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| author | Jason Merrill <jason@redhat.com> | 2013-04-02 17:09:38 -0400 |
|---|---|---|
| committer | Jason Merrill <jason@gcc.gnu.org> | 2013-04-02 17:09:38 -0400 |
| commit | 8b00b643987c8b2fe8a2d90253be58ce98a040ce (patch) | |
| tree | 5d007408f4fe3731f7c28e6619d6e9e116feb7f3 | |
| parent | 622849c9371e14fcec645c22b87adedaa16e34e4 (diff) | |
| download | gcc-8b00b643987c8b2fe8a2d90253be58ce98a040ce.zip gcc-8b00b643987c8b2fe8a2d90253be58ce98a040ce.tar.gz gcc-8b00b643987c8b2fe8a2d90253be58ce98a040ce.tar.bz2 | |
re PR c++/34949 (Dead code in empty destructors.)
PR c++/34949
* decl.c (begin_destructor_body): Clobber the object in a cleanup.
From-SVN: r197375
| -rw-r--r-- | gcc/cp/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/cp/decl.c | 8 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/opt/vt2.C | 24 |
3 files changed, 37 insertions, 0 deletions
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 7b73e03..1b847a9 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,8 @@ +2013-04-02 Jason Merrill <jason@redhat.com> + + PR c++/34949 + * decl.c (begin_destructor_body): Clobber the object in a cleanup. + 2013-04-02 Paolo Carlini <paolo.carlini@oracle.com> * friend.c (do_friend): Use COMPLETE_OR_OPEN_TYPE_P. diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 40200b0..70137f4 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -13555,6 +13555,14 @@ begin_destructor_body (void) initialize_vtbl_ptrs (current_class_ptr); finish_compound_stmt (compound_stmt); + /* Insert a cleanup to let the back end know that the object is dead + when we exit the destructor, either normally or via exception. */ + tree clobber = build_constructor (current_class_type, NULL); + TREE_THIS_VOLATILE (clobber) = true; + tree exprstmt = build2 (MODIFY_EXPR, current_class_type, + current_class_ref, clobber); + finish_decl_cleanup (NULL_TREE, exprstmt); + /* And insert cleanups for our bases and members so that they will be properly destroyed if we throw. */ push_base_cleanups (); diff --git a/gcc/testsuite/g++.dg/opt/vt2.C b/gcc/testsuite/g++.dg/opt/vt2.C new file mode 100644 index 0000000..a77db38 --- /dev/null +++ b/gcc/testsuite/g++.dg/opt/vt2.C @@ -0,0 +1,24 @@ +// PR c++/34949 +// { dg-options "-O3" } +// { dg-final { scan-assembler-not "mov\[^\n\]*_ZTV" { target i?86-*-* x86_64-*-* } } } + +class Foo +{ +public: + virtual ~Foo(); +}; + +Foo::~Foo() +{ +} + + +class Bar : public Foo +{ +public: + virtual ~Bar(); +}; + +Bar::~Bar() +{ +} |