From 30b07d033db90fb3722583c3210be1ab63679e3f Mon Sep 17 00:00:00 2001 From: Paolo Carlini Date: Wed, 20 Feb 2013 09:02:35 +0000 Subject: [PATCH] re PR c++/56373 (-Wzero-as-null-pointer-constant: does not catch issues with smart pointers) /cp 2013-02-20 Paolo Carlini PR c++/56373 * tree.c (maybe_warn_zero_as_null_pointer_constant): Add. * cvt.c (ocp_convert): Use the latter. (cp_convert_to_pointer): Likewise. * decl.c (check_default_argument): Likewise. * typeck.c (cp_build_binary_op): Likewise. * cp-tree.h (maybe_warn_zero_as_null_pointer_constant): Declare. /testsuite 2013-02-20 Paolo Carlini PR c++/56373 * g++.dg/cpp0x/Wzero-as-null-pointer-constant-2.C: New. From-SVN: r196165 --- gcc/cp/ChangeLog | 10 ++++++++++ gcc/cp/cp-tree.h | 1 + gcc/cp/cvt.c | 13 +++++++------ gcc/cp/decl.c | 9 ++------- gcc/cp/tree.c | 15 +++++++++++++++ gcc/cp/typeck.c | 9 +++------ gcc/testsuite/ChangeLog | 5 +++++ .../cpp0x/Wzero-as-null-pointer-constant-2.C | 14 ++++++++++++++ 8 files changed, 57 insertions(+), 19 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/Wzero-as-null-pointer-constant-2.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 52fac3af74c..b7816a90339 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,13 @@ +2013-02-20 Paolo Carlini + + PR c++/56373 + * tree.c (maybe_warn_zero_as_null_pointer_constant): Add. + * cvt.c (ocp_convert): Use the latter. + (cp_convert_to_pointer): Likewise. + * decl.c (check_default_argument): Likewise. + * typeck.c (cp_build_binary_op): Likewise. + * cp-tree.h (maybe_warn_zero_as_null_pointer_constant): Declare. + 2013-02-15 Jonathan Wakely Paolo Carlini diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index d9270e2270d..4a597d8b3a6 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -5834,6 +5834,7 @@ extern bool cast_valid_in_integral_constant_expression_p (tree); extern bool cxx_type_hash_eq (const_tree, const_tree); extern void cxx_print_statistics (void); +extern bool maybe_warn_zero_as_null_pointer_constant (tree, location_t); /* in ptree.c */ extern void cxx_print_xnode (FILE *, tree, int); diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c index 8e8ce53325e..348e6082ceb 100644 --- a/gcc/cp/cvt.c +++ b/gcc/cp/cvt.c @@ -203,11 +203,8 @@ cp_convert_to_pointer (tree type, tree expr, tsubst_flags_t complain) if (null_ptr_cst_p (expr)) { - if ((complain & tf_warning) - && c_inhibit_evaluation_warnings == 0 - && !NULLPTR_TYPE_P (TREE_TYPE (expr))) - warning_at (loc, OPT_Wzero_as_null_pointer_constant, - "zero as null pointer constant"); + if (complain & tf_warning) + maybe_warn_zero_as_null_pointer_constant (expr, loc); if (TYPE_PTRMEMFUNC_P (type)) return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0, @@ -783,7 +780,11 @@ ocp_convert (tree type, tree expr, int convtype, int flags, return ignore_overflows (converted, e); } if (NULLPTR_TYPE_P (type) && e && null_ptr_cst_p (e)) - return nullptr_node; + { + if (complain & tf_warning) + maybe_warn_zero_as_null_pointer_constant (e, loc); + return nullptr_node; + } if (POINTER_TYPE_P (type) || TYPE_PTRMEM_P (type)) return fold_if_not_in_template (cp_convert_to_pointer (type, e, complain)); if (code == VECTOR_TYPE) diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 3d63389e404..661969f441c 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -10861,15 +10861,10 @@ check_default_argument (tree decl, tree arg) --cp_unevaluated_operand; if (warn_zero_as_null_pointer_constant - && c_inhibit_evaluation_warnings == 0 && TYPE_PTR_OR_PTRMEM_P (decl_type) && null_ptr_cst_p (arg) - && !NULLPTR_TYPE_P (TREE_TYPE (arg))) - { - warning (OPT_Wzero_as_null_pointer_constant, - "zero as null pointer constant"); - return nullptr_node; - } + && maybe_warn_zero_as_null_pointer_constant (arg, input_location)) + return nullptr_node; /* [dcl.fct.default] diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c index 0b033c2bfb4..41c8759096c 100644 --- a/gcc/cp/tree.c +++ b/gcc/cp/tree.c @@ -3939,6 +3939,21 @@ cp_tree_operand_length (const_tree t) return TREE_OPERAND_LENGTH (t); } } + +/* Implement -Wzero_as_null_pointer_constant. Return true if the + conditions for the warning hold, false otherwise. */ +bool +maybe_warn_zero_as_null_pointer_constant (tree expr, location_t loc) +{ + if (c_inhibit_evaluation_warnings == 0 + && !NULLPTR_TYPE_P (TREE_TYPE (expr))) + { + warning_at (loc, OPT_Wzero_as_null_pointer_constant, + "zero as null pointer constant"); + return true; + } + return false; +} #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007) /* Complain that some language-specific thing hanging off a tree diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index 688c2665b4f..58295d73d15 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -4293,12 +4293,9 @@ cp_build_binary_op (location_t location, delta0, integer_one_node, complain); - - if ((complain & tf_warning) - && c_inhibit_evaluation_warnings == 0 - && !NULLPTR_TYPE_P (TREE_TYPE (op1))) - warning (OPT_Wzero_as_null_pointer_constant, - "zero as null pointer constant"); + + if (complain & tf_warning) + maybe_warn_zero_as_null_pointer_constant (op1, input_location); e2 = cp_build_binary_op (location, EQ_EXPR, e2, integer_zero_node, diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 68ea2bd0c85..0135609ad3b 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2013-02-20 Paolo Carlini + + PR c++/56373 + * g++.dg/cpp0x/Wzero-as-null-pointer-constant-2.C: New. + 2013-02-19 Richard Biener PR tree-optimization/56384 diff --git a/gcc/testsuite/g++.dg/cpp0x/Wzero-as-null-pointer-constant-2.C b/gcc/testsuite/g++.dg/cpp0x/Wzero-as-null-pointer-constant-2.C new file mode 100644 index 00000000000..eea2c2fcf31 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/Wzero-as-null-pointer-constant-2.C @@ -0,0 +1,14 @@ +// PR c++/56373 +// { dg-options "-std=c++11 -Wzero-as-null-pointer-constant" } + +struct shared_ptr +{ + shared_ptr(decltype(nullptr)); +}; + +void f() +{ + shared_ptr a = 0; // { dg-warning "zero as null pointer" } + shared_ptr b(0); // { dg-warning "zero as null pointer" } + shared_ptr c{0}; // { dg-warning "zero as null pointer" } +} -- 2.30.2