Clang implements something we don't have:
__attribute__((deprecated("message", "replacement")));
which seems pretty neat so I wrote this patch to add it to gcc.
It doesn't allow the optional second argument in the standard [[]]
form so as not to clash with possible future standard additions.
I had hoped we could print a nice fix-it replacement hint, but that
won't be possible until warn_deprecated_use gets something better than
input_location.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
PR c++/102049
gcc/c-family/ChangeLog:
* c-attribs.c (c_common_attribute_table): Increase max_len for
deprecated.
(handle_deprecated_attribute): Allow an optional second argument
in the GNU form of attribute deprecated.
gcc/c/ChangeLog:
* c-parser.c (c_parser_std_attribute): Give a diagnostic when
the standard form of an attribute deprecated has a second argument.
gcc/ChangeLog:
* doc/extend.texi: Document attribute deprecated with an
optional second argument.
* tree.c (warn_deprecated_use): Print the replacement argument,
if any.
gcc/testsuite/ChangeLog:
* gcc.dg/c2x-attr-deprecated-3.c: Adjust dg-error.
* c-c++-common/Wdeprecated-arg-1.c: New test.
---
gcc/c-family/c-attribs.c | 17 ++++++++++++-
gcc/c/c-parser.c | 8 ++++++
gcc/doc/extend.texi | 24 ++++++++++++++++++
.../c-c++-common/Wdeprecated-arg-1.c | 21 ++++++++++++++++
gcc/testsuite/gcc.dg/c2x-attr-deprecated-3.c | 2 +-
gcc/tree.c | 25 +++++++++++++++----
6 files changed, 90 insertions(+), 7 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/Wdeprecated-arg-1.c
diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index 007b928c54b..ef857a9ae2c 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -409,7 +409,7 @@ const struct attribute_spec c_common_attribute_table[] =
to prevent its usage in source code. */
{ "no vops", 0, 0, true, false, false, false,
handle_novops_attribute, NULL },
- { "deprecated", 0, 1, false, false, false, false,
+ { "deprecated", 0, 2, false, false, false, false,
handle_deprecated_attribute, NULL },
{ "unavailable", 0, 1, false, false, false, false,
handle_unavailable_attribute, NULL },
@@ -4107,6 +4107,21 @@ handle_deprecated_attribute (tree *node, tree name,
error ("deprecated message is not a string");
*no_add_attrs = true;
}
+ else if (TREE_CHAIN (args) != NULL_TREE)
+ {
+ /* We allow an optional second argument in the GNU form of
+ attribute deprecated, which specifies the replacement. */
+ if (flags & ATTR_FLAG_CXX11)
+ {
+ error ("replacement argument only allowed in GNU attributes");
+ *no_add_attrs = true;
+ }
+ else if (TREE_CODE (TREE_VALUE (TREE_CHAIN (args))) != STRING_CST)
+ {
+ error ("replacement argument is not a string");
+ *no_add_attrs = true;
+ }
+ }
if (DECL_P (*node))
{
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index fa29d2c15fc..2b47f01d166 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -4952,6 +4952,14 @@ c_parser_std_attribute (c_parser *parser, bool for_tm)
TREE_VALUE (attribute)
= c_parser_attribute_arguments (parser, takes_identifier,
require_string, false);
+ if (c_parser_next_token_is (parser, CPP_COMMA)
+ && strcmp (IDENTIFIER_POINTER (name), "deprecated") == 0)
+ {
+ error_at (open_loc, "replacement argument only allowed in "
+ "GNU attributes");
+ c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
+ return error_mark_node;
+ }
}
else
c_parser_balanced_token_sequence (parser);
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 9501a60f20e..7d399f4b2bc 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -2860,6 +2860,7 @@ StrongAlias (allocate, alloc);
@item deprecated
@itemx deprecated (@var{msg})
+@itemx deprecated (@var{msg}, @var{replacement})
@cindex @code{deprecated} function attribute
The @code{deprecated} attribute results in a warning if the function
is used anywhere in the source file. This is useful when identifying
@@ -2880,6 +2881,13 @@ results in a warning on line 3 but not line 2. The
optional @var{msg}
argument, which must be a string, is printed in the warning if
present.
+This attribute accepts an optional second argument which specifies
+the replacement that ought to be used instead:
+
+@smallexample
+int old_fn () __attribute__ ((deprecated("unsafe", "new_fn")));
+@end smallexample
+
The @code{deprecated} attribute can also be used for variables and
types (@pxref{Variable Attributes}, @pxref{Type Attributes}.)
@@ -7409,6 +7417,7 @@ attribute is also not copied. @xref{Common Function Attributes}.
@item deprecated
@itemx deprecated (@var{msg})
+@itemx deprecated (@var{msg}, @var{replacement})
@cindex @code{deprecated} variable attribute
The @code{deprecated} attribute results in a warning if the variable
is used anywhere in the source file. This is useful when identifying
@@ -7429,6 +7438,13 @@ results in a warning on line 3 but not line 2. The
optional @var{msg}
argument, which must be a string, is printed in the warning if
present.
+This attribute accepts an optional second argument which specifies
+the replacement that ought to be used instead:
+
+@smallexample
+extern int old_var __attribute__ ((deprecated("unsafe", "new_var")));
+@end smallexample
+
The @code{deprecated} attribute can also be used for functions and
types (@pxref{Common Function Attributes},
@pxref{Common Type Attributes}).
