On Wed, Oct 20, 2021 at 10:57 AM Marek Polacek via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Wed, Oct 20, 2021 at 03:49:09PM +0000, Qing Zhao via Gcc-patches wrote:
> > Hi,
> >
> > In GCC, there are many utility routines for reporting error, warning, or
> > information, for example:
> >
> > warning (0, "weak declaration of %q+D not supported", decl);
> > warning_at (stmtloc, OPT_Wmaybe_uninitialized, "%qE may be used
> > uninitialized", ptr));
> > inform (loc, "in a call to %qT declared with " "attribute %<%s%>", fntype,
> > access_str);
> > error ("%qD is unavailable: %s", node, (const char *) msg);
> >
> > There are format-strings inside them, “%q+D”, “%qE”, “%qT”, “%qD”, etc,
> > where can I find a doc for the details of
> > These format-strings? Or which source files I should read to understand the
> > details?
>
> You can take a look at cp/error.c:
>
> /* Called from output_format -- during diagnostic message processing --
> to handle C++ specific format specifier with the following meanings:
> %A function argument-list.
> %C tree code.
> %D declaration.
> %E expression.
> %F function declaration.
> %H type difference (from).
> %I type difference (to).
> %L language as used in extern "lang".
> %O binary operator.
> %P function parameter whose position is indicated by an integer.
> %Q assignment operator.
> %S substitution (template + args)
> %T type.
> %V cv-qualifier.
> %X exception-specification. */
> static bool
> cp_printer (pretty_printer *pp, text_info *text, const char *spec,
>
> or c/c-objc-common.c:
>
> /* Called during diagnostic message formatting process to print a
> source-level entity onto BUFFER. The meaning of the format specifiers
> is as follows:
> %D: a general decl,
> %E: an identifier or expression,
> %F: a function declaration,
> %T: a type.
> %V: a list of type qualifiers from a tree.
> %v: an explicit list of type qualifiers
> %#v: an explicit list of type qualifiers of a function type.
>
> Please notice when called, the `%' part was already skipped by the
> diagnostic machinery. */
> static bool
> c_tree_printer (pretty_printer *pp, text_info *text, const char *spec,
>
> Marek
>
Note that this is bug 92435: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92435
