c++, contracts: Abstract interfaces to constexpr [NFC].
Commit Message
Another small preparation patch for C++26 upstreaming.
Tested on x86_64-darwin, powerpc64le-linux,
OK for trunk?
thanks
Iain
--- 8< ---
We want to move to having different representations of the contract
semantic for C++26, since that wants values outside the range that
can be accommodated using the cxx2a mechanisms. First part, abstract
the interfaces to constexpr, so that they do not see the underlying
source of data.
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_constant_expression): Use revised
interfaces to determine if contracts are ignored and, if not,
whether they are evaluated.
* contracts.h (contract_ignored_p, contract_evaluated_p): New.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
---
gcc/cp/constexpr.cc | 5 ++---
gcc/cp/contracts.h | 15 +++++++++++++++
2 files changed, 17 insertions(+), 3 deletions(-)
Comments
On 9/17/25 5:35 PM, Iain Sandoe wrote:
> Another small preparation patch for C++26 upstreaming.
> Tested on x86_64-darwin, powerpc64le-linux,
> OK for trunk?
OK.
> --- 8< ---
>
> We want to move to having different representations of the contract
> semantic for C++26, since that wants values outside the range that
> can be accommodated using the cxx2a mechanisms. First part, abstract
> the interfaces to constexpr, so that they do not see the underlying
> source of data.
>
> gcc/cp/ChangeLog:
>
> * constexpr.cc (cxx_eval_constant_expression): Use revised
> interfaces to determine if contracts are ignored and, if not,
> whether they are evaluated.
> * contracts.h (contract_ignored_p, contract_evaluated_p): New.
>
> Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
> ---
> gcc/cp/constexpr.cc | 5 ++---
> gcc/cp/contracts.h | 15 +++++++++++++++
> 2 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
> index db363dc2760..b0e55712cbe 100644
> --- a/gcc/cp/constexpr.cc
> +++ b/gcc/cp/constexpr.cc
> @@ -10112,14 +10112,13 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
> case PRECONDITION_STMT:
> case POSTCONDITION_STMT:
> {
> - contract_semantic semantic = get_contract_semantic (t);
> - if (semantic == CCS_IGNORE)
> + if (contract_ignored_p (t))
> break;
>
> if (!cxx_eval_assert (ctx, CONTRACT_CONDITION (t),
> G_("contract predicate is false in "
> "constant expression"),
> - EXPR_LOCATION (t), checked_contract_p (semantic),
> + EXPR_LOCATION (t), contract_evaluated_p (t),
> non_constant_p, overflow_p))
> *non_constant_p = true;
> r = void_node;
> diff --git a/gcc/cp/contracts.h b/gcc/cp/contracts.h
> index ead07d19fb7..54eacd9a4c5 100644
> --- a/gcc/cp/contracts.h
> +++ b/gcc/cp/contracts.h
> @@ -334,4 +334,19 @@ set_contract_semantic (tree t, contract_semantic semantic)
> }
>
>
> +/* Will this contract be ignored. */
> +
> +inline bool
> +contract_ignored_p (const_tree contract)
> +{
> + return (get_contract_semantic (contract) <= CCS_IGNORE);
> +}
> +
> +/* Will this contract be evaluated? */
> +
> +inline bool
> +contract_evaluated_p (const_tree contract)
> +{
> + return (get_contract_semantic (contract) >= CCS_NEVER);
> +}
> #endif /* ! GCC_CP_CONTRACT_H */
@@ -10112,14 +10112,13 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
case PRECONDITION_STMT:
case POSTCONDITION_STMT:
{
- contract_semantic semantic = get_contract_semantic (t);
- if (semantic == CCS_IGNORE)
+ if (contract_ignored_p (t))
break;
if (!cxx_eval_assert (ctx, CONTRACT_CONDITION (t),
G_("contract predicate is false in "
"constant expression"),
- EXPR_LOCATION (t), checked_contract_p (semantic),
+ EXPR_LOCATION (t), contract_evaluated_p (t),
non_constant_p, overflow_p))
*non_constant_p = true;
r = void_node;
@@ -334,4 +334,19 @@ set_contract_semantic (tree t, contract_semantic semantic)
}
+/* Will this contract be ignored. */
+
+inline bool
+contract_ignored_p (const_tree contract)
+{
+ return (get_contract_semantic (contract) <= CCS_IGNORE);
+}
+
+/* Will this contract be evaluated? */
+
+inline bool
+contract_evaluated_p (const_tree contract)
+{
+ return (get_contract_semantic (contract) >= CCS_NEVER);
+}
#endif /* ! GCC_CP_CONTRACT_H */