Package: cc-mode;
Reported by: Zhiwei Chen <condy0919 <at> gmail.com>
Date: Sat, 2 Jul 2022 19:13:01 UTC
Severity: normal
Done: Alan Mackenzie <acm <at> muc.de>
Bug is archived. No further changes may be made.
Message #13 received at 56362-done <at> debbugs.gnu.org (full text, mbox):
From: Alan Mackenzie <acm <at> muc.de> To: Zhiwei Chen <condy0919 <at> gmail.com> Cc: 56362-done <at> debbugs.gnu.org, acm <at> muc.de Subject: Re: bug#56362: CC Mode 5.35.1 (C++//l); Highlight for C++20 keywords Date: Tue, 4 Oct 2022 17:32:40 +0000
Hello again, Zhiwei.
I've now committed the changes to standalone CC Mode and the Emacs
master branch.
As a matter of interest, I've also committed support for C++20 concepts
and modules.
I'm closing the bug with this post.
--
Alan Mackenzie (Nuremberg, Germany).
On Wed, Sep 07, 2022 at 13:01:24 +0000, Alan Mackenzie wrote:
> Hello, Zhiwei.
> First of all, sorry that it's taken me two months to reply.
> Secondly, thanks for taking the trouble to submit this bug. I have fixed
> the problems, partly, but I still have a lot of work to do to bring CC
> Mode up to the C++20 standard. In particular, "concepts" and "requires"
> will need a lot doing. I hope to do this work in the coming weeks.
> I have included a patch for these problems below; could you please test
> this patch on your CC Mode and your real C++ source files, and let me
> know how it goes. As I said, it is not perfect, but it should be better
> than it was. If you want any help with the patching or byte compiling of
> CC Mode, feel free to send me private email.
> For the problems you raised:
> On Sun, Jul 03, 2022 at 03:12:28 +0800, Zhiwei Chen wrote:
> > Package: cc-mode
> > See the comments.
> > #+begin_src C++
> > #if __has_include(<bits/stdc++.h>)
> > #include <bits/stdc++.h>
> > #endif
> > #include <cstdint>
> > #include <concepts>
> > // no highlight for consteval keyword
> > consteval int sqr(int x) {
> > return x * x;
> > }
> Now fixed.
> > // no highlight for constinit keyword
> > constinit int four = sqr(16);
> Now fixed.
> > class Foo {
> > public:
> > // <=> highlights wrong
> > auto operator<=>(const Foo&) const = default;
> Now fixed.
> > private:
> > // no highlight for alignas keyword
> > alignas(alignof(std::uint64_t)) int val_;
> > };
> Now fixed. It's also worth noting that "alignas" in a struct/class:
> class alignas(64) Foo { ..... }
> should now fontify correctly.
> > template <typename T>
> > requires std::integral<T> // 'requires' occasionally has a font-lock-type-face
> > T add(T a, T b) {
> > return a + b;
> > }
> Here's where I still need to make "requires" work properly. I've
> temporarily make "requires" and "concept" C++ keywords, but in the above
> piece of code, "T add(T a, T b) {" is not correctly fontified. But
> "requires" should now always be fontified as a keyword.
> > int main() {
> > const char8_t c1 = 0; // char8_t is missing in `c-primitive-type-kwds'. cc-langs.el L2205
> > return 0;
> > }
> > #+end_src
> char8_t is now in c-primitive-type-kwds.
> > Emacs : GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.34, cairo version 1.17.6)
> > of 2022-07-02
> > Package: CC Mode 5.35.1 (C++//l)
> > Buffer Style: gnu
> > c-emacs-features: (pps-extended-state col-0-paren posix-char-classes gen-string-delim gen-comment-delim syntax-properties 1-bit)
> [ CC Mode configuration appreciated, but snipped ]
> Here's the patch:
> diff -r 87af98f62eec cc-langs.el
> --- a/cc-langs.el Wed Aug 31 18:28:12 2022 +0000
> +++ b/cc-langs.el Wed Sep 07 12:38:20 2022 +0000
> @@ -1301,6 +1301,10 @@
> ,@(when (c-major-mode-is 'java-mode)
> '(">>>")))
> + ;; The C++ "spaceship" operator.
> + ,@(when (c-major-mode-is 'c++-mode)
> + `((left-assoc "<=>")))
> +
> ;; Relational.
