We have many classes that copy cotr and assignment operator are deleted in different projects, gcc, gdb and gold. So this patch adds a macro to do this, and replace these existing mechanical code with macro DISABLE_COPY_AND_ASSIGN.
The patch was posted in gdb-patches, https://sourceware.org/ml/gdb-patches/2017-07/msg00254.html but we think it is better to put this macro in include/ansidecl.h so that other projects can use it too. Boostrapped on x86_64-linux-gnu. Is it OK? include: 2017-07-19 Yao Qi <yao...@linaro.org> Pedro Alves <pal...@redhat.com> * ansidecl.h (DISABLE_COPY_AND_ASSIGN): New macro. gcc/cp: 2017-07-19 Yao Qi <yao...@linaro.org> * cp-tree.h (class ovl_iterator): Use DISABLE_COPY_AND_ASSIGN. * name-lookup.c (struct name_loopup): Likewise. gcc: 2017-07-19 Yao Qi <yao...@linaro.org> * tree-ssa-scopedtables.h (class avail_exprs_stack): Use DISABLE_COPY_AND_ASSIGN. (class const_and_copies): Likewise. --- gcc/cp/cp-tree.h | 4 +--- gcc/cp/name-lookup.c | 3 +-- gcc/tree-ssa-scopedtables.h | 6 ++---- include/ansidecl.h | 19 +++++++++++++++++++ 4 files changed, 23 insertions(+), 9 deletions(-) diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index abc9b65..9a45680 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -718,9 +718,7 @@ class ovl_iterator } private: - /* Do not duplicate. */ - ovl_iterator &operator= (const ovl_iterator &); - ovl_iterator (const ovl_iterator &); + DISABLE_COPY_AND_ASSIGN (ovl_iterator); public: operator bool () const diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c index cd7428a..f80958d 100644 --- a/gcc/cp/name-lookup.c +++ b/gcc/cp/name-lookup.c @@ -194,8 +194,7 @@ public: } private: /* Uncopyable, unmovable, unassignable. I am a rock. */ - name_lookup (const name_lookup &); - name_lookup &operator= (const name_lookup &); + DISABLE_COPY_AND_ASSIGN (name_lookup); protected: static bool seen_p (tree scope) diff --git a/gcc/tree-ssa-scopedtables.h b/gcc/tree-ssa-scopedtables.h index df304ae..692da8a 100644 --- a/gcc/tree-ssa-scopedtables.h +++ b/gcc/tree-ssa-scopedtables.h @@ -158,8 +158,7 @@ class avail_exprs_stack /* We do not allow copying this object or initializing one from another. */ - avail_exprs_stack& operator= (const avail_exprs_stack&); - avail_exprs_stack (class avail_exprs_stack &); + DISABLE_COPY_AND_ASSIGN (avail_exprs_stack); }; /* This class defines an unwindable const/copy equivalence table @@ -197,8 +196,7 @@ class const_and_copies private: vec<tree> m_stack; - const_and_copies& operator= (const const_and_copies&); - const_and_copies (class const_and_copies &); + DISABLE_COPY_AND_ASSIGN (const_and_copies); }; void initialize_expr_from_cond (tree cond, struct hashable_expr *expr); diff --git a/include/ansidecl.h b/include/ansidecl.h index f6e1761..796f744 100644 --- a/include/ansidecl.h +++ b/include/ansidecl.h @@ -354,6 +354,25 @@ So instead we use the macro below and test it against specific values. */ # define FINAL #endif +/* A macro to disable the copy constructor and assignment operator. + When building with C++11 and above, the methods are explicitly + deleted, causing a compile-time error if something tries to copy. + For C++03, this just declares the methods, causing a link-time + error if the methods end up called (assuming you don't + define them). For C++03, for best results, place the macro + under the private: access specifier, so that most attempts at + copy are caught at compile-time. */ + +#if __cplusplus >= 201103 +#define DISABLE_COPY_AND_ASSIGN(TYPE) \ + TYPE (const TYPE&) = delete; \ + void operator= (const TYPE &) = delete + #else +#define DISABLE_COPY_AND_ASSIGN(TYPE) \ + TYPE (const TYPE&); \ + void operator= (const TYPE &) +#endif /* __cplusplus >= 201103 */ + #ifdef __cplusplus } #endif -- 1.9.1
