In discussion of PR98463, Jakub noted that cxx_fold_indirect_ref_1 was
bailing out early for empty bases even when we do have fields for them (in
C++17 mode or later). This corrects that.
Tested x86_64-pc-linux-gnu, applying to trunk.
gcc/cp/ChangeLog:
* constexpr.c (cxx_fold_indirect_ref_1): Only set *empty_base if we
don't find a field.
---
gcc/cp/constexpr.c | 38 ++++++++++++++++++--------------------
1 file changed, 18 insertions(+), 20 deletions(-)
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index fa7eaed945a..9481a5bfd3c 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -4734,28 +4734,17 @@ cxx_fold_indirect_ref_1 (const constexpr_ctx *ctx,
location_t loc, tree type,
{
tree optype = TREE_TYPE (op);
unsigned HOST_WIDE_INT const_nunits;
- if (off == 0)
- {
- if (similar_type_p (optype, type))
- return op;
- /* Also handle conversion to an empty base class, which
- is represented with a NOP_EXPR. */
- /* *(foo *)&complexfoo => __real__ complexfoo */
- else if (TREE_CODE (optype) == COMPLEX_TYPE
- && similar_type_p (type, TREE_TYPE (optype)))
- return build1_loc (loc, REALPART_EXPR, type, op);
- }
- /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
+ if (off == 0 && similar_type_p (optype, type))
+ return op;
else if (TREE_CODE (optype) == COMPLEX_TYPE
- && similar_type_p (type, TREE_TYPE (optype))
- && tree_to_uhwi (TYPE_SIZE_UNIT (type)) == off)
- return build1_loc (loc, IMAGPART_EXPR, type, op);
- if (is_empty_class (type)
- && CLASS_TYPE_P (optype)
- && DERIVED_FROM_P (type, optype))
+ && similar_type_p (type, TREE_TYPE (optype)))
{
- *empty_base = true;
- return op;
+ /* *(foo *)&complexfoo => __real__ complexfoo */
+ if (off == 0)
+ return build1_loc (loc, REALPART_EXPR, type, op);
+ /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
+ else if (tree_to_uhwi (TYPE_SIZE_UNIT (type)) == off)
+ return build1_loc (loc, IMAGPART_EXPR, type, op);
}
/* ((foo*)&vectorfoo)[x] => BIT_FIELD_REF<vectorfoo,...> */
else if (VECTOR_TYPE_P (optype)
@@ -4834,6 +4823,15 @@ cxx_fold_indirect_ref_1 (const constexpr_ctx *ctx,
location_t loc, tree type,
return ret;
}
}
+ /* Also handle conversion to an empty base class, which
+ is represented with a NOP_EXPR. */
+ if (is_empty_class (type)
+ && CLASS_TYPE_P (optype)
+ && DERIVED_FROM_P (type, optype))
+ {
+ *empty_base = true;
+ return op;
+ }
}
return NULL_TREE;
base-commit: 449d7b40f6f6be8d7f9aa7232c73b0371f0963bf
prerequisite-patch-id: 39f358d55a4ba496b673d13e00215152266caa54
prerequisite-patch-id: f0d6c56fe2c9e16572f0760fb223f6d4df3e859e
prerequisite-patch-id: 8188da37013371fd5864b80fb0cc5ad4596a1ff6
prerequisite-patch-id: f9c0d88147525dd47cab54ddfdde9341b7b10a4c
--
2.27.0