> (left-assoc "<" ">" "<=" ">="
> ,@(when (c-major-mode-is 'java-mode)
> @@ -1414,7 +1418,7 @@
> "^" "??'" "xor" "&" "bitand" "|" "??!" "bitor" "~" "??-" "compl"
> "!" "=" "<" ">" "+=" "-=" "*=" "/=" "%=" "^="
> "??'=" "xor_eq" "&=" "and_eq" "|=" "??!=" "or_eq"
> - "<<" ">>" ">>=" "<<=" "==" "!=" "not_eq" "<=" ">="
> + "<<" ">>" ">>=" "<<=" "==" "!=" "not_eq" "<=>" "<=" ">="
> "&&" "and" "||" "??!??!" "or" "++" "--" "," "->*" "->"
> "()" "[]" "<::>" "??(??)")
> ;; These work like identifiers in Pike.
> @@ -1535,8 +1539,10 @@
> "List of all arithmetic operators, including \"+=\", etc."
> ;; Note: in the following, there are too many operators for AWK and IDL.
> t (append (c-lang-const c-assignment-operators)
> - '("+" "-" "*" "/" "%"
> + `("+" "-" "*" "/" "%"
> "<<" ">>"
> + ,@(if (c-major-mode-is 'c++-mode)
> + '("<=>"))
> "<" ">" "<=" ">="
> "==" "!="
> "&" "^" "|"
> @@ -2187,7 +2193,7 @@
> '("_Bool" "_Complex" "_Imaginary") ; Conditionally defined in C99.
> (c-lang-const c-primitive-type-kwds))
> c++ (append
> - '("bool" "wchar_t" "char16_t" "char32_t")
> + '("bool" "wchar_t" "char8_t" "char16_t" "char32_t")
> (c-lang-const c-primitive-type-kwds))
> ;; Objective-C extends C, but probably not the new stuff in C99.
> objc (append
> @@ -2580,8 +2586,8 @@
> t nil
> (c c++) '("extern" "inline" "register" "static")
> c (append '("auto") (c-lang-const c-modifier-kwds))
> - c++ (append '("constexpr" "explicit" "friend" "mutable" "template"
> - "thread_local" "virtual")
> + c++ (append '("consteval" "constexpr" "constinit" "explicit" "friend"
> + "mutable" "template" "thread_local" "virtual")
> ;; "using" is now handled specially (2020-09-14).
> (c-lang-const c-modifier-kwds))
> objc '("auto" "bycopy" "byref" "extern" "in" "inout" "oneway" "out" "static")
> @@ -2655,7 +2661,8 @@
> (c c++) '(;; GCC extension.
> "__attribute__"
> ;; MSVC extension.
> - "__declspec"))
> + "__declspec")
> + c++ (append (c-lang-const c-decl-hangon-kwds) '("alignas")))
> (c-lang-defconst c-decl-hangon-key
> ;; Adorned regexp matching `c-decl-hangon-kwds'.
> @@ -2880,7 +2887,7 @@
> "__attribute__"
> ;; MSVC extension.
> "__declspec")
> - c++ (append (c-lang-const c-paren-nontype-kwds) '("noexcept")))
> + c++ (append (c-lang-const c-paren-nontype-kwds) '("noexcept" "alignas")))
> (c-lang-defconst c-paren-nontype-key
> t (c-make-keywords-re t (c-lang-const c-paren-nontype-kwds)))
> @@ -3256,11 +3263,17 @@
> (c-lang-defconst c-keywords
> ;; All keywords as a list.
> t (c--delete-duplicates
> - (c-lang-defconst-eval-immediately
> - `(append ,@(mapcar (lambda (kwds-lang-const)
> - `(c-lang-const ,kwds-lang-const))
> - c-kwds-lang-consts)
> - nil))
> + (append ; Temporary, 2022-09-07
> + (c-lang-defconst-eval-immediately
> + `(append ,@(mapcar (lambda (kwds-lang-const)
> + `(c-lang-const ,kwds-lang-const))
> + c-kwds-lang-consts)
> + nil))
> + ;; Temporary addition for C++ until concepts have been worked out properly.
> + ;; 2022-09-07.
> + `(,@(if (c-major-mode-is 'c++-mode)
> + '("concept" "requires")))
> + nil)
> :test 'string-equal))
> (c-lang-defconst c-keywords-regexp
> --
> Alan Mackenzie (Nuremberg, Germany).
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