *stmt_p, int *walk
> break;
> }
>
> + if (call_expr_nargs (stmt) == 0)
> + if (tree fndecl = cp_get_callee_fndecl (stmt))
> + if (DECL_IMMEDIATE_FUNCTION_P (fndecl)
> + && source_location_current_p (fndecl))
> + {
> + *stmt_p = cxx_constant_value (stmt, NULL_TREE);
You can drop the ", NULL_TREE".
Thanks,
Marek
