Hi.
The patch ensures that a deleted new/delete pair has a same context.
That will fix the issue presented in the PR.
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
Ready to be installed?
Thanks,
Martin
gcc/ChangeLog:
2020-03-30 Martin Liska <mli...@suse.cz>
PR c++/94314
* tree-ssa-dce.c (propagate_necessity): Verify that
DECL_CONTEXT of a new/delete operators do match.
gcc/testsuite/ChangeLog:
2020-03-30 Martin Liska <mli...@suse.cz>
PR c++/94314
* g++.dg/pr94314.C: New test.
---
gcc/testsuite/g++.dg/pr94314.C | 84 ++++++++++++++++++++++++++++++++++
gcc/tree-ssa-dce.c | 31 +++++++++----
2 files changed, 105 insertions(+), 10 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/pr94314.C
diff --git a/gcc/testsuite/g++.dg/pr94314.C b/gcc/testsuite/g++.dg/pr94314.C
new file mode 100644
index 00000000000..76cd9d8d2a4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr94314.C
@@ -0,0 +1,84 @@
+/* PR c++/94314. */
+/* { dg-options "-O2 -fdump-tree-cddce-details" } */
+/* { dg-additional-options "-fdelete-null-pointer-checks" } */
+
+#include <stdio.h>
+
+struct A
+{
+ __attribute__((malloc,noinline))
+ static void* operator new(unsigned long sz)
+ {
+ ++count;
+ return ::operator new(sz);
+ }
+
+ static void operator delete(void* ptr)
+ {
+ --count;
+ ::operator delete(ptr);
+ }
+
+ static int count;
+};
+
+int A::count = 0;
+
+struct B
+{
+ __attribute__((malloc,noinline))
+ static void* operator new(unsigned long sz)
+ {
+ ++count;
+ return ::operator new(sz);
+ }
+
+ __attribute__((noinline))
+ static void operator delete(void* ptr)
+ {
+ --count;
+ ::operator delete(ptr);
+ }
+
+ static int count;
+};
+
+int B::count = 0;
+
+struct C
+{
+ static void* operator new(unsigned long sz)
+ {
+ ++count;
+ return ::operator new(sz);
+ }
+
+ static void operator delete(void* ptr)
+ {
+ --count;
+ ::operator delete(ptr);
+ }
+
+ static int count;
+};
+
+int C::count = 0;
+
+int main(){
+ delete new A;
+ if (A::count != 0)
+ __builtin_abort ();
+
+ delete new B;
+ if (B::count != 0)
+ __builtin_abort ();
+
+ delete new C;
+ if (C::count != 0)
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "Deleting : operator delete" 1 "cddce1"} } */
+/* { dg-final { scan-tree-dump-times "Deleting : B::operator delete" 1 "cddce1"} } */
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index e4077b58890..d86234ead23 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -824,16 +824,27 @@ propagate_necessity (bool aggressive)
|| DECL_FUNCTION_CODE (def_callee) == BUILT_IN_CALLOC))
|| DECL_IS_REPLACEABLE_OPERATOR_NEW_P (def_callee)))
{
- /* Delete operators can have alignment and (or) size as next
- arguments. When being a SSA_NAME, they must be marked
- as necessary. */
- if (is_delete_operator && gimple_call_num_args (stmt) >= 2)
- for (unsigned i = 1; i < gimple_call_num_args (stmt); i++)
- {
- tree arg = gimple_call_arg (stmt, i);
- if (TREE_CODE (arg) == SSA_NAME)
- mark_operand_necessary (arg);
- }
+ if (is_delete_operator)
+ {
+ /* Verify that new and delete operators have the same
+ context. */
+ if (DECL_IS_REPLACEABLE_OPERATOR_NEW_P (def_callee)
+ && (DECL_CONTEXT (def_callee)
+ != DECL_CONTEXT (gimple_call_fndecl (stmt))))
+ mark_operand_necessary (gimple_call_arg (stmt, 0));
+
+ /* Delete operators can have alignment and (or) size
+ as next arguments. When being a SSA_NAME, they
+ must be marked as necessary. */
+ if (gimple_call_num_args (stmt) >= 2)
+ for (unsigned i = 1; i < gimple_call_num_args (stmt);
+ i++)
+ {
+ tree arg = gimple_call_arg (stmt, i);
+ if (TREE_CODE (arg) == SSA_NAME)
+ mark_operand_necessary (arg);
+ }
+ }
continue;
}
