diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2021-06-11 15:50:34 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2021-06-11 15:52:23 +0200 |
| commit | 117c64266405e244da4dae3ae7b60905af63b955 (patch) | |
| tree | 54db8563f16d0bb55f7d4b90929984386071d3ef /gcc/cp/call.c | |
| parent | 9d20ec97475b1102d6ca005ad165056d34615a3d (diff) | |
| download | gcc-117c64266405e244da4dae3ae7b60905af63b955.zip gcc-117c64266405e244da4dae3ae7b60905af63b955.tar.gz gcc-117c64266405e244da4dae3ae7b60905af63b955.tar.bz2 | |
c++: Add C++23 consteval if support - P1938R3 [PR100974]
The following patch implements consteval if support.
There is a new IF_STMT_CONSTEVAL_P flag on IF_STMT and IF_COND is
boolean_false_node to match the non-manifestly constant evaluation
behavior, while constexpr evaluation special-cases it. Perhaps cleaner
would be to set the condition to __builtin_is_constant_evaluated () call
but we need the IF_STMT_CONSTEVAL_P flag anyway and the IL would be larger.
And I'm not changing the libstdc++ side, where perhaps we could change
std::is_constant_evaluated definition for
#ifdef __cpp_if_consteval
case to if consteval { return true; } else { return false; }
but we need to keep it defined to __builtin_is_constant_evaluated ()
for C++20 or older.
2021-06-11 Jakub Jelinek <jakub@redhat.com>
PR c++/100974
gcc/c-family/
* c-cppbuiltin.c (c_cpp_builtins): Predefine __cpp_if_consteval for
-std=c++2b for P1938R3 consteval if support.
gcc/cp/
* cp-tree.h (struct saved_scope): Add consteval_if_p
member. Formatting fix for the discarded_stmt comment.
(in_consteval_if_p, IF_STMT_CONSTEVAL_P): Define.
* parser.c (cp_parser_lambda_expression): Temporarily disable
in_consteval_if_p when parsing lambda body.
(cp_parser_selection_statement): Parse consteval if.
* decl.c (struct named_label_entry): Add in_consteval_if member.
(level_for_consteval_if): New function.
(poplevel_named_label_1, check_previous_goto_1, check_goto): Handle
consteval if.
* constexpr.c (cxx_eval_builtin_function_call): Clarify in comment
why CP_BUILT_IN_IS_CONSTANT_EVALUATED needs to *non_constant_p
for !ctx->manifestly_const_eval.
(cxx_eval_conditional_expression): For IF_STMT_CONSTEVAL_P evaluate
condition as if it was __builtin_is_constant_evaluated call.
(potential_constant_expression_1): For IF_STMT_CONSTEVAL_P always
recurse on both branches.
* cp-gimplify.c (genericize_if_stmt): Genericize IF_STMT_CONSTEVAL_P
as the else branch.
* pt.c (tsubst_expr) <case IF_STMT>: Copy IF_STMT_CONSTEVAL_P.
Temporarily set in_consteval_if_p when recursing on
IF_STMT_CONSTEVAL_P then branch.
(tsubst_lambda_expr): Temporarily disable
in_consteval_if_p when instantiating lambda body.
* call.c (immediate_invocation_p): Return false when
in_consteval_if_p.
gcc/testsuite/
* g++.dg/cpp23/consteval-if1.C: New test.
* g++.dg/cpp23/consteval-if2.C: New test.
* g++.dg/cpp23/consteval-if3.C: New test.
* g++.dg/cpp23/consteval-if4.C: New test.
* g++.dg/cpp23/consteval-if5.C: New test.
* g++.dg/cpp23/consteval-if6.C: New test.
* g++.dg/cpp23/consteval-if7.C: New test.
* g++.dg/cpp23/consteval-if8.C: New test.
* g++.dg/cpp23/consteval-if9.C: New test.
* g++.dg/cpp23/consteval-if10.C: New test.
* g++.dg/cpp23/feat-cxx2b.C: Add __cpp_if_consteval tests.
Diffstat (limited to 'gcc/cp/call.c')
| -rw-r--r-- | gcc/cp/call.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/gcc/cp/call.c b/gcc/cp/call.c index d2f6ca8..9f03534c 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -8840,6 +8840,7 @@ immediate_invocation_p (tree fn, int nargs) || !DECL_IMMEDIATE_FUNCTION_P (current_function_decl)) && (current_binding_level->kind != sk_function_parms || !current_binding_level->immediate_fn_ctx_p) + && !in_consteval_if_p /* As an exception, we defer std::source_location::current () invocations until genericization because LWG3396 mandates special behavior for it. */ |