On 6/16/21 10:35 AM, Jason Merrill wrote:
On 6/16/21 12:11 PM, Martin Sebor wrote:
On 6/16/21 9:06 AM, David Malcolm wrote:
On Wed, 2021-06-16 at 08:52 -0600, Martin Sebor wrote:
On 6/16/21 6:38 AM, David Malcolm wrote:
On Tue, 2021-06-15 at 19:48 -0600, Martin Sebor wrote:
Thanks for writing the patch.
While debugging locations I noticed the semi_embedded_vec template
in line-map.h doesn't declare a copy ctor or copy assignment, but
is being copied in a couple of places in the C++ parser (via
gcc_rich_location). It gets away with it most likely because it
never grows beyond the embedded buffer.
Where are these places? I wasn't aware of this.
They're in the attached file along with the diff to reproduce
the errors.
Thanks.
Looks like:
gcc_rich_location richloc = tok->location;
is implicitly constructing a gcc_rich_location, then copying it to
richloc. This should instead be simply:
gcc_rich_location richloc (tok->location);
which directly constructs the richloc in place, as I understand it.
I see, tok->location is location_t here, and the gcc_rich_location
ctor that takes it is not declared explicit (that would prevent
the implicit conversion).
The attached patch solves the rich_location problem by a) making
the ctor explicit, b) disabling the rich_location copy ctor, c)
changing the parser to use direct initialization. (I CC Jason
as a heads up on the C++ FE bits.)
The C++ bits are fine.
The semi_embedded_vec should be fixed as well, regardless of this
particular use and patch. Let me know if it's okay to commit (I'm
not open to disabling its copy ctor).
+ /* Not copyable or assignable. */
This comment needs a rationale.
Done in the attached patch.
Providing a rationale in each instance sounds like a good addition
to the coding conventions. Let me propose a patch for that.
Martin
gcc/cp/ChangeLog:
* parser.c (cp_parser_selection_statement): Use direct initialization
instead of copy.
gcc/ChangeLog:
* gcc-rich-location.h (gcc_rich_location): Make ctor explicit.
libcpp/ChangeLog:
* include/line-map.h (class rich_location): Disable copying and
assignment.
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index d57ddc4560d..848e4823258 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -12355,7 +12355,7 @@ cp_parser_selection_statement (cp_parser* parser, bool *if_p,
IF_STMT_CONSTEVAL_P (statement) = true;
condition = finish_if_stmt_cond (boolean_false_node, statement);
- gcc_rich_location richloc = tok->location;
+ gcc_rich_location richloc (tok->location);
bool non_compound_stmt_p = false;
if (cp_lexer_next_token_is_not (parser->lexer, CPP_OPEN_BRACE))
{
@@ -12383,7 +12383,7 @@ cp_parser_selection_statement (cp_parser* parser, bool *if_p,
RID_ELSE))
{
cp_token *else_tok = cp_lexer_peek_token (parser->lexer);
- gcc_rich_location else_richloc = else_tok->location;
+ gcc_rich_location else_richloc (else_tok->location);
guard_tinfo = get_token_indent_info (else_tok);
/* Consume the `else' keyword. */
cp_lexer_consume_token (parser->lexer);
diff --git a/gcc/gcc-rich-location.h b/gcc/gcc-rich-location.h
index 00747631025..2a9e5db65d5 100644
--- a/gcc/gcc-rich-location.h
+++ b/gcc/gcc-rich-location.h
@@ -21,14 +21,16 @@ along with GCC; see the file COPYING3. If not see
#define GCC_RICH_LOCATION_H
/* A gcc_rich_location is libcpp's rich_location with additional
- helper methods for working with gcc's types. */
+ helper methods for working with gcc's types. The class is not
+ copyable or assignable because rich_location isn't. */
+
class gcc_rich_location : public rich_location
{
public:
/* Constructors. */
/* Constructing from a location. */
- gcc_rich_location (location_t loc, const range_label *label = NULL)
+ explicit gcc_rich_location (location_t loc, const range_label *label = NULL)
: rich_location (line_table, loc, label)
{
}
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index 7d964172469..464494bfb5b 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -1670,6 +1670,12 @@ class rich_location
/* Destructor. */
~rich_location ();
+ /* The class manages the memory pointed to by the elements of
+ the M_FIXIT_HINTS vector and is not meant to be copied or
+ assigned. */
+ rich_location (const rich_location &) = delete;
+ void operator= (const rich_location &) = delete;
+
/* Accessors. */
location_t get_loc () const { return get_loc (0); }
location_t get_loc (unsigned int idx) const;
