Add -Wconflicts-sr and -Wconflicts-rr.

Thus, conflict reports are now affected by -Werror and -Wnone
(unless %expect or %expect-rr is specified).  Reported by George
Neuner at
<http://lists.gnu.org/archive/html/bug-bison/2010-08/msg00002.html>.
* NEWS (2.5): Document.
* doc/bison.texinfo (Bison Options): Document.
* src/complain.c, src/complain.h (set_warning_issued): Export
function.
* src/conflicts.c (conflicts_print): Suppress conflict report
based on -Wno-conflicts-sr and -Wno-conflicts-rr, and treat
conflicts as errors if -Werror.
* src/getargs.c (warnings_flag): Initialize with
warnings_conflicts_sr and warnings_conflicts_rr as well.
(warnings_args, warnings_types): Add entries for
warnings_conflicts_sr and warnings_conflicts_rr.
(usage): Update.
* src/getargs.h (enum warnings): Add entries for
warnings_conflicts_sr and warnings_conflicts_rr.
* tests/conflicts.at (-W versus %expect and %expect-rr): New test
group.
* tests/local.at (AT_BISON_CHECK_NO_XML): Update now that the
conflict report can produce a "warnings being treated as errors"
message.  Also, check that stderr is now fully scrubbed by -Wnone
when the exit status is 0.

tests/conflicts.at

@@ -1440,3 +1440,104 @@ AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0,
 state 1
 ]])
 AT_CLEANUP
+
+
+## --------------------------------- ##
+## -W versus %expect and %expect-rr  ##
+## --------------------------------- ##
+
+AT_SETUP([[-W versus %expect and %expect-rr]])
+
+AT_DATA([[sr-rr.y]],
+[[%glr-parser
+%%
+start: 'a' | A 'a' | B 'a' ;
+A: ;
+B: ;
+]])
+AT_DATA([[sr.y]],
+[[%glr-parser
+%%
+start: 'a' | A 'a' ;
+A: ;
+]])
+AT_DATA([[rr.y]],
+[[%glr-parser
+%%
+start: A | B ;
+A: ;
+B: ;
+]])
+
+AT_BISON_CHECK([[sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: conflicts: 1 shift/reduce, 1 reduce/reduce
+]])
+AT_BISON_CHECK([[-Wno-conflicts-sr sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: conflicts: 1 reduce/reduce
+]])
+AT_BISON_CHECK([[-Wno-conflicts-rr sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: conflicts: 1 shift/reduce
+]])
+
+[for gram in sr-rr sr rr; do
+  for sr_exp_i in '' 0 1 2; do
+    for rr_exp_i in '' 0 1 2; do
+      test -z "$sr_exp_i" && test -z "$rr_exp_i" && continue
+
+      # Build grammar file.
+      sr_exp=0
+      rr_exp=0
+      file=$gram
+      directives=
+      if test -n "$sr_exp_i"; then
+        sr_exp=$sr_exp_i
+        file=$file-expect-$sr_exp
+        directives="%expect $sr_exp"
+      fi
+      if test -n "$rr_exp_i"; then
+        rr_exp=$rr_exp_i
+        file=$file-expect-rr-$rr_exp
+        directives="$directives %expect-rr $rr_exp"
+      fi
+      file=$file.y
+      echo "$directives" > $file
+      cat $gram.y >> $file
+
+      # Count actual conflicts.
+      conflicts=
+      sr_count=0
+      rr_count=0
+      if test $gram = sr || test $gram = sr-rr; then
+        conflicts="1 shift/reduce"
+        sr_count=1
+      fi
+      if test $gram = rr || test $gram = sr-rr; then
+        if test -n "$conflicts"; then
+          conflicts="$conflicts, "
+        fi
+        conflicts="${conflicts}1 reduce/reduce"
+        rr_count=1
+      fi
+
+      # Run tests.
+      if test $sr_count -eq $sr_exp && test $rr_count -eq $rr_exp; then
+        ]AT_BISON_CHECK([[-Wnone $file]])[
+        ]AT_BISON_CHECK([[-Werror $file]])[
+      else
+        echo "$file: conflicts: $conflicts" > experr
+        if test $sr_count -ne $sr_exp; then
+          if test $sr_exp -ne 1; then s=s; else s= ; fi
+          echo "$file: expected $sr_exp shift/reduce conflict$s" >> experr
+        fi
+        if test $rr_count -ne $rr_exp; then
+          if test $rr_exp -ne 1; then s=s; else s= ; fi
+          echo "$file: expected $rr_exp reduce/reduce conflict$s" >> experr
+        fi
+        ]AT_BISON_CHECK([[-Wnone $file]], [[1]], [[]], [[experr]])[
+        ]AT_BISON_CHECK([[-Werror $file]], [[1]], [[]], [[experr]])[
+      fi
+    done
+  done
+done]
+
+AT_CLEANUP

tests/local.at

@@ -301,6 +301,13 @@ m4_if(m4_bregexp([$4], [: warning: ]), [-1], [],
             sed -n '/: warning: /=' at-bison-check-warnings \
             | sed -n 1p \
           `"
+          at_bison_check_first_tmp="` \
+            sed -n '/conflicts: [0-9].*reduce$/=' at-bison-check-warnings \
+            | sed -n 1p \
+          `"
+          if test $at_bison_check_first_tmp -lt $at_bison_check_first; then
+            at_bison_check_first=$at_bison_check_first_tmp
+          fi
           if test $at_bison_check_first -gt 1; then
             sed -n "1,`expr $at_bison_check_first - 1`"p \
               at-bison-check-warnings > experr
@@ -330,9 +337,9 @@ m4_if(m4_bregexp([$4], [: warning: ]), [-1], [],
           # -Werror doesn't change the exit status when -Wnone or
           # --warnings=none is specified.
           ]AT_CHECK(AT_QUELL_VALGRIND[[ bison ]$1[ -Wnone -Werror]],
-                    [[0]], [expout], [ignore])[
+                    [[0]], [expout])[
           ]AT_CHECK(AT_QUELL_VALGRIND[[ bison ]$1[ --warnings=none \
-                    -Werror]], [[0]], [expout], [ignore])[
+                    -Werror]], [[0]], [expout])[
 
           # Restore caller's files.
           if test -f at-bison-check-expout.bak; then