@@ -8492,6 +8508,7 @@ struct __attribute__ ((copy ( (struct A *)0)) B @{ /*
@r{@dots{}} */ @};
@item deprecated
@itemx deprecated (@var{msg})
+@itemx deprecated (@var{msg}, @var{replacement})
@cindex @code{deprecated} type attribute
The @code{deprecated} attribute results in a warning if the type
is used anywhere in the source file. This is useful when identifying
@@ -8522,6 +8539,13 @@ present. Control characters in the string will be
replaced with
escape sequences, and if the @option{-fmessage-length} option is set
to 0 (its default value) then any newline characters will be ignored.
+This attribute accepts an optional second argument which specifies
+the replacement that ought to be used instead:
+
+@smallexample
+typedef int oldtype __attribute__ ((deprecated("unsafe", "newtype")));
+@end smallexample
+
The @code{deprecated} attribute can also be used for functions and
variables (@pxref{Function Attributes}, @pxref{Variable Attributes}.)
diff --git a/gcc/testsuite/c-c++-common/Wdeprecated-arg-1.c b/gcc/testsuite/c-c++-common/Wdeprecated-arg-1.c
new file mode 100644
index 00000000000..b03e0e42ad6
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wdeprecated-arg-1.c
@@ -0,0 +1,21 @@
+/* PR c++/102049 */
+/* { dg-do compile } */
+/* { dg-additional-options "-std=c++11" { target c++ } } */
+
+typedef int __attribute__((deprecated("obsolete", "newtype"))) oldtype;
+__attribute__((deprecated("unsafe", "get_it_s"))) void get_it (int); /* { dg-message
"declared here" } */
+[[gnu::deprecated("g", "")]] void g(); /* { dg-error "only allowed in GNU
attributes" } */
+[[deprecated("h", "")]] void h(); /* { dg-error "only allowed in GNU
attributes" } */
+__attribute__((deprecated("unsafe", 1))) void f2(); /* { dg-error "argument is not
a string" } */
+__attribute__((deprecated("unsafe", "newvar"))) int oldvar; /* { dg-message
"declared here" } */
+
+int
+main ()
+{
+ get_it (42); /* { dg-warning "is deprecated: unsafe" } */
+ /* { dg-message "use .get_it_s. instead" "" { target *-*-* } .-1 } */
+ oldtype t; /* { dg-warning "is deprecated: obsolete" } */
+ /* { dg-message "use .newtype. instead" "" { target *-*-* } .-1 } */
+ int i = oldvar; /* { dg-warning "is deprecated: unsafe" } */
+ /* { dg-message "use .newvar. instead" "" { target *-*-* } .-1 } */
+}
diff --git a/gcc/testsuite/gcc.dg/c2x-attr-deprecated-3.c
b/gcc/testsuite/gcc.dg/c2x-attr-deprecated-3.c
index 044725e5123..6cb70705bbf 100644
--- a/gcc/testsuite/gcc.dg/c2x-attr-deprecated-3.c
+++ b/gcc/testsuite/gcc.dg/c2x-attr-deprecated-3.c
@@ -6,6 +6,6 @@
[[deprecated(0)]] int b; /* { dg-error "expected" } */
-[[deprecated("", 123)]] int c; /* { dg-error "expected" } */
+[[deprecated("", 123)]] int c; /* { dg-error "only allowed in GNU attributes"
} */
[[deprecated((""))]] int d; /* { dg-error "expected" } */
diff --git a/gcc/tree.c b/gcc/tree.c
index 561b9cd56bd..5cb2d57a960 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -12002,8 +12002,9 @@ bool
warn_deprecated_use (tree node, tree attr)
{
escaped_string msg;
+ escaped_string rep;
- if (node == 0 || !warn_deprecated_decl)
+ if (node == NULL_TREE || !warn_deprecated_decl)
return false;
if (!attr)
@@ -12023,7 +12024,12 @@ warn_deprecated_use (tree node, tree attr)
attr = lookup_attribute ("deprecated", attr);
if (attr)
- msg.escape (TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (attr))));
+ {
+ tree val = TREE_VALUE (attr);
+ msg.escape (TREE_STRING_POINTER (TREE_VALUE (val)));
+ if (TREE_CHAIN (val))
+ rep.escape (TREE_STRING_POINTER (TREE_VALUE (TREE_CHAIN (val))));
+ }
bool w = false;
if (DECL_P (node))
@@ -12036,7 +12042,11 @@ warn_deprecated_use (tree node, tree attr)
w = warning (OPT_Wdeprecated_declarations,
"%qD is deprecated", node);
if (w)
- inform (DECL_SOURCE_LOCATION (node), "declared here");
+ {
+ if (rep)
+ inform (input_location, "use %qs instead", (const char *) rep);
+ inform (DECL_SOURCE_LOCATION (node), "declared here");
+ }
}
else if (TYPE_P (node))
{
@@ -12072,8 +12082,13 @@ warn_deprecated_use (tree node, tree attr)
"type is deprecated");
}
- if (w && decl)
- inform (DECL_SOURCE_LOCATION (decl), "declared here");
+ if (w)
+ {
+ if (rep)
+ inform (input_location, "use %qs instead", (const char *) rep);
+ if (decl)
+ inform (DECL_SOURCE_LOCATION (decl), "declared here");
+ }
}
return w;
base-commit: f6a05b23cc2e53c38e8321ddb5d2cbe40737e506
--
2.31.1
