m4 macro: apostrophes are not recognized correctly

[lifenjoiner]

Yeah, half of single quotes ...

v24.07r5332 ba5c8a8 Screenshot:

AC_ARG_VAR([PKG_CONFIG_PATH], [directories to add to pkg-config's search path])
AC_ARG_VAR([PKG_CONFIG_LIBDIR], [path overriding pkg-config's built-in search path])

[zufuliu]

It's hard to fix, single quote has at least three means in M4:

• backquote + single quote pair, see https://www.gnu.org/software/m4/manual/m4.html#Quoted-strings and https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.72/autoconf.html#Changequote-is-Evil
• single quotes pair in shell code
• plain quote character in macro description text (e.g. as in your screenshot).

[lifenjoiner]

https://english.stackexchange.com/questions/36046/apostrophe-vs-single-quote: An apostrophe is only used within or at the very end of a word - it is part of the word. Single quotes are only used around words - they come in pairs, and are not part of any word.

Test the previous char?

[zufuliu]

f956b782a15df84d4e6f6c5a3cf7f4173ebfa338 added simple workaround for one's, don't and backquote + single quote pair.

[lifenjoiner]

+ friends'? https://en.wikipedia.org/wiki/Apostrophe#Importance_for_disambiguation

[zufuliu]

• friends'?

Done in 4638d63ec53c1197564a002f009836579c2bfce4.

[lifenjoiner]

Need to exclude to be single quotes:

  if test "$am_compiler_list" = ""; then
     am_compiler_list=`sed -n ['s/^#*\([a-zA-Z0-9]*\))$/\1/p'] < ./depcomp`
  fi

[zufuliu]

Need to exclude to be single quotes

Handled by fc63706177dab165b7c6c2793afcf0ecc447d9d5.