The initial ISO C standard and its 1999 revision removed support for many C language features that were widely known as sources of application bugs due to accidental misuse. For backwards compatibility, GCC 13 and earlier diagnosed use of these features as warnings only. Although these warnings have been enabled by default for many releases, experience shows that these warnings are easily ignored, resulting in difficult to diagnose bugs. In GCC 14, these issues are now reported as errors, and no output file is created, providing clearer feedback to programmers that something is wrong.

従来警告だったものをエラーにするようにしたというのがあって、続いていろいろ書かれている

Implicit int types (-Werror=implicit-int)
Implicit function declarations (-Werror=implicit-function-declaration)
Typos in function prototypes (-Werror=declaration-missing-parameter-type)
Incorrect uses of the return statement (-Werror=return-mismatch)
Using pointers as integers and vice versa (-Werror=int-conversion)
Type checking on pointer types (-Werror=incompatible-pointer-types)

↑これらをまとめて「記述要素」としたんだろうか

GCC 14 Release Series — Changes, New Features, and Fixes - GNU Project

Bit-precise integer types (_BitInt (N) and unsigned _BitInt (N)): integer types with a specified number of bits. These are only supported on IA-32, x86-64 and AArch64 (little-endian) at present.

これ(_BitInt (N) and unsigned _BitInt (N))、C++23にはないよねえ

When a diagnostic occurrs involving a C++ template, GCC will now quote the source code of the context at which the template is instantiated (“required from here”), rather than just print filename and line/column numbers.

「quote the source code of the context (at which the template is instantiated)」は単純に「ソースの引用」とはちょっと違うんじゃなかろうか

この記事にはないけど、今回の変更点の一つで気になったもの

GCC 14 Release Series - Changes, New Features, and Fixes - GNU Project

Support for the GCC extension, a structure containing a C99 flexible array member, or a union containing such a structure, is not the last field of another structure, is deprecated.

from stdin

Opening Windows in Linux with sockets, bare hands and 200 lines of C | Hacker News に出てきた

In fact, two definitions and a couple trivial syntax fixes are enough to get Chez Scheme to evaluate it without warnings:
 $ awk -f - vmx.ss <<EOF | scheme -q
   BEGIN {
       print "(define / fxdiv)"
       print "(define (log . args) (for-each display args))"
   }
   {
       gsub(//, "'()")
       gsub(/ 0x/, " #x")
       print
   } 
 EOF
 $

awkとschemeの両方にそのソースコードを標準入力から渡しているのがちょっと面白かった。

まあawkの方はふつーに書いてもいいんじゃないかと思うけど (bashなどなら複数行のスクリプトを単純にクォートするだけで渡せるはず)。

ed

突然、GNU edの編集対象のテキストの管理方法が気になったのでソースコードを眺めてみた。行ごとにテキストを保持してそれぞれを linked listにしているんだろうかと思いつつヘッダーを見ると

ed/ed.h at master · Distrotech/ed · GitHub

typedef struct line             /* Line node */
  {
  struct line * q_forw;
  struct line * q_back;
  long pos;                     /* position of text in scratch buffer */
  int len;                      /* length of line */
  }
line_t;

なにこれ。

じゃあv7ではどうだったんだ? と v7unix/v7/usr/src/cmd/ed.c at master · v7unix/v7unix を見たがこっちはこっちでよくわからん😓

色々ダメ(本年n回目)

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