syntax-check: add a rule to help enforce the no-AC_LIBOBJ-in-m4/ policy

* Makefile (sc_prohibit_AC_LIBOBJ_in_m4): New rule.

diff --git a/ChangeLog b/ChangeLog
index 9fc8e4bcb1fa72f41f887dd2f8ac7ea7f23ac568..6c4999b57d4bcc1a2c9358f558aeab9dba63a499 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-06-13  Jim Meyering  <meyering@redhat.com>
+
+       syntax-check: add a rule to help enforce the no-AC_LIBOBJ-in-m4/ policy
+       * Makefile (sc_prohibit_AC_LIBOBJ_in_m4): New rule.
+
 2011-05-23  Bruno Haible  <bruno@clisp.org>
 
        yesno: Move AC_LIBOBJ invocations to module description.

diff --git a/Makefile b/Makefile
index c9bfc1615b0e49309636fe053a9a0f25a93279f9..ca9a516e8e9e08eb2f90d33b4ea97cdc0bd60c4f 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -37,6 +37,42 @@ sc_prohibit_augmenting_PATH_via_TESTS_ENVIRONMENT:
                 "  see <$$url>" 1>&2; exit 1; } || :                   \
        else :; fi
 
+# Files in m4/ that (exceptionally) may use AC_LIBOBJ.
+# Do not include their ".m4" suffix.
+allow_AC_LIBOBJ =      \
+  close                        \
+  dprintf              \
+  dup2                 \
+  faccessat            \
+  fchdir               \
+  fclose               \
+  fcntl                        \
+  fprintf-posix                \
+  open                 \
+  printf-posix         \
+  snprintf             \
+  sprintf-posix                \
+  stdio_h              \
+  vasnprintf           \
+  vasprintf            \
+  vdprintf             \
+  vfprintf-posix       \
+  vprintf-posix                \
+  vsnprintf            \
+  vsprintf-posix
+
+allow_AC_LIBOBJ_or := $(shell echo $(allow_AC_LIBOBJ) | tr -s ' ' '|')
+
+sc_prohibit_AC_LIBOBJ_in_m4:
+       url=http://article.gmane.org/gmane.comp.lib.gnulib.bugs/26995;  \
+       if test -d .git; then                                           \
+         git ls-files m4                                               \
+            | grep -Ev '^m4/($(allow_AC_LIBOBJ_or))\.m4$$'             \
+            | xargs grep '^ *AC_LIBOBJ('                               \
+           && { printf '%s\n' 'Do not use AC_LIBOBJ in m4/*.m4;'       \
+                "see <$$url>"; exit 1; } || :;                         \
+       else :; fi
+
 sc_pragma_columns:
        if test -d .git; then                                           \
          git ls-files|grep '\.in\.h$$'                                 \