Make 'c-c++-common/goacc/kernels-decompose-pr100400-1-*.c' behave consistently, regardless of checking level

Fix-up for commit c14ea6a72fb1ae66e3d32ac8329558497c6e4403
"Catch 'GIMPLE_DEBUG' misbehavior in OpenACC 'kernels' decomposition
[PR100400, PR103836, PR104061]".

For C++ compilation of 'c-c++-common/goacc/kernels-decompose-pr100400-1-2.c',
we first emit a 'sorry' diagnostic, and then a 'gcc_unreachable' (or
'internal_error', see below) diagnostic, but for example, for
'--enable-checking=release' (thus, '!CHECKING_P'), the second one may actually
be turned into a 'confused by earlier errors, bailing out' diagnostic.  (See
'gcc/diagnostic.cc:diagnostic_report_diagnostic': "When not checking, ICEs are
converted to fatal errors when an error has already occurred.")  Thus, make
'c-c++-common/goacc/kernels-decompose-pr100400-1-2.c' behave consistently via
'-Wfatal-errors', and thus only matching the 'sorry' diagnostic.

For example, for '--enable-checking=no' (thus, '!ENABLE_ASSERT_CHECKING'), a
call to 'gcc_unreachable' cannot be assumed emit an 'internal_error'-like
diagnostic, so explicitly call 'internal_error' in
'gcc/omp-oacc-kernels-decompose.cc:visit_loops_in_gang_single_region', in the
'GIMPLE_OMP_FOR' case, to avoid regressing
'c-c++-common/goacc/kernels-decompose-pr100400-1-3.c', and
'c-c++-common/goacc/kernels-decompose-pr100400-1-4.c'.

	PR middle-end/100400
	gcc/
	* omp-oacc-kernels-decompose.cc
	(visit_loops_in_gang_single_region) <GIMPLE_OMP_FOR>: Explicitly
	call 'internal_error'.
	gcc/testsuite/
	* c-c++-common/goacc/kernels-decompose-pr100400-1-2.c: Specify
	'-Wfatal-errors'.

2 files changed, 11 insertions, 7 deletions

diff --git a/gcc/omp-oacc-kernels-decompose.cc b/gcc/omp-oacc-kernels-decompose.cc
index 4386787..ec9b0fa 100644
--- a/gcc/omp-oacc-kernels-decompose.cc
+++ b/gcc/omp-oacc-kernels-decompose.cc
@@ -239,7 +239,13 @@ visit_loops_in_gang_single_region (gimple_stmt_iterator *gsi_p,
     case GIMPLE_OMP_FOR:
       /*TODO Given the current 'adjust_region_code' algorithm, this is
 	actually...  */
+#if 0
       gcc_unreachable ();
+#else
+      /* ..., but due to bugs (PR100400), we may actually come here.
+	 Reliably catch this, regardless of checking level.  */
+      internal_error ("PR100400");
+#endif
 
       {
 	tree clauses = gimple_omp_for_clauses (stmt);
diff --git a/gcc/testsuite/c-c++-common/goacc/kernels-decompose-pr100400-1-2.c b/gcc/testsuite/c-c++-common/goacc/kernels-decompose-pr100400-1-2.c
index a643f10..8b65e07 100644
--- a/gcc/testsuite/c-c++-common/goacc/kernels-decompose-pr100400-1-2.c
+++ b/gcc/testsuite/c-c++-common/goacc/kernels-decompose-pr100400-1-2.c
@@ -1,8 +1,8 @@
 /* { dg-additional-options "--param openacc-kernels=decompose" } */
 
-/* { dg-additional-options "-fchecking" }
-   { dg-ice TODO { c++ } }
-   { dg-prune-output "during GIMPLE pass: omp_oacc_kernels_decompose" } */
+/* Ensure consistent diagnostics, regardless of checking level:
+   { dg-additional-options -Wfatal-errors }
+   { dg-message {terminated due to -Wfatal-errors} TODO { target *-*-* } 0 } */
 
 /* { dg-additional-options "-g" } */
 /* { dg-additional-options "-O1" } so that we may get some 'GIMPLE_DEBUG's.  */
@@ -19,18 +19,16 @@ foo (void)
   /* { dg-bogus {sorry, unimplemented: 'gimple_debug' not yet supported} TODO { xfail *-*-* } .+1 } */
 #pragma acc kernels /* { dg-line l_compute1 } */
   /* { dg-note {OpenACC 'kernels' decomposition: variable 'p' in 'copy' clause requested to be made addressable} {} { target *-*-* } l_compute1 }
-     { dg-note {variable 'p' made addressable} {} { target *-*-* xfail c++ } l_compute1 } */
+     { dg-note {variable 'p' made addressable} {} { xfail *-*-* } l_compute1 } */
   /* { dg-note {variable 'c' declared in block is candidate for adjusting OpenACC privatization level} {} { xfail *-*-* } l_compute1 } */
   /* { dg-note {variable 'c\.0' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} {} { xfail *-*-* } l_compute1 } */
   {
-    /* { dg-bogus {note: beginning 'gang-single' part in OpenACC 'kernels' region} {w/ debug} { xfail c++ } .-1 }
-       { dg-bogus {note: beginning 'gang-single' part in OpenACC 'kernels' region} {w/ debug} { xfail c } .+1 } */
     int c;
 
     /* { dg-note {beginning 'gang-single' part in OpenACC 'kernels' region} {} { xfail *-*-* } .+1 } */
     p = &c;
 
-    /* { dg-note {parallelized loop nest in OpenACC 'kernels' region} {} { xfail c++ } .+1 } */
+    /* { dg-note {parallelized loop nest in OpenACC 'kernels' region} {} { xfail *-*-* } .+1 } */
 #pragma acc loop independent /* { dg-line l_loop_c1 } */
     /* { dg-note {variable 'c\.0' in 'private' clause isn't candidate for adjusting OpenACC privatization level: not addressable} {} { xfail *-*-* } l_loop_c1 } */
     /* { dg-note {variable 'c' in 'private' clause is candidate for adjusting OpenACC privatization level} {} { xfail *-*-* } l_loop_c1 }