[Automake-NG] [FYI] [ng] maintcheck: avoid spurious failures

[Stefano Lattarini]

* t/suffix-custom-link.sh: Rewrite a little to avoid triggering warnings
from the 'sc_tests_here_document_format' maintainer check.
* syntax-checks.mk (sc_diff_aclocal_in_aclocal,
sc_diff_automake_in_automake): Rename ...
(sc_diff_aclocal_in_aclocal,
sc_diff_automake_in_automake): ... respectively to these, rewrite to use
static pattern rules and 'diff -u' instead of bare 'diff', and fix the
count of expected differences to account for the removed substitution of
'@SHELL@' in automake.in.
(syntax_check_rules): Adjust.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 syntax-checks.mk        |   36 ++++++++++++++++++++----------------
 t/suffix-custom-link.sh |    5 +++--
 2 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/syntax-checks.mk b/syntax-checks.mk
index a13ce38..0503684 100644
--- a/syntax-checks.mk
+++ b/syntax-checks.mk
@@ -40,8 +40,8 @@ pms := $(dist_perllib_DATA)
 # guaranteed to work on my machine.
 syntax_check_rules = \
 $(sc_tests_plain_check_rules) \
-sc_diff_automake_in_automake \
-sc_diff_aclocal_in_aclocal \
+sc_diff_automake \
+sc_diff_aclocal \
 sc_perl_syntax \
 sc_no_brace_variable_expansions \
 sc_rm_minus_f \
@@ -84,21 +84,25 @@ sc_tabs_in_texi \
 sc_at_in_texi
 
 ## These check avoids accidental configure substitutions in the source.
-## There are exactly 9 lines that should be modified from automake.in to
+## There are exactly 8 lines that should be modified from automake.in to
 ## automake, and 10 lines that should be modified from aclocal.in to
-## aclocal; these wors out to 32 and 34 lines of diffs, respectively.
-sc_diff_automake_in_automake:
-       @if test `diff $(srcdir)/automake.in automake | wc -l` -ne 32; then \
-         echo "found too many diffs between automake.in and automake" 1>&2; \
-         diff -c $(srcdir)/automake.in automake; \
-         exit 1; \
-       fi
-sc_diff_aclocal_in_aclocal:
-       @if test `diff $(srcdir)/aclocal.in aclocal | wc -l` -ne 34; then \
-         echo "found too many diffs between aclocal.in and aclocal" 1>&2; \
-         diff -c $(srcdir)/aclocal.in aclocal; \
-         exit 1; \
-       fi
+## aclocal.
+automake_diff_no = 8
+aclocal_diff_no = 10
+sc_diff_automake sc_diff_aclocal: sc_diff_% :
+       @set +e; tmp=$*-diffs.tmp; \
+        diff -u $(srcdir)/$*.in $* > $$tmp; test $$? -eq 1 || exit 1; \
+        added=`grep -v '^+++ ' $$tmp | grep -c '^+'` || exit 1; \
+        removed=`grep -v '^--- ' $$tmp | grep -c '^-'` || exit 1; \
+        test $$added,$$removed = $($*_diff_no),$($*_diff_no) \
+         || { \
+           echo "Found unexpected diffs between $*.in and $*"; \
+           echo "Lines added:   $$added"  ; \
+           echo "Lines removed: $$removed"; \
+           cat $$tmp >&2; \
+           exit 1; \
+         } >&1; \
+       rm -f $$tmp
 
 ## Syntax check with default Perl (on my machine, Perl 5).
 sc_perl_syntax:
diff --git a/t/suffix-custom-link.sh b/t/suffix-custom-link.sh
index 0b7814f..1a3c013 100755
--- a/t/suffix-custom-link.sh
+++ b/t/suffix-custom-link.sh
@@ -28,7 +28,8 @@ END
 
 cat > Makefile.am <<'END'
 %.$(OBJEXT): %.xt
-       sed -e 's/@/o/g' -e 's/!/;/g' $< >$*-t.cc \
+## Creative quoting to plase maintainer checks.
+       sed -e 's/@/o/g' -e 's/!/;/g' -e 's/<-/<''</g' $< >$*-t.cc \
          && $(CXX) -c $*-t.cc \
          && rm -f $*-t.cc \
          && mv -f $*-t.$(OBJEXT) $@
@@ -52,7 +53,7 @@ cat > 2.xt <<'END'
 void say_hell@ (address@hidden)
 {
   using namespace std!
-  address@hidden << "Hell@, address@hidden" << endl!
+  address@hidden <- "Hell@, address@hidden" <- endl!
 }
 END
 
-- 
1.7.9.5