[PATCH] c++: Remove GCC12 FIXME for DR1312

[Marek Polacek via Gcc-patches]

This patch removes a FIXME I left for myself for GCC 12, along with
adjusting the relevant test.

Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

gcc/cp/ChangeLog:

        DR 1312
        * constexpr.c (cxx_eval_constant_expression): Don't check
        integer_zerop.

gcc/testsuite/ChangeLog:

        DR 1312
        * g++.dg/cpp0x/constexpr-cast2.C: Remove XFAILs.
---
 gcc/cp/constexpr.c                           | 3 +--
 gcc/testsuite/g++.dg/cpp0x/constexpr-cast2.C | 6 +++---
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index fa7eaed945a..64112ff88c5 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -6747,8 +6747,7 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, 
tree t,
        /* [expr.const]: a conversion from type cv void* to a pointer-to-object
           type cannot be part of a core constant expression as a resolution to
           DR 1312.  */
-       if (integer_zerop (op) /* FIXME: Remove in GCC 12.  */
-           && TYPE_PTROB_P (type)
+       if (TYPE_PTROB_P (type)
            && TYPE_PTR_P (TREE_TYPE (op))
            && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (op)))
            /* Inside a call to std::construct_at or to
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-cast2.C 
b/gcc/testsuite/g++.dg/cpp0x/constexpr-cast2.C
index 7c37f6a3f5a..b79e8a90131 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-cast2.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-cast2.C
@@ -6,11 +6,11 @@ static int i;
 constexpr void *vp0 = nullptr;
 constexpr void *vpi = &i;
 constexpr int *p1 = (int *) vp0; // { dg-error "cast from .void\\*. is not 
allowed" }
-constexpr int *p2 = (int *) vpi; // { dg-error "cast from .void\\*. is not 
allowed" "integer_zerop" { xfail *-*-* } }
+constexpr int *p2 = (int *) vpi; // { dg-error "cast from .void\\*. is not 
allowed" }
 constexpr int *p3 = static_cast<int *>(vp0); // { dg-error "cast from 
.void\\*. is not allowed" }
-constexpr int *p4 = static_cast<int *>(vpi); // { dg-error "cast from 
.void\\*. is not allowed" "integer_zerop" { xfail *-*-* } }
+constexpr int *p4 = static_cast<int *>(vpi); // { dg-error "cast from 
.void\\*. is not allowed" }
 constexpr void *p5 = vp0;
 constexpr void *p6 = vpi;
 
 constexpr int *pi = &i;
-constexpr bool b = ((int *)(void *) pi == pi); // { dg-error "cast from 
.void\\*. is not allowed" "integer_zerop" { xfail *-*-* } }
+constexpr bool b = ((int *)(void *) pi == pi); // { dg-error "cast from 
.void\\*. is not allowed" }

base-commit: e4aefface2a0e34d84b85844b11652eb28f2cf0c
-- 
2.31.1