https://gcc.gnu.org/g:173cf7c9b8c0d61bb2cb0bd3a9e3150b393ab59a
commit r15-7810-g173cf7c9b8c0d61bb2cb0bd3a9e3150b393ab59a
Author: Marek Polacek <pola...@redhat.com>
Date: Thu Feb 27 17:42:49 2025 -0500
c++: ICE with RANGE_EXPR and array init [PR109431]
We crash because we generate
{[0 ... 1]={.low=0, .high=1}, [1]={.low=0, .high=1}}
which output_constructor_regular_field doesn't want to see. This
happens since r9-1483: process_init_constructor_array can now create
a RANGE_EXPR. But the bug isn't in that patch; the problem is that
build_vec_init doesn't handle RANGE_EXPRs.
build_vec_init has a FOR_EACH_CONSTRUCTOR_ELT loop which populates
const_vec. In this case it loops over the elements of
{[0 ... 1]={.low=0, .high=1}}
but assumes that each element initializes one element. So after the
loop num_initialized_elts was 1, and then below:
HOST_WIDE_INT last = tree_to_shwi (maxindex);
if (num_initialized_elts <= last)
{
tree field = size_int (num_initialized_elts);
if (num_initialized_elts != last)
field = build2 (RANGE_EXPR, sizetype, field,
size_int (last));
CONSTRUCTOR_APPEND_ELT (const_vec, field, e);
}
we added the extra initializer.
It seemed convenient to use range_expr_nelts like below.
PR c++/109431
gcc/cp/ChangeLog:
* cp-tree.h (range_expr_nelts): Declare.
* init.cc (build_vec_init): If the CONSTRUCTOR's index is a
RANGE_EXPR, use range_expr_nelts to count how many elements
were initialized.
gcc/testsuite/ChangeLog:
* g++.dg/init/array67.C: New test.
Reviewed-by: Jason Merrill <ja...@redhat.com>
Diff:
---
gcc/cp/cp-tree.h | 1 +
gcc/cp/init.cc | 5 ++++-
gcc/testsuite/g++.dg/init/array67.C | 29 +++++++++++++++++++++++++++++
3 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index c76a92dd39be..583d04963642 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -8621,6 +8621,7 @@ extern tree mangle_decomp (tree,
vec<tree> &);
extern void mangle_module_substitution (int);
extern int mangle_module_component (tree id, bool partition);
extern tree mangle_module_global_init (int);
+extern unsigned HOST_WIDE_INT range_expr_nelts (tree);
/* in dump.cc */
extern bool cp_dump_tree (void *, tree);
diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index f77da4267cbd..ce6e58e05f2f 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -4802,7 +4802,10 @@ build_vec_init (tree base, tree maxindex, tree init,
tree baseref = build1 (INDIRECT_REF, type, base);
tree one_init;
- num_initialized_elts++;
+ if (field && TREE_CODE (field) == RANGE_EXPR)
+ num_initialized_elts += range_expr_nelts (field);
+ else
+ num_initialized_elts++;
/* We need to see sub-array TARGET_EXPR before cp_fold_r so we can
handle cleanup flags properly. */
diff --git a/gcc/testsuite/g++.dg/init/array67.C
b/gcc/testsuite/g++.dg/init/array67.C
new file mode 100644
index 000000000000..8aee8fd481a6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/array67.C
@@ -0,0 +1,29 @@
+// PR c++/109431
+// { dg-do run { target c++11 } }
+
+struct RangeLimits
+{
+ int low = 0;
+ int high = 1;
+ constexpr RangeLimits() { }
+};
+
+template <int>
+int parameterLimits(void)
+{
+ static RangeLimits constexpr param_limits[2] = {};
+ if (param_limits[0].low != 0
+ || param_limits[0].high != 1
+ || param_limits[1].low != 0
+ || param_limits[1].high != 1)
+ __builtin_abort ();
+ auto const &limits = param_limits[1];
+ return 0;
+}
+
+auto s = parameterLimits<1>();
+
+int
+main ()
+{
+}
