[groff] 23/34: m4/groff.m4: Fail if cpp is pre-C89.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit ff103f9da5f704c1b780aed186033d9492955f56
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sat Aug 28 11:34:20 2021 +1000

    m4/groff.m4: Fail if cpp is pre-C89.
    
    * m4/groff.m4 (TRADITIONAL_CPP): Update `AC_MSG_CHECKING` argument to
      refer to "pre-ISO C90 syntax" instead of a "traditional" preprocessor.
      Call `AC_MSG_ERROR` (aborting configuration) if the check (for pre-C90
      transformation) succeeds.  We thus withdraw support for such
      superannuated ("Reiser") C preprocessors.
---
 ChangeLog   | 9 +++++++++
 m4/groff.m4 | 5 ++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index ff3b5ab..b44b17f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2021-08-28  G. Branden Robinson <g.branden.robinson@gmail.com>
 
+       * m4/groff.m4 (TRADITIONAL_CPP): Update `AC_MSG_CHECKING`
+       argument to refer to "pre-ISO C90 syntax" instead of a
+       "traditional" preprocessor.  Call `AC_MSG_ERROR` (aborting
+       configuration) if the check (for pre-C90 transformation)
+       succeeds.  We thus withdraw support for such superannuated
+       {"Reiser"} C preprocessors.
+
+2021-08-28  G. Branden Robinson <g.branden.robinson@gmail.com>
+
        [libgroff]: Un-indirect token concatenation through macro.
 
        * src/include/itable.h:
diff --git a/m4/groff.m4 b/m4/groff.m4
index 44a037c..a5f90e5 100644
--- a/m4/groff.m4
+++ b/m4/groff.m4
@@ -821,7 +821,7 @@ delete [] p;
 
 AC_DEFUN([GROFF_TRADITIONAL_CPP],
   [AC_LANG_PUSH([C++])
-   AC_MSG_CHECKING([traditional preprocessor])
+   AC_MSG_CHECKING([whether C preprocessor uses pre-ISO C90 syntax])
    AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
 
@@ -835,8 +835,7 @@ int name2(foo, bar);
        ]])
      ],
      [AC_MSG_RESULT([yes])
-      AC_DEFINE([TRADITIONAL_CPP], [1],
-       [Define if your C++ compiler uses a traditional (Reiser) 
preprocessor.])],
+      AC_MSG_ERROR([an ISO C90-conformant C preprocessor is required])],
      [AC_MSG_RESULT([no])])
    AC_LANG_POP([C++])])