c++: Remove PMF special cases from cxx_get_alias_set [PR119969]

The use of 0 alias set for PMF * types seems to break modref for some reason,
but because PMFs are canonicalized, there should be no reason to special
case the alias set of PMF or PMF * anymore.

2025-11-27  Jakub Jelinek  <jakub@redhat.com>

	PR c++/119969
	* cp-objcp-common.cc (cxx_get_alias_set): Remove special cases
	for TYPE_PTRMEMFUNC_P and INDIRECT_TYPE_P for TYPE_PTRMEMFUNC_P.

	* g++.dg/torture/pr119969.C: New test.

diff --git a/gcc/cp/cp-objcp-common.cc b/gcc/cp/cp-objcp-common.cc
index c7e88cb7bfea0bbe72906781e28c5e6fdd85c2d3..859c7d69746d9d87baa23fb611718092599dabf4 100644 (file)
--- a/gcc/cp/cp-objcp-common.cc
+++ b/gcc/cp/cp-objcp-common.cc
@@ -180,12 +180,6 @@ cxx_get_alias_set (tree t)
        complete type.  */
     return get_alias_set (TYPE_CONTEXT (t));
 
-  /* Punt on PMFs until we canonicalize functions properly.  */
-  if (TYPE_PTRMEMFUNC_P (t)
-      || (INDIRECT_TYPE_P (t)
-         && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))))
-    return 0;
-
   return c_common_get_alias_set (t);
 }
 

diff --git a/gcc/testsuite/g++.dg/torture/pr119969.C b/gcc/testsuite/g++.dg/torture/pr119969.C
new file mode 100644 (file)
index 0000000..25a4053
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr119969.C
@@ -0,0 +1,46 @@
+// PR c++/119969
+// { dg-do run }
+
+struct S {};
+using PMF = void (S::*)();
+using Block = PMF[16];
+using BlockPtr = Block*;
+
+struct IteratorImp {
+  Block** d_blockPtr_p;
+  PMF*  d_value_p;
+
+  void operator++();
+  PMF& operator*() const { return *d_value_p; }
+};
+
+void IteratorImp::operator++() {
+  int offset = 1 + (d_value_p - **d_blockPtr_p);
+  d_blockPtr_p += offset / 16;
+  d_value_p = **d_blockPtr_p + (offset % 16);
+}
+
+struct iterator {
+  IteratorImp d_imp;
+};
+
+struct D {
+  Block* d_blockPtrs[1];
+  Block  d_block;
+  PMF*   d_start_p;
+};
+
+D mX;
+
+void privateInit(int numElements) {
+  mX.d_blockPtrs[0] = &mX.d_block;
+  mX.d_start_p = mX.d_block + (numElements + 7);
+}
+
+int main() {
+  privateInit(0);
+  iterator cbgn = {{mX.d_blockPtrs, mX.d_block + 7}};
+  auto clast = cbgn;
+  ++clast.d_imp;
+  if (&*cbgn.d_imp == &*clast.d_imp) return 1;
+}