diff options
| author | Robin Haberkorn <rhaberkorn@fmsbw.de> | 2025-10-20 00:02:34 +0200 |
|---|---|---|
| committer | Robin Haberkorn <rhaberkorn@fmsbw.de> | 2025-10-20 00:02:34 +0200 |
| commit | 243a3be9185412a5a29ba189c77569fa96c85e89 (patch) | |
| tree | b5aaa8ec1820262392676ad64474efd18982efe3 /m4 | |
| parent | f223cfada825d87dcab393611f604b8014f2b172 (diff) | |
scintilla: use AX_PTRDIFF_ALIASES_INT to check whether ptrdiff_t aliases int
* Scintilla had build problems if ptrdiff_t doesn't alias int if it has the
same storage size (e.g. on NetBSD 10 (armv6)).
* Unfortunately, Neil Hodgson refused to merge my previous Scintilla patches that
would have fixed the issue at the core.
See https://groups.google.com/g/scintilla-interest/c/STAv6LgLyCo
* He only agreed to introducing a separate flag to work around the issue
(`-DPTRDIFF_DOESNT_ALIAS_INT`).
* In order to continue to support all standard C/C++ conforming platforms
we therefore need a compile-time check to check for the aliasability
of ptrdiff_t and int.
Diffstat (limited to 'm4')
| -rw-r--r-- | m4/ax_ptrdiff_aliases_int.m4 | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/m4/ax_ptrdiff_aliases_int.m4 b/m4/ax_ptrdiff_aliases_int.m4 new file mode 100644 index 0000000..f7175cd --- /dev/null +++ b/m4/ax_ptrdiff_aliases_int.m4 @@ -0,0 +1,16 @@ + +AC_DEFUN([AX_PTRDIFF_ALIASES_INT], [ + AC_CACHE_CHECK([whether ptrdiff_t aliases int], [ax_cv_ptrdiff_aliases_int], [ + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ + @%:@include <stddef.h> + ]], [[ + int a = 23; + ptrdiff_t *b = &a; + ]])], + [ax_cv_ptrdiff_aliases_int=yes], + [ax_cv_ptrdiff_aliases_int=no]) + ]) + AS_IF([test "x$ax_cv_ptrdiff_aliases_int" = "xyes"], [ + AC_DEFINE([PTRDIFF_ALIASES_INT], [1], [Whether ptrdiff_t aliases int]) + ]) +])dnl |