output: do not generate source files when early errors are caught

Reported by Alexandre Duret-Lutz as "second problem" in:
http://lists.gnu.org/archive/html/bug-bison/2013-09/msg00015.html

One problem is that some errors are caught early, before the
generation of output files, while others can only be detected
afterwards (since, for instance, skeletons can raise errors
themselves).

This will be addressed in two steps: early errors do not generate
source files at all, while later errors will remove the files that
have already been generated.

* src/scan-skel.l (yyout): Open to /dev/null when there are errors.
* tests/output.at (AT_CHECK_FILES): Factored out of...
(AT_CHECK_OUTPUT): this.
Fuse the "SHELLIO" argument in the "FLAGS" one.
Use $5 to denote the expected exit status.
Add a test case for early errors.

1 files changed, 23 insertions, 12 deletions

diff --git a/tests/output.at b/tests/output.at
index 266a5032..66a3e5e9 100644
--- a/tests/output.at
+++ b/tests/output.at
@@ -17,12 +17,23 @@
 
 AT_BANNER([[Output file names.]])
 
+# AT_CHECK_FILES(EXPECTED-FILES, [IGNORED-FILES])
+# -----------------------------------------------
+# Check that the current directory contains FILE... (sorted).
+m4_define([AT_CHECK_FILES],
+[AT_CHECK([[find . -type f |
+           $PERL -ne '
+      s,\./,,; chomp;
+      push @file, $_ unless m{^($2|testsuite.log)$};
+      END { print join (" ", sort @file), "\n" }']],
+          [], [$1
+])])
 
-# AT_CHECK_OUTPUT(INPUT-FILE, [DIRECTIVES], [FLAGS], EXPECTED-FILES, [SHELLIO],
+# AT_CHECK_OUTPUT(INPUT-FILE, [DIRECTIVES], [FLAGS], EXPECTED-FILES, [STATUS],
 #                 [ADDITIONAL-TESTS], [PRE-TESTS])
 # -----------------------------------------------------------------------------
 m4_define([AT_CHECK_OUTPUT],
-[AT_SETUP([[Output files: ]$2 $3 $5])[
+[AT_SETUP([[Output files: ]$2 $3])[
 ]$7[
 for file in ]$1 $4[; do
   case $file in
@@ -35,15 +46,9 @@ done
 foo: {};
 ]])[
 
-]AT_BISON_CHECK([$3 $1 $5], 0)[
+]AT_BISON_CHECK([$3 $1], [$5], [], [ignore])[
 # Ignore the files non-generated files
-]AT_CHECK([[find . -type f |
-           $PERL -ne '
-      s,\./,,; chomp;
-      push @file, $_ unless m{^($1|testsuite.log)$};
-      END { print join (" ", sort @file), "\n" }']],
-          [], [$4
-])[
+]AT_CHECK_FILES([$4], [$1])[
 ]$6[
 ]AT_CLEANUP[
 ]])
@@ -54,9 +59,9 @@ AT_CHECK_OUTPUT([foo.y], [], [-dv],
 # Some versions of Valgrind (at least valgrind-3.6.0.SVN-Debian) report
 # "fgrep: write error: Bad file descriptor" when stdout is closed, so we
 # skip this test group during maintainer-check-valgrind.
-AT_CHECK_OUTPUT([foo.y], [], [-dv],
+AT_CHECK_OUTPUT([foo.y], [], [-dv >&-],
                 [foo.output foo.tab.c foo.tab.h],
-                [>&-], [],
+                [], [],
                 [AT_CHECK([[case "$PREBISON" in *valgrind*) exit 77;; esac]])])
 
 AT_CHECK_OUTPUT([foo.y], [], [-dv -o foo.c],
@@ -114,6 +119,12 @@ AT_CHECK_OUTPUT([foo.yy], [],
                 [-o foo.c++ --graph=foo.gph],
                 [foo.c++ foo.gph])
 
+# Do not generate code when there are early errors (even warnings as
+# errors).
+AT_CHECK_OUTPUT([foo.y], [%type <foo> useless],
+                [--defines --graph --xml --report=all -Wall -Werror],
+                [foo.dot foo.output foo.xml],
+                [1])
 
 ## ------------ ##
 ## C++ output.  ##