diff mbox series

[pushed] c++: mutable temps in rodata

Message ID 20230613120934.4183450-1-jason@redhat.com
State New
Headers show
Series [pushed] c++: mutable temps in rodata | expand

Commit Message

Jason Merrill June 13, 2023, 12:09 p.m. UTC 
Tested x86_64-pc-linux-gnu, applying to trunk.

-- 8< --

If the type of a temporary has mutable members, we can't set TREE_READONLY
on the VAR_DECL; this is parallel to the check in
cp_apply_type_quals_to_decl.

gcc/cp/ChangeLog:

	* tree.cc (build_target_expr): Check TYPE_HAS_MUTABLE_P.

gcc/testsuite/ChangeLog:

	* g++.dg/tree-ssa/initlist-opt6.C: New test.
---
 gcc/cp/tree.cc                                |  1 +
 gcc/testsuite/g++.dg/tree-ssa/initlist-opt6.C | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/tree-ssa/initlist-opt6.C


base-commit: d438b67e005bf8fc9e4af26410bf69816c30e969
diff mbox series

Patch

diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
index 751c9adeb62..799183dc646 100644
--- a/gcc/cp/tree.cc
+++ b/gcc/cp/tree.cc
@@ -522,6 +522,7 @@  build_target_expr (tree decl, tree value, tsubst_flags_t complain)
   if (CP_TYPE_CONST_NON_VOLATILE_P (type)
       && !TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
       && !VOID_TYPE_P (TREE_TYPE (value))
+      && !TYPE_HAS_MUTABLE_P (type)
       && reduced_constant_expression_p (value))
     TREE_READONLY (decl) = true;
 
diff --git a/gcc/testsuite/g++.dg/tree-ssa/initlist-opt6.C b/gcc/testsuite/g++.dg/tree-ssa/initlist-opt6.C
new file mode 100644
index 00000000000..ea1bf5d935e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/initlist-opt6.C
@@ -0,0 +1,18 @@ 
+// { dg-do compile { target c++11 } }
+// { dg-additional-options -fdump-tree-gimple }
+// { dg-final { scan-tree-dump-not {static const struct S} "gimple" } }
+
+// Test that mutable prevents putting this init-list array in rodata.
+
+#include <initializer_list>
+
+struct S {
+    constexpr S(int i) : i(i) {}
+    mutable int i;
+};
+
+void f(std::initializer_list<S>);
+
+int main() {
+    f({1,2,3});
+